bindings_regressor.py

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import unittest
 
import pinocchio as pin
from pinocchio.utils import zero
from test_case import PinocchioTestCase as TestCase
 
 
class TestRegressorBindings(TestCase):
    def test_staticRegressor(self):
        model = pin.buildSampleModelHumanoidRandom()
 
        data = model.createData()
        data_ref = model.createData()
 
        model.lowerPositionLimit[:7] = -1.0
        model.upperPositionLimit[:7] = 1.0
 
        q = pin.randomConfiguration(model)
        pin.computeStaticRegressor(model, data, q)
 
        phi = zero(4 * (model.njoints - 1))
        for k in range(1, model.njoints):
            Y = model.inertias[k]
            phi[4 * (k - 1)] = Y.mass
            phi[4 * k - 3 : 4 * k] = Y.mass * Y.lever
 
        static_com_ref = pin.centerOfMass(model, data_ref, q)
        static_com = data.staticRegressor.dot(phi)
 
        self.assertApprox(static_com, static_com_ref)
 
    def test_bodyRegressor(self):
        In = pin.Inertia.Random()
        v = pin.Motion.Random()
        a = pin.Motion.Random()
 
        f = In * a + In.vxiv(v)
 
        f_regressor = pin.bodyRegressor(v, a).dot(In.toDynamicParameters())
 
        self.assertApprox(f_regressor, f.vector)
 
    def test_jointBodyRegressor(self):
        model = pin.buildSampleModelManipulator()
        data = model.createData()
 
        JOINT_ID = model.njoints - 1
 
        q = pin.randomConfiguration(model)
        v = pin.utils.rand(model.nv)
        a = pin.utils.rand(model.nv)
 
        pin.rnea(model, data, q, v, a)
 
        f = data.f[JOINT_ID]
 
        f_regressor = pin.jointBodyRegressor(model, data, JOINT_ID).dot(
            model.inertias[JOINT_ID].toDynamicParameters()
        )
 
        self.assertApprox(f_regressor, f.vector)
 
    def test_frameBodyRegressor(self):
        model = pin.buildSampleModelManipulator()
 
        JOINT_ID = model.njoints - 1
 
        framePlacement = pin.SE3.Random()
        FRAME_ID = model.addBodyFrame("test_body", JOINT_ID, framePlacement, -1)
 
        data = model.createData()
 
        q = pin.randomConfiguration(model)
        v = pin.utils.rand(model.nv)
        a = pin.utils.rand(model.nv)
 
        pin.rnea(model, data, q, v, a)
 
        f = framePlacement.actInv(data.f[JOINT_ID])
        In = framePlacement.actInv(model.inertias[JOINT_ID])
 
        f_regressor = pin.frameBodyRegressor(model, data, FRAME_ID).dot(
            In.toDynamicParameters()
        )
 
        self.assertApprox(f_regressor, f.vector)
 
    def test_joint_torque_regressor(self):
        model = pin.buildSampleModelHumanoidRandom()
        model.lowerPositionLimit[:7] = -1.0
        model.upperPositionLimit[:7] = 1.0
 
        data = model.createData()
        data_ref = model.createData()
 
        q = pin.randomConfiguration(model)
        v = pin.utils.rand(model.nv)
        a = pin.utils.rand(model.nv)
 
        pin.rnea(model, data_ref, q, v, a)
 
        params = zero(10 * (model.njoints - 1))
        for i in range(1, model.njoints):
            params[(i - 1) * 10 : i * 10] = model.inertias[i].toDynamicParameters()
 
        pin.computeJointTorqueRegressor(model, data, q, v, a)
 
        tau_regressor = data.jointTorqueRegressor.dot(params)
 
        self.assertApprox(tau_regressor, data_ref.tau)
 
 
if __name__ == "__main__":
    unittest.main()