IIR Filter

Implement infinite impulse response (IIR) filter

• Library:

• Motor Control Blockset / Signal Management

• 

Description

The IIR Filter block implements a discrete infinite impulse response (IIR) low pass filter on the specified input signal. The block supports fixed point and floating point data types.

Equations

The block uses this equation to implement the IIR filter:

$$y\left(k\right)=a\times x_k+(1-a)\times y_{k-1}$$

where:

• $$a$$ is the filter coefficient in the range (0, 1].

• $y\left(k\right)$ is the filtered output value at time $$k$$.

• $y_{k-1}$ is the filtered output value at time $k-1$.

• $x_k$ is the sampled input value at time $$k$$.

You can define a filter coefficient in the block parameter. A lower filter coefficient gives better filtering, but it increases the delay in the response time.

Ports

Input

x — Sampled input signal

scalar

Sampled values of the raw input signal in the time domain.

Data Types: single | double | fixed point

Output

y — Filtered output signal

scalar

Filtered output signal returned by the IIR Filter block in the time domain.

Data Types: single | double | fixed point

Parameters

Filter co-efficient — Filter coefficient of IIR block

0.01 (default) | scalar in the range (0,1]

Filter coefficient of the IIR block.

Extended Capabilities

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

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

Introduced in R2020a