Optical mouse sensor for velocity measurement. I need some recommendation

Other Hardware Sensors
1

I want to install a velocity measurement system on my mini 4WD vehicle. It's a palm sized toy car without steering system which runs on plastic surface tracks with fences.

I considered several options but nothing fits my needs so far.

-GPS
Its indoor environment and the circuits is like 2meters x 4meters. It could be a option if US military GPS were available

-IMU based velocity estimation

=) NO

Besides, metering IMU 6dof data with mini 4WD was fun. I could find out on which par of the track my car became unstable during runs.

-Tachometer
Mini 4wd car does not have steering system and to change its direction, it only has to slide against fences on corners.
For that this toy completely depends on slips for cornering, I should not rely on measuring wheel revolution for speed measurements.

-Optical flow system, or mouse sensors.

I think it should be the best option, but there are some questionable.

  1. I need >300 IPS(inches per second, roughly 30KPH and 20MPH) detection ranges. this narrows down my options.
  2. the most common application (I mean, on eBay) of mouse sensors for embedded system sensor was like for drones, which requires ~30cm minimum distance from the surface, which is not suitable for my project.
  3. I think could break some high-end gaming mouses and get the board, but if I do so, the board will be too bulky, and I think I cannot find adequate documentations easily. is there any packaged module suitable for my project?

Any idea is welcomed and thanks for reading my post.

2

Perhaps have the track the device is on track the device.

Example: Several break-beams placed around the track, time from start and time from beam to beam could be realized and translated into speed.

3

Mouse sensors are very limited in range. This is intentional, so you can pick up the mouse 1cm and move it across the desk without moving the pointer.

Can you keep the sensor within 1cm of the ground when moving at those speeds? (Actually, testing the mouse in my hand it's more like 0.5cm.)

Obviously the same technology will work with different optics for longer ranges. But the price will jump up rather suddenly.

I would measure RPM on both sides and average it.

4

What military has a GPS that accurate? The optical mouse sensor should work, when they are on a computer system the output is controlled by dividing the counts coming from the sensor by the computer, its movement is not limited. Sensitivity is typically controlled by the gain at the sensor. Give that a try. This response is to help you get started in solving your problem, not solve it for you.
Good Luck & Have Fun!
Gil