DAQ in Matlab with incremental encoder

HALLO;

How can one calculate the speed of an incremental encoder in Simulink?

Answer 1

[Simon]

Hi Mahmoud,

You can calculate incremental encoder speed in Simulink using the pulse counting method as follows:

1. Encoder Pulse Input – Read channel A (or B) via Digital Input, this is your DAQ input.

2. Detect Rise Positive – Output a single pulse for each rising edge.

3. Counter – Count pulses between resets using a Discrete-Time Integrator or counter logic. 

4. Triggered Subsystem – Trigger every second to read and reset the counter. Read the current count and subtract it using a unit delay.

5. First Gain block – Convert to rad/s (Converts encoder counts difference to counts per second)

Value can be 1/(PRR*Interval), create the variables and values accordingly

PRR - Pulses per Revolution

Interval: This is the time between your measurements.

This gain converts the change in encoder counts per sample into a real-world rotational speed (rad/s)

6. To get RPM – multiply second gain block value as 60

7. Display/Scope – Show or log speed.

This method is simple and works well for medium–high speeds. For very low speeds, consider period measurement.

There’s some information available to refer:

Encoder - Measure incremental position and direction of rotating motor - Simulink

Hope it helps!