コード例 #1
0
def createContactForEffector(invdyn, robot, phase, eeName):
    contactNormal = np.matrix(cfg.Robot.dict_normal[eeName]).T
    contactNormal = cfg.Robot.dict_offset[
        eeName].rotation * contactNormal  # apply offset transform
    if cfg.Robot.cType == "_3_DOF":
        contact = tsid.ContactPoint("contact_" + eeName, robot, eeName,
                                    contactNormal, cfg.MU, cfg.fMin, cfg.fMax)
        mask = np.matrix(np.ones(3)).transpose()
        contact.useLocalFrame(False)
    else:
        contact_Points = buildRectangularContactPoints(eeName)
        contact = tsid.Contact6d("contact_" + eeName, robot, eeName,
                                 contact_Points, contactNormal, cfg.MU,
                                 cfg.fMin, cfg.fMax)
        mask = np.matrix(np.ones(6)).transpose()
    contact.setKp(cfg.kp_contact * mask)
    contact.setKd(2.0 * np.sqrt(cfg.kp_contact) * mask)
    ref = getCurrentEffectorPosition(robot, invdyn.data(), eeName)
    contact.setReference(ref)
    invdyn.addRigidContact(contact, cfg.w_forceRef)
    if cfg.WB_VERBOSE:
        print "create contact for effector ", eeName
        if cfg.Robot.cType == "_3_DOF":
            print "create contact point"
        else:
            print "create rectangular contact"
            print "contact points : \n", contact_Points
        print "contact placement : ", ref
        print "contact_normal : ", contactNormal
    return contact
コード例 #2
0
ファイル: walk.py プロジェクト: mklvcm/tsid
def AttachContact(name):
    i = contact_frames.index(name)
    contacts[i] = tsid.ContactPoint(name, robot, name, contactNormal, mu, fMin, fMax)
    contacts[i].setKp(kp_contact * matlib.ones(3).T)
    contacts[i].setKd(2.0 * np.sqrt(kp_contact) * matlib.ones(3).T)
    H_rf_ref = robot.framePosition(data, robot.model().getFrameId(name))
    contacts[i].setReference(H_rf_ref)
    contacts[i].useLocalFrame(False)
    invdyn.addRigidContact(contacts[i], w_forceRef, 1.0, 1)
コード例 #3
0
def createContactForEffector(cfg,
                             invdyn,
                             robot,
                             eeName,
                             patch,
                             use_force_reg=True):
    """
    Add a contact task in invdyn for the given effector, at it's current placement
    :param invdyn:
    :param robot:
    :param eeName: name of the effector
    :param patch: the ContactPatch object to use. Take friction coefficient and placement for the contact from this object
    :param use_force_reg: if True, use the cfg.w_forceRef_init otherwise use cfg.w_forceRef_end
    :return: the contact task
    """
    contactNormal = np.array(cfg.Robot.dict_normal[eeName])
    contactNormal = cfg.Robot.dict_offset[
        eeName].rotation @ contactNormal  # apply offset transform
    logger.info("create contact for effector %s", eeName)
    logger.info("contact placement : %s", patch.placement)
    logger.info("contact_normal : %s", contactNormal)
    if patch.contact_model.contact_type == ContactType.CONTACT_POINT:
        contact = tsid.ContactPoint("contact_" + eeName, robot, eeName,
                                    contactNormal, patch.friction, cfg.fMin,
                                    cfg.fMax)
        mask = np.ones(3)
        force_ref = np.zeros(3)
        contact.useLocalFrame(False)
        logger.info("create contact point")
    elif patch.contact_model.contact_type == ContactType.CONTACT_PLANAR:
        contact_points = patch.contact_model.contact_points_positions
        contact = tsid.Contact6d("contact_" + eeName, robot, eeName,
                                 contact_points, contactNormal, patch.friction,
                                 cfg.fMin, cfg.fMax)
        mask = np.ones(6)
        force_ref = np.zeros(6)
        logger.info("create rectangular contact")
        logger.info("contact points : \n %s", contact_points)
    else:
        raise RuntimeError("Unknown contact type : ",
                           patch.contact_model.contact_type)
    contact.setKp(cfg.kp_contact * mask)
    contact.setKd(2.0 * np.sqrt(cfg.kp_contact) * mask)
    contact.setReference(patch.placement)
    contact.setForceReference(force_ref)
    if use_force_reg:
        w_forceRef = cfg.w_forceRef_init
    else:
        w_forceRef = cfg.w_forceRef_end
    invdyn.addRigidContact(contact, w_forceRef)
    return contact
コード例 #4
0
    def __init__(self, conf, viewer=True):
        self.conf = conf
        self.contact_frame_names = conf.contact_frame_names
        print('Robot files:')
        print(conf.urdf)
        print(conf.srdf)
        vector = pin.StdVec_StdString()
        vector.extend(item for item in conf.path)
        self.robot = tsid.RobotWrapper(conf.urdf, vector,
                                       pin.JointModelFreeFlyer(), False)
        robot = self.robot
        self.model = robot.model()

        pin.loadReferenceConfigurations(self.model, conf.srdf, False)
        self.q0 = q = self.model.referenceConfigurations[
            conf.reference_config_q_name]
        v = np.zeros(robot.nv)

        assert (all([
            self.model.existFrame(frame_name)
            for frame_name in self.contact_frame_names
        ]))

        invdyn = tsid.InverseDynamicsFormulationAccForce('tsid', robot, False)
        invdyn.computeProblemData(0.0, q, v)
        data = invdyn.data()

        robot.computeAllTerms(data, q, v)

        #####################################
        # define contact and associated tasks
        #####################################

        self.contact_frame_ids = [
            self.model.getFrameId(frame_name)
            for frame_name in self.contact_frame_names
        ]
        self.nc = len(self.contact_frame_ids)  # contact number

        self.contacts = self.nc * [None]
        self.tasks_tracking_foot = self.nc * [None]
        self.traj_feet = self.nc * [None]
        self.sample_feet = self.nc * [None]
        mask = np.ones(6)
        if not conf.contact6d:
            mask[3:] = 0
        for i_foot, (frame_name, fid) in enumerate(
                zip(self.contact_frame_names, self.contact_frame_ids)):
            Hf_ref = robot.framePosition(data, fid)

            if conf.contact6d:
                # DEFINE FOOT CONTACT POINTS LOCATION WRT LOCAL FOOT FRAMES
                # contact_points = np.ones((3,4)) * conf.lz
                contact_points = -np.ones((3, 4)) * conf.lz
                contact_points[0, :] = [
                    -conf.lxn, -conf.lxn, conf.lxp, conf.lxp
                ]
                contact_points[1, :] = [
                    -conf.lyn, conf.lyp, -conf.lyn, conf.lyp
                ]

                # RIGID CONTACT RIGHT FOOT
                self.contacts[i_foot] = tsid.Contact6d(
                    'contact_{}'.format(frame_name), robot, frame_name,
                    contact_points, conf.contactNormal, conf.mu, conf.fMin,
                    conf.fMax)
                self.contacts[i_foot].setKp(conf.kp_contact * np.ones(6).T)
                self.contacts[i_foot].setKd(2.0 * np.sqrt(conf.kp_contact) *
                                            np.ones(6).T)
                self.contacts[i_foot].setReference(Hf_ref)
                invdyn.addRigidContact(self.contacts[i_foot], conf.w_forceRef)

            else:
                # RIGID POINT CONTACTS
                self.contacts[i_foot] = tsid.ContactPoint(
                    'contact_{}'.format(frame_name), robot, frame_name,
                    conf.contactNormal, conf.mu, conf.fMin, conf.fMax)
                self.contacts[i_foot].setKp(conf.kp_contact * np.ones(3))
                self.contacts[i_foot].setKd(2.0 * np.sqrt(conf.kp_contact) *
                                            np.ones(3))
                self.contacts[i_foot].setReference(Hf_ref)
                self.contacts[i_foot].useLocalFrame(conf.useLocalFrame)
                invdyn.addRigidContact(self.contacts[i_foot], conf.w_forceRef)

            # FEET TRACKING TASKS
            self.tasks_tracking_foot[i_foot] = tsid.TaskSE3Equality(
                'task-foot{}'.format(i_foot), self.robot,
                self.contact_frame_names[i_foot])
            self.tasks_tracking_foot[i_foot].setKp(conf.kp_foot * mask)
            self.tasks_tracking_foot[i_foot].setKd(
                2.0 * np.sqrt(conf.kp_foot) * mask)
            self.tasks_tracking_foot[i_foot].setMask(mask)
            self.tasks_tracking_foot[i_foot].useLocalFrame(False)
            invdyn.addMotionTask(self.tasks_tracking_foot[i_foot], conf.w_foot,
                                 conf.priority_foot, 0.0)

            self.traj_feet[i_foot] = tsid.TrajectorySE3Constant(
                'traj-foot{}'.format(i_foot), Hf_ref)
            self.sample_feet[i_foot] = self.traj_feet[i_foot].computeNext()

        #############
        # Other tasks
        #############

        # COM TASK
        self.comTask = tsid.TaskComEquality('task-com', robot)
        self.comTask.setKp(conf.kp_com * np.ones(3))
        self.comTask.setKd(2.0 * np.sqrt(conf.kp_com) * np.ones(3))
        invdyn.addMotionTask(self.comTask, conf.w_com, conf.priority_com, 1.0)

        # POSTURE TASK
        self.postureTask = tsid.TaskJointPosture('task-posture', robot)
        self.postureTask.setKp(conf.kp_posture * np.ones(robot.nv - 6))
        self.postureTask.setKd(2.0 * np.sqrt(conf.kp_posture) *
                               np.ones(robot.nv - 6))
        invdyn.addMotionTask(self.postureTask, conf.w_posture,
                             conf.priority_posture, 0.0)

        # TRUNK Task
        self.trunkTask = tsid.TaskSE3Equality("keepTrunk", robot, 'root_joint')
        self.trunkTask.setKp(conf.kp_trunk * np.ones(6))
        self.trunkTask.setKd(2.0 * np.sqrt(conf.kp_trunk) * np.ones(6))
        # Add a Mask to the task which will select the vector dimensions on which the task will act.
        # In this case the trunk configuration is a vector 6d (position and orientation -> SE3)
        # Here we set a mask = [0 0 0 1 1 1] so the task on the trunk will act on the orientation of the robot
        mask = np.ones(6)
        mask[:3] = 0.
        self.trunkTask.useLocalFrame(False)
        self.trunkTask.setMask(mask)
        invdyn.addMotionTask(self.trunkTask, conf.w_trunk, conf.priority_trunk,
                             0.0)

        # TORQUE BOUND TASK
        # self.tau_max = conf.tau_max_scaling*robot.model().effortLimit[-robot.na:]
        # self.tau_min = -self.tau_max
        # actuationBoundsTask = tsid.TaskActuationBounds('task-actuation-bounds', robot)
        # actuationBoundsTask.setBounds(self.tau_min, self.tau_max)
        # if(conf.w_torque_bounds>0.0):
        #     invdyn.addActuationTask(actuationBoundsTask, conf.w_torque_bounds, conf.priority_torque_bounds, 0.0)

        # JOINT BOUND TASK
        # jointBoundsTask = tsid.TaskJointBounds('task-joint-bounds', robot, conf.dt)
        # self.v_max = conf.v_max_scaling * robot.model().velocityLimit[-robot.na:]
        # self.v_min = -self.v_max
        # jointBoundsTask.setVelocityBounds(self.v_min, self.v_max)
        # if(conf.w_joint_bounds>0.0):
        #     invdyn.addMotionTask(jointBoundsTask, conf.w_joint_bounds, conf.priority_joint_bounds, 0.0)

        ##################################
        # Init task reference trajectories
        ##################################

        self.sample_feet = self.nc * [None]
        self.sample_feet_pos = self.nc * [None]
        self.sample_feet_vel = self.nc * [None]
        self.sample_feet_acc = self.nc * [None]
        for i_foot, traj in enumerate(self.traj_feet):
            self.sample_feet[i_foot] = traj.computeNext()
            self.sample_feet_pos[i_foot] = self.sample_feet[i_foot].pos()
            self.sample_feet_vel[i_foot] = self.sample_feet[i_foot].vel()
            self.sample_feet_acc[i_foot] = self.sample_feet[i_foot].acc()

        com_ref = robot.com(data)
        self.trajCom = tsid.TrajectoryEuclidianConstant('traj_com', com_ref)
        self.sample_com = self.trajCom.computeNext()

        q_ref = q[7:]
        self.trajPosture = tsid.TrajectoryEuclidianConstant(
            'traj_joint', q_ref)
        self.postureTask.setReference(self.trajPosture.computeNext())

        self.trunk_link_id = self.model.getFrameId('base_link')
        R_trunk_init = robot.framePosition(data, self.trunk_link_id).rotation
        self.trunk_ref = self.robot.framePosition(data, self.trunk_link_id)
        self.trajTrunk = tsid.TrajectorySE3Constant("traj_base_link",
                                                    self.trunk_ref)
        self.sample_trunk = self.trajTrunk.computeNext()
        pos_trunk = np.hstack([np.zeros(3), R_trunk_init.flatten()])
        self.sample_trunk.pos()
        self.sample_trunk.vel(np.zeros(6))
        self.sample_trunk.acc(np.zeros(6))
        self.trunkTask.setReference(self.sample_trunk)

        self.solver = tsid.SolverHQuadProgFast('qp solver')
        self.solver.resize(invdyn.nVar, invdyn.nEq, invdyn.nIn)

        self.invdyn = invdyn
        self.q = q
        self.v = v

        self.active_contacts = self.nc * [True]

        # for gepetto viewer
        if (viewer):
            self.robot_display = pin.RobotWrapper.BuildFromURDF(
                conf.urdf, [
                    conf.path,
                ], pin.JointModelFreeFlyer())
            l = subprocess.getstatusoutput(
                "ps aux |grep 'gepetto-gui'|grep -v 'grep'|wc -l")
            if int(l[1]) == 0:
                os.system('gepetto-gui &')
            time.sleep(1)
            gepetto.corbaserver.Client()
            self.robot_display.initViewer(loadModel=True)
            self.robot_display.displayCollisions(False)
            self.robot_display.displayVisuals(True)
            self.robot_display.display(q)

            self.gui = self.robot_display.viewer.gui
            self.gui.setCameraTransform('python-pinocchio',
                                        conf.CAMERA_TRANSFORM)
            self.gui.addFloor('world/floor')
            self.gui.setLightingMode('world/floor', 'OFF')

            self.gui.addSphere('world/com', conf.SPHERE_RADIUS,
                               conf.COM_SPHERE_COLOR)
            self.gui.addSphere('world/com_ref', conf.REF_SPHERE_RADIUS,
                               conf.COM_REF_SPHERE_COLOR)
            for frame_name in self.contact_frame_names:
                self.gui.addSphere('world/{}'.format(frame_name),
                                   conf.SPHERE_RADIUS, conf.F_SPHERE_COLOR)
                self.gui.addSphere('world/{}_ref'.format(frame_name),
                                   conf.REF_SPHERE_RADIUS,
                                   conf.F_REF_SPHERE_COLOR)
コード例 #5
0
path = filename + '/../models/romeo'
urdf = path + '/urdf/romeo.urdf'
vector = se3.StdVec_StdString()
vector.extend(item for item in path)
robot = tsid.RobotWrapper(urdf, vector, se3.JointModelFreeFlyer(), False)
model = robot.model()
data = robot.data()

mu = 0.3
fMin = 10.0
fMax = 1000.0
frameName = "RAnkleRoll"
contactNormal = np.matrix(np.zeros(3)).transpose()
contactNormal[2] = 1.0

contact = tsid.ContactPoint("contactPoint", robot, frameName, contactNormal,
                            mu, fMin, fMax)

assert contact.n_motion == 3
assert contact.n_force == 3

Kp = np.matrix(np.ones(3)).transpose()
Kd = 2 * Kp
contact.setKp(Kp)
contact.setKd(Kd)

assert np.linalg.norm(contact.Kp - Kp, 2) < tol
assert np.linalg.norm(contact.Kd - Kd, 2) < tol

q = model.neutralConfiguration
v = np.matrix(np.zeros(robot.nv)).transpose()
robot.computeAllTerms(data, q, v)
コード例 #6
0
ファイル: demo_quadruped.py プロジェクト: stack-of-tasks/tsid
assert [robot.model().existFrame(name) for name in contact_frames]

t = 0.0  # time
invdyn = tsid.InverseDynamicsFormulationAccForce("tsid", robot, False)
invdyn.computeProblemData(t, q, v)
data = invdyn.data()

# Place the robot onto the ground.
id_contact = robot_display.model.getFrameId(contact_frames[0])
q[2] -= robot.framePosition(data, id_contact).translation[2]
robot.computeAllTerms(data, q, v)

contacts = 4 * [None]
for i, name in enumerate(contact_frames):
    contacts[i] = tsid.ContactPoint(name, robot, name, contactNormal, mu, fMin,
                                    fMax)
    contacts[i].setKp(kp_contact * np.ones(3))
    contacts[i].setKd(2.0 * np.sqrt(kp_contact) * np.ones(3))
    H_rf_ref = robot.framePosition(data, robot.model().getFrameId(name))
    contacts[i].setReference(H_rf_ref)
    contacts[i].useLocalFrame(False)
    invdyn.addRigidContact(contacts[i], w_forceRef, 1.0, 1)

comTask = tsid.TaskComEquality("task-com", robot)
comTask.setKp(kp_com * np.ones(3))
comTask.setKd(2.0 * np.sqrt(kp_com) * np.ones(3))
invdyn.addMotionTask(comTask, w_com, 1, 0.0)

postureTask = tsid.TaskJointPosture("task-posture", robot)
postureTask.setKp(kp_posture * np.ones(robot.nv - 6))
postureTask.setKd(2.0 * np.sqrt(kp_posture) * np.ones(robot.nv - 6))
コード例 #7
0
    def __init__(self, N_simulation, k_mpc, n_periods):

        self.q_ref = np.array([[0.0, 0.0, 0.2027682, 0.0, 0.0, 0.0, 1.0,
                                0.0, 0.8, -1.6, 0, 0.8, -1.6,
                                0, -0.8, 1.6, 0, -0.8, 1.6]]).transpose()

        self.qtsid = self.q_ref.copy()
        self.vtsid = np.zeros((18, 1))
        self.ades = np.zeros((18, 1))

        self.error = False
        self.verbose = True

        # List with the names of all feet frames
        self.foot_frames = ['FL_FOOT', 'FR_FOOT', 'HL_FOOT', 'HR_FOOT']

        # Constraining the contacts
        mu = 0.9 				# friction coefficient
        fMin = 1.0				# minimum normal force
        fMax = 25.0  			# maximum normal force
        contactNormal = np.matrix([0., 0., 1.]).T  # direction of the normal to the contact surface

        # Coefficients of the posture task
        kp_posture = 10.0		# proportionnal gain of the posture task
        w_posture = 1.0         # weight of the posture task

        # Coefficients of the contact tasks
        kp_contact = 100.0         # proportionnal gain for the contacts
        self.w_forceRef = 50.0  # weight of the forces regularization
        self.w_reg_f = 50.0

        # Coefficients of the foot tracking task
        kp_foot = 100.0               # proportionnal gain for the tracking task
        self.w_foot = 500.0       # weight of the tracking task

        # Arrays to store logs
        k_max_loop = N_simulation
        self.f_pos = np.zeros((4, k_max_loop, 3))
        self.f_vel = np.zeros((4, k_max_loop, 3))
        self.f_acc = np.zeros((4, k_max_loop, 3))
        self.f_pos_ref = np.zeros((4, k_max_loop, 3))
        self.f_vel_ref = np.zeros((4, k_max_loop, 3))
        self.f_acc_ref = np.zeros((4, k_max_loop, 3))
        self.b_pos = np.zeros((k_max_loop, 6))
        self.b_vel = np.zeros((k_max_loop, 6))
        self.com_pos = np.zeros((k_max_loop, 3))
        self.com_pos_ref = np.zeros((k_max_loop, 3))
        self.c_forces = np.zeros((4, k_max_loop, 3))
        self.h_ref_feet = np.zeros((k_max_loop, ))
        self.goals = np.zeros((3, 4))
        self.vgoals = np.zeros((3, 4))
        self.agoals = np.zeros((3, 4))
        self.mgoals = np.zeros((6, 4))

        # Position of the shoulders in local frame
        self.shoulders = np.array([[0.19, 0.19, -0.19, -0.19], [0.15005, -0.15005, 0.15005, -0.15005]])
        self.footsteps = self.shoulders.copy()
        self.memory_contacts = self.shoulders.copy()

        # Foot trajectory generator
        max_height_feet = 0.05
        t_lock_before_touchdown = 0.05
        self.ftgs = [ftg.Foot_trajectory_generator(max_height_feet, t_lock_before_touchdown) for i in range(4)]

        # Which pair of feet is active (0 for [1, 2] and 1 for [0, 3])
        self.pair = -1

        # Number of TSID steps for 1 step of the MPC
        self.k_mpc = k_mpc

        # For update_feet_tasks function
        self.dt = 0.001  #  [s], time step
        self.t1 = 0.14  # [s], duration of swing phase

        # Rotation matrix
        self.R = np.eye(3)

        # Feedforward torques
        self.tau_ff = np.zeros((12, 1))

        # Torques sent to the robot
        self.torques12 = np.zeros((12, 1))
        self.tau = np.zeros((12, ))

        self.ID_base = None  # ID of base link
        self.ID_feet = [None] * 4  # ID of feet links

        # Footstep planner object
        # self.fstep_planner = FootstepPlanner.FootstepPlanner(0.001, 32)
        self.vu_m = np.zeros((6, 1))
        self.t_stance = 0.16
        self.T_gait = 0.32
        self.n_periods = n_periods
        self.h_ref = 0.235 - 0.01205385
        self.t_swing = np.zeros((4, ))  # Total duration of current swing phase for each foot

        self.contacts_order = [0, 1, 2, 3]

        # Parameter to enable/disable hybrid control
        self.enable_hybrid_control = False

        # Time since the start of the simulation
        self.t = 0.0

        ########################################################################
        #             Definition of the Model and TSID problem                 #
        ########################################################################

        # Set the paths where the urdf and srdf file of the robot are registered
        modelPath = "/opt/openrobots/share/example-robot-data/robots"
        urdf = modelPath + "/solo_description/robots/solo12.urdf"
        srdf = modelPath + "/solo_description/srdf/solo.srdf"
        vector = pin.StdVec_StdString()
        vector.extend(item for item in modelPath)

        # Create the robot wrapper from the urdf model (which has no free flyer) and add a free flyer
        self.robot = tsid.RobotWrapper(urdf, vector, pin.JointModelFreeFlyer(), False)
        self.model = self.robot.model()

        # Creation of the Invverse Dynamics HQP problem using the robot
        # accelerations (base + joints) and the contact forces
        self.invdyn = tsid.InverseDynamicsFormulationAccForce("tsid", self.robot, False)

        # Compute the problem data with a solver based on EiQuadProg
        t = 0.0
        self.invdyn.computeProblemData(t, self.qtsid, self.vtsid)

        # Saving IDs for later
        self.ID_base = self.model.getFrameId("base_link")
        for i, name in enumerate(self.foot_frames):
            self.ID_feet[i] = self.model.getFrameId(name)

        # Store a frame object to avoid creating one each time
        self.pos_foot = self.robot.framePosition(self.invdyn.data(), self.ID_feet[0])

        #####################
        # LEGS POSTURE TASK #
        #####################

        # Task definition (creating the task object)
        self.postureTask = tsid.TaskJointPosture("task-posture", self.robot)
        self.postureTask.setKp(kp_posture * matlib.ones(self.robot.nv-6).T)  # Proportional gain
        self.postureTask.setKd(2.0 * np.sqrt(kp_posture) * matlib.ones(self.robot.nv-6).T)  # Derivative gain

        # Add the task to the HQP with weight = w_posture, priority level = 1 (not real constraint)
        # and a transition duration = 0.0
        self.invdyn.addMotionTask(self.postureTask, w_posture, 1, 0.0)

        # TSID Trajectory (creating the trajectory object and linking it to the task)
        pin.loadReferenceConfigurations(self.model, srdf, False)
        self.trajPosture = tsid.TrajectoryEuclidianConstant("traj_joint", self.q_ref[7:])
        self.samplePosture = self.trajPosture.computeNext()
        self.postureTask.setReference(self.samplePosture)

        ############
        # CONTACTS #
        ############

        self.contacts = 4*[None]  # List to store the rigid contact tasks

        for i, name in enumerate(self.foot_frames):

            # Contact definition (creating the contact object)
            self.contacts[i] = tsid.ContactPoint(name, self.robot, name, contactNormal, mu, fMin, fMax)
            self.contacts[i].setKp((kp_contact * matlib.ones(3).T))
            self.contacts[i].setKd((2.0 * np.sqrt(kp_contact) * matlib.ones(3).T))
            self.contacts[i].useLocalFrame(False)

            # Set the contact reference position
            H_ref = self.robot.framePosition(self.invdyn.data(), self.ID_feet[i])
            H_ref.translation = np.matrix(
                [H_ref.translation[0, 0],
                 H_ref.translation[1, 0],
                 0.0]).T
            self.contacts[i].setReference(H_ref)

            # Regularization weight for the force tracking subtask
            self.contacts[i].setRegularizationTaskWeightVector(
                np.matrix([self.w_reg_f, self.w_reg_f, self.w_reg_f]).T)

            # Adding the rigid contact after the reference contact force has been set
            self.invdyn.addRigidContact(self.contacts[i], self.w_forceRef)

        #######################
        # FOOT TRACKING TASKS #
        #######################

        self.feetTask = 4*[None]  # List to store the foot tracking tasks
        mask = np.matrix([1.0, 1.0, 1.0, 0.0, 0.0, 0.0]).T

        # Task definition (creating the task object)
        for i_foot in range(4):
            self.feetTask[i_foot] = tsid.TaskSE3Equality(
                "foot_track_" + str(i_foot), self.robot, self.foot_frames[i_foot])
            self.feetTask[i_foot].setKp(kp_foot * mask)
            self.feetTask[i_foot].setKd(2.0 * np.sqrt(kp_foot) * mask)
            self.feetTask[i_foot].setMask(mask)
            self.feetTask[i_foot].useLocalFrame(False)

        # The reference will be set later when the task is enabled

        ##########
        # SOLVER #
        ##########

        # Use EiquadprogFast solver
        self.solver = tsid.SolverHQuadProgFast("qp solver")

        # Resize the solver to fit the number of variables, equality and inequality constraints
        self.solver.resize(self.invdyn.nVar, self.invdyn.nEq, self.invdyn.nIn)
コード例 #8
0
    def __init__(self):

        ########################################################################
        #             Definition of the Model and TSID problem                 #
        ########################################################################

        # set the path
        path = "/opt/openrobots/share/example-robot-data/robots/solo_description/robots"
        urdf = path + "/solo12.urdf"
        srdf = "/opt/openrobots/share/example-robot-data/robots/solo_description/srdf/solo.srdf"
        vec = pin.StdVec_StdString()
        vec.extend(item for item in path)

        # get the solo12 wrapper
        self.solo12_wrapper = tsid.RobotWrapper(urdf, vec,
                                                pin.JointModelFreeFlyer(),
                                                False)
        self.solo12_model = self.solo12_wrapper.model()
        pin.loadReferenceConfigurations(self.solo12_model, srdf, False)

        # problem formulation
        self.formulation = tsid.InverseDynamicsFormulationAccForce(
            "tsid", self.solo12_wrapper, False)
        self.q0 = self.solo12_model.referenceConfigurations[
            "straight_standing"]
        self.v0 = np.zeros(self.solo12_model.nv)
        self.formulation.computeProblemData(0.0, self.q0, self.v0)
        self.data = self.formulation.data()

        # get frame ID
        self.ID_FL = self.solo12_model.getFrameId("FL_FOOT")
        self.ID_FR = self.solo12_model.getFrameId("FR_FOOT")
        self.ID_HL = self.solo12_model.getFrameId("HL_FOOT")
        self.ID_HR = self.solo12_model.getFrameId("HR_FOOT")
        self.ID_BASE = self.solo12_model.getFrameId("base_link")

        ############
        # COM TASK #
        ############
        self.kp_com = 50
        self.w_com = 3
        self.comTask = tsid.TaskComEquality("task-com", self.solo12_wrapper)
        self.comTask.setKp(self.kp_com * np.ones(3).T)
        self.comTask.setKd(2 * np.sqrt(self.kp_com) * np.ones(3).T)
        self.formulation.addMotionTask(self.comTask, self.w_com, 1, 0.0)
        self.com_ref = self.solo12_wrapper.com(self.data)
        self.trajCom = tsid.TrajectoryEuclidianConstant(
            "traj-com", self.com_ref)

        #################
        # SE3 BASE TASK #
        #################
        self.kp_trunk = 50
        self.w_trunk = 1
        self.trunkTask = tsid.TaskSE3Equality("task-trunk",
                                              self.solo12_wrapper, 'base_link')
        mask = np.matrix([1.0, 1.0, 0.0, 1.0, 1.0, 1.0]).T
        self.trunkTask.setKp(
            np.matrix([
                self.kp_trunk, self.kp_trunk, 0.0, self.kp_trunk,
                self.kp_trunk, self.kp_trunk
            ]).T)
        self.trunkTask.setKd(
            np.matrix([
                2.0 * np.sqrt(self.kp_trunk), 2.0 * np.sqrt(self.kp_trunk),
                0.0, 2.0 * np.sqrt(self.kp_trunk),
                2.0 * np.sqrt(self.kp_trunk), 2.0 * np.sqrt(self.kp_trunk)
            ]).T)
        self.trunkTask.useLocalFrame(False)
        self.trunkTask.setMask(mask)
        self.formulation.addMotionTask(self.trunkTask, self.w_trunk, 1, 0.0)
        self.trunk_ref = self.solo12_wrapper.framePosition(
            self.data, self.ID_BASE)
        self.trajTrunk = tsid.TrajectorySE3Constant("traj_base_link",
                                                    self.trunk_ref)

        ##################
        # CONTACT FORCES #
        ##################

        self.contactNormal = np.array([0, 0, 1])
        self.kp_contact = 30
        self.mu = 0.5

        self.contactFL = tsid.ContactPoint("contactFL", self.solo12_wrapper,
                                           "FL_FOOT", self.contactNormal,
                                           self.mu, 1, 1000)
        self.contactFL.setKp(self.kp_contact * np.ones(6).T)
        self.contactFL.setKd(2 * np.sqrt(self.kp_contact) * np.ones(6).T)
        self.fl_ref = self.solo12_wrapper.framePosition(self.data, self.ID_FL)
        self.contactFL.setReference(self.fl_ref)
        self.formulation.addRigidContact(self.contactFL, 10)

        self.contactFR = tsid.ContactPoint("contactFR", self.solo12_wrapper,
                                           "FR_FOOT", self.contactNormal,
                                           self.mu, 1, 1000)
        self.contactFR.setKp(self.kp_contact * np.ones(6).T)
        self.contactFR.setKd(2 * np.sqrt(self.kp_contact) * np.ones(6).T)
        self.fr_ref = self.solo12_wrapper.framePosition(self.data, self.ID_FR)
        self.contactFR.setReference(self.fr_ref)
        self.formulation.addRigidContact(self.contactFR, 10)

        self.contactHR = tsid.ContactPoint("contactHR", self.solo12_wrapper,
                                           "HR_FOOT", self.contactNormal,
                                           self.mu, 1, 1000)
        self.contactHR.setKp(self.kp_contact * np.ones(6).T)
        self.contactHR.setKd(2 * np.sqrt(self.kp_contact) * np.ones(6).T)
        self.hr_ref = self.solo12_wrapper.framePosition(self.data, self.ID_HR)
        self.contactHR.setReference(self.hr_ref)
        self.formulation.addRigidContact(self.contactHR, 10)

        self.contactHL = tsid.ContactPoint("contactHL", self.solo12_wrapper,
                                           "HL_FOOT", self.contactNormal,
                                           self.mu, 1, 1000)
        self.contactHL.setKp(self.kp_contact * np.ones(6).T)
        self.contactHL.setKd(2 * np.sqrt(self.kp_contact) * np.ones(6).T)
        self.hl_ref = self.solo12_wrapper.framePosition(self.data, self.ID_HL)
        self.contactHL.setReference(self.hl_ref)
        self.formulation.addRigidContact(self.contactHL, 10)

        ##########
        # SOLVER #
        ##########

        self.solver = tsid.SolverHQuadProgFast("qp solver")
        self.solver.resize(self.formulation.nVar, self.formulation.nEq,
                           self.formulation.nIn)
    def __init__(self, q0, omega, t):

        self.omega = omega
        self.qdes = q0.copy()
        self.vdes = np.zeros((18, 1))
        self.ades = np.zeros((18, 1))
        self.error = False

        kp_posture = 10.0  # proportionnal gain of the posture task
        w_posture = 1.0  # weight of the posture task

        kp_com = 100.0  # proportionnal gain of the CoM task
        w_com = 100.0  # weight of the CoM task

        kp_lock = 1.0  # proportionnal gain of the lock task
        w_lock = 100.0  # weight of the lock task

        # For the contacts
        mu = 0.3  # friction coefficient
        fMin = 1.0  # minimum normal force
        fMax = 100.0  # maximum normal force

        w_forceRef = 1e-3  # weight of the forces regularization
        kp_contact = 1.0  # proportionnal gain for the contacts

        foot_frames = ['HL_FOOT', 'HR_FOOT', 'FL_FOOT',
                       'FR_FOOT']  # tab with all the foot frames names
        contactNormal = np.matrix(
            [0., 0., 1.]).T  # direction of the normal to the contact surface

        ########################################################################
        #             Definition of the Model and TSID problem                 #
        ########################################################################

        ## Set the paths where the urdf and srdf file of the robot are registered

        modelPath = "/opt/openrobots/lib/python3.5/site-packages/../../../share/example-robot-data/robots"
        urdf = modelPath + "/solo_description/robots/solo12.urdf"
        srdf = modelPath + "/solo_description/srdf/solo.srdf"
        vector = pin.StdVec_StdString()
        vector.extend(item for item in modelPath)

        ## Create the robot wrapper from the urdf model (without the free flyer)

        self.robot = tsid.RobotWrapper(urdf, vector, pin.JointModelFreeFlyer(),
                                       False)

        self.model = self.robot.model()

        ## Creation of the Invverse Dynamics HQP problem using the robot
        ## accelerations (base + joints) and the contact forces

        self.invdyn = tsid.InverseDynamicsFormulationAccForce(
            "tsid", self.robot, False)
        # Compute the problem data with a solver based on EiQuadProg
        self.invdyn.computeProblemData(t, self.qdes, self.vdes)
        # Get the initial data
        self.data = self.invdyn.data()

        ## Task definition

        # POSTURE Task
        self.postureTask = tsid.TaskJointPosture("task-posture", self.robot)
        self.postureTask.setKp(
            kp_posture * matlib.ones(self.robot.nv - 6).T)  # Proportional gain
        self.postureTask.setKd(
            2.0 * np.sqrt(kp_posture) *
            matlib.ones(self.robot.nv - 6).T)  # Derivative gain
        # Add the task to the HQP with weight = w_posture, priority level = 0 (as real constraint) and a transition duration = 0.0
        self.invdyn.addMotionTask(self.postureTask, w_posture, 1, 0.0)

        # COM Task
        self.comTask = tsid.TaskComEquality("task-com", self.robot)
        self.comTask.setKp(
            kp_com * matlib.ones(3).T)  # Proportional gain of the CoM task
        self.comTask.setKd(2.0 * np.sqrt(kp_com) *
                           matlib.ones(3).T)  # Derivative gain
        self.invdyn.addMotionTask(
            self.comTask, w_com, 1, 0.0
        )  # Add the task to the HQP with weight = w_com, priority level = 1 (in the cost function) and a transition duration = 0.0

        # LOCK Task
        self.lockTask = tsid.TaskJointPosture("task-lock-shoulder", self.robot)
        self.lockTask.setKp(kp_lock * matlib.ones(self.robot.nv - 6).T)
        self.lockTask.setKd(2.0 * np.sqrt(kp_lock) *
                            matlib.ones(self.robot.nv - 6).T)
        mask = np.matrix(np.zeros(
            self.robot.nv -
            6))  # Add a mask to take into account only the shoulders joints
        for i in [0, 3, 6, 9]:
            mask[0, i] = 1
        self.lockTask.mask(mask.T)
        self.invdyn.addMotionTask(
            self.lockTask, w_lock, 0,
            0.0)  # Add the task as real constraint (priority level = 0)

        ## CONTACTS

        self.contacts = 4 * [None]

        for i, name in enumerate(foot_frames):
            self.contacts[i] = tsid.ContactPoint(name, self.robot, name,
                                                 contactNormal, mu, fMin, fMax)
            self.contacts[i].setKp(kp_contact * matlib.ones(3).T)
            self.contacts[i].setKd(2.0 * np.sqrt(kp_contact) *
                                   matlib.ones(3).T)
            H_ref = self.robot.framePosition(self.data,
                                             self.model.getFrameId(name))
            self.contacts[i].setReference(H_ref)
            self.contacts[i].useLocalFrame(False)
            self.invdyn.addRigidContact(self.contacts[i], w_forceRef, 1.0, 1)

        ## TSID Trajectory

        # POSTURE Task
        pin.loadReferenceConfigurations(self.model, srdf, False)

        self.q_ref = self.model.referenceConfigurations['straight_standing']
        self.trajPosture = tsid.TrajectoryEuclidianConstant(
            "traj_joint", self.q_ref[7:])
        # Set the trajectory as reference for the posture task
        self.samplePosture = self.trajPosture.computeNext()
        self.postureTask.setReference(self.samplePosture)

        # COM Task
        self.com_ref = self.data.com[0].copy()  # Initial value of the CoM
        self.trajCom = tsid.TrajectoryEuclidianConstant(
            "traj_com", self.com_ref)

        self.sampleCom = self.trajCom.computeNext()
        self.comTask.setReference(self.sampleCom)

        # LOCK Task
        # The mask is enough to set the shoulder acceleration to 0 because 0 is the initial configuration for the shoulders
        trajLock = tsid.TrajectoryEuclidianConstant("traj_lock_shoulder",
                                                    self.q_ref[7:])

        sampleLock = trajLock.computeNext()
        self.lockTask.setReference(sampleLock)

        ## Initialization of the solver

        # Use EiquadprogFast solver
        self.solver = tsid.SolverHQuadProgFast("qp solver")
        # Resize the solver to fit the number of variables, equality and inequality constraints
        self.solver.resize(self.invdyn.nVar, self.invdyn.nEq, self.invdyn.nIn)
コード例 #10
0
    def __init__(self,
                 urdf_path,
                 model_path,
                 eff_arr,
                 q0,
                 v0,
                 mu=0.6,
                 fz_max=75):
        """
        Input:
            urdf_path: path to urdf of robot
            model_path: path to model of robot (required by TSID)
            eff_arr : end effector name array
            q0: initial configuration
            v0: initial velocity
            tau_max: vector of maximum torques for each joint
            mu: coefficient of friction at end-effectors
        """
        self.kp_com = 0.0001
        self.kp_contact = 5.0
        self.kp_posture = 10.0
        self.kp_orientation = 0.002

        self.w_com = 1.0
        self.w_posture = 1e0
        self.w_force = 1.0
        self.w_orientation = 1e-6

        self.contact_transition = 0.1

        self.eff_arr = eff_arr
        self.curr_cnt_array = np.zeros(len(self.eff_arr))

        #self.tau_max = tau_max
        #self.tau_min = -1*self.tau_max

        self.tsid_robot = tsid.RobotWrapper(urdf_path, [model_path],
                                            pin.JointModelFreeFlyer(), False)
        self.nq = self.tsid_robot.nq
        self.nv = self.tsid_robot.nv
        self.tsid_model = self.tsid_robot.model()
        self.invdyn = tsid.InverseDynamicsFormulationAccForce(
            "tsid", self.tsid_robot, False)
        self.qp_solver = tsid.SolverHQuadProgFast("qp_solver")

        #Set up initial solve
        self.invdyn.computeProblemData(0, q0.copy(), v0.copy())
        self.inv_dyn_data = self.invdyn.data()
        self.tsid_robot.computeAllTerms(self.inv_dyn_data, q0, v0)

        self.mu = mu

        # Add Contact Tasks (setup as equality constraints)
        contactNormal = np.array([0., 0., 1.])
        self.contact_arr = len(self.eff_arr) * [None]
        for i, name in enumerate(self.eff_arr):
            self.contact_arr[i] = tsid.ContactPoint(name, self.tsid_robot,
                                                    name, contactNormal,
                                                    self.mu, 0.01, fz_max)
            self.contact_arr[i].setKp(self.kp_contact * np.ones(3))
            self.contact_arr[i].setKd(.03 * np.ones(3))
            cnt_ref = self.tsid_robot.framePosition(
                self.inv_dyn_data,
                self.tsid_robot.model().getFrameId(name))
            self.contact_arr[i].setReference(cnt_ref)
            self.contact_arr[i].useLocalFrame(False)
            self.invdyn.addRigidContact(self.contact_arr[i], self.w_force)

        # Add posture tasks (in the cost function)
        self.postureTask = tsid.TaskJointPosture("posture_task",
                                                 self.tsid_robot)
        self.postureTask.setKp(self.kp_posture *
                               np.ones(self.tsid_robot.nv - 6))
        self.postureTask.setKd(.05 * np.ones(3))
        self.invdyn.addMotionTask(self.postureTask, self.w_posture, 1, 0.0)

        #Add CoM task (in the cost function)
        # self.comTask = tsid.TaskComEquality("task-com", self.tsid_robot)
        # self.comTask.setKp(self.kp_com * np.ones(6))
        # self.comTask.setKd(.01 * np.ones(6))
        # self.invdyn.addMotionTask(self.comTask, self.w_com, 1, 0.0)

        #Add orientation task (in the cost function)
        # self.oriTask = tsid.TaskSE3Equality("orientation", self.tsid_robot, "base_link")
        # self.oriTask.setKp(self.kp_orientation * np.ones(6))
        # self.oriTask.setKd(2.0 * np.sqrt(self.kp_orientation) * np.ones(6))
        # mask = np.ones(6)
        # mask[:3] = 0
        # self.oriTask.setMask(mask)
        # self.invdyn.addMotionTask(self.oriTask, self.w_orientation, 1, 0.0)

        #Setup trajectories (des_q, des_v, des_a)
        # self.com_ref = self.tsid_robot.com(self.inv_dyn_data)
        # self.trajCom = tsid.TrajectoryEuclidianConstant("trajectory_com", self.com_ref)
        # self.com_reference = self.trajCom.computeNext()
        #
        self.trajPosture = tsid.TrajectoryEuclidianConstant(
            "trajectory_posture", q0[7:])
        self.traj_reference = self.trajPosture.computeNext()
        self.postureTask.setReference(self.traj_reference)

        # self.ori_ref = self.tsid_robot.position(self.inv_dyn_data, self.tsid_robot.model().getJointId("base_link"))
        # self.oriTraj = tsid.TrajectorySE3Constant("trajectory_orientation", self.ori_ref)
        # self.ori_reference = self.oriTraj.computeNext()

        ### --- Actuation Bounds --- ###
        # Get actuator effort limits (i.e. torque limits) from URDF:
        # tau_max = self.actuator_scaling * self.tsid_model.effortLimit
        #actuationBounds = tsid.TaskActuationBounds("torque-actuation-bounds", self.tsid_robot)
        #actuationBounds.setBounds(self.tau_min, self.tau_max)
        #formulation.addActuationTask(actuationBounds, w_torque_bounds, 0, 0.0)

        self.qp_solver.resize(self.invdyn.nVar, self.invdyn.nEq,
                              self.invdyn.nIn)
コード例 #11
0
ファイル: tsid_quadruped.py プロジェクト: skleff1994/consim
    def __init__(self,
                 conf,
                 dt,
                 robot,
                 com_offset,
                 com_frequency,
                 com_amplitude,
                 q0=None,
                 viewer=True):
        self.conf = conf
        self.dt = dt
        self.robot = tsid.RobotWrapper(robot.model, False)

        if q0 is None:
            q = robot.model.neutralConfiguration
        else:
            q = np.copy(q0)
#        q = se3.getNeutralConfiguration(robot.model(), conf.srdf, False)
#        q = robot.model().referenceConfigurations["half_sitting"]
        v = np.zeros(robot.nv)

        # for gepetto viewer
        if (viewer):
            # se3.RobotWrapper.BuildFromURDF(conf.urdf, [conf.path, ], se3.JointModelFreeFlyer())
            self.robot_display = robot
            prompt = subprocess.getstatusoutput(
                "ps aux |grep 'gepetto-gui'|grep -v 'grep'|wc -l")
            if int(prompt[1]) == 0:
                os.system('gepetto-gui &')
            time.sleep(1)
            gepetto.corbaserver.Client()
            self.robot_display.initViewer(loadModel=True)
            self.robot_display.displayCollisions(False)
            self.robot_display.displayVisuals(True)
            self.robot_display.display(q)
            self.gui = self.robot_display.viewer.gui
            self.gui.setCameraTransform('gepetto', conf.CAMERA_TRANSFORM)

        robot = self.robot
        self.model = robot.model()

        #        assert [robot.model().existFrame(name) for name in conf.contact_frames]

        formulation = tsid.InverseDynamicsFormulationAccForce(
            "tsid", robot, False)
        formulation.computeProblemData(0.0, q, v)
        data = formulation.data()

        contacts = len(conf.contact_frames) * [None]
        self.contact_ids = {}
        for i, name in enumerate(conf.contact_frames):
            contacts[i] = tsid.ContactPoint(name, robot, name,
                                            conf.contact_normal, conf.mu,
                                            conf.fMin, conf.fMax)
            contacts[i].setKp(conf.kp_contact * np.ones(3))
            contacts[i].setKd(2.0 * np.sqrt(conf.kp_contact) * np.ones(3))
            self.contact_ids[name] = robot.model().getFrameId(name)
            H_ref = robot.framePosition(data, robot.model().getFrameId(name))
            contacts[i].setReference(H_ref)
            contacts[i].useLocalFrame(False)
            formulation.addRigidContact(contacts[i], conf.w_forceRef, 1.0, 1)

        # modify initial robot configuration so that foot is on the ground (z=0)
#        q[2] -= H_rf_ref.translation[2,0] # 0.84    # fix this
#        formulation.computeProblemData(0.0, q, v)
#        data = formulation.data()
#        H_rf_ref = robot.position(data, self.RF)
#        contactRF.setReference(H_rf_ref)
#        formulation.addRigidContact(contactRF, conf.w_forceRef)

        comTask = tsid.TaskComEquality("task-com", robot)
        comTask.setKp(conf.kp_com * np.ones(3))
        comTask.setKd(2.0 * np.sqrt(conf.kp_com) * np.ones(3))
        formulation.addMotionTask(comTask, conf.w_com, 1, 0.0)

        postureTask = tsid.TaskJointPosture("task-posture", robot)
        postureTask.setKp(conf.kp_posture * np.ones(robot.nv - 6))
        postureTask.setKd(2.0 * np.sqrt(conf.kp_posture) *
                          np.ones(robot.nv - 6))
        formulation.addMotionTask(postureTask, conf.w_posture, 1, 0.0)

        #        self.leftFootTask = tsid.TaskSE3Equality("task-left-foot", self.robot, self.conf.lf_frame_name)
        #        self.leftFootTask.setKp(self.conf.kp_foot * np.array(np.ones(6)).T)
        #        self.leftFootTask.setKd(2.0 * np.sqrt(self.conf.kp_foot) * np.array(np.ones(6)).T)
        #        self.trajLF = tsid.TrajectorySE3Constant("traj-left-foot", H_lf_ref)
        #
        #        self.rightFootTask = tsid.TaskSE3Equality("task-right-foot", self.robot, self.conf.rf_frame_name)
        #        self.rightFootTask.setKp(self.conf.kp_foot * np.array(np.ones(6)).T)
        #        self.rightFootTask.setKd(2.0 * np.sqrt(self.conf.kp_foot) * np.array(np.ones(6)).T)
        #        self.trajRF = tsid.TrajectorySE3Constant("traj-right-foot", H_rf_ref)
        #
        com_ref = robot.com(data)
        trajCom = tsid.TrajectoryEuclidianConstant("traj_com", com_ref)

        q_ref = q[7:]
        trajPosture = tsid.TrajectoryEuclidianConstant("traj_joint", q_ref)

        comTask.setReference(trajCom.computeNext())
        postureTask.setReference(trajPosture.computeNext())

        solver = tsid.SolverHQuadProgFast("qp solver")
        solver.resize(formulation.nVar, formulation.nEq, formulation.nIn)

        self.trajCom = trajCom
        self.trajPosture = trajPosture
        self.comTask = comTask
        self.postureTask = postureTask
        self.contacts = contacts
        self.formulation = formulation
        self.solver = solver
        self.q = q
        self.v = v

        self.contacts_active = {}
        for name in conf.contact_frames:
            self.contacts_active[name] = True

#        com_pos = np.empty((3, N_SIMULATION))*nan
#        com_vel = np.empty((3, N_SIMULATION))*nan
#        com_acc = np.empty((3, N_SIMULATION))*nan
#        com_pos_ref = np.empty((3, N_SIMULATION))*nan
#        com_vel_ref = np.empty((3, N_SIMULATION))*nan
#        com_acc_ref = np.empty((3, N_SIMULATION))*nan
#        # acc_des = acc_ref - Kp*pos_err - Kd*vel_err
#        com_acc_des = np.empty((3, N_SIMULATION))*nan
        self.offset = com_offset + self.robot.com(self.formulation.data())
        self.two_pi_f = np.copy(com_frequency)
        self.amp = np.copy(com_amplitude)
        self.two_pi_f_amp = self.two_pi_f * self.amp
        self.two_pi_f_squared_amp = self.two_pi_f * self.two_pi_f_amp
        self.sampleCom = self.trajCom.computeNext()
        self.reset(q, v, 0.0)