Пример #1
0
    def __init__(self, body, sc, method, nb_seg, order, solver, ode_class, ode_kwargs, ph_name, snopt_opts=None,
                 rec_file=None):

        NLP.__init__(self, body, sc, method, nb_seg, order, solver, snopt_opts=snopt_opts, rec_file=rec_file)

        # Transcription object
        if self.method == 'gauss-lobatto':
            self.transcription = GaussLobatto(num_segments=self.nb_seg, order=self.order, compressed=True)
        elif self.method == 'radau-ps':
            self.transcription = Radau(num_segments=self.nb_seg, order=self.order, compressed=True)
        elif self.method == 'runge-kutta':
            self.transcription = RungeKutta(num_segments=self.nb_seg, order=self.order, compressed=True)
        else:
            raise ValueError('method must be either gauss-lobatto or radau-ps')

        # Phase object
        self.phase = self.trajectory.add_phase(ph_name, Phase(ode_class=ode_class, ode_init_kwargs=ode_kwargs,
                                                              transcription=self.transcription))
        self.phase_name = ''.join(['traj.', ph_name])

        # discretization nodes
        self.state_nodes = None
        self.control_nodes = None
        self.t_all = None
        self.t_state = None
        self.t_control = None
        self.idx_state_control = None

        # time of flight
        self.tof = None
    def test_solver_defects_single_phase_reverse_propagation(self):
        prob = Problem()

        num_seg = 5
        seg_ends, _ = lgl(num_seg + 1)

        # First phase: normal operation.

        transcription = Radau(num_segments=5,
                              order=5,
                              segment_ends=seg_ends,
                              compressed=True)
        phase0 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p0 = prob.model.add_subsystem('phase0', phase0)

        traj_p0.set_time_options(fix_initial=True, fix_duration=True)
        traj_p0.set_state_options('state_of_charge',
                                  fix_initial=True,
                                  fix_final=False,
                                  solve_segments=True)

        prob.setup()

        prob['phase0.t_initial'] = 0
        prob['phase0.t_duration'] = -1.0 * 3600
        prob['phase0.states:state_of_charge'][:] = 0.63464982

        prob.set_solver_print(level=0)
        prob.run_model()

        soc0 = prob['phase0.states:state_of_charge']
        assert_rel_error(self, soc0[-1], 1.0, 1e-6)
Пример #3
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    def __init__(self, body, sc, method, nb_seg, order, solver, ode_class, ode_kwargs, ph_name, snopt_opts=None,
                 rec_file=None):

        if isinstance(order, int):
            order = tuple(order for _ in range(len(nb_seg)))

        if isinstance(method, str):
            method = tuple(method for _ in range(len(nb_seg)))

        NLP.__init__(self, body, sc, method, nb_seg, order, solver, snopt_opts=snopt_opts, rec_file=rec_file)

        # Transcription objects list
        self.transcription = []

        for i in range(len(self.nb_seg)):
            if self.method[i] == 'gauss-lobatto':
                t = GaussLobatto(num_segments=self.nb_seg[i], order=self.order[i], compressed=True)
            elif self.method[i] == 'radau-ps':
                t = Radau(num_segments=self.nb_seg[i], order=self.order[i], compressed=True)
            elif self.method[i] == 'runge-kutta':
                t = RungeKutta(num_segments=self.nb_seg[i], order=self.order[i], compressed=True)
            else:
                raise ValueError('method must be either gauss-lobatto, radau-ps or runge-kutta')
            self.transcription.append(t)

        # Phase objects list
        self.phase = []
        self.phase_name = []

        for i in range(len(self.nb_seg)):
            ph = self.trajectory.add_phase(ph_name[i], Phase(ode_class=ode_class[i], ode_init_kwargs=ode_kwargs[i],
                                                             transcription=self.transcription[i]))
            self.phase.append(ph)
            self.phase_name.append(''.join(['traj.', ph_name[i]]))
Пример #4
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    def test_control_rate2_path_constraint_radau(self):
        from openmdao.api import Problem, Group, ScipyOptimizeDriver, DirectSolver
        from openmdao.utils.assert_utils import assert_rel_error
        from dymos import Phase, Radau
        from dymos.examples.brachistochrone.brachistochrone_ode import BrachistochroneODE

        p = Problem(model=Group())
        p.driver = ScipyOptimizeDriver()

        phase = Phase(ode_class=BrachistochroneODE,
                      transcription=Radau(num_segments=10, compressed=False))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(initial_bounds=(0, 0), duration_bounds=(.5, 10))

        phase.set_state_options('x', fix_initial=True, fix_final=True)
        phase.set_state_options('y', fix_initial=True, fix_final=True)
        phase.set_state_options('v', fix_initial=True)

        phase.add_control('theta', units='deg', lower=0.01, upper=179.9)

        phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

        # Minimize time at the end of the phase
        phase.add_objective('time', loc='final', scaler=10)

        phase.add_path_constraint('theta_rate2',
                                  lower=-200,
                                  upper=200,
                                  units='rad/s**2')

        p.model.linear_solver = DirectSolver()
        p.model.options['assembled_jac_type'] = 'csc'

        p.setup()

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10],
                                                 nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5],
                                                 nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100.5],
                                                       nodes='control_input')

        # Solve for the optimal trajectory
        p.run_driver()

        # Test the results
        assert_rel_error(self,
                         p.get_val('phase0.timeseries.time')[-1],
                         1.8016,
                         tolerance=1.0E-3)
Пример #5
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    def test_objective_design_parameter_radau(self):
        p = Problem(model=Group())

        p.driver = ScipyOptimizeDriver()

        p.driver.options['dynamic_simul_derivs'] = True

        phase = Phase(ode_class=BrachistochroneODE,
                      transcription=Radau(num_segments=20,
                                          order=3,
                                          compressed=True))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(fix_initial=True, duration_bounds=(4, 10))

        phase.set_state_options('x', fix_initial=True, fix_final=True)
        phase.set_state_options('y', fix_initial=True, fix_final=True)
        phase.set_state_options('v', fix_initial=True, fix_final=False)

        phase.add_control('theta',
                          continuity=True,
                          rate_continuity=True,
                          units='deg',
                          lower=0.01,
                          upper=179.9)

        phase.add_design_parameter('g', units='m/s**2', opt=True, val=9.80665)

        # Minimize time at the end of the phase
        phase.add_objective('g')

        p.model.options['assembled_jac_type'] = 'csc'
        p.model.linear_solver = DirectSolver()
        p.setup(check=True)

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10],
                                                 nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5],
                                                 nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100],
                                                       nodes='control_input')
        p['phase0.design_parameters:g'] = 9.80665

        p.run_driver()

        assert_rel_error(self, p['phase0.t_duration'], 10, tolerance=1.0E-3)
    def test_solver_defects_reverse_propagation(self):
        prob = Problem()

        num_seg = 5
        seg_ends, _ = lgl(num_seg + 1)

        traj = prob.model.add_subsystem('traj', Trajectory())

        # First phase: normal operation.
        transcription = Radau(num_segments=5,
                              order=5,
                              segment_ends=seg_ends,
                              compressed=True)
        phase0 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p0 = traj.add_phase('phase0', phase0)

        traj_p0.set_time_options(fix_initial=True, fix_duration=True)
        traj_p0.set_state_options('state_of_charge',
                                  fix_initial=True,
                                  fix_final=False,
                                  solve_segments=True)

        # Second phase: normal operation.
        phase1 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p1 = traj.add_phase('phase1', phase1)

        traj_p1.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1.set_state_options('state_of_charge',
                                  fix_initial=False,
                                  fix_final=False,
                                  solve_segments=True)
        traj_p1.add_objective('time', loc='final')

        traj.link_phases(phases=['phase0', 'phase1'],
                         vars=['state_of_charge', 'time'],
                         connected=True)

        prob.setup()

        prob['traj.phase0.t_initial'] = 0
        prob['traj.phase0.t_duration'] = -1.0 * 3600
        prob['traj.phase0.states:state_of_charge'][:] = 0.23794217

        prob['traj.phase1.t_initial'] = 0
        prob['traj.phase1.t_duration'] = -1.0 * 3600

        prob.set_solver_print(level=0)
        prob.run_model()

        soc1 = prob['traj.phase1.states:state_of_charge']
        assert_rel_error(self, soc1[-1], 1.0, 1e-6)
Пример #7
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    def _make_problem(self, transcription, num_seg, transcription_order=3):
        p = Problem(model=Group())

        p.driver = ScipyOptimizeDriver()

        # Compute sparsity/coloring when run_driver is called
        p.driver.options['dynamic_simul_derivs'] = True

        t = {'gauss-lobatto': GaussLobatto(num_segments=num_seg, order=transcription_order),
             'radau-ps': Radau(num_segments=num_seg, order=transcription_order),
             'runge-kutta': RungeKutta(num_segments=num_seg)}

        phase = Phase(ode_class=_BrachistochroneTestODE, transcription=t[transcription])

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(initial_bounds=(1, 1), duration_bounds=(.5, 10))

        phase.set_state_options('x', fix_initial=True)
        phase.set_state_options('y', fix_initial=True)
        phase.set_state_options('v', fix_initial=True)

        phase.add_control('theta', units='deg', rate_continuity=True, lower=0.01, upper=179.9)

        phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

        phase.add_boundary_constraint('x', loc='final', equals=10)
        phase.add_boundary_constraint('y', loc='final', equals=5)

        # Minimize time at the end of the phase
        phase.add_objective('time', loc='final', scaler=10)

        p.model.linear_solver = DirectSolver()

        p.setup()

        p['phase0.t_initial'] = 1.0
        p['phase0.t_duration'] = 3.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10], nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5], nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9], nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100.5], nodes='control_input')

        return p
    def test_radau(self):

        p = Problem(model=Group())

        phase = Phase(ode_class=MyODE,
                      ode_init_kwargs={'n_traj': n_traj},
                      transcription=Radau(num_segments=25,
                                          order=3,
                                          compressed=True))

        p.model.add_subsystem('phase0', phase)

        phase.add_input_parameter('alpha', val=np.ones((n_traj, 2)), units='m')

        try:
            p.setup()
        except Exception as e:
            self.fail('Exception encountered in setup:\n' + str(e))
Пример #9
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    def test_timeseries_radau(self):
        p = Problem(model=Group())

        p.driver = ScipyOptimizeDriver()
        p.driver.options['dynamic_simul_derivs'] = True

        phase = Phase(ode_class=BrachistochroneODE,
                      transcription=Radau(num_segments=8,
                                          order=3,
                                          compressed=True))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(fix_initial=True, duration_bounds=(.5, 10))

        phase.set_state_options('x', fix_initial=True, fix_final=True)
        phase.set_state_options('y', fix_initial=True, fix_final=True)
        phase.set_state_options('v', fix_initial=True, fix_final=False)

        phase.add_control('theta',
                          continuity=True,
                          rate_continuity=True,
                          units='deg',
                          lower=0.01,
                          upper=179.9)

        phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

        # Minimize time at the end of the phase
        phase.add_objective('time_phase', loc='final', scaler=10)

        p.model.options['assembled_jac_type'] = 'csc'
        p.model.linear_solver = DirectSolver()
        p.setup(check=True)

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10],
                                                 nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5],
                                                 nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100],
                                                       nodes='control_input')
        p['phase0.design_parameters:g'] = 9.80665

        p.run_driver()

        gd = phase.options['transcription'].grid_data
        state_input_idxs = gd.subset_node_indices['state_input']
        control_input_idxs = gd.subset_node_indices['control_input']

        assert_rel_error(self, p.get_val('phase0.time'),
                         p.get_val('phase0.timeseries.time')[:, 0])

        assert_rel_error(self, p.get_val('phase0.time_phase'),
                         p.get_val('phase0.timeseries.time_phase')[:, 0])

        for state in ('x', 'y', 'v'):
            assert_rel_error(
                self, p.get_val('phase0.states:{0}'.format(state)),
                p.get_val('phase0.timeseries.states:'
                          '{0}'.format(state))[state_input_idxs])

        for control in ('theta', ):
            assert_rel_error(
                self, p.get_val('phase0.controls:{0}'.format(control)),
                p.get_val('phase0.timeseries.controls:'
                          '{0}'.format(control))[control_input_idxs])

        for dp in ('g', ):
            for i in range(gd.subset_num_nodes['all']):
                assert_rel_error(
                    self,
                    p.get_val('phase0.design_parameters:{0}'.format(dp))[0, :],
                    p.get_val('phase0.timeseries.design_parameters:'
                              '{0}'.format(dp))[i])
Пример #10
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    def test_reentry_radau_dymos(self):

        p = Problem(model=Group())
        p.driver = pyOptSparseDriver()
        p.driver.declare_coloring()

        traj = p.model.add_subsystem("traj", Trajectory())
        phase0 = traj.add_phase(
            "phase0",
            Phase(ode_class=ShuttleODE,
                  transcription=Radau(num_segments=50, order=3)))

        phase0.set_time_options(fix_initial=True, units="s", duration_ref=200)
        phase0.set_state_options("h",
                                 fix_initial=True,
                                 fix_final=True,
                                 units="ft",
                                 rate_source="hdot",
                                 targets=["h"],
                                 lower=0,
                                 ref0=75000,
                                 ref=300000,
                                 defect_ref=1000)
        phase0.set_state_options("gamma",
                                 fix_initial=True,
                                 fix_final=True,
                                 units="rad",
                                 rate_source="gammadot",
                                 targets=["gamma"],
                                 lower=-89. * np.pi / 180,
                                 upper=89. * np.pi / 180)
        phase0.set_state_options("phi",
                                 fix_initial=True,
                                 fix_final=False,
                                 units="rad",
                                 rate_source="phidot",
                                 lower=0,
                                 upper=89. * np.pi / 180)
        phase0.set_state_options("psi",
                                 fix_initial=True,
                                 fix_final=False,
                                 units="rad",
                                 rate_source="psidot",
                                 targets=["psi"],
                                 lower=0,
                                 upper=90. * np.pi / 180)
        phase0.set_state_options("theta",
                                 fix_initial=True,
                                 fix_final=False,
                                 units="rad",
                                 rate_source="thetadot",
                                 targets=["theta"],
                                 lower=-89. * np.pi / 180,
                                 upper=89. * np.pi / 180)
        phase0.set_state_options("v",
                                 fix_initial=True,
                                 fix_final=True,
                                 units="ft/s",
                                 rate_source="vdot",
                                 targets=["v"],
                                 lower=0,
                                 ref0=2500,
                                 ref=25000)
        phase0.add_control("alpha",
                           units="rad",
                           opt=True,
                           lower=-np.pi / 2,
                           upper=np.pi / 2,
                           targets=["alpha"])
        phase0.add_control("beta",
                           units="rad",
                           opt=True,
                           lower=-89 * np.pi / 180,
                           upper=1 * np.pi / 180,
                           targets=["beta"])
        phase0.add_path_constraint("q",
                                   lower=0,
                                   upper=70,
                                   units="Btu/ft**2/s",
                                   ref=70)
        phase0.add_objective("theta", loc="final", ref=-0.01)

        p.driver.options["optimizer"] = 'SNOPT'
        p.driver.opt_settings["iSumm"] = 6

        p.setup(check=True)

        p.set_val("traj.phase0.states:h",
                  phase0.interpolate(ys=[260000, 80000], nodes="state_input"),
                  units="ft")
        p.set_val("traj.phase0.states:gamma",
                  phase0.interpolate(ys=[-1 * np.pi / 180, -5 * np.pi / 180],
                                     nodes="state_input"),
                  units="rad")
        p.set_val("traj.phase0.states:phi",
                  phase0.interpolate(ys=[0, 75 * np.pi / 180],
                                     nodes="state_input"),
                  units="rad")
        p.set_val("traj.phase0.states:psi",
                  phase0.interpolate(ys=[90 * np.pi / 180, 10 * np.pi / 180],
                                     nodes="state_input"),
                  units="rad")
        p.set_val("traj.phase0.states:theta",
                  phase0.interpolate(ys=[0, 25 * np.pi / 180],
                                     nodes="state_input"),
                  units="rad")
        p.set_val("traj.phase0.states:v",
                  phase0.interpolate(ys=[25600, 2500], nodes="state_input"),
                  units="ft/s")
        p.set_val("traj.phase0.t_initial", 0, units="s")
        p.set_val("traj.phase0.t_duration", 2000, units="s")
        p.set_val("traj.phase0.controls:alpha",
                  phase0.interpolate(
                      ys=[17.4 * np.pi / 180, 17.4 * np.pi / 180],
                      nodes="control_input"),
                  units="rad")
        p.set_val("traj.phase0.controls:beta",
                  phase0.interpolate(ys=[-75 * np.pi / 180, 0 * np.pi / 180],
                                     nodes="control_input"),
                  units="rad")

        p.run_driver()

        print(p.get_val("traj.phase0.timeseries.time")[-1])
        print(p.get_val("traj.phase0.timeseries.states:theta")[-1])
        assert_rel_error(self,
                         p.get_val("traj.phase0.timeseries.time")[-1],
                         2181.90371131,
                         tolerance=1e-3)
        assert_rel_error(self,
                         p.get_val("traj.phase0.timeseries.states:theta")[-1],
                         .53440626,
                         tolerance=1e-3)
    def test_solver_defects(self):
        prob = Problem()

        num_seg = 5
        seg_ends, _ = lgl(num_seg + 1)

        traj = prob.model.add_subsystem('traj', Trajectory())

        # First phase: normal operation.

        transcription = Radau(num_segments=5,
                              order=5,
                              segment_ends=seg_ends,
                              compressed=True)
        phase0 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p0 = traj.add_phase('phase0', phase0)

        traj_p0.set_time_options(fix_initial=True, fix_duration=True)
        traj_p0.set_state_options('state_of_charge',
                                  fix_initial=True,
                                  fix_final=False,
                                  solve_segments=True)

        # Second phase: normal operation.
        phase1 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p1 = traj.add_phase('phase1', phase1)

        traj_p1.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1.set_state_options('state_of_charge',
                                  fix_initial=False,
                                  fix_final=False,
                                  solve_segments=True)
        traj_p1.add_objective('time', loc='final')

        # Second phase, but with battery failure.
        phase1_bfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_battery': 2},
                             transcription=transcription)
        traj_p1_bfail = traj.add_phase('phase1_bfail', phase1_bfail)

        traj_p1_bfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_bfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False,
                                        solve_segments=True)

        # Second phase, but with motor failure.
        phase1_mfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_motor': 2},
                             transcription=transcription)
        traj_p1_mfail = traj.add_phase('phase1_mfail', phase1_mfail)

        traj_p1_mfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_mfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False,
                                        solve_segments=True)

        traj.link_phases(phases=['phase0', 'phase1'],
                         vars=['state_of_charge', 'time'],
                         connected=True)
        traj.link_phases(phases=['phase0', 'phase1_bfail'],
                         vars=['state_of_charge', 'time'],
                         connected=True)
        traj.link_phases(phases=['phase0', 'phase1_mfail'],
                         vars=['state_of_charge', 'time'],
                         connected=True)

        prob.setup()

        prob['traj.phase0.t_initial'] = 0
        prob['traj.phase0.t_duration'] = 1.0 * 3600

        prob['traj.phase1.t_initial'] = 1.0 * 3600
        prob['traj.phase1.t_duration'] = 1.0 * 3600

        prob['traj.phase1_bfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_bfail.t_duration'] = 1.0 * 3600

        prob['traj.phase1_mfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_mfail.t_duration'] = 1.0 * 3600

        prob['traj.phase0.states:state_of_charge'][:] = 1.0

        prob.set_solver_print(level=0)
        prob.run_model()

        soc0 = prob['traj.phase0.states:state_of_charge']
        soc1 = prob['traj.phase1.states:state_of_charge']
        soc1b = prob['traj.phase1_bfail.states:state_of_charge']
        soc1m = prob['traj.phase1_mfail.states:state_of_charge']

        # Final value for State of Charge in each segment should be a good test.
        assert_rel_error(self, soc0[-1], 0.63464982, 1e-6)
        assert_rel_error(self, soc1[-1], 0.23794217, 1e-6)
        assert_rel_error(self, soc1b[-1], 0.0281523, 1e-6)
        assert_rel_error(self, soc1m[-1], 0.18625395, 1e-6)
    def test_optimizer_segments_direct_connections(self):
        prob = Problem()

        if optimizer == 'SNOPT':
            opt = prob.driver = pyOptSparseDriver()
            opt.options['optimizer'] = optimizer
            opt.options['dynamic_simul_derivs'] = True

            opt.opt_settings['Major iterations limit'] = 1000
            opt.opt_settings['Major feasibility tolerance'] = 1.0E-6
            opt.opt_settings['Major optimality tolerance'] = 1.0E-6
            opt.opt_settings["Linesearch tolerance"] = 0.10
            opt.opt_settings['iSumm'] = 6

        else:
            opt = prob.driver = ScipyOptimizeDriver()
            opt.options['dynamic_simul_derivs'] = True

        num_seg = 5
        seg_ends, _ = lgl(num_seg + 1)

        traj = prob.model.add_subsystem('traj', Trajectory())

        # First phase: normal operation.
        transcription = Radau(num_segments=5,
                              order=5,
                              segment_ends=seg_ends,
                              compressed=True)
        phase0 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p0 = traj.add_phase('phase0', phase0)
        traj_p0.set_time_options(fix_initial=True, fix_duration=True)
        traj_p0.set_state_options('state_of_charge',
                                  fix_initial=True,
                                  fix_final=False)

        # Second phase: normal operation.

        phase1 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p1 = traj.add_phase('phase1', phase1)
        traj_p1.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1.set_state_options('state_of_charge',
                                  fix_initial=False,
                                  fix_final=False)
        traj_p1.add_objective('time', loc='final')

        # Second phase, but with battery failure.
        phase1_bfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_battery': 2},
                             transcription=transcription)
        traj_p1_bfail = traj.add_phase('phase1_bfail', phase1_bfail)
        traj_p1_bfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_bfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False)

        # Second phase, but with motor failure.

        phase1_mfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_motor': 2},
                             transcription=transcription)
        traj_p1_mfail = traj.add_phase('phase1_mfail', phase1_mfail)
        traj_p1_mfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_mfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False)

        traj.link_phases(phases=['phase0', 'phase1'],
                         vars=['state_of_charge', 'time'],
                         connected=True)
        traj.link_phases(phases=['phase0', 'phase1_bfail'],
                         vars=['state_of_charge', 'time'],
                         connected=True)
        traj.link_phases(phases=['phase0', 'phase1_mfail'],
                         vars=['state_of_charge', 'time'],
                         connected=True)

        prob.model.options['assembled_jac_type'] = 'csc'
        prob.model.linear_solver = DirectSolver(assemble_jac=True)

        prob.setup()

        prob['traj.phase0.t_initial'] = 0
        prob['traj.phase0.t_duration'] = 1.0 * 3600

        prob['traj.phase1.t_initial'] = 1.0 * 3600
        prob['traj.phase1.t_duration'] = 1.0 * 3600

        prob['traj.phase1_bfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_bfail.t_duration'] = 1.0 * 3600

        prob['traj.phase1_mfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_mfail.t_duration'] = 1.0 * 3600

        prob.set_solver_print(level=0)
        prob.run_driver()

        soc0 = prob['traj.phase0.states:state_of_charge']
        soc1 = prob['traj.phase1.states:state_of_charge']
        soc1b = prob['traj.phase1_bfail.states:state_of_charge']
        soc1m = prob['traj.phase1_mfail.states:state_of_charge']

        # Final value for State of Chrage in each segment should be a good test.
        assert_rel_error(self, soc0[-1], 0.63464982, 1e-6)
        assert_rel_error(self, soc1[-1], 0.23794217, 1e-6)
        assert_rel_error(self, soc1b[-1], 0.0281523, 1e-6)
        assert_rel_error(self, soc1m[-1], 0.18625395, 1e-6)
Пример #13
0
import numpy as np 
import matplotlib.pyplot as plt 
from openmdao.api import Problem, Group, ScipyOptimizeDriver, SqliteRecorder, CaseReader, IndepVarComp
from dymos import Trajectory, GaussLobatto, Phase, Radau
from shuttle_ode import ShuttleODE

prob = Problem(model=Group())

traj = prob.model.add_subsystem("traj", Trajectory())

phase0 = Phase(ode_class=ShuttleODE, transcription=Radau(num_segments=20, order=3))
traj.add_phase(name="phase0", phase=phase0)

phase0.set_time_options(fix_initial=True, units="s", duration_ref=200)#, duration_ref=2000, duration_bounds=(50, 3000)

phase0.set_state_options("h", fix_initial=True, fix_final=True, units="ft", rate_source="hdot", targets=["h"], lower=0)#, ref=260000, defect_ref=260000, ref0=80000
phase0.set_state_options("gamma", fix_initial=True, fix_final=True, units="rad", rate_source="gammadot", targets=["gamma"], lower=-89.*np.pi/180, upper=89.*np.pi/180)
phase0.set_state_options("phi", fix_initial=True, fix_final=False, units="rad", rate_source="phidot", lower=0, upper=89.*np.pi/180)
phase0.set_state_options("psi", fix_initial=True, fix_final=False, units="rad", rate_source="psidot", targets=["psi"], lower=0, upper=90.*np.pi/180)
phase0.set_state_options("theta", fix_initial=True, fix_final=False, units="rad", rate_source="thetadot", targets=["theta"], lower=-89.*np.pi/180, upper=89.*np.pi/180)
phase0.set_state_options("v", fix_initial=True, fix_final=True, units="ft/s", rate_source="vdot", targets=["v"], lower=0)#, ref=25600, defect_ref=25600, ref0=2500

phase0.add_control("alpha", units="rad", opt=True, lower=-np.pi/2, upper=np.pi/2, targets=["alpha"])
phase0.add_control("beta", units="rad", opt=True, lower=-89*np.pi/180, upper=1*np.pi/180, targets=["beta"])

phase0.add_path_constraint("q", lower=0, upper=70, units="Btu/ft**2/s", ref=70)#

phase0.add_objective("theta", loc="final", ref=-1)

prob.driver = ScipyOptimizeDriver()
prob.driver.declare_coloring()
Пример #14
0
    def test_brachistochrone_integrated_control_radau_ps(self):
        import numpy as np
        from openmdao.api import Problem, Group, ScipyOptimizeDriver, DirectSolver
        from openmdao.utils.assert_utils import assert_rel_error
        from dymos import Phase, Radau

        p = Problem(model=Group())
        p.driver = ScipyOptimizeDriver()

        phase = Phase(ode_class=BrachistochroneODE,
                      transcription=Radau(num_segments=10))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(initial_bounds=(0, 0), duration_bounds=(.5, 10))

        phase.set_state_options('x', fix_initial=True, fix_final=True)
        phase.set_state_options('y', fix_initial=True, fix_final=True)
        phase.set_state_options('v', fix_initial=True)
        phase.set_state_options('theta', targets='theta', fix_initial=False)

        phase.add_control('theta_dot',
                          units='deg/s',
                          rate_continuity=True,
                          lower=0,
                          upper=60)

        phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

        # Minimize time at the end of the phase
        phase.add_objective('time', loc='final', scaler=10)

        p.model.linear_solver = DirectSolver()
        p.model.options['assembled_jac_type'] = 'csc'

        p.setup()

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10],
                                                 nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5],
                                                 nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.states:theta'] = np.radians(
            phase.interpolate(ys=[0.05, 100.0], nodes='state_input'))
        p['phase0.controls:theta_dot'] = phase.interpolate(
            ys=[50, 50], nodes='control_input')

        # Solve for the optimal trajectory
        p.run_driver()

        # Test the results
        assert_rel_error(self,
                         p.get_val('phase0.timeseries.time')[-1],
                         1.8016,
                         tolerance=1.0E-3)

        sim_out = phase.simulate(times_per_seg=20)

        x_sol = p.get_val('phase0.timeseries.states:x')
        y_sol = p.get_val('phase0.timeseries.states:y')
        v_sol = p.get_val('phase0.timeseries.states:v')
        theta_sol = p.get_val('phase0.timeseries.states:theta')
        theta_dot_sol = p.get_val('phase0.timeseries.controls:theta_dot')
        time_sol = p.get_val('phase0.timeseries.time')

        x_sim = sim_out.get_val('phase0.timeseries.states:x')
        y_sim = sim_out.get_val('phase0.timeseries.states:y')
        v_sim = sim_out.get_val('phase0.timeseries.states:v')
        theta_sim = sim_out.get_val('phase0.timeseries.states:theta')
        theta_dot_sim = sim_out.get_val('phase0.timeseries.controls:theta_dot')
        time_sim = sim_out.get_val('phase0.timeseries.time')

        x_interp = interp1d(time_sim[:, 0], x_sim[:, 0])
        y_interp = interp1d(time_sim[:, 0], y_sim[:, 0])
        v_interp = interp1d(time_sim[:, 0], v_sim[:, 0])
        theta_interp = interp1d(time_sim[:, 0], theta_sim[:, 0])
        theta_dot_interp = interp1d(time_sim[:, 0], theta_dot_sim[:, 0])

        assert_rel_error(self, x_interp(time_sol), x_sol, tolerance=1.0E-5)
        assert_rel_error(self, y_interp(time_sol), y_sol, tolerance=1.0E-5)
        assert_rel_error(self, v_interp(time_sol), v_sol, tolerance=1.0E-5)
        assert_rel_error(self,
                         theta_interp(time_sol),
                         theta_sol,
                         tolerance=1.0E-5)
        assert_rel_error(self,
                         theta_dot_interp(time_sol),
                         theta_dot_sol,
                         tolerance=1.0E-5)
Пример #15
0
def brachistochrone_min_time(transcription='gauss-lobatto',
                             num_segments=8,
                             transcription_order=3,
                             compressed=True,
                             sim_record='brach_min_time_sim.db',
                             optimizer='SLSQP',
                             dynamic_simul_derivs=True,
                             force_alloc_complex=False,
                             solve_segments=False,
                             run_driver=True):
    p = Problem(model=Group())

    if optimizer == 'SNOPT':
        p.driver = pyOptSparseDriver()
        p.driver.options['optimizer'] = optimizer
        p.driver.opt_settings['Major iterations limit'] = 100
        p.driver.opt_settings['Major feasibility tolerance'] = 1.0E-6
        p.driver.opt_settings['Major optimality tolerance'] = 1.0E-6
        p.driver.opt_settings['iSumm'] = 6
    else:
        p.driver = ScipyOptimizeDriver()

    p.driver.options['dynamic_simul_derivs'] = dynamic_simul_derivs

    if transcription == 'runge-kutta':
        transcription = RungeKutta(num_segments=num_segments,
                                   compressed=compressed)
    elif transcription == 'gauss-lobatto':
        transcription = GaussLobatto(num_segments=num_segments,
                                     order=transcription_order,
                                     compressed=compressed)
    elif transcription == 'radau-ps':
        transcription = Radau(num_segments=num_segments,
                              order=transcription_order,
                              compressed=compressed)

    phase = Phase(ode_class=BrachistochroneVectorStatesODE,
                  transcription=transcription)

    p.model.add_subsystem('phase0', phase)

    phase.set_time_options(fix_initial=True, duration_bounds=(.5, 10))

    fix_final = not solve_segments  # can't fix final position if you're solving the segments
    phase.set_state_options('pos',
                            fix_initial=True,
                            fix_final=fix_final,
                            solve_segments=solve_segments)
    phase.set_state_options('v',
                            fix_initial=True,
                            fix_final=False,
                            solve_segments=solve_segments)

    phase.add_control('theta',
                      continuity=True,
                      rate_continuity=True,
                      units='deg',
                      lower=0.01,
                      upper=179.9)

    phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

    # Minimize time at the end of the phase
    phase.add_objective('time', loc='final', scaler=10)

    p.model.linear_solver = DirectSolver()
    p.setup(check=True, force_alloc_complex=force_alloc_complex)

    p['phase0.t_initial'] = 0.0
    p['phase0.t_duration'] = 2.0

    pos0 = [0, 10]
    posf = [10, 5]

    p['phase0.states:pos'] = phase.interpolate(ys=[pos0, posf],
                                               nodes='state_input')
    p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9], nodes='state_input')
    p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100],
                                                   nodes='control_input')
    p['phase0.design_parameters:g'] = 9.80665

    p.run_model()
    if run_driver:
        p.run_driver()

    # Plot results
    if SHOW_PLOTS:
        p.run_driver()
        exp_out = phase.simulate(record_file=sim_record)

        fig, ax = plt.subplots()
        fig.suptitle('Brachistochrone Solution')

        x_imp = p.get_val('phase0.timeseries.states:pos')[:, 0]
        y_imp = p.get_val('phase0.timeseries.states:pos')[:, 1]

        x_exp = exp_out.get_val('phase0.timeseries.states:pos')[:, 0]
        y_exp = exp_out.get_val('phase0.timeseries.states:pos')[:, 1]

        ax.plot(x_imp, y_imp, 'ro', label='implicit')
        ax.plot(x_exp, y_exp, 'b-', label='explicit')

        ax.set_xlabel('x (m)')
        ax.set_ylabel('y (m)')
        ax.grid(True)
        ax.legend(loc='upper right')

        fig, ax = plt.subplots()
        fig.suptitle('Brachistochrone Solution')

        x_imp = p.get_val('phase0.timeseries.time')
        y_imp = p.get_val('phase0.timeseries.control_rates:theta_rate2')

        x_exp = exp_out.get_val('phase0.timeseries.time')
        y_exp = exp_out.get_val('phase0.timeseries.control_rates:theta_rate2')

        ax.plot(x_imp, y_imp, 'ro', label='implicit')
        ax.plot(x_exp, y_exp, 'b-', label='explicit')

        ax.set_xlabel('time (s)')
        ax.set_ylabel('theta rate2 (rad/s**2)')
        ax.grid(True)
        ax.legend(loc='lower right')

        plt.show()

    return p
Пример #16
0
    def test_basic(self):
        import matplotlib.pyplot as plt

        from openmdao.api import Problem, ScipyOptimizeDriver, DirectSolver
        from openmdao.utils.assert_utils import assert_rel_error

        from dymos import Trajectory, Phase, Radau
        from dymos.examples.battery_multibranch.battery_multibranch_ode import BatteryODE
        from dymos.utils.lgl import lgl

        prob = Problem()

        opt = prob.driver = ScipyOptimizeDriver()
        opt.options['dynamic_simul_derivs'] = True
        opt.options['optimizer'] = 'SLSQP'

        num_seg = 5
        seg_ends, _ = lgl(num_seg + 1)

        traj = prob.model.add_subsystem('traj', Trajectory())

        # First phase: normal operation.
        transcription = Radau(num_segments=num_seg,
                              order=5,
                              segment_ends=seg_ends,
                              compressed=False)
        phase0 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p0 = traj.add_phase('phase0', phase0)

        traj_p0.set_time_options(fix_initial=True, fix_duration=True)
        traj_p0.set_state_options('state_of_charge',
                                  fix_initial=True,
                                  fix_final=False)

        # Second phase: normal operation.

        phase1 = Phase(ode_class=BatteryODE, transcription=transcription)
        traj_p1 = traj.add_phase('phase1', phase1)

        traj_p1.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1.set_state_options('state_of_charge',
                                  fix_initial=False,
                                  fix_final=False)
        traj_p1.add_objective('time', loc='final')

        # Second phase, but with battery failure.

        phase1_bfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_battery': 2},
                             transcription=transcription)
        traj_p1_bfail = traj.add_phase('phase1_bfail', phase1_bfail)

        traj_p1_bfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_bfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False)

        # Second phase, but with motor failure.

        phase1_mfail = Phase(ode_class=BatteryODE,
                             ode_init_kwargs={'num_motor': 2},
                             transcription=transcription)
        traj_p1_mfail = traj.add_phase('phase1_mfail', phase1_mfail)

        traj_p1_mfail.set_time_options(fix_initial=False, fix_duration=True)
        traj_p1_mfail.set_state_options('state_of_charge',
                                        fix_initial=False,
                                        fix_final=False)

        traj.link_phases(phases=['phase0', 'phase1'],
                         vars=['state_of_charge', 'time'])
        traj.link_phases(phases=['phase0', 'phase1_bfail'],
                         vars=['state_of_charge', 'time'])
        traj.link_phases(phases=['phase0', 'phase1_mfail'],
                         vars=['state_of_charge', 'time'])

        prob.model.options['assembled_jac_type'] = 'csc'
        prob.model.linear_solver = DirectSolver(assemble_jac=True)

        prob.setup()

        prob['traj.phase0.t_initial'] = 0
        prob['traj.phase0.t_duration'] = 1.0 * 3600

        prob['traj.phase1.t_initial'] = 1.0 * 3600
        prob['traj.phase1.t_duration'] = 1.0 * 3600

        prob['traj.phase1_bfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_bfail.t_duration'] = 1.0 * 3600

        prob['traj.phase1_mfail.t_initial'] = 1.0 * 3600
        prob['traj.phase1_mfail.t_duration'] = 1.0 * 3600

        prob.set_solver_print(level=0)
        prob.run_driver()

        soc0 = prob['traj.phase0.states:state_of_charge']
        soc1 = prob['traj.phase1.states:state_of_charge']
        soc1b = prob['traj.phase1_bfail.states:state_of_charge']
        soc1m = prob['traj.phase1_mfail.states:state_of_charge']

        # Final value for State of Chrage in each segment should be a good test.
        print('State of Charge after 1 hour')
        assert_rel_error(self, soc0[-1], 0.63464982, 1e-6)
        print('State of Charge after 2 hours')
        assert_rel_error(self, soc1[-1], 0.23794217, 1e-6)
        print('State of Charge after 2 hours, battery fails at 1 hour')
        assert_rel_error(self, soc1b[-1], 0.0281523, 1e-6)
        print('State of Charge after 2 hours, motor fails at 1 hour')
        assert_rel_error(self, soc1m[-1], 0.18625395, 1e-6)

        # Plot Results
        t0 = prob['traj.phases.phase0.time.time'] / 3600
        t1 = prob['traj.phases.phase1.time.time'] / 3600
        t1b = prob['traj.phases.phase1_bfail.time.time'] / 3600
        t1m = prob['traj.phases.phase1_mfail.time.time'] / 3600

        plt.subplot(2, 1, 1)
        plt.plot(t0, soc0, 'b')
        plt.plot(t1, soc1, 'b')
        plt.plot(t1b, soc1b, 'r')
        plt.plot(t1m, soc1m, 'c')
        plt.xlabel('Time (hour)')
        plt.ylabel('State of Charge (percent)')

        I_Li0 = prob['traj.phases.phase0.rhs_all.pwr_balance.I_Li']
        I_Li1 = prob['traj.phases.phase1.rhs_all.pwr_balance.I_Li']
        I_Li1b = prob['traj.phases.phase1_bfail.rhs_all.pwr_balance.I_Li']
        I_Li1m = prob['traj.phases.phase1_mfail.rhs_all.pwr_balance.I_Li']

        plt.subplot(2, 1, 2)
        plt.plot(t0, I_Li0, 'b')
        plt.plot(t1, I_Li1, 'b')
        plt.plot(t1b, I_Li1b, 'r')
        plt.plot(t1m, I_Li1m, 'c')
        plt.xlabel('Time (hour)')
        plt.ylabel('Line Current (A)')

        plt.legend([
            'Phase 1', 'Phase 2', 'Phase 2 Battery Fail', 'Phase 2 Motor Fail'
        ],
                   loc=2)

        plt.show()
Пример #17
0
    def test_dynamic_input_params(self):
        prob = Problem(model=Group())

        traj = prob.model.add_subsystem('traj', Trajectory())

        # First phase: normal operation.
        # NOTE: using RK4 integration here

        P_DEMAND = 2.0

        phase0 = Phase(ode_class=BatteryODE, transcription=RungeKutta(num_segments=200))
        phase0.set_time_options(fix_initial=True, fix_duration=True)
        phase0.set_state_options('state_of_charge', fix_initial=True, fix_final=False)
        phase0.add_timeseries_output('battery.V_oc', output_name='V_oc', units='V')
        phase0.add_timeseries_output('battery.V_pack', output_name='V_pack', units='V')
        phase0.add_timeseries_output('pwr_balance.I_Li', output_name='I_Li', units='A')
        phase0.add_input_parameter('P_demand', val=P_DEMAND, units='W')
        traj.add_phase('phase0', phase0)

        # Second phase: normal operation.

        transcription = Radau(num_segments=5, order=5, compressed=True)
        phase1 = Phase(ode_class=BatteryODE, transcription=transcription)
        phase1.set_time_options(fix_initial=False, fix_duration=True)
        phase1.set_state_options('state_of_charge', fix_initial=False, fix_final=False, solve_segments=True)
        phase1.add_timeseries_output('battery.V_oc', output_name='V_oc', units='V')
        phase1.add_timeseries_output('battery.V_pack', output_name='V_pack', units='V')
        phase1.add_timeseries_output('pwr_balance.I_Li', output_name='I_Li', units='A')
        phase1.add_input_parameter('P_demand', val=P_DEMAND, units='W')
        traj.add_phase('phase1', phase1)

        # Second phase, but with battery failure.

        phase1_bfail = Phase(ode_class=BatteryODE, ode_init_kwargs={'num_battery': 2},
                             transcription=transcription)
        phase1_bfail.set_time_options(fix_initial=False, fix_duration=True)
        phase1_bfail.set_state_options('state_of_charge', fix_initial=False, fix_final=False, solve_segments=True)
        phase1_bfail.add_timeseries_output('battery.V_oc', output_name='V_oc', units='V')
        phase1_bfail.add_timeseries_output('battery.V_pack', output_name='V_pack', units='V')
        phase1_bfail.add_timeseries_output('pwr_balance.I_Li', output_name='I_Li', units='A')
        phase1_bfail.add_input_parameter('P_demand', val=P_DEMAND, units='W')
        traj.add_phase('phase1_bfail', phase1_bfail)

        # Second phase, but with motor failure.

        phase1_mfail = Phase(ode_class=BatteryODE, ode_init_kwargs={'num_motor': 2},
                             transcription=transcription)
        phase1_mfail.set_time_options(fix_initial=False, fix_duration=True)
        phase1_mfail.set_state_options('state_of_charge', fix_initial=False, fix_final=False, solve_segments=True)
        phase1_mfail.add_timeseries_output('battery.V_oc', output_name='V_oc', units='V')
        phase1_mfail.add_timeseries_output('battery.V_pack', output_name='V_pack', units='V')
        phase1_mfail.add_timeseries_output('pwr_balance.I_Li', output_name='I_Li', units='A')
        phase1_mfail.add_input_parameter('P_demand', val=P_DEMAND, units='W')
        traj.add_phase('phase1_mfail', phase1_mfail)

        traj.link_phases(phases=['phase0', 'phase1'], vars=['state_of_charge', 'time'], connected=True)
        traj.link_phases(phases=['phase0', 'phase1_bfail'], vars=['state_of_charge', 'time'], connected=True)
        traj.link_phases(phases=['phase0', 'phase1_mfail'], vars=['state_of_charge', 'time'], connected=True)

        # prob.model.linear_solver = DirectSolver(assemble_jac=True)

        prob.setup()
        prob.final_setup()

        prob['traj.phases.phase0.time_extents.t_initial'] = 0
        prob['traj.phases.phase0.time_extents.t_duration'] = 1.0*3600

        # prob['traj.phases.phase1.time_extents.t_initial'] = 1.0*3600
        prob['traj.phases.phase1.time_extents.t_duration'] = 1.0*3600

        # prob['traj.phases.phase1_bfail.time_extents.t_initial'] = 1.0*3600
        prob['traj.phases.phase1_bfail.time_extents.t_duration'] = 1.0*3600

        # prob['traj.phases.phase1_mfail.time_extents.t_initial'] = 1.0*3600
        prob['traj.phases.phase1_mfail.time_extents.t_duration'] = 1.0*3600

        prob.set_solver_print(level=0)
        prob.run_model()

        plot = True
        if plot:
            import matplotlib
            matplotlib.use('Agg')
            import matplotlib.pyplot as plt

            t0 = prob['traj.phase0.timeseries.time']
            t1 = prob['traj.phase1.timeseries.time']
            t1b = prob['traj.phase1_bfail.timeseries.time']
            t1m = prob['traj.phase1_mfail.timeseries.time']
            soc0 = prob['traj.phase0.timeseries.states:state_of_charge']
            soc1 = prob['traj.phase1.timeseries.states:state_of_charge']
            soc1b = prob['traj.phase1_bfail.timeseries.states:state_of_charge']
            soc1m = prob['traj.phase1_mfail.timeseries.states:state_of_charge']

            plt.subplot(2, 2, 1)
            plt.plot(t0, soc0, 'b')
            plt.plot(t1, soc1, 'b')
            plt.plot(t1b, soc1b, 'r')
            plt.plot(t1m, soc1m, 'c')
            plt.xlabel('Time (hour)')
            plt.ylabel('State of Charge (percent)')

            V_oc0 = prob['traj.phase0.timeseries.V_oc']
            V_oc1 = prob['traj.phase1.timeseries.V_oc']
            V_oc1b = prob['traj.phase1_bfail.timeseries.V_oc']
            V_oc1m = prob['traj.phase1_mfail.timeseries.V_oc']

            plt.subplot(2, 2, 2)
            plt.plot(t0, V_oc0, 'b')
            plt.plot(t1, V_oc1, 'b')
            plt.plot(t1b, V_oc1b, 'r')
            plt.plot(t1m, V_oc1m, 'c')
            plt.xlabel('Time (hour)')
            plt.ylabel('Open Circuit Voltage (V)')

            V_pack0 = prob['traj.phase0.timeseries.V_pack']
            V_pack1 = prob['traj.phase1.timeseries.V_pack']
            V_pack1b = prob['traj.phase1_bfail.timeseries.V_pack']
            V_pack1m = prob['traj.phase1_mfail.timeseries.V_pack']

            plt.subplot(2, 2, 3)
            plt.plot(t0, V_pack0, 'b')
            plt.plot(t1, V_pack1, 'b')
            plt.plot(t1b, V_pack1b, 'r')
            plt.plot(t1m, V_pack1m, 'c')
            plt.xlabel('Time (hour)')
            plt.ylabel('Terminal Voltage (V)')

            I_Li0 = prob['traj.phase0.timeseries.I_Li']
            I_Li1 = prob['traj.phase1.timeseries.I_Li']
            I_Li1b = prob['traj.phase1_bfail.timeseries.I_Li']
            I_Li1m = prob['traj.phase1_mfail.timeseries.I_Li']

            plt.subplot(2, 2, 4)
            plt.plot(t0, I_Li0, 'b')
            plt.plot(t1, I_Li1, 'b')
            plt.plot(t1b, I_Li1b, 'r')
            plt.plot(t1m, I_Li1m, 'c')
            plt.xlabel('Time (hour)')
            plt.ylabel('Line Current (A)')

            plt.show()
Пример #18
0
    def test_brachistochrone_undecorated_ode_radau(self):
        import numpy as np
        import matplotlib
        matplotlib.use('Agg')
        import matplotlib.pyplot as plt
        from openmdao.api import Problem, Group, ScipyOptimizeDriver, DirectSolver
        from openmdao.utils.assert_utils import assert_rel_error
        from dymos import Phase, Radau

        p = Problem(model=Group())
        p.driver = ScipyOptimizeDriver()

        phase = Phase(ode_class=BrachistochroneODE,
                      transcription=Radau(num_segments=10))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(initial_bounds=(0, 0),
                               duration_bounds=(.5, 10),
                               units='s')

        phase.set_state_options('x',
                                fix_initial=True,
                                fix_final=True,
                                rate_source='xdot',
                                units='m')
        phase.set_state_options('y',
                                fix_initial=True,
                                fix_final=True,
                                rate_source='ydot',
                                units='m')
        phase.set_state_options('v',
                                fix_initial=True,
                                rate_source='vdot',
                                targets=['v'],
                                units='m/s')

        phase.add_control('theta',
                          units='deg',
                          rate_continuity=False,
                          lower=0.01,
                          upper=179.9,
                          targets=['theta'])

        phase.add_design_parameter('g',
                                   units='m/s**2',
                                   opt=False,
                                   val=9.80665,
                                   targets=['g'])

        # Minimize time at the end of the phase
        phase.add_objective('time', loc='final', scaler=10)

        p.model.linear_solver = DirectSolver()

        p.setup()

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        p['phase0.states:x'] = phase.interpolate(ys=[0, 10],
                                                 nodes='state_input')
        p['phase0.states:y'] = phase.interpolate(ys=[10, 5],
                                                 nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100.5],
                                                       nodes='control_input')

        # Solve for the optimal trajectory
        p.run_driver()

        # Test the results
        assert_rel_error(self,
                         p.get_val('phase0.timeseries.time')[-1],
                         1.8016,
                         tolerance=1.0E-3)
Пример #19
0
from __future__ import print_function, division, absolute_import

import numpy as np

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt

from openmdao.api import Problem, Group
from dymos import Phase, Radau
from dymos.examples.brachistochrone.brachistochrone_ode import BrachistochroneODE

p = Problem(model=Group())
phase = Phase(ode_class=BrachistochroneODE,
              transcription=Radau(num_segments=4, order=[3, 5, 3, 5]))
p.model.add_subsystem('phase0', phase)

p.setup()
p['phase0.t_initial'] = 1.0
p['phase0.t_duration'] = 9.0
p.run_model()

grid_data = phase.options['transcription'].grid_data

t_all = p.get_val('phase0.timeseries.time')
t_disc = t_all[grid_data.subset_node_indices['state_disc'], 0]
t_col = t_all[grid_data.subset_node_indices['col'], 0]


def f(x):  # pragma: no cover
    return np.sin(x) / x + 1
Пример #20
0
    def test_reentry_mixed_controls(self):

        p = om.Problem(model=om.Group())
        p.driver = om.pyOptSparseDriver()
        p.driver.declare_coloring(tol=1.0E-12)
        p.driver.options['optimizer'] = 'IPOPT'
        p.driver.opt_settings['alpha_for_y'] = 'safer-min-dual-infeas'
        p.driver.opt_settings['print_level'] = 5
        p.driver.opt_settings['nlp_scaling_method'] = 'gradient-based'
        p.driver.opt_settings['mu_strategy'] = 'monotone'

        traj = p.model.add_subsystem('traj', Trajectory())
        phase0 = traj.add_phase(
            'phase0',
            Phase(ode_class=ShuttleODE,
                  transcription=Radau(num_segments=30, order=3)))

        phase0.set_time_options(fix_initial=True, units='s', duration_ref=200)
        phase0.add_state('h',
                         fix_initial=True,
                         fix_final=True,
                         units='ft',
                         rate_source='hdot',
                         targets=['h'],
                         lower=0,
                         ref0=75000,
                         ref=300000,
                         defect_ref=1000)
        phase0.add_state('gamma',
                         fix_initial=True,
                         fix_final=True,
                         units='rad',
                         rate_source='gammadot',
                         targets=['gamma'],
                         lower=-89. * np.pi / 180,
                         upper=89. * np.pi / 180)
        phase0.add_state('phi',
                         fix_initial=True,
                         fix_final=False,
                         units='rad',
                         rate_source='phidot',
                         lower=0,
                         upper=89. * np.pi / 180)
        phase0.add_state('psi',
                         fix_initial=True,
                         fix_final=False,
                         units='rad',
                         rate_source='psidot',
                         targets=['psi'],
                         lower=0,
                         upper=90. * np.pi / 180)
        phase0.add_state('theta',
                         fix_initial=True,
                         fix_final=False,
                         units='rad',
                         rate_source='thetadot',
                         targets=['theta'],
                         lower=-89. * np.pi / 180,
                         upper=89. * np.pi / 180)
        phase0.add_state('v',
                         fix_initial=True,
                         fix_final=True,
                         units='ft/s',
                         rate_source='vdot',
                         targets=['v'],
                         lower=500,
                         ref0=2500,
                         ref=25000)
        phase0.add_control('alpha',
                           units='rad',
                           opt=True,
                           lower=-np.pi / 2,
                           upper=np.pi / 2)
        phase0.add_polynomial_control('beta',
                                      order=9,
                                      units='rad',
                                      opt=True,
                                      lower=-89 * np.pi / 180,
                                      upper=1 * np.pi / 180)

        phase0.add_objective('theta', loc='final', ref=-0.01)
        phase0.add_path_constraint('q', lower=0, upper=70, ref=70)

        p.setup(check=True, force_alloc_complex=True)

        p.set_val('traj.phase0.states:h',
                  phase0.interp('h', [260000, 80000]),
                  units='ft')
        p.set_val('traj.phase0.states:gamma',
                  phase0.interp('gamma', [-1 * np.pi / 180, -5 * np.pi / 180]),
                  units='rad')
        p.set_val('traj.phase0.states:phi',
                  phase0.interp('phi', [0, 75 * np.pi / 180]),
                  units='rad')
        p.set_val('traj.phase0.states:psi',
                  phase0.interp('psi', [90 * np.pi / 180, 10 * np.pi / 180]),
                  units='rad')
        p.set_val('traj.phase0.states:theta',
                  phase0.interp('theta', [0, 25 * np.pi / 180]),
                  units='rad')
        p.set_val('traj.phase0.states:v',
                  phase0.interp('v', [25600, 2500]),
                  units='ft/s')
        p.set_val('traj.phase0.t_initial', 0, units='s')
        p.set_val('traj.phase0.t_duration', 2000, units='s')
        p.set_val('traj.phase0.controls:alpha',
                  phase0.interp('alpha', [17.4, 17.4]),
                  units='deg')
        p.set_val('traj.phase0.polynomial_controls:beta',
                  phase0.interp('beta', [-20, 0]),
                  units='deg')

        run_problem(p, simulate=True)

        sol = om.CaseReader('dymos_solution.db').get_case('final')
        sim = om.CaseReader('dymos_simulation.db').get_case('final')

        from scipy.interpolate import interp1d

        t_sol = sol.get_val('traj.phase0.timeseries.time')
        beta_sol = sol.get_val(
            'traj.phase0.timeseries.polynomial_controls:beta', units='deg')

        t_sim = sim.get_val('traj.phase0.timeseries.time')
        beta_sim = sim.get_val(
            'traj.phase0.timeseries.polynomial_controls:beta', units='deg')

        sol_interp = interp1d(t_sol.ravel(), beta_sol.ravel())
        sim_interp = interp1d(t_sim.ravel(), beta_sim.ravel())

        t = np.linspace(0, t_sol.ravel()[-1], 1000)

        assert_near_equal(sim_interp(t), sol_interp(t), tolerance=0.01)

        assert_near_equal(p.get_val('traj.phase0.timeseries.time')[-1],
                          expected_results['constrained']['time'],
                          tolerance=1e-2)

        assert_near_equal(p.get_val('traj.phase0.timeseries.states:theta',
                                    units='deg')[-1],
                          expected_results['constrained']['theta'],
                          tolerance=1e-2)
    def test_brachistochrone_vector_ode_path_constraints_radau_no_indices(
            self):

        p = Problem(model=Group())

        p.driver = ScipyOptimizeDriver()
        p.driver.options['dynamic_simul_derivs'] = True

        phase = Phase(ode_class=BrachistochroneVectorStatesODE,
                      transcription=Radau(num_segments=20, order=3))

        p.model.add_subsystem('phase0', phase)

        phase.set_time_options(fix_initial=True, duration_bounds=(.5, 10))

        phase.set_state_options('pos', fix_initial=True, fix_final=True)
        phase.set_state_options('v', fix_initial=True, fix_final=False)

        phase.add_control('theta',
                          continuity=True,
                          rate_continuity=True,
                          units='deg',
                          lower=0.01,
                          upper=179.9)

        phase.add_design_parameter('g', units='m/s**2', opt=False, val=9.80665)

        phase.add_path_constraint('pos_dot',
                                  shape=(2, ),
                                  units='m/s',
                                  lower=-4,
                                  upper=12)

        phase.add_timeseries_output('pos_dot', shape=(2, ), units='m/s')

        # Minimize time at the end of the phase
        phase.add_objective('time', loc='final', scaler=10)

        p.model.linear_solver = DirectSolver()
        p.setup(check=True, force_alloc_complex=True)

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 2.0

        pos0 = [0, 10]
        posf = [10, 5]

        p['phase0.states:pos'] = phase.interpolate(ys=[pos0, posf],
                                                   nodes='state_input')
        p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9],
                                                 nodes='state_input')
        p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100],
                                                       nodes='control_input')
        p['phase0.design_parameters:g'] = 9.80665

        p.run_driver()

        assert_rel_error(self,
                         np.min(p.get_val('phase0.timeseries.pos_dot')[:, -1]),
                         -4,
                         tolerance=1.0E-2)

        # Plot results
        if SHOW_PLOTS:
            exp_out = phase.simulate(times_per_seg=50)

            fig, ax = plt.subplots()
            fig.suptitle('Brachistochrone Solution')

            x_imp = p.get_val('phase0.timeseries.states:pos')[:, 0]
            y_imp = p.get_val('phase0.timeseries.states:pos')[:, 1]

            x_exp = exp_out.get_val('phase0.timeseries.states:pos')[:, 0]
            y_exp = exp_out.get_val('phase0.timeseries.states:pos')[:, 1]

            ax.plot(x_imp, y_imp, 'ro', label='implicit')
            ax.plot(x_exp, y_exp, 'b-', label='explicit')

            ax.set_xlabel('x (m)')
            ax.set_ylabel('y (m)')
            ax.grid(True)
            ax.legend(loc='upper right')

            fig, ax = plt.subplots()
            fig.suptitle('Brachistochrone Solution\nVelocity')

            t_imp = p.get_val('phase0.timeseries.time')
            t_exp = exp_out.get_val('phase0.timeseries.time')

            xdot_imp = p.get_val('phase0.timeseries.pos_dot')[:, 0]
            ydot_imp = p.get_val('phase0.timeseries.pos_dot')[:, 1]

            xdot_exp = exp_out.get_val('phase0.timeseries.pos_dot')[:, 0]
            ydot_exp = exp_out.get_val('phase0.timeseries.pos_dot')[:, 1]

            ax.plot(t_imp, xdot_imp, 'bo', label='implicit')
            ax.plot(t_exp, xdot_exp, 'b-', label='explicit')

            ax.plot(t_imp, ydot_imp, 'ro', label='implicit')
            ax.plot(t_exp, ydot_exp, 'r-', label='explicit')

            ax.set_xlabel('t (s)')
            ax.set_ylabel('v (m/s)')
            ax.grid(True)
            ax.legend(loc='upper right')

            fig, ax = plt.subplots()
            fig.suptitle('Brachistochrone Solution')

            x_imp = p.get_val('phase0.timeseries.time')
            y_imp = p.get_val('phase0.timeseries.control_rates:theta_rate2')

            x_exp = exp_out.get_val('phase0.timeseries.time')
            y_exp = exp_out.get_val(
                'phase0.timeseries.control_rates:theta_rate2')

            ax.plot(x_imp, y_imp, 'ro', label='implicit')
            ax.plot(x_exp, y_exp, 'b-', label='explicit')

            ax.set_xlabel('time (s)')
            ax.set_ylabel('theta rate2 (rad/s**2)')
            ax.grid(True)
            ax.legend(loc='lower right')

            plt.show()

        return p
Пример #22
0
def brachistochrone_min_time(transcription='gauss-lobatto',
                             num_segments=8,
                             transcription_order=3,
                             run_driver=True,
                             compressed=True,
                             optimizer='SLSQP'):
    p = Problem(model=Group())

    # if optimizer == 'SNOPT':
    p.driver = pyOptSparseDriver()
    p.driver.options['optimizer'] = optimizer
    p.driver.options['dynamic_simul_derivs'] = True

    if transcription == 'gauss-lobatto':
        t = GaussLobatto(num_segments=num_segments,
                         order=transcription_order,
                         compressed=compressed)
    elif transcription == 'radau-ps':
        t = Radau(num_segments=num_segments,
                  order=transcription_order,
                  compressed=compressed)
    elif transcription == 'runge-kutta':
        t = RungeKutta(num_segments=num_segments,
                       order=transcription_order,
                       compressed=compressed)

    phase = Phase(ode_class=BrachistochroneODE, transcription=t)

    p.model.add_subsystem('phase0', phase)

    phase.set_time_options(fix_initial=True, duration_bounds=(.5, 10))

    phase.set_state_options('x',
                            fix_initial=True,
                            fix_final=False,
                            solve_segments=False)
    phase.set_state_options('y',
                            fix_initial=True,
                            fix_final=False,
                            solve_segments=False)
    phase.set_state_options('v',
                            fix_initial=True,
                            fix_final=False,
                            solve_segments=False)

    phase.add_control('theta',
                      continuity=True,
                      rate_continuity=True,
                      units='deg',
                      lower=0.01,
                      upper=179.9)

    phase.add_input_parameter('g', units='m/s**2', val=9.80665)

    phase.add_boundary_constraint('x', loc='final', equals=10)
    phase.add_boundary_constraint('y', loc='final', equals=5)
    # Minimize time at the end of the phase
    phase.add_objective('time_phase', loc='final', scaler=10)

    p.model.linear_solver = DirectSolver()
    p.setup(check=True)

    p['phase0.t_initial'] = 0.0
    p['phase0.t_duration'] = 2.0

    p['phase0.states:x'] = phase.interpolate(ys=[0, 10], nodes='state_input')
    p['phase0.states:y'] = phase.interpolate(ys=[10, 5], nodes='state_input')
    p['phase0.states:v'] = phase.interpolate(ys=[0, 9.9], nodes='state_input')
    p['phase0.controls:theta'] = phase.interpolate(ys=[5, 100],
                                                   nodes='control_input')
    p['phase0.input_parameters:g'] = 9.80665

    p.run_model()

    if run_driver:
        p.run_driver()

    # Plot results
    if SHOW_PLOTS:
        exp_out = phase.simulate()

        fig, ax = plt.subplots()
        fig.suptitle('Brachistochrone Solution')

        x_imp = p.get_val('phase0.timeseries.states:x')
        y_imp = p.get_val('phase0.timeseries.states:y')

        x_exp = exp_out.get_val('phase0.timeseries.states:x')
        y_exp = exp_out.get_val('phase0.timeseries.states:y')

        ax.plot(x_imp, y_imp, 'ro', label='implicit')
        ax.plot(x_exp, y_exp, 'b-', label='explicit')

        ax.set_xlabel('x (m)')
        ax.set_ylabel('y (m)')
        ax.grid(True)
        ax.legend(loc='upper right')

        fig, ax = plt.subplots()
        fig.suptitle('Brachistochrone Solution')

        x_imp = p.get_val('phase0.timeseries.time_phase')
        y_imp = p.get_val('phase0.timeseries.controls:theta')

        x_exp = exp_out.get_val('phase0.timeseries.time_phase')
        y_exp = exp_out.get_val('phase0.timeseries.controls:theta')

        ax.plot(x_imp, y_imp, 'ro', label='implicit')
        ax.plot(x_exp, y_exp, 'b-', label='explicit')

        ax.set_xlabel('time (s)')
        ax.set_ylabel('theta (rad)')
        ax.grid(True)
        ax.legend(loc='lower right')

        plt.show()

    return p
Пример #23
0
    def test_battery_power(self):
        """
            for battery explicit integration testings
        """
        _, local_opt = set_pyoptsparse_opt('SNOPT')
        if local_opt != 'SNOPT':
            raise unittest.SkipTest("pyoptsparse is not providing SNOPT")

        p = om.Problem()

        p.driver = om.pyOptSparseDriver()
        p.driver.options['optimizer'] = 'SNOPT'
        p.driver.opt_settings['Major iterations limit'] = 100
        p.driver.opt_settings['Major optimality tolerance'] = 5.0E-3
        p.driver.opt_settings['Major feasibility tolerance'] = 1e-6
        p.driver.opt_settings['iSumm'] = 6

        transcription = Radau(num_segments=15, order=3, compressed=True)

        phase0 = Phase(transcription=transcription, ode_class=BatteryGroup)

        phase0.set_time_options(fix_initial=True, duration_bounds=(30, 30))

        p.model.add_subsystem(name='phase0', subsys=phase0)

        phase0.add_state('SOC',
                         fix_initial=True,
                         rate_source='dXdt:SOC',
                         lower=0.0,
                         upper=1.)
        phase0.add_state('U_Th',
                         units='V',
                         fix_initial=False,
                         rate_source='dXdt:V_{thev}',
                         lower=0.0,
                         upper=5.0)

        # phase0.add_parameter('P_out', units='W', opt=False)

        # phase0.add_boundary_constraint('U_pack', units='V', loc='initial', equals=5100)

        phase0.add_objective('time', loc='final', ref=1)

        p.model.linear_solver = om.DirectSolver(assemble_jac=True)

        phase0.add_timeseries_output('Q_{batt}',
                                     output_name='Q_{batt}',
                                     units='W')
        # phase0.add_timeseries_output('U_pack', output_name='V', units='V')

        p.setup()

        # p.check_partials()

        T0 = 10 + 273

        p['phase0.t_initial'] = 0.0
        p['phase0.t_duration'] = 30

        p['phase0.states:SOC'] = phase0.interpolate(ys=[1.0, 0.0],
                                                    nodes='state_input')
        p['phase0.states:U_Th'] = phase0.interpolate(ys=[0.1, 0.1],
                                                     nodes='state_input')
        # p['phase0.parameters:P_out'][:] = 72000.

        p.run_driver()

        fig, ax = plt.subplots(3, 1, sharex=True)
        fig.suptitle('Temperature Plots')

        t_opt = p.get_val('phase0.timeseries.time')
        SOC_opt = p.get_val('phase0.timeseries.states:SOC', units=None)

        Q_batt_opt = p.get_val('phase0.timeseries.Q_{batt}', units='kW')

        ax[1].plot(t_opt, Q_batt_opt * 128 * 40, 'r', label='$Q_{cell}$')

        ax[2].plot(t_opt, SOC_opt, 'r', label='$SOC$')

        #spot check final values
        # assert_rel_error(self, T_batt_opt[-1], 1.25934406, tolerance=1.0E-6)

        # ax[3].plot(t_opt, V_opt, 'r', label='$Voltage$')

        # axarr = fig.add_subplot(1, 2, 2)
        # axarr.plot(sim_out.get_values('time'),sim_out.get_values('electric.battery.I_Li'), 'b')
        # # # axarr.plot(p['phase0.state_interp.state_col:r'],
        # # #            p['phase0.controls:h'], 'bo', ms=4)
        # axarr.set_ylabel('I_Li, amps')
        # axarr.set_xlabel('time, s')
        # axarr.axes.get_xaxis().set_visible(True)

        import matplotlib
        matplotlib.use(
            'agg')  # <--- comment out if you want to show this plot.
        plt.show()
    def test_two_phase_cannonball_for_docs(self):
        from openmdao.api import Problem, Group, IndepVarComp, DirectSolver, SqliteRecorder, \
            pyOptSparseDriver
        from openmdao.utils.assert_utils import assert_rel_error

        from dymos import Phase, Trajectory, Radau, GaussLobatto
        from dymos.examples.cannonball.cannonball_ode import CannonballODE

        from dymos.examples.cannonball.size_comp import CannonballSizeComp

        p = Problem(model=Group())

        p.driver = pyOptSparseDriver()
        p.driver.options['optimizer'] = 'SLSQP'
        p.driver.options['dynamic_simul_derivs'] = True

        external_params = p.model.add_subsystem('external_params', IndepVarComp())

        external_params.add_output('radius', val=0.10, units='m')
        external_params.add_output('dens', val=7.87, units='g/cm**3')

        external_params.add_design_var('radius', lower=0.01, upper=0.10, ref0=0.01, ref=0.10)

        p.model.add_subsystem('size_comp', CannonballSizeComp())

        traj = p.model.add_subsystem('traj', Trajectory())

        transcription = Radau(num_segments=5, order=3, compressed=True)
        ascent = Phase(ode_class=CannonballODE, transcription=transcription)

        ascent = traj.add_phase('ascent', ascent)

        # All initial states except flight path angle are fixed
        # Final flight path angle is fixed (we will set it to zero so that the phase ends at apogee)
        ascent.set_time_options(fix_initial=True, duration_bounds=(1, 100),
                                duration_ref=100, units='s')
        ascent.set_state_options('r', fix_initial=True, fix_final=False)
        ascent.set_state_options('h', fix_initial=True, fix_final=False)
        ascent.set_state_options('gam', fix_initial=False, fix_final=True)
        ascent.set_state_options('v', fix_initial=False, fix_final=False)

        # Limit the muzzle energy
        ascent.add_boundary_constraint('kinetic_energy.ke', loc='initial', units='J',
                                       upper=400000, lower=0, ref=100000, shape=(1,))

        # Second Phase (descent)
        transcription = GaussLobatto(num_segments=5, order=3, compressed=True)
        descent = Phase(ode_class=CannonballODE, transcription=transcription)

        traj.add_phase('descent', descent)

        # All initial states and time are free (they will be linked to the final states of ascent.
        # Final altitude is fixed (we will set it to zero so that the phase ends at ground impact)
        descent.set_time_options(initial_bounds=(.5, 100), duration_bounds=(.5, 100),
                                 duration_ref=100)
        descent.set_state_options('r', fix_initial=False, fix_final=False)
        descent.set_state_options('h', fix_initial=False, fix_final=True)
        descent.set_state_options('gam', fix_initial=False, fix_final=False)
        descent.set_state_options('v', fix_initial=False, fix_final=False)

        descent.add_objective('r', loc='final', scaler=-1.0)

        # Add internally-managed design parameters to the trajectory.
        traj.add_design_parameter('CD', val=0.5, units=None, opt=False)
        traj.add_design_parameter('CL', val=0.0, units=None, opt=False)
        traj.add_design_parameter('T', val=0.0, units='N', opt=False)
        traj.add_design_parameter('alpha', val=0.0, units='deg', opt=False)

        # Add externally-provided design parameters to the trajectory.
        traj.add_input_parameter('mass',
                                 target_params={'ascent': 'm', 'descent': 'm'},
                                 val=1.0)

        traj.add_input_parameter('S', val=0.005)

        # Link Phases (link time and all state variables)
        traj.link_phases(phases=['ascent', 'descent'], vars=['*'])

        # Issue Connections
        p.model.connect('external_params.radius', 'size_comp.radius')
        p.model.connect('external_params.dens', 'size_comp.dens')

        p.model.connect('size_comp.mass', 'traj.input_parameters:mass')
        p.model.connect('size_comp.S', 'traj.input_parameters:S')

        # Finish Problem Setup
        p.model.linear_solver = DirectSolver()

        p.driver.add_recorder(SqliteRecorder('ex_two_phase_cannonball.db'))

        p.setup(check=True)

        # Set Initial Guesses
        p.set_val('external_params.radius', 0.05, units='m')
        p.set_val('external_params.dens', 7.87, units='g/cm**3')

        p.set_val('traj.design_parameters:CD', 0.5)
        p.set_val('traj.design_parameters:CL', 0.0)
        p.set_val('traj.design_parameters:T', 0.0)

        p.set_val('traj.ascent.t_initial', 0.0)
        p.set_val('traj.ascent.t_duration', 10.0)

        p.set_val('traj.ascent.states:r', ascent.interpolate(ys=[0, 100], nodes='state_input'))
        p.set_val('traj.ascent.states:h', ascent.interpolate(ys=[0, 100], nodes='state_input'))
        p.set_val('traj.ascent.states:v', ascent.interpolate(ys=[200, 150], nodes='state_input'))
        p.set_val('traj.ascent.states:gam', ascent.interpolate(ys=[25, 0], nodes='state_input'),
                  units='deg')

        p.set_val('traj.descent.t_initial', 10.0)
        p.set_val('traj.descent.t_duration', 10.0)

        p.set_val('traj.descent.states:r', descent.interpolate(ys=[100, 200], nodes='state_input'))
        p.set_val('traj.descent.states:h', descent.interpolate(ys=[100, 0], nodes='state_input'))
        p.set_val('traj.descent.states:v', descent.interpolate(ys=[150, 200], nodes='state_input'))
        p.set_val('traj.descent.states:gam', descent.interpolate(ys=[0, -45], nodes='state_input'),
                  units='deg')

        p.run_driver()

        assert_rel_error(self, p.get_val('traj.descent.states:r')[-1],
                         3183.25, tolerance=1.0E-2)

        exp_out = traj.simulate()

        print('optimal radius: {0:6.4f} m '.format(p.get_val('external_params.radius',
                                                             units='m')[0]))
        print('cannonball mass: {0:6.4f} kg '.format(p.get_val('size_comp.mass',
                                                               units='kg')[0]))
        print('launch angle: {0:6.4f} '
              'deg '.format(p.get_val('traj.ascent.timeseries.states:gam',  units='deg')[0, 0]))
        print('maximum range: {0:6.4f} '
              'm '.format(p.get_val('traj.descent.timeseries.states:r')[-1, 0]))

        fig, axes = plt.subplots(nrows=1, ncols=1, figsize=(10, 6))

        time_imp = {'ascent': p.get_val('traj.ascent.timeseries.time'),
                    'descent': p.get_val('traj.descent.timeseries.time')}

        time_exp = {'ascent': exp_out.get_val('traj.ascent.timeseries.time'),
                    'descent': exp_out.get_val('traj.descent.timeseries.time')}

        r_imp = {'ascent': p.get_val('traj.ascent.timeseries.states:r'),
                 'descent': p.get_val('traj.descent.timeseries.states:r')}

        r_exp = {'ascent': exp_out.get_val('traj.ascent.timeseries.states:r'),
                 'descent': exp_out.get_val('traj.descent.timeseries.states:r')}

        h_imp = {'ascent': p.get_val('traj.ascent.timeseries.states:h'),
                 'descent': p.get_val('traj.descent.timeseries.states:h')}

        h_exp = {'ascent': exp_out.get_val('traj.ascent.timeseries.states:h'),
                 'descent': exp_out.get_val('traj.descent.timeseries.states:h')}

        axes.plot(r_imp['ascent'], h_imp['ascent'], 'bo')

        axes.plot(r_imp['descent'], h_imp['descent'], 'ro')

        axes.plot(r_exp['ascent'], h_exp['ascent'], 'b--')

        axes.plot(r_exp['descent'], h_exp['descent'], 'r--')

        axes.set_xlabel('range (m)')
        axes.set_ylabel('altitude (m)')

        fig, axes = plt.subplots(nrows=4, ncols=1, figsize=(10, 6))
        states = ['r', 'h', 'v', 'gam']
        for i, state in enumerate(states):
            x_imp = {'ascent': p.get_val('traj.ascent.timeseries.states:{0}'.format(state)),
                     'descent': p.get_val('traj.descent.timeseries.states:{0}'.format(state))}

            x_exp = {'ascent': exp_out.get_val('traj.ascent.timeseries.states:{0}'.format(state)),
                     'descent': exp_out.get_val('traj.descent.timeseries.states:{0}'.format(state))}

            axes[i].set_ylabel(state)

            axes[i].plot(time_imp['ascent'], x_imp['ascent'], 'bo')
            axes[i].plot(time_imp['descent'], x_imp['descent'], 'ro')
            axes[i].plot(time_exp['ascent'], x_exp['ascent'], 'b--')
            axes[i].plot(time_exp['descent'], x_exp['descent'], 'r--')

        params = ['CL', 'CD', 'T', 'alpha', 'm', 'S']
        fig, axes = plt.subplots(nrows=6, ncols=1, figsize=(12, 6))
        for i, param in enumerate(params):
            p_imp = {
                'ascent': p.get_val('traj.ascent.timeseries.traj_parameters:{0}'.format(param)),
                'descent': p.get_val('traj.descent.timeseries.traj_parameters:{0}'.format(param))}

            p_exp = {'ascent': exp_out.get_val('traj.ascent.timeseries.'
                                               'traj_parameters:{0}'.format(param)),
                     'descent': exp_out.get_val('traj.descent.timeseries.'
                                                'traj_parameters:{0}'.format(param))}

            axes[i].set_ylabel(param)

            axes[i].plot(time_imp['ascent'], p_imp['ascent'], 'bo')
            axes[i].plot(time_imp['descent'], p_imp['descent'], 'ro')
            axes[i].plot(time_exp['ascent'], p_exp['ascent'], 'b--')
            axes[i].plot(time_exp['descent'], p_exp['descent'], 'r--')

        plt.show()