PythonLinearNonlinearControl/tests/models/test_two_wheeled.py

101 lines
3.2 KiB
Python

import pytest
import numpy as np
from PythonLinearNonlinearControl.models.two_wheeled import TwoWheeledModel
from PythonLinearNonlinearControl.configs.two_wheeled \
import TwoWheeledConfigModule
class TestTwoWheeledModel():
"""
"""
def test_step(self):
config = TwoWheeledConfigModule()
two_wheeled_model = TwoWheeledModel(config)
curr_x = np.ones(config.STATE_SIZE)
curr_x[-1] = np.pi / 6.
u = np.ones((1, config.INPUT_SIZE))
next_x = two_wheeled_model.predict_traj(curr_x, u)
pos_x = np.cos(curr_x[-1]) * u[0, 0] * config.DT + curr_x[0]
pos_y = np.sin(curr_x[-1]) * u[0, 0] * config.DT + curr_x[1]
expected = np.array([[1., 1., np.pi / 6.],
[pos_x, pos_y, curr_x[-1] + u[0, 1] * config.DT]])
assert next_x == pytest.approx(expected)
def test_predict_traj(self):
config = TwoWheeledConfigModule()
two_wheeled_model = TwoWheeledModel(config)
curr_x = np.ones(config.STATE_SIZE)
curr_x[-1] = np.pi / 6.
u = np.ones((1, config.INPUT_SIZE))
pred_xs = two_wheeled_model.predict_traj(curr_x, u)
u = np.tile(u, (1, 1, 1))
pred_xs_alltogether = two_wheeled_model.predict_traj(curr_x, u)[0]
assert pred_xs_alltogether == pytest.approx(pred_xs)
def test_gradient_state(self):
config = TwoWheeledConfigModule()
two_wheeled_model = TwoWheeledModel(config)
xs = np.ones((1, config.STATE_SIZE))
xs[0, -1] = np.pi / 6.
us = np.ones((1, config.INPUT_SIZE))
grad = two_wheeled_model.calc_f_x(xs, us, config.DT)
# expected cost
expected_grad = np.zeros((1, config.STATE_SIZE, config.STATE_SIZE))
eps = 1e-4
for i in range(config.STATE_SIZE):
tmp_x = xs.copy()
tmp_x[0, i] = xs[0, i] + eps
forward = \
two_wheeled_model.predict_next_state(tmp_x[0], us[0])
tmp_x = xs.copy()
tmp_x[0, i] = xs[0, i] - eps
backward = \
two_wheeled_model.predict_next_state(tmp_x[0], us[0])
expected_grad[0, :, i] = (forward - backward) / (2. * eps)
assert grad == pytest.approx(expected_grad)
def test_gradient_input(self):
config = TwoWheeledConfigModule()
two_wheeled_model = TwoWheeledModel(config)
xs = np.ones((1, config.STATE_SIZE))
xs[0, -1] = np.pi / 6.
us = np.ones((1, config.INPUT_SIZE))
grad = two_wheeled_model.calc_f_u(xs, us, config.DT)
# expected cost
expected_grad = np.zeros((1, config.STATE_SIZE, config.INPUT_SIZE))
eps = 1e-4
for i in range(config.INPUT_SIZE):
tmp_u = us.copy()
tmp_u[0, i] = us[0, i] + eps
forward = \
two_wheeled_model.predict_next_state(xs[0], tmp_u[0])
tmp_u = us.copy()
tmp_u[0, i] = us[0, i] - eps
backward = \
two_wheeled_model.predict_next_state(xs[0], tmp_u[0])
expected_grad[0, :, i] = (forward - backward) / (2. * eps)
assert grad == pytest.approx(expected_grad)