Fixed-Point State-Space (Simulink Reference)

Simulink Reference

Fixed-Point State-Space

Implement discrete-time state space

Library

Additional Math & Discrete / Additional Discrete

Description

The Fixed-Point State-Space block implements the system described by

where u is the input, x is the state, and y is the output. Both equations have the same data type.

The matrices A, B, C and D have the following characteristics:

A must be an n-by-n matrix, where n is the number of states.
B must be an n-by-m matrix, where m is the number of inputs.
C must be an r-by-n matrix, where r is the number of outputs.
D must be an r-by-m matrix.

In addition:

The state x must be a n-by-1 vector
The input u must be a m-by-1 vector
The output y must be a r-by-1 vector

The block accepts one input and generates one output. The input vector width is determined by the number of columns in the B and D matrices. The output vector width is determined by the number of rows in the C and D matrices.

Data Type Support

The Fixed-Point State-Space block accepts signals of any data type supported by Simulink, including fixed-point data types.

Parameters and Dialog Box

The Main pane of the Fixed-Point State-Space block dialog appears as follows:

State Matrix A: Specify the matrix of states.
Input Matrix B: Specify the column vector of inputs.
Output Matrix C: Specify the column vector of outputs.
Direct Feedthrough Matrix D: Specify the matrix for direct feedthrough.
Initial condition for state: Specify the initial condition for the state.

The Signal data types pane of the Fixed-Point State-Space block dialog appears as follows:

Data type for internal calculations: Specify the data type for internal calculations.
Scaling for State Equation AX+BU: Specify the scaling for state equations.
Scaling for Output Equation CX+DU: Specify the scaling for output equations.
Lock output scaling so autoscaling tool can't change it: If you select this check box, the output scaling is locked.
Round toward: Select the rounding mode for fixed-point operations.
Saturate to max or min when overflows occur: If selected, fixed-point overflows saturate.

Characteristics

Direct Feedthrough
Yes

Scalar Expansion
Yes, of initial conditions

Direct Feedthrough	Yes
Scalar Expansion	Yes, of initial conditions

First-Order Hold For Iterator