コード例 #1
0
ファイル: suspended_mass.py プロジェクト: Agtiger/mocopaper
    def track(self, prediction_solution, exponent=2):

        track = osim.MocoTrack()
        track.setName('suspended_mass_tracking')
        track.setModel(osim.ModelProcessor(self.build_model()))
        track.setStatesReference(
            osim.TableProcessor(prediction_solution.exportToStatesTable()))
        track.set_states_global_tracking_weight(10.0)
        track.set_allow_unused_references(True)
        # track.set_control_effort_weight(1.0)
        track.set_mesh_interval(0.003)

        study = track.initialize()
        problem = study.updProblem()
        problem.setStateInfo("/jointset/tx/tx/value",
                             [-self.width, self.width], self.xinit)
        problem.setStateInfo("/jointset/ty/ty/value", [-2 * self.width, 0],
                             self.yinit)
        problem.setStateInfo("/forceset/left/activation", [0, 1], 0)
        problem.setStateInfo("/forceset/middle/activation", [0, 1], 0)
        problem.setStateInfo("/forceset/right/activation", [0, 1], 0)
        problem.updPhase().setDefaultSpeedBounds(osim.MocoBounds(-15, 15))
        tracking = osim.MocoStateTrackingGoal.safeDownCast(
            problem.updGoal('state_tracking'))
        tracking.setPattern('.*(value|speed)$')

        effort = osim.MocoControlGoal.safeDownCast(
            problem.updGoal('control_effort'))
        effort.setExponent(exponent)

        solver = osim.MocoCasADiSolver.safeDownCast(study.updSolver())
        solver.set_optim_convergence_tolerance(-1)
        solver.set_optim_constraint_tolerance(-1)

        solution = study.solve()

        return solution
コード例 #2
0
ファイル: squat_to_stand.py プロジェクト: Agtiger/mocopaper
    def predict_assisted(self, root_dir):
        model = self.assisted_model(root_dir)

        moco = self.create_study(model)
        problem = moco.updProblem()
        problem.addGoal(osim.MocoControlGoal('effort'))
        problem.addGoal(osim.MocoInitialActivationGoal('init_activation'))
        problem.addGoal(osim.MocoFinalTimeGoal('time'))

        problem.addParameter(
            osim.MocoParameter('stiffness', '/forceset/spring',
                               'stiffness', osim.MocoBounds(0, 100)))

        solver = osim.MocoCasADiSolver.safeDownCast(moco.updSolver())
        solver.resetProblem(problem)

        guess = solver.createGuess()

        N = guess.getNumTimes()
        for muscle in model.getMuscles():
            dgf = osim.DeGrooteFregly2016Muscle.safeDownCast(muscle)
            if not dgf.get_ignore_tendon_compliance():
                guess.setState(
                    '%s/normalized_tendon_force' % muscle.getAbsolutePathString(),
                    osim.createVectorLinspace(N, 0.1, 0.1))
            guess.setState(
                '%s/activation' % muscle.getAbsolutePathString(),
                osim.createVectorLinspace(N, 0.05, 0.05))
            guess.setControl(muscle.getAbsolutePathString(),
                             osim.createVectorLinspace(N, 0.05, 0.05))
        solver.setGuess(guess)

        solver.set_parameters_require_initsystem(False)
        solution = moco.solve()
        # moco.visualize(solution)
        solution.write(self.predict_assisted_solution_file % root_dir)
コード例 #3
0
independentCoords.append('tx')
constraint.setIndependentCoordinateNames(independentCoords)
constraint.setDependentCoordinateName('ty')
coefficients = osim.Vector(3, 0)  # 3 elements initialized to 0.
# The polynomial is c0*tx^2 + c1*tx + c2; set c0 = 1, c1 = c2 = 0.
coefficients.set(0, 1)
constraint.setFunction(osim.PolynomialFunction(coefficients))
model.addConstraint(constraint)

study = osim.MocoStudy()
problem = study.updProblem()
problem.setModel(model)

phase0 = problem.getPhase(0)
# Setting stricter bounds for the speeds improves convergence.
phase0.setDefaultSpeedBounds(osim.MocoBounds(-5, 5))

problem.setTimeBounds(0, 0.8)
# Start the motion at (-1, 1).
problem.setStateInfo('/jointset/tx/tx/value', [-2, 2], -1.0)
problem.setStateInfo('/jointset/ty/ty/value', [-2, 2], 1.0)

solver = study.initCasADiSolver()
solution = study.solve()

# If matplotlib is installed, plot the trajectory of the mass and the
# constraint force applied to the mass throughout the motion.
has_pylab = False
try:
    import pylab as pl
    from scipy.interpolate import InterpolatedUnivariateSpline
コード例 #4
0
# ===================================
problem = moco.updProblem()

# Model (dynamics).
# -----------------
problem.setModel(model)

# Bounds.
# -------
# Initial time must be 0, final time is finalTime.
problem.setTimeBounds(osim.MocoInitialBounds(0.),
                      osim.MocoFinalBounds(finalTime))

# Position must be within [-5, 5] throughout the motion.
# Initial position must be -0.5, final position must be within [0.25, 0.75].
problem.setStateInfo('/slider/position/value', osim.MocoBounds(-5., 5.),
                     osim.MocoInitialBounds(-0.5),
                     osim.MocoFinalBounds(0.25, 0.75))

# Speed must be within [-20, 20] throughout the motion.
# Initial and final speed must be 0. Use compact syntax.
problem.setStateInfo('/slider/position/speed', [-20, 20], [0], [0])

# Add Parameter. The default initial guess for a parameter is the midpoint of
# its bounds, *not* the value of a property in the model.
problem.addParameter(
    osim.MocoParameter('oscillator_mass', 'body', 'mass',
                       osim.MocoBounds(0, 10)))

# Cost.
# -----
problem = moco.updProblem()

#Set the time bounds (from kinematics file)
problem.setTimeBounds(osim.MocoInitialBounds(3.572),
                      osim.MocoFinalBounds(6.044))

#Set kinematic bounds (mins and maxes)

#Shoulder elevation
charValue = '/jointset/' + coordSet.get('shoulder_elv').getJoint().getName(
) + '/' + coordSet.get('shoulder_elv').getName() + '/value'
charSpeed = '/jointset/' + coordSet.get('shoulder_elv').getJoint().getName(
) + '/' + coordSet.get('shoulder_elv').getName() + '/speed'
mn = coordSet.get('shoulder_elv').getRangeMin()
mx = coordSet.get('shoulder_elv').getRangeMax()
problem.setStateInfo(charValue, osim.MocoBounds(mn, mx))
problem.setStateInfo(charSpeed, osim.MocoBounds(-50, 50))
del (mn, mx, charValue, charSpeed)

#Shoulder rotation
charValue = '/jointset/' + coordSet.get('shoulder_rot').getJoint().getName(
) + '/' + coordSet.get('shoulder_rot').getName() + '/value'
charSpeed = '/jointset/' + coordSet.get('shoulder_rot').getJoint().getName(
) + '/' + coordSet.get('shoulder_rot').getName() + '/speed'
mn = coordSet.get('shoulder_rot').getRangeMin()
mx = coordSet.get('shoulder_rot').getRangeMax()
problem.setStateInfo(charValue, osim.MocoBounds(mn, mx))
problem.setStateInfo(charSpeed, osim.MocoBounds(-50, 50))
del (mn, mx, charValue, charSpeed)

#Elevation plane
コード例 #6
0
# Define the optimal control problem.
# ===================================
problem = study.updProblem()

# Model (dynamics).
# -----------------
problem.setModel(model)

# Bounds.
# -------
# Initial time must be 0, final time can be within [0, 5].
problem.setTimeBounds(osim.MocoInitialBounds(0.), osim.MocoFinalBounds(0., 5.))

# Position must be within [-5, 5] throughout the motion.
# Initial position must be 0, final position must be 1.
problem.setStateInfo('/slider/position/value', osim.MocoBounds(-5, 5),
                     osim.MocoInitialBounds(0), osim.MocoFinalBounds(1))
# Speed must be within [-50, 50] throughout the motion.
# Initial and final speed must be 0. Use compact syntax.
problem.setStateInfo('/slider/position/speed', [-50, 50], [0], [0])

# Applied force must be between -50 and 50.
problem.setControlInfo('/actuator', osim.MocoBounds(-50, 50))

# Cost.
# -----
problem.addGoal(osim.MocoFinalTimeGoal())

# Configure the solver.
# =====================
solver = study.initCasADiSolver()
コード例 #7
0
    def test_bounds(self):
        model = osim.Model()
        model.setName('sliding_mass')
        model.set_gravity(osim.Vec3(0, 0, 0))
        body = osim.Body('body', 2.0, osim.Vec3(0), osim.Inertia(0))
        model.addComponent(body)

        joint = osim.SliderJoint('slider', model.getGround(), body)
        coord = joint.updCoordinate()
        coord.setName('position')
        model.addComponent(joint)

        actu = osim.CoordinateActuator()
        actu.setCoordinate(coord)
        actu.setName('actuator')
        actu.setOptimalForce(1)
        model.addComponent(actu)

        study = osim.MocoStudy()
        study.setName('sliding_mass')

        mp = study.updProblem()

        mp.setModel(model)
        ph0 = mp.getPhase()

        mp.setTimeBounds(osim.MocoInitialBounds(0.),
                         osim.MocoFinalBounds(0.1, 5.))
        assert ph0.getTimeInitialBounds().getLower() == 0
        assert ph0.getTimeInitialBounds().getUpper() == 0
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getLower(), 0.1)
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getUpper(), 5.0)

        mp.setTimeBounds([0.2, 0.3], [3.5])
        self.assertAlmostEqual(ph0.getTimeInitialBounds().getLower(), 0.2)
        self.assertAlmostEqual(ph0.getTimeInitialBounds().getUpper(), 0.3)
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getLower(), 3.5)
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getUpper(), 3.5)

        # Use setter on MocoPhase.
        ph0.setTimeBounds([2.2, 2.3], [4.5])
        self.assertAlmostEqual(ph0.getTimeInitialBounds().getLower(), 2.2)
        self.assertAlmostEqual(ph0.getTimeInitialBounds().getUpper(), 2.3)
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getLower(), 4.5)
        self.assertAlmostEqual(ph0.getTimeFinalBounds().getUpper(), 4.5)

        mp.setStateInfo('slider/position/value', osim.MocoBounds(-5, 5),
                        osim.MocoInitialBounds(0))
        assert -5 == ph0.getStateInfo(
            'slider/position/value').getBounds().getLower()
        assert 5 == ph0.getStateInfo(
            'slider/position/value').getBounds().getUpper()
        assert isnan(
            ph0.getStateInfo(
                'slider/position/value').getFinalBounds().getLower())
        assert isnan(
            ph0.getStateInfo(
                'slider/position/value').getFinalBounds().getUpper())
        mp.setStateInfo('slider/position/speed', [-50, 50], [-3], 1.5)
        assert -50 == ph0.getStateInfo(
            'slider/position/speed').getBounds().getLower()
        assert 50 == ph0.getStateInfo(
            'slider/position/speed').getBounds().getUpper()
        assert -3 == ph0.getStateInfo(
            'slider/position/speed').getInitialBounds().getLower()
        assert -3 == ph0.getStateInfo(
            'slider/position/speed').getInitialBounds().getUpper()
        self.assertAlmostEqual(
            1.5,
            ph0.getStateInfo(
                'slider/position/speed').getFinalBounds().getLower())
        self.assertAlmostEqual(
            1.5,
            ph0.getStateInfo(
                'slider/position/speed').getFinalBounds().getUpper())

        # Use setter on MocoPhase.
        ph0.setStateInfo('slider/position/speed', [-6, 10], [-4, 3], [0])
        assert -6 == ph0.getStateInfo(
            'slider/position/speed').getBounds().getLower()
        assert 10 == ph0.getStateInfo(
            'slider/position/speed').getBounds().getUpper()
        assert -4 == ph0.getStateInfo(
            'slider/position/speed').getInitialBounds().getLower()
        assert 3 == ph0.getStateInfo(
            'slider/position/speed').getInitialBounds().getUpper()
        assert 0 == ph0.getStateInfo(
            'slider/position/speed').getFinalBounds().getLower()
        assert 0 == ph0.getStateInfo(
            'slider/position/speed').getFinalBounds().getUpper()

        # Controls.
        mp.setControlInfo('actuator', osim.MocoBounds(-50, 50))
        assert -50 == ph0.getControlInfo('actuator').getBounds().getLower()
        assert 50 == ph0.getControlInfo('actuator').getBounds().getUpper()
        mp.setControlInfo('actuator', [18])
        assert 18 == ph0.getControlInfo('actuator').getBounds().getLower()
        assert 18 == ph0.getControlInfo('actuator').getBounds().getUpper()
コード例 #8
0
ファイル: tracking_walking.py プロジェクト: Agtiger/mocopaper
    def run_tracking_problem(self, root_dir, config):

        modelProcessor = self.create_model_processor(root_dir,
                                                     for_inverse=False,
                                                     config=config)
        model = modelProcessor.process()
        model.initSystem()

        # Count the number of Force objects in the model. We'll use this to 
        # normalize the control effort cost.
        numForces = 0
        for actu in model.getComponentsList():
            if (actu.getConcreteClassName().endswith('Muscle') or
                    actu.getConcreteClassName().endswith('Actuator')):
                numForces += 1

        # Construct the base tracking problem
        # -----------------------------------
        track = osim.MocoTrack()
        track.setName('tracking_walking')
        track.setModel(modelProcessor)
        
        if self.coordinate_tracking:
            tableProcessor = osim.TableProcessor(os.path.join(root_dir,
                    'resources/Rajagopal2016/coordinates.mot'))
            tableProcessor.append(osim.TabOpLowPassFilter(6))
            tableProcessor.append(osim.TabOpUseAbsoluteStateNames())
            track.setStatesReference(tableProcessor)
            track.set_states_global_tracking_weight(
                config.tracking_weight / (2 * model.getNumCoordinates()))
            # Don't track some pelvis coordinates to avoid poor walking motion
            # solutions.
            stateWeights = osim.MocoWeightSet()
            weightList = list()
            weightList.append(('/jointset/ground_pelvis/pelvis_ty/value', 0))
            weightList.append(('/jointset/ground_pelvis/pelvis_tz/value', 0))
            weightList.append(('/jointset/ground_pelvis/pelvis_list/value', 0))
            weightList.append(('/jointset/ground_pelvis/pelvis_tilt/value', 0))
            weightList.append(('/jointset/ground_pelvis/pelvis_rotation/value', 0))
            weightList.append(('/jointset/hip_r/hip_rotation_r/value', 0))
            # weightList.append(('/jointset/hip_r/hip_adduction_r/value', 0))
            weightList.append(('/jointset/hip_l/hip_rotation_l/value', 0))
            # weightList.append(('/jointset/hip_l/hip_adduction_l/value', 0))
            # weightList.append(('/jointset/ankle_r/ankle_angle_r/value', 10))
            # weightList.append(('/jointset/ankle_l/ankle_angle_l/value', 10))
            for weight in weightList:
                stateWeights.cloneAndAppend(osim.MocoWeight(weight[0], weight[1]))
            track.set_states_weight_set(stateWeights)
            track.set_apply_tracked_states_to_guess(True)
            # track.set_scale_state_weights_with_range(True);
        else:
            track.setMarkersReferenceFromTRC(os.path.join(root_dir,
                    'resources/Rajagopal2016/markers.trc'))
            track.set_markers_global_tracking_weight(
                config.tracking_weight / (2 * model.getNumMarkers()))
            iktool = osim.InverseKinematicsTool(os.path.join(root_dir,
                    'resources/Rajagopal2016/ik_setup_walk.xml'))
            iktasks = iktool.getIKTaskSet()
            markerWeights = osim.MocoWeightSet()
            for marker in model.getComponentsList():
                if not type(marker) is osim.Marker: continue
                for i in np.arange(iktasks.getSize()):
                    iktask = iktasks.get(int(i))
                    if iktask.getName() == marker.getName():
                        weight = osim.MocoWeight(iktask.getName(), 
                            iktask.getWeight())
                        markerWeights.cloneAndAppend(weight)
            track.set_markers_weight_set(markerWeights)

        track.set_allow_unused_references(True)
        track.set_track_reference_position_derivatives(True)
        track.set_control_effort_weight(config.effort_weight / numForces)
        track.set_initial_time(self.initial_time)
        track.set_final_time(self.half_time)
        track.set_mesh_interval(self.mesh_interval)

        # Customize the base tracking problem
        # -----------------------------------
        study = track.initialize()
        problem = study.updProblem()
        problem.setTimeBounds(self.initial_time, 
                [self.half_time-0.2, self.half_time+0.2])

        # Set the initial values for the lumbar and pelvis coordinates that
        # produce "normal" walking motions.
        problem.setStateInfo('/jointset/back/lumbar_extension/value', [], -0.12)
        problem.setStateInfo('/jointset/back/lumbar_bending/value', [], 0)
        problem.setStateInfo('/jointset/back/lumbar_rotation/value', [], 0.04)
        problem.setStateInfo('/jointset/ground_pelvis/pelvis_tx/value', [], 0.446)
        problem.setStateInfo('/jointset/ground_pelvis/pelvis_tilt/value', [], 0)
        problem.setStateInfo('/jointset/ground_pelvis/pelvis_list/value', [], 0)
        problem.setStateInfo('/jointset/ground_pelvis/pelvis_rotation/value', [], 0)

        # Update the control effort goal to a cost of transport type cost.
        effort = osim.MocoControlGoal().safeDownCast(
                problem.updGoal('control_effort'))
        effort.setDivideByDisplacement(True)
        # Weight residual and reserve actuators low in the effort cost since
        # they are already weak.
        if config.effort_weight:
            for actu in model.getComponentsList():
                actuName = actu.getName()
                if actu.getConcreteClassName().endswith('Actuator'):
                    effort.setWeightForControl(actu.getAbsolutePathString(),
                        0.001)
            for muscle in ['psoas', 'iliacus']:
                for side in ['l', 'r']:
                    effort.setWeightForControl(
                        '/forceset/%s_%s' % (muscle, side), 0.25)

        speedGoal = osim.MocoAverageSpeedGoal('speed')
        speedGoal.set_desired_average_speed(1.235)
        problem.addGoal(speedGoal)

        # MocoFrameDistanceConstraint
        # ---------------------------
        if self.coordinate_tracking:
            distanceConstraint = osim.MocoFrameDistanceConstraint()
            distanceConstraint.setName('distance_constraint')
            # Step width is 0.13 * leg_length
            # distance = 0.10 # TODO Should be closer to 0.11.
            # Donelan JM, Kram R, Kuo AD. Mechanical and metabolic determinants
            # of the preferred step width in human walking.
            # Proc Biol Sci. 2001;268(1480):1985–1992.
            # doi:10.1098/rspb.2001.1761
            # https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1088839/
            distanceConstraint.addFramePair(
                    osim.MocoFrameDistanceConstraintPair(
                    '/bodyset/calcn_l', '/bodyset/calcn_r', 0.09, np.inf))
            distanceConstraint.addFramePair(
                    osim.MocoFrameDistanceConstraintPair(
                    '/bodyset/toes_l', '/bodyset/toes_r', 0.06, np.inf))
            # distanceConstraint.addFramePair(
            #         osim.MocoFrameDistanceConstraintPair(
            #         '/bodyset/calcn_l', '/bodyset/toes_r', distance, np.inf))
            # distanceConstraint.addFramePair(
            #         osim.MocoFrameDistanceConstraintPair(
            #         '/bodyset/toes_l', '/bodyset/calcn_r', distance, np.inf))
            distanceConstraint.setProjection("vector")
            distanceConstraint.setProjectionVector(osim.Vec3(0, 0, 1))
            problem.addPathConstraint(distanceConstraint)

        # Symmetry constraints
        # --------------------
        statesRef = osim.TimeSeriesTable('tracking_walking_tracked_states.sto')
        initIndex = statesRef.getNearestRowIndexForTime(self.initial_time)
        symmetry = osim.MocoPeriodicityGoal('symmetry')
        # Symmetric coordinate values (except for pelvis_tx) and speeds.
        for coord in model.getComponentsList():
            if not type(coord) is osim.Coordinate: continue

            coordName = coord.getName()
            coordValue = coord.getStateVariableNames().get(0)
            coordSpeed = coord.getStateVariableNames().get(1)

            if coordName.endswith('_r'):
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordValue, coordValue.replace('_r/', '_l/')))
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordSpeed, coordSpeed.replace('_r/', '_l/')))
            elif coordName.endswith('_l'):
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordValue, coordValue.replace('_l/', '_r/')))
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordSpeed, coordSpeed.replace('_l/', '_r/')))
            elif (coordName.endswith('_bending') or
                  coordName.endswith('_rotation') or
                  coordName.endswith('_tz') or
                  coordName.endswith('_list')):
                # This does not include hip rotation,
                # because that ends with _l or _r.
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordValue))
                symmetry.addNegatedStatePair(osim.MocoPeriodicityGoalPair(
                    coordSpeed))
            elif not coordName.endswith('_tx'):
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordValue))
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    coordSpeed))
        symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
            '/jointset/ground_pelvis/pelvis_tx/speed'))
        # Symmetric activations.
        for actu in model.getComponentsList():
            if (not actu.getConcreteClassName().endswith('Muscle') and 
                not actu.getConcreteClassName().endswith('Actuator')): continue
            if actu.getName().endswith('_r'):
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    actu.getStateVariableNames().get(0),
                    actu.getStateVariableNames().get(0).replace('_r/', '_l/')))
            elif actu.getName().endswith('_l'):
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    actu.getStateVariableNames().get(0),
                    actu.getStateVariableNames().get(0).replace('_l/', '_r/')))
            elif (actu.getName().endswith('_bending') or 
                  actu.getName().endswith('_rotation') or
                  actu.getName().endswith('_tz') or
                  actu.getName().endswith('_list')):
                symmetry.addNegatedStatePair(osim.MocoPeriodicityGoalPair(
                    actu.getStateVariableNames().get(0),
                    actu.getStateVariableNames().get(0)))
            else:
                symmetry.addStatePair(osim.MocoPeriodicityGoalPair(
                    actu.getStateVariableNames().get(0),
                    actu.getStateVariableNames().get(0)))
        problem.addGoal(symmetry)

        # Contact tracking
        # ----------------
        forceNamesRightFoot = ['forceset/contactSphereHeel_r',
                               'forceset/contactLateralRearfoot_r',
                               'forceset/contactLateralMidfoot_r',
                               'forceset/contactLateralToe_r',
                               'forceset/contactMedialToe_r',
                               'forceset/contactMedialMidfoot_r']
        forceNamesLeftFoot = ['forceset/contactSphereHeel_l',
                              'forceset/contactLateralRearfoot_l',
                              'forceset/contactLateralMidfoot_l',
                              'forceset/contactLateralToe_l',
                              'forceset/contactMedialToe_l',
                              'forceset/contactMedialMidfoot_l']
        if self.contact_tracking:
            contactTracking = osim.MocoContactTrackingGoal('contact', 0.001)
            contactTracking.setExternalLoadsFile(
                'resources/Rajagopal2016/grf_walk.xml')
            contactTracking.addContactGroup(forceNamesRightFoot, 'Right_GRF')
            contactTracking.addContactGroup(forceNamesLeftFoot, 'Left_GRF')
            contactTracking.setProjection("plane")
            contactTracking.setProjectionVector(osim.Vec3(0, 0, 1))
            problem.addGoal(contactTracking)

        # Configure the solver
        # --------------------
        solver = osim.MocoCasADiSolver.safeDownCast(study.updSolver())
        solver.resetProblem(problem)
        solver.set_optim_constraint_tolerance(1e-3)
        solver.set_optim_convergence_tolerance(1e-3)
        solver.set_multibody_dynamics_mode('implicit')
        solver.set_minimize_implicit_multibody_accelerations(True)
        solver.set_implicit_multibody_accelerations_weight(
            1e-6 / model.getNumCoordinates())
        solver.set_implicit_multibody_acceleration_bounds(
                osim.MocoBounds(-200, 200))

        # Set the guess
        # -------------
        # Create a guess compatible with this problem.
        guess = solver.createGuess()
        # Load the inverse problem solution and set its states and controls
        # trajectories to the guess.
        inverseSolution = osim.MocoTrajectory(
            os.path.join(root_dir, self.inverse_solution_relpath))
        inverseStatesTable = inverseSolution.exportToStatesTable()
        guess.insertStatesTrajectory(inverseStatesTable, True)
        # Changing this initial guess has a large negative effect on the
        # solution! Lots of knee flexion.
        # guess.setState('/jointset/ground_pelvis/pelvis_ty/value',
        #                osim.Vector(guess.getNumTimes(), 1.01))
        inverseControlsTable = inverseSolution.exportToControlsTable()
        guess.insertControlsTrajectory(inverseControlsTable, True)
        solver.setGuess(guess)

        # Solve and print solution.
        # -------------------------
        solution = study.solve()
        solution.write(self.get_solution_path(root_dir, config))

        # Create a full gait cycle trajectory from the periodic solution.
        fullTraj = osim.createPeriodicTrajectory(solution)
        fullTraj.write(self.get_solution_path_fullcycle(root_dir, config))

        # Compute ground reaction forces generated by contact sphere from the 
        # full gait cycle trajectory.
        externalLoads = osim.createExternalLoadsTableForGait(
                model, fullTraj, forceNamesRightFoot, forceNamesLeftFoot)
        osim.writeTableToFile(externalLoads,
                              self.get_solution_path_grfs(root_dir, config))