Measuing Shaft rotation

[pjohn]

Hi all,

I was wondering whether I can use an accelerometer or gyroscope or both to measure the speed of rotation for a motor shaft. To be honset I have read alot of stuff on the internet but am kind of confused as to what will be the best solution.

Basic idea is that If I can mount my circuit securely on the motor shaft it would output the speed of rotation. Any advise or guidance regarding this matter will be much helpful.

 

[shatruddha]

For measuring the speed of rotation of a shaft, I would suggest you to use optical encoders. You can use a gyroscope, but mounting it on the shaft will be a tedious task. Moreover, you will need to put slip rings to connect the circuit on your shaft to your stationary system. There is a great possibility of disturbance in the signal because of ripples coming out.
For starters, you can open some old mouse and take out its rotating flywheel (scroll). That will serve your purpose pretty much.

 

[paulfjujo]

hello,

what is the range of speed rotation ?
what accuracy do you need ?
sample time ?

solution can be as easy as a simple inductif sensor wich detect each tour
or a Tacho Dynamo coulpled to the axis wich can deliver 60V per 1000 Tr/Mn
or an encoder 500 up to 5000 impuls / tour
after you have to think about how to interface and treat the sensor
and what is the final value ..
Tr/mn , Hz , radians/seconde

 

[pjohn]

Thanks for the reply guys.

I have a very strong magnet that I intened to connect to the shaft. This magnet will house the circuit, so the whole system will be rotating with the shaft. The shaft diameter is about 2 inches. After measureing speed, I intended to log the rotation speed for later analysis in the EEPROM.

My intended frequency measurement is between 5Hz to 250Hz.

 

[tpetar]

See this project

**broken link removed**

 

[pjohn]

Hi,

Thanks for the link tpetar. But I was wondering if I can employ Gyrosope to do the same thing, it will also help me to understand the Gyro concepts as well. Any help on Gyro to acheive the same objective?

 

[tpetar]

Something like this are used in modern top submarines for navigation systems.