def __connect_input__(self, input_signal=None, base_system=None, block_diagram=None):
"""
Connects an input signal to a SystemBase object in a new simupy.BlockDiagram or in an existing simupy.BlockDiagram.
"""
if base_system is None:
base_system = self
elif not isinstance(base_system, SystemBase):
error_text = '[SystemBase.__connect_input__] The system should be an SystemBase instance.'
raise TypeError(error_text)
if input_signal is None:
if block_diagram is None:
BD = BlockDiagram(base_system.system)
elif not base_system.system in set(block_diagram.systems):
BD = block_diagram
BD.add_system(base_system.system)
else:
if block_diagram is None:
BD = BlockDiagram(input_signal.system, base_system.system)
else:
BD = block_diagram
BD.add_system(input_signal.system)
if not base_system.system in set(block_diagram.systems):
BD.add_system(base_system.system)
BD.connect(input_signal.system, base_system.system)
return BD
def create_block_diagram(self, forward_systems:list=None, backward_systems:list=None):
"""
Create a closed loop block diagram with negative feedback. The loop contains a list of SystemBase objects in the forward path and ControllerBase objects in the backward path.
Parameters
-----------
forward_systems : list, optional (at least one system should be present in the loop)
A list of SystemBase objects. All input and output dimensions should match.
backward_systems: list, optional (at least one system should be present in the loop)
A list of ControllerBase objects. All input and output dimensions should match.
Returns
--------
BD : a simupy's BlockDiagram object
contains the configuration of the closed-loop.
indices : dict
information on the ranges of the states and outputs in the output vectors of a simulation dataset.
"""
if (forward_systems is None):
if (self.system is None):
error_text = "[ClosedLoop.create_block_diagram] Both the forward_systems argument and the ClosedLoop.system variable are empty. Please provide a forward_system."
assert AssertionError(error_text)
else:
forward_systems = [self.system]
if (backward_systems is None):
if (self.system is None):
error_text = "[ClosedLoop.create_block_diagram] Both the backward_systems argument and the ClosedLoop.controller variable are empty. Please provide a backward_system."
assert AssertionError(error_text)
else:
backward_systems = [self.controller]
BD = BlockDiagram()
# Order of adding systems is important. The negative feedback_block needs to be added before the backward systems. This can be seen from simupy.block_diagram.BlockDiagram.output_equation_function(). Possibly only for stateless systems important. #TODO: check whether there is a problem with list of backward systems.
output_startidx_process = 0
output_endidx_process = -1
state_startidx_process = 0
state_endidx_process = -1
if (len(forward_systems) is not 0):
for forward_system in forward_systems:
forward_sys = forward_system.system
BD.add_system(forward_sys)
output_endidx_process += forward_sys.dim_output
state_endidx_process += forward_sys.dim_state
output_endidx_process += 1
state_endidx_process += 1
output_startidx_controller = output_endidx_process
output_endidx_controller = output_startidx_controller
state_startidx_controller = state_endidx_process
state_endidx_controller = state_startidx_controller
if (len(backward_systems) is not 0):
negative_feedback = gain_block(-1, backward_systems[-1].system.dim_output)
BD.add_system(negative_feedback)
output_startidx_controller += negative_feedback.dim_output
output_endidx_controller = output_startidx_controller
for backward_system in backward_systems:
backward_sys = backward_system.system
BD.add_system(backward_sys)
output_endidx_controller += backward_sys.dim_output
state_endidx_controller += backward_sys.dim_state
else:
negative_feedback = gain_block(-1, forward_systems[-1].system.dim_output)
BD.add_system(negative_feedback)
for i in range(len(forward_systems)):
if (i == len(forward_systems) - 1):
BD.connect(forward_systems[i].system, backward_systems[0].system)
else:
BD.connect(forward_systems[i].system, forward_systems[i + 1].system)
if (len(backward_systems) == 0):
BD.add_system(negative_feedback)
BD.connect(forward_systems[-1].system, negative_feedback)
BD.connect(negative_feedback, forward_systems[0].system)
else:
for j in range(len(backward_systems)):
if (j == len(backward_systems) - 1):
BD.connect(backward_systems[j].system, negative_feedback)
BD.connect(negative_feedback, forward_systems[0].system)
else:
BD.connect(backward_systems[j].system, backward_systems[j + 1].system)
indices = {
'process': {
'output': [output_endidx_process] if output_startidx_process == output_endidx_process\
else [output_startidx_process, output_endidx_process],
'state': None if state_endidx_process is 0\
else[state_endidx_process] if state_startidx_process == state_endidx_process\
else [state_startidx_process, state_endidx_process]
},
'controller': {
'output': [output_endidx_controller] if output_startidx_controller == output_endidx_controller\
else [output_startidx_controller, output_endidx_controller],
'state': None if state_endidx_controller == state_endidx_process\
else[state_endidx_controller] if state_startidx_controller == state_endidx_controller\
else [state_startidx_controller, state_endidx_controller]
}
}
return BD, indices
