Transfer Fcn Lead or Lag

Implement discrete-time lead or lag compensator

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  • Library:

  • Simulink / Discrete

Description

The Transfer Fcn Lead or Lag block implements a discrete-time lead or lag compensator of the input. The instantaneous gain of the compensator is 1, and the DC gain is equal to (1-z)/(1-p), where z is the zero and p is the pole of the compensator.

The block implements a lead compensator when 0<z<p<1, and implements a lag compensator when 0<p<z<1.

Ports

Input

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Input signal that the block applies the discrete-time lead or lag compensation to.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fixed point

Output

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Output signal that is discrete-time lead or lag compensation of the input sign.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | fixed point

Parameters

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Specify the pole of the compensator.

Programmatic Use

Block Parameter: PoleZ
Type: character vector
Value: real scalar
Default: '0.95'

Specify the zero of compensator in the Z plane.

Programmatic Use

Block Parameter: ZeroZ
Type: character vector
Value: real scalar
Default: '0.75'

Specify the initial condition for the previous output.

Programmatic Use

Block Parameter: ICPrevOutput
Type: character vector
Value: real scalar
Default: '0.0'

Specify the initial condition for the previous input.

Programmatic Use

Block Parameter: ICPrevInput
Type: character vector
Value: real scalar
Default: '0.0'

Specify the initial condition for the previous output.

Programmatic Use

Block Parameter: ICPrevOutput
Type: character vector
Value: real scalar
Default: '0.0'

Specify the rounding mode for fixed-point operations. For more information, see Rounding (Fixed-Point Designer).

Block parameters always round to the nearest representable value. To control the rounding of a block parameter, enter an expression using a MATLAB® rounding function into the mask field.

Programmatic Use

Block Parameter: RndMeth
Type: character vector
Values: 'Ceiling' | 'Convergent' | 'Floor' | 'Nearest' | 'Round' | 'Simplest' | 'Zero'
Default: 'Floor'

When you select this check box, overflows saturate to the maximum or minimum value that the data type can represent. Otherwise, overflows wrap.

When you select this check box, saturation applies to every internal operation on the block, not just the output or result. In general, the code generation process can detect when overflow is not possible. In this case, the code generator does not produce saturation code.

Programmatic Use

Block Parameter: DoSatur
Type: character vector
Values: 'off' | 'on'
Default: 'off'

Model Examples

Fixed-Point Lead and Lag Filters

Fixed-Point Lead and Lag Filters

Sample fixed-point implementations of a discrete lead filter and a discrete lag filter along with reference implementations in floating point.

Open Model

Block Characteristics

Data Types

Boolean[a] | double | fixed point | integer | single

Direct Feedthrough

no

Multidimensional Signals

no

Variable-Size Signals

yes

Zero-Crossing Detection

no

[a] This block is not recommended for use with Boolean signals.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

PLC Code Generation
Generate Structured Text code using Simulink® PLC Coder™.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

See Also

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Introduced before R2006a

Simulink Documentation
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