Model Element

Description

The POUTPUT element defines the outputs from a mechanical system or plant.  This is part of the information necessary to create a linearized model of the plant or for co-simulation.  You also need to specify the inputs to the plant using the PINPUT element.  Given the inputs and outputs, you may use the Simulate command of type Linear to compute the matrices in the following linearized, state space form:

x(t) are the states, u(t) are the inputs, and y(t) are the outputs. A, B, C, and D denote the state matrix, the input matrix, the output matrix, and the direct feed-through matrix, respectively.  These matrices are often useful as a starting point in control systems design.

Attribute Summary

Usage

Poutput (variables=list, optional arguments)

Attributes

variables

List of existing Variables

Specifies the list Variables that define the outputs from the plant.

This attribute is mandatory

id

Element identification number (integer>0).  This number is unique among all the Poutput elements.

label

The name of the Poutput element.

hold_order

Int

Specifies the order of interpolation applied to the control signal(s) propagating out from Control_PlantInput.  The default value is 1.0.

sampling_period

Double

Specifies the sample time of an output port.  A value of 0.0 specifies continuous sampling while any other non-zero value specifies discrete sampling.  This value cannot be negative.  The default value is 0.0.  In most cases, this value need not be changed from its default, except in models where a discrete sampling is required. This parameter is to be used only in the case of co-simulation with MATLAB/Simulink.

offset_time

Double

Specifies the sample time offset for each output port.  The sample time offset must be strictly less than the sampling_period if the latter is non-zero.  If the sampling_period is 0.0 (continuous), thenoffset_time defaults to 0.0 as well.  In most cases, this value need not be changed from its default, except in models where a discrete sampling is required.  This parameter is to be used only in case of co-simulation with MATLAB/Simulink.

Comments

See Control_PlantOutput

Example

var1 = Variable ( function=”AZ(21,11)”, label=”Joint Angle” )

var2 = Variable ( function=”WZ(21,11,11)”, label=”Joint Angular Velocity” )

pin1 = Poutput (label="Joint Angle & Velocity", variables=[var1, var2])