def test_interconnect_docstring():
"""Test the examples from the interconnect() docstring"""
# MIMO interconnection (note: use [C, P] instead of [P, C] for state order)
P = ct.LinearIOSystem(
ct.rss(2, 2, 2, strictly_proper=True), name='P')
C = ct.LinearIOSystem(ct.rss(2, 2, 2), name='C')
T = ct.interconnect(
[C, P],
connections = [
['P.u[0]', 'C.y[0]'], ['P.u[1]', 'C.y[1]'],
['C.u[0]', '-P.y[0]'], ['C.u[1]', '-P.y[1]']],
inplist = ['C.u[0]', 'C.u[1]'],
outlist = ['P.y[0]', 'P.y[1]'],
)
T_ss = ct.feedback(P * C, ct.ss([], [], [], np.eye(2)))
np.testing.assert_almost_equal(T.A, T_ss.A)
np.testing.assert_almost_equal(T.B, T_ss.B)
np.testing.assert_almost_equal(T.C, T_ss.C)
np.testing.assert_almost_equal(T.D, T_ss.D)
# Implicit interconnection (note: use [C, P, sumblk] for proper state order)
P = ct.tf2io(ct.tf(1, [1, 0]), inputs='u', outputs='y')
C = ct.tf2io(ct.tf(10, [1, 1]), inputs='e', outputs='u')
sumblk = ct.summing_junction(inputs=['r', '-y'], output='e')
T = ct.interconnect([C, P, sumblk], inplist='r', outlist='y')
T_ss = ct.feedback(P * C, 1)
np.testing.assert_almost_equal(T.A, T_ss.A)
np.testing.assert_almost_equal(T.B, T_ss.B)
np.testing.assert_almost_equal(T.C, T_ss.C)
np.testing.assert_almost_equal(T.D, T_ss.D)
def test_interconnect_exceptions():
# First make sure the docstring example works
P = ct.tf2io(ct.tf(1, [1, 0]), input='u', output='y')
C = ct.tf2io(ct.tf(10, [1, 1]), input='e', output='u')
sumblk = ct.summing_junction(inputs=['r', '-y'], output='e')
T = ct.interconnect((P, C, sumblk), input='r', output='y')
assert (T.ninputs, T.noutputs, T.nstates) == (1, 1, 2)
# Unrecognized arguments
# LinearIOSystem
with pytest.raises(TypeError, match="unknown parameter"):
P = ct.LinearIOSystem(ct.rss(2, 1, 1), output_name='y')
# Interconnect
with pytest.raises(TypeError, match="unknown parameter"):
T = ct.interconnect((P, C, sumblk), input_name='r', output='y')
# Interconnected system
with pytest.raises(TypeError, match="unknown parameter"):
T = ct.InterconnectedSystem((P, C, sumblk), input_name='r', output='y')
# NonlinearIOSytem
with pytest.raises(TypeError, match="unknown parameter"):
nlios = ct.NonlinearIOSystem(
None, lambda t, x, u, params: u*u, input_count=1, output_count=1)
# Summing junction
with pytest.raises(TypeError, match="input specification is required"):
sumblk = ct.summing_junction()
with pytest.raises(TypeError, match="unknown parameter"):
sumblk = ct.summing_junction(input_count=2, output_count=2)
def test_string_inputoutput():
# regression test for gh-692
P1 = ct.rss(2, 1, 1)
P1_iosys = ct.LinearIOSystem(P1, inputs='u1', outputs='y1')
P2 = ct.rss(2, 1, 1)
P2_iosys = ct.LinearIOSystem(P2, inputs='y1', outputs='y2')
P_s1 = ct.interconnect([P1_iosys, P2_iosys], inputs='u1', outputs=['y2'])
assert P_s1.input_index == {'u1' : 0}
P_s2 = ct.interconnect([P1_iosys, P2_iosys], input='u1', outputs=['y2'])
assert P_s2.input_index == {'u1' : 0}
P_s1 = ct.interconnect([P1_iosys, P2_iosys], inputs=['u1'], outputs='y2')
assert P_s1.output_index == {'y2' : 0}
P_s2 = ct.interconnect([P1_iosys, P2_iosys], inputs=['u1'], output='y2')
assert P_s2.output_index == {'y2' : 0}
def test_interconnect_implicit():
"""Test the use of implicit connections in interconnect()"""
import random
# System definition
P = ct.ss2io(
ct.rss(2, 1, 1, strictly_proper=True),
inputs='u', outputs='y', name='P')
kp = ct.tf(random.uniform(1, 10), [1])
ki = ct.tf(random.uniform(1, 10), [1, 0])
C = ct.tf2io(kp + ki, inputs='e', outputs='u', name='C')
# Block diagram computation
Tss = ct.feedback(P * C, 1)
# Construct the interconnection explicitly
Tio_exp = ct.interconnect(
(C, P),
connections = [['P.u', 'C.u'], ['C.e', '-P.y']],
inplist='C.e', outlist='P.y')
# Compare to bdalg computation
np.testing.assert_almost_equal(Tio_exp.A, Tss.A)
np.testing.assert_almost_equal(Tio_exp.B, Tss.B)
np.testing.assert_almost_equal(Tio_exp.C, Tss.C)
np.testing.assert_almost_equal(Tio_exp.D, Tss.D)
# Construct the interconnection via a summing junction
sumblk = ct.summing_junction(inputs=['r', '-y'], output='e', name="sum")
Tio_sum = ct.interconnect(
(C, P, sumblk), inplist=['r'], outlist=['y'])
np.testing.assert_almost_equal(Tio_sum.A, Tss.A)
np.testing.assert_almost_equal(Tio_sum.B, Tss.B)
np.testing.assert_almost_equal(Tio_sum.C, Tss.C)
np.testing.assert_almost_equal(Tio_sum.D, Tss.D)
# Setting connections to False should lead to an empty connection map
empty = ct.interconnect(
(C, P, sumblk), connections=False, inplist=['r'], outlist=['y'])
np.testing.assert_array_equal(empty.connect_map, np.zeros((4, 3)))
# Implicit summation across repeated signals
kp_io = ct.tf2io(kp, inputs='e', outputs='u', name='kp')
ki_io = ct.tf2io(ki, inputs='e', outputs='u', name='ki')
Tio_sum = ct.interconnect(
(kp_io, ki_io, P, sumblk), inplist=['r'], outlist=['y'])
np.testing.assert_almost_equal(Tio_sum.A, Tss.A)
np.testing.assert_almost_equal(Tio_sum.B, Tss.B)
np.testing.assert_almost_equal(Tio_sum.C, Tss.C)
np.testing.assert_almost_equal(Tio_sum.D, Tss.D)
# TODO: interconnect a MIMO system using implicit connections
# P = control.ss2io(
# control.rss(2, 2, 2, strictly_proper=True),
# input_prefix='u', output_prefix='y', name='P')
# C = control.ss2io(
# control.rss(2, 2, 2),
# input_prefix='e', output_prefix='u', name='C')
# sumblk = control.summing_junction(
# inputs=['r', '-y'], output='e', dimension=2)
# S = control.interconnect([P, C, sumblk], inplist='r', outlist='y')
# Make sure that repeated inplist/outlist names generate an error
# Input not unique
Cbad = ct.tf2io(ct.tf(10, [1, 1]), inputs='r', outputs='x', name='C')
with pytest.raises(ValueError, match="not unique"):
Tio_sum = ct.interconnect(
(Cbad, P, sumblk), inplist=['r'], outlist=['y'])
# Output not unique
Cbad = ct.tf2io(ct.tf(10, [1, 1]), inputs='e', outputs='y', name='C')
with pytest.raises(ValueError, match="not unique"):
Tio_sum = ct.interconnect(
(Cbad, P, sumblk), inplist=['r'], outlist=['y'])
# Signal not found
with pytest.raises(ValueError, match="could not find"):
Tio_sum = ct.interconnect(
(C, P, sumblk), inplist=['x'], outlist=['y'])
with pytest.raises(ValueError, match="could not find"):
Tio_sum = ct.interconnect(
(C, P, sumblk), inplist=['r'], outlist=['x'])
#
# We construct the system using the InterconnectedSystem constructor and using
# signal labels to keep track of everything.
steering = ct.interconnect(
# List of subsystems
(trajgen, controller, vehicle),
name='steering',
# Interconnections between subsystems
connections=(['controller.ex', 'trajgen.xd',
'-vehicle.x'], ['controller.ey', 'trajgen.yd', '-vehicle.y'],
['controller.etheta', 'trajgen.thetad',
'-vehicle.theta'], ['controller.vd', 'trajgen.vd'],
['controller.phid',
'trajgen.phid'], ['vehicle.v', 'controller.v'
], ['vehicle.phi', 'controller.phi']),
# System inputs
inplist=['trajgen.vref', 'trajgen.yref'],
inputs=['yref', 'vref'],
# System outputs
outlist=[
'vehicle.x', 'vehicle.y', 'vehicle.theta', 'controller.v',
'controller.phi'
],
outputs=['x', 'y', 'theta', 'v', 'phi'])
# Set up the simulation conditions
yref = 1
T = np.linspace(0, 5, 100)