## How to calculate the speed accurately based on low-level resolution Encoder?

Level 2
Level 2

Hi， I am using  a low-level resolution Encoder for the control of PMSM， and I have a question， how to calculate the speed accurately based on low-level resolution Encoder?

1 Solution

## Re: How to calculate the speed accurately based on low-level resolution Encoder?

Moderator
Moderator

Hi, @wanglipeng00000 ,

If you are using a low-level resolution encoder for the control of PMSM, accurately calculating the speed can be challenging due to the limited resolution of the encoder. Here are some methods you can refer to:

1) Counting Method: This method involves counting the number of encoder pulses within a fixed time period, and then using the count to calculate the speed. The calculation can be done using the following formula:

Speed = (Pulses per second) / (Pulses per revolution)

Where Pulses per second is the number of pulses counted within the fixed time period, and Pulses per revolution is the number of pulses per revolution for the encoder.

2) Period Measurement Method: This method involves measuring the time between two consecutive encoder pulses, and then using the period to calculate the speed. The calculation can be done using the following formula:

Speed = (60 * Pulses per revolution) / (Period * Encoder resolution)

Where Period is the time between two consecutive encoder pulses, and Encoder resolution is the number of pulses per revolution for the encoder.

BR,

Owen

## Re: How to calculate the speed accurately based on low-level resolution Encoder?

Moderator
Moderator

Hi, @wanglipeng00000 ,

If you are using a low-level resolution encoder for the control of PMSM, accurately calculating the speed can be challenging due to the limited resolution of the encoder. Here are some methods you can refer to:

1) Counting Method: This method involves counting the number of encoder pulses within a fixed time period, and then using the count to calculate the speed. The calculation can be done using the following formula:

Speed = (Pulses per second) / (Pulses per revolution)

Where Pulses per second is the number of pulses counted within the fixed time period, and Pulses per revolution is the number of pulses per revolution for the encoder.

2) Period Measurement Method: This method involves measuring the time between two consecutive encoder pulses, and then using the period to calculate the speed. The calculation can be done using the following formula:

Speed = (60 * Pulses per revolution) / (Period * Encoder resolution)

Where Period is the time between two consecutive encoder pulses, and Encoder resolution is the number of pulses per revolution for the encoder.