Simulink^®

Rate Limiter - Limit rate of change of signal

Library

Discontinuities

Description

The Rate Limiter block limits the first derivative of the signal passing through it. The output changes no faster than the specified limit. The derivative is calculated using this equation.

u(i) and t(i) are the current block input and time, and y(i-1) and t(i-1) are the output and time at the previous step. The output is determined by comparing rate to the Rising slew rate and Falling slew rate parameters:

If rate is greater than the Rising slew rate parameter (R), the output is calculated as
If rate is less than the Falling slew rate parameter (F), the output is calculated as
If rate is between the bounds of R and F, the change in output is equal to the change in input:

Data Type Support

The Rate Limiter block accepts and outputs signals of any data type supported by Simulink^® software, except Boolean. The Rate Limiter block supports fixed-point data types.

Parameters and Dialog Box

Rising slew rate: Specify the limit of the derivative of an increasing input signal. This parameter is tunable for fixed-point inputs.
Falling slew rate: Specify the limit of the derivative of a decreasing input signal. This parameter is tunable for fixed-point inputs.
Sample time mode: Specify the sample time mode, continuous or inherited from the driving block.
Initial condition: Set the initial output of the simulation. Simulink software does not allow you to set the initial condition of this block to inf or NaN.
Treat as gain when linearizing: Linearization commands in Simulink software treat this block as a gain in state space. Select this check box to cause the linearization commands to treat the gain as 1; otherwise, the commands treat the gain as 0.

Characteristics