67 lines
2.1 KiB
Python
67 lines
2.1 KiB
Python
"""This module asserts correct runtime behaviour of the pyrate.act.pid module."""
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# Test environment
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from unittest import TestCase
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# Mathematics
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from numpy import array
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from numpy import eye
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from numpy import Inf
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from numpy.linalg import norm
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from numpy import vstack
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# Package under test
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from pyrate.act.control import Lqr
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class TestLqr(TestCase):
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"""Test for correct runtime behaviour in pyrate.act.control.lqr."""
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# In this context, we reproduce a common controller notation
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# pylint: disable=invalid-name
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def setUp(self) -> None:
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"""Setup the LQR specification for testing."""
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# Model specification
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self.A = array([[0, 1], [0, 0]])
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self.B = array([0, 1])[:, None]
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self.C = array([1, 0])[None, :]
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self.dt = 0.5
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# Cost matrix specification
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self.Q = eye(2)
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self.R = array([[1.0]])
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# State and target
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# Target is already reached in this example
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self.state = vstack([0.0, 0.0])
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self.desired = vstack([0.0])
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def test_process_tracking(self) -> None:
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"""Assert that a pandas.DataFrame with process data is created."""
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# Initialize PID controller
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lqr = Lqr(self.A, self.B, self.C, self.Q, self.R, self.dt, keep_trace=True)
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# Execute a few control steps
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state = self.state.copy()
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previous_error = Inf
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for _ in range(10):
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control_signal = lqr.control(desired=self.desired, state=self.state)
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state += self.A.dot(state) + self.B.dot(control_signal)
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error = norm(state - self.desired).item() # Convert from numpy scalar to Python float
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assert error < previous_error or error == 0, "Error did not get lower."
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previous_error = error
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# Assert correct process tracing with LQR controller
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assert lqr.process is not None, "LQR did not keep trace of process"
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assert len(lqr.process.index) == 10, "LQR has not traced enough steps"
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# Reset PID
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lqr.reset()
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# Assert correct reset to initial state
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assert len(lqr.process.index) == 0, "LQR has not dropped process trace properly"
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