330 lines
10 KiB
Python
330 lines
10 KiB
Python
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#!/usr/bin/python
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#
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# RBDL - Rigid Body Dynamics Library
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# Copyright (c) 2011-2015 Martin Felis <martin@fysx.org>
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#
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# Licensed under the zlib license. See LICENSE for more details.
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import unittest
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import math
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import numpy as np
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from numpy.testing import *
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import rbdl
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class JointTests (unittest.TestCase):
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def test_JointConstructorAxesSimple(self):
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axis = np.asarray([[1., 0., 0., 0., 0., 0.]])
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joint_rot_x = rbdl.Joint.fromJointAxes (axis)
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assert_equal (joint_rot_x.getJointAxis(0), axis[0])
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def test_JointConstructorAxes6DoF(self):
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axis = np.asarray([
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[1., 0., 0., 0., 0., 0.],
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[0., 1., 0., 0., 0., 0.],
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[0., 0., 1., 0., 0., 0.],
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[0., 0., 0., 1., 0., 0.],
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[0., 0., 0., 0., 1., 0.],
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[0., 0., 0., 0., 0., 1.],
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])
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joint = rbdl.Joint.fromJointAxes (axis)
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for i in range (axis.shape[0]):
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assert_equal (joint.getJointAxis(i), axis[i])
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class SampleModel3R (unittest.TestCase):
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""" Example planar triple pendulum
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- All joints along the positive Z axis in rest position
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- All joints revolute y joints
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- all "links" are 1 unit length
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"""
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def setUp(self):
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self.model = rbdl.Model()
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joint_rot_y = rbdl.Joint.fromJointType ("JointTypeRevoluteY")
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self.body = rbdl.Body.fromMassComInertia (1., np.array([0., 0.0, 0.5]), np.eye(3) *
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0.05)
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self.xtrans = rbdl.SpatialTransform()
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self.xtrans.r = np.array([0., 0., 1.])
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self.body_1 = self.model.AppendBody (rbdl.SpatialTransform(), joint_rot_y, self.body)
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self.body_2 = self.model.AppendBody (self.xtrans, joint_rot_y, self.body)
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self.body_3 = self.model.AppendBody (self.xtrans, joint_rot_y, self.body)
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self.q = np.zeros (self.model.q_size)
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self.qdot = np.zeros (self.model.qdot_size)
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self.qddot = np.zeros (self.model.qdot_size)
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self.tau = np.zeros (self.model.qdot_size)
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def test_CoordinateTransformBodyBase (self):
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"""
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Checks whether CalcBodyToBaseCoordinates and CalcBaseToBodyCoordinates
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give the right results.
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"""
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q = np.random.rand(self.model.q_size)
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point_local = np.array ([1., 2., 3.])
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point_base = rbdl.CalcBodyToBaseCoordinates (
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self.model,
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q,
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self.body_3,
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point_local)
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point_local_2 = rbdl.CalcBaseToBodyCoordinates (
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self.model,
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q,
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self.body_3,
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point_base)
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assert_almost_equal (point_local, point_local_2)
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def test_CalcPointVelocity (self):
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"""
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Checks whether CalcBodyToBaseCoordinates and CalcBaseToBodyCoordinates
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give the right results.
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"""
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q = np.zeros(self.model.q_size)
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qdot = np.zeros(self.model.q_size)
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qdot[0] = 1.
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point_local = np.array ([0., 0., 0.])
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point_vel = rbdl.CalcPointVelocity (
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self.model,
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q,
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qdot,
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self.body_3,
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point_local
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)
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assert_almost_equal (np.array([2., 0., 0.]), point_vel)
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def test_CalcCenterOfMass (self):
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""" Tests calculation of center of mass
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TODO: add checks for angular momentum
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"""
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com = np.array ([-1., -1., -1.])
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com_vel = np.array([-2., -2., -2.])
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ang_mom = np.array([-3., -3., -3.])
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self.qdot[0] = 1.
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mass = rbdl.CalcCenterOfMass (
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self.model,
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self.q,
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self.qdot,
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None,
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com,
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None,
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None
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)
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self.assertEqual (3, mass)
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assert_almost_equal (np.array([0., 0., 1.5]), com)
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assert_almost_equal (np.array([0., 0., 1.5]), com)
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mass = rbdl.CalcCenterOfMass (
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self.model,
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self.q,
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self.qdot,
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None,
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com,
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com_vel,
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None
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)
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self.assertEqual (3, mass)
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assert_almost_equal (np.array([0., 0., 1.5]), com)
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assert_almost_equal (np.array([1.5, 0., 0.0]), com_vel)
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mass = rbdl.CalcCenterOfMass (
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self.model,
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self.q,
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self.qdot,
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None,
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com,
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com_vel,
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ang_mom
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)
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self.assertEqual (3, mass)
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assert_almost_equal (np.array([0., 0., 1.5]), com)
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def test_DynamicsConsistency (self):
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""" Checks whether forward and inverse dynamics are consistent """
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q = np.random.rand (self.model.q_size)
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qdot = np.random.rand (self.model.q_size)
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qddot = np.random.rand (self.model.q_size)
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tau = np.random.rand (self.model.q_size)
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rbdl.ForwardDynamics (
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self.model,
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q,
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qdot,
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tau,
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qddot)
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tau_id = np.zeros ((self.model.q_size))
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rbdl.InverseDynamics (
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self.model,
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q,
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qdot,
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qddot,
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tau_id
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)
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assert_almost_equal (tau, tau_id)
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def test_NonlinearEffectsConsistency (self):
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""" Checks whether NonlinearEffects is consistent with InverseDynamics """
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q = np.random.rand (self.model.q_size)
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qdot = np.random.rand (self.model.q_size)
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nle_id = np.random.rand (self.model.q_size)
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rbdl.InverseDynamics(
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self.model,
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q,
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qdot,
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np.zeros (self.model.qdot_size),
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nle_id)
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nle = np.zeros ((self.model.q_size))
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rbdl.NonlinearEffects (
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self.model,
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q,
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qdot,
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nle
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)
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assert_almost_equal (nle_id, nle)
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def test_CalcPointJacobian (self):
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""" Computes point Jacobian and checks whether G * qdot is consistent
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with CalcPointVelocity. """
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q = np.zeros (self.model.q_size)
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G = np.zeros ([3, self.model.q_size])
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point_coords = np.array ([0., 0., 1.])
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rbdl.CalcPointJacobian (
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self.model,
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q,
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self.body_3,
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point_coords,
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G
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)
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qdot = np.ones(self.model.qdot_size)
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point_vel = rbdl.CalcPointVelocity (
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self.model,
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q,
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qdot,
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self.body_3,
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point_coords
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)
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jac_point_vel = np.dot (G, qdot)
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assert_almost_equal (jac_point_vel, point_vel)
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def test_CalcPointJacobianNonSquare (self):
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""" Computes point Jacobian and checks whether G * qdot is consistent
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with CalcPointVelocity. """
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self.model = rbdl.Model()
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joint_trans_xyz = rbdl.Joint.fromJointType ("JointTypeTranslationXYZ")
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self.body_1 = self.model.AppendBody (rbdl.SpatialTransform(),
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joint_trans_xyz, self.body)
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self.body_4 = self.model.AppendBody (rbdl.SpatialTransform(),
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joint_trans_xyz, self.body)
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point_coords = np.array ([0., 0., 1.])
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q = np.zeros (self.model.q_size)
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G = np.zeros ([3, self.model.q_size])
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rbdl.CalcPointJacobian (
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self.model,
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q,
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self.body_4,
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point_coords,
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G
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)
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qdot = np.ones(self.model.qdot_size)
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jac_point_vel = np.dot (G, qdot)
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point_vel = rbdl.CalcPointVelocity (
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self.model,
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q,
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qdot,
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self.body_4,
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point_coords
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)
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assert_almost_equal (jac_point_vel, point_vel)
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class FloatingBaseModel (unittest.TestCase):
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""" Model with a floating base
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"""
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def setUp(self):
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self.model = rbdl.Model()
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joint_rot_y = rbdl.Joint.fromJointType ("JointTypeFloatingBase")
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self.body = rbdl.Body.fromMassComInertia (1., np.array([0., 0.0, 0.5]), np.eye(3) *
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0.05)
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self.xtrans = rbdl.SpatialTransform()
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self.xtrans.r = np.array([0., 0., 0.])
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self.body_1 = self.model.AppendBody (rbdl.SpatialTransform(), joint_rot_y, self.body)
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self.q = np.zeros (self.model.q_size)
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self.qdot = np.zeros (self.model.qdot_size)
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self.qddot = np.zeros (self.model.qdot_size)
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self.tau = np.zeros (self.model.qdot_size)
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def test_Dimensions (self):
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"""
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Checks whether the dimensions of q and qdot are correct
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"""
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q = np.random.rand(self.model.q_size)
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self.assertEqual (7, self.model.q_size)
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self.assertEqual (6, self.model.qdot_size)
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def test_SetQuaternion (self):
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mat = np.asarray ([[0., 1., 0.], [-1., 0., 0.], [0., 0., 1.]])
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rbdl_quat = rbdl.Quaternion.fromPythonMatrix (mat)
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ref_q = self.q.copy()
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self.model.SetQuaternion (2, rbdl_quat.toNumpy(), self.q)
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ref_q[3:6] = rbdl_quat[0:3]
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ref_q[-1] = rbdl_quat[3]
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assert_array_equal (ref_q, self.q)
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def test_GetQuaternion (self):
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mat = np.asarray ([[0., 1., 0.], [-1., 0., 0.], [0., 0., 1.]])
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rbdl_quat = rbdl.Quaternion.fromPythonMatrix (mat)
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self.assertEqual (4, len(rbdl_quat))
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self.q[5] = math.sqrt(2.) * 0.5
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self.q[6] = math.sqrt(2.) * 0.5
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ref_quat = [0., 0., math.sqrt(2.) * 0.5, math.sqrt(2.) * 0.5]
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quat = self.model.GetQuaternion (2, self.q)
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assert_array_equal (np.asarray(ref_quat), quat)
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class ConstraintSetTests (unittest.TestCase):
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def test_Simple (self):
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# only tests whether the API seems to work. No functional
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# tests yet.
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cs = rbdl.ConstraintSet()
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idx = cs.AddContactConstraint (1, [1., 2., 3.], [4., 5., 6.])
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assert_equal (0, idx)
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X = rbdl.SpatialTransform()
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sv = rbdl.SpatialVector.fromPythonArray ([1., 2., 3., 4., 5., 6.])
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idx2 = cs.AddLoopConstraint (1, 2, X, X, sv, 1.)
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assert_equal (1, idx2)
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if __name__ == '__main__':
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unittest.main()
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