Measuring belt slippage

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weddell
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Joined: Wed Sep 30, 2020 6:08 pm

Measuring belt slippage

Post by weddell »

Is it possible to use pico to give a percentage of slip on a belt. I have digital speed sensors on each shaft with belt drive between them. Can a maths channel be used to highlight any difference of ratio between the shafts?

Thanks

James

Gerry
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Re: Measuring belt slippage

Post by Gerry »

Hi James,

The answer is possibly, if the output of the sensor is in a format that the software for the Data Acquisition Device (i.e. PicoScope or Data Logger) can plot. So, we would need to know what format the output is in (if by digital you mean an encoder output, or if it is individual bits, or a serial communication protocol, etc)?

Regards,

Gerry
Gerry
Technical Specialist

weddell
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Joined: Wed Sep 30, 2020 6:08 pm

Re: Measuring belt slippage

Post by weddell »

I have 3 digital speed sensors on 3 shafts. One engine driving 2 shafts by belt. I would like to know if the driven shafts are slipping on the belt under load. The load changes are sudden and frequent.

Thanks for your help.

Gerry
PICO STAFF
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Posts: 953
Joined: Mon Aug 11, 2014 11:14 am

Re: Measuring belt slippage

Post by Gerry »

Hi James,

This is relatively straightforward in terms of a method and one that springs to mind is:- if the speed sensors on the shafts are detecting rate of rotation, and the shafts are all the same diameter, then you can just subtract each rotation rate of the shafts being driven, from the rotation rate of the driving shaft, then when you get a non-zero value, that shaft will have slipped. If the shafts are different diameters then you will have to factor that into the Math. You can do simple Math like this in PicoScope 6 (you can even differentiate the speed to find the rate of change in speed. or severity of slippage).

However, the difficulty may be getting the data into a tool to preform the Math. If the data is encoded into a serial transmission protocol, then all you will be able to do with a Data Acquisition (DAQ) device that has serial decoding capability (such as a PicoScope), is capture the serial data and then, once the capture has stopped, decode the data to find the speed values (which is no good from a monitoring point of view). You would also have to export the data to do the Math, as Math Channels only work on live, non serial encoded data arriving on input channels of the DAQ device. If, on the other hand, the data is arriving at the DAQ device as a serial bit stream (i.e. digital bits) but with the frequency of the bits indicating the rotational speed of the shaft, then you can plot the speed in real-time. Note that Quadrature Encoded data still provides a live bitstream (you just won't be able to infer rotation direction without full quadrature decoding) This is why I asked for the information regarding what type of digital data is output from the sensor.

Regards,

Gerry
Gerry
Technical Specialist

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