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By eyal20
#190399
hello!

I have been looking for an optical speed sensor which can give me the speed in real time of a perpendicular movement.
The basic principle is the same as ordinary optical computer mouse.

As you know, optical mouse uses CMOS camera to take hundreds of images per second. while doing so, a microchip detect patterns in those images and by comparing the locations of the patterns between the images, it retrieve the distance and the direction of the change.

So I need this kind of sensor to measure speed, but the sensor needs to be about 50cm (1.5 feet) above the platform.

dose anyone recognizes if something like it exists ??

Thank you all !
User avatar
By Jimbo72
#190460
Such a sensor would be giving you angular position. To convert this to speed you would need to know the distance to the object for each image and time between images. A bit of trig would give you velocity. At best the accuracy would be set by the accuracy of the measured distance from the sensor. i.e if you plug in 1.5 feet into the algorithm and it is actually 3.0 feet your calculated velocity would be half of the actual.
Can you use a camera? If your object has a bright spot, it should be simple to derive the location.
You can go to a machine vision house and tell them what you want to do. Some machine vision cameras can do pretty amazing things with simple setups.