control.InterconnectedSystem¶
- class control.InterconnectedSystem(syslist, connections=[], inplist=[], outlist=[], params={}, warn_duplicate=None, **kwargs)¶
Bases:
InputOutputSystem
Interconnection of a set of input/output systems.
This class is used to implement a system that is an interconnection of input/output systems. The sys consists of a collection of subsystems whose inputs and outputs are connected via a connection map. The overall system inputs and outputs are subsets of the subsystem inputs and outputs.
See
interconnect()
for a list of parameters.Methods
Check for unused subsystem inputs and outputs
Make a copy of an input/output system
Compute the dynamics of a differential or difference equation.
Feedback interconnection between two input/output systems
Find the index for an input given its name (None if not found)
Find the index for an output given its name (None if not found)
Find the index for a state given its name (None if not found)
Check to see if a system is a continuous-time system
Check to see if a system is a discrete-time system
Check to see if a system is single input, single output
Linearize an input/output system at a given state and input.
Compute the output of the system
Set the connection map for an interconnected I/O system.
Set the input map for an interconnected I/O system.
Set the number/names of the system inputs.
Set the output map for an interconnected I/O system.
Set the number/names of the system outputs.
Set the number/names of the system states.
Find unused subsystem inputs and outputs
- __add__(sys2)¶
Add two input/output systems (parallel interconnection)
- __mul__(sys1)¶
Multiply two input/output systems (series interconnection)
- __neg__()¶
Negate an input/output systems (rescale)
- __radd__(sys2)¶
Parallel addition of input/output system to a compatible object.
- __rmul__(sys2)¶
Pre-multiply an input/output systems by a scalar/matrix
- __rsub__(sys2)¶
Parallel subtraction of I/O system to a compatible object.
- __sub__(sys2)¶
Subtract two input/output systems (parallel interconnection)
- check_unused_signals(ignore_inputs=None, ignore_outputs=None)¶
Check for unused subsystem inputs and outputs
If any unused inputs or outputs are found, emit a warning.
- Parameters
ignore_inputs (list of input-spec) –
- Subsystem inputs known to be unused. input-spec can be any of:
’sig’, ‘sys.sig’, (isys, isig), (‘sys’, isig)
If the ‘sig’ form is used, all subsystem inputs with that name are considered ignored.
ignore_outputs (list of output-spec) –
- Subsystem outputs known to be unused. output-spec can be any of:
’sig’, ‘sys.sig’, (isys, isig), (‘sys’, isig)
If the ‘sig’ form is used, all subsystem outputs with that name are considered ignored.
- copy(name=None, use_prefix_suffix=True)¶
Make a copy of an input/output system
A copy of the system is made, with a new name. The name keyword can be used to specify a specific name for the system. If no name is given and use_prefix_suffix is True, the name is constructed by prepending config.defaults[‘iosys.duplicate_system_name_prefix’] and appending config.defaults[‘iosys.duplicate_system_name_suffix’]. Otherwise, a generic system name of the form sys[<id>] is used, where <id> is based on an internal counter.
- dynamics(t, x, u)¶
Compute the dynamics of a differential or difference equation.
Given time t, input u and state x, returns the value of the right hand side of the dynamical system. If the system is continuous, returns the time derivative
dx/dt = f(t, x, u)
where f is the system’s (possibly nonlinear) dynamics function. If the system is discrete-time, returns the next value of x:
x[t+dt] = f(t, x[t], u[t])
Where t is a scalar.
The inputs x and u must be of the correct length.
- Parameters
t (float) – the time at which to evaluate
x (array_like) – current state
u (array_like) – input
- Returns
dx/dt or x[t+dt]
- Return type
ndarray
- feedback(other=1, sign=-1, params={})¶
Feedback interconnection between two input/output systems
- Parameters
sys1 (InputOutputSystem) – The primary process.
sys2 (InputOutputSystem) – The feedback process (often a feedback controller).
sign (scalar, optional) – The sign of feedback. sign = -1 indicates negative feedback, and sign = 1 indicates positive feedback. sign is an optional argument; it assumes a value of -1 if not specified.
- Returns
out
- Return type
- Raises
ValueError – if the inputs, outputs, or timebases of the systems are incompatible.
- find_input(name)¶
Find the index for an input given its name (None if not found)
- find_output(name)¶
Find the index for an output given its name (None if not found)
- find_state(name)¶
Find the index for a state given its name (None if not found)
- isctime(strict=False)¶
Check to see if a system is a continuous-time system
- Parameters
sys (Named I/O system) – System to be checked
strict (bool, optional) – If strict is True, make sure that timebase is not None. Default is False.
- isdtime(strict=False)¶
Check to see if a system is a discrete-time system
- Parameters
strict (bool, optional) – If strict is True, make sure that timebase is not None. Default is False.
- issiso()¶
Check to see if a system is single input, single output
- linearize(x0, u0, t=0, params={}, eps=1e-06, name=None, copy=False, **kwargs)¶
Linearize an input/output system at a given state and input.
Return the linearization of an input/output system at a given state and input value as a StateSpace system. See
linearize()
for complete documentation.
- ninputs¶
Number of system inputs.
- noutputs¶
Number of system outputs.
- nstates¶
Number of system states.
- output(t, x, u)¶
Compute the output of the system
Given time t, input u and state x, returns the output of the system:
y = g(t, x, u)
The inputs x and u must be of the correct length.
- Parameters
t (float) – the time at which to evaluate
x (array_like) – current state
u (array_like) – input
- Returns
y
- Return type
ndarray
- set_connect_map(connect_map)¶
Set the connection map for an interconnected I/O system.
- Parameters
connect_map (2D array) – Specify the matrix that will be used to multiply the vector of subsystem outputs to obtain the vector of subsystem inputs.
- set_input_map(input_map)¶
Set the input map for an interconnected I/O system.
- Parameters
input_map (2D array) – Specify the matrix that will be used to multiply the vector of system inputs to obtain the vector of subsystem inputs. These values are added to the inputs specified in the connection map.
- set_inputs(inputs, prefix='u')¶
Set the number/names of the system inputs.
- Parameters
inputs (int, list of str, or None) – Description of the system inputs. This can be given as an integer count or as a list of strings that name the individual signals. If an integer count is specified, the names of the signal will be of the form u[i] (where the prefix u can be changed using the optional prefix parameter).
prefix (string, optional) – If inputs is an integer, create the names of the states using the given prefix (default = ‘u’). The names of the input will be of the form prefix[i].
- set_output_map(output_map)¶
Set the output map for an interconnected I/O system.
- Parameters
output_map (2D array) – Specify the matrix that will be used to multiply the vector of subsystem outputs to obtain the vector of system outputs.
- set_outputs(outputs, prefix='y')¶
Set the number/names of the system outputs.
- Parameters
outputs (int, list of str, or None) – Description of the system outputs. This can be given as an integer count or as a list of strings that name the individual signals. If an integer count is specified, the names of the signal will be of the form u[i] (where the prefix u can be changed using the optional prefix parameter).
prefix (string, optional) – If outputs is an integer, create the names of the states using the given prefix (default = ‘y’). The names of the input will be of the form prefix[i].
- set_states(states, prefix='x')¶
Set the number/names of the system states.
- Parameters
states (int, list of str, or None) – Description of the system states. This can be given as an integer count or as a list of strings that name the individual signals. If an integer count is specified, the names of the signal will be of the form u[i] (where the prefix u can be changed using the optional prefix parameter).
prefix (string, optional) – If states is an integer, create the names of the states using the given prefix (default = ‘x’). The names of the input will be of the form prefix[i].
- unused_signals()¶
Find unused subsystem inputs and outputs
- Returns
unused_inputs (dict) – A mapping from tuple of indices (isys, isig) to string ‘{sys}.{sig}’, for all unused subsystem inputs.
unused_outputs (dict) – A mapping from tuple of indices (isys, isig) to string ‘{sys}.{sig}’, for all unused subsystem outputs.