# X Y Speed detection

**URL:** <https://forums.openmv.io/t/x-y-speed-detection/481>\
**Category:** OpenMV Boards\
**Created:** [November 11, 2017, 7:52am UTC](https://forums.openmv.io/t/x-y-speed-detection/481 "2017-11-11T07:52:16Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![riodda](https://avatars.discourse-cdn.com/v4/letter/r/e36b37/32.png) [@riodda](https://forums.openmv.io/u/riodda)\
**Post date:** [November 11, 2017, 7:52am UTC](https://forums.openmv.io/t/x-y-speed-detection/481/1 "2017-11-11T07:52:16Z")

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Hi all, i came accross open mvcam while doing some research for an optical flow sensor.  
I would like to develop an XY speed sensor for high performance vechiles (like correvit datron on a budget) and i would like to know if the mv cam will suit the task, i need to know expecially how to understand if with the appropriate lens i can detect up to high speed ( i guess i need to know the max frame rate).  
For first the Y/X speed ratio detetection will be enough but i need very high speed (up to 250 km/h).  
I think i can put the camera no more than 30-40 cm from the ground.  
Many thanks for any help !

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**Author:** ![riodda](https://avatars.discourse-cdn.com/v4/letter/r/e36b37/32.png) [@riodda](https://forums.openmv.io/u/riodda)\
**Post date:** [November 11, 2017, 9:18am UTC](https://forums.openmv.io/t/x-y-speed-detection/481/2 "2017-11-11T09:18:42Z")

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I had a quick look to the specs and as far as i have understood i should be able to get maximum 120 fps from the sensor, and considering 50% overlap between the frames, 120° fov lens and 40cm from the ground i should have a max speed of detection of 86 m/s that is more than enough therfore i would like to know if:

1. Is it plausible to get 120 fps out from the

```python
 [delta_x, delta_y, response] = old.find_displacement(img)

```

function considering even a 32X32 resolution ?  
2. Is it the tarmac grain the right surface to evalute displacement ?

As anoter option i was thinking about taking “long” exposure picture in this way the grain will be blurred lines and use the line or segments angle functions but i haven’t found how to control exposure and sensitivity.

Many thanks for guidance.

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**Author:** ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)\
**Post date:** [November 11, 2017, 3:38pm UTC](https://forums.openmv.io/t/x-y-speed-detection/481/3 "2017-11-11T15:38:58Z")

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Hi, with the M7 processor you might be able to get about 56 FPS using find\_displacement with a 32x32 image. The kind of application you are trying to do seems like something you’d need a really high end camera for. Can you describe your setup for the camera better?

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**Author:** ![riodda](https://avatars.discourse-cdn.com/v4/letter/r/e36b37/32.png) [@riodda](https://forums.openmv.io/u/riodda)\
**Post date:** [November 15, 2017, 7:47am UTC](https://forums.openmv.io/t/x-y-speed-detection/481/4 "2017-11-15T07:47:35Z")

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Thanks kwagyeman for you answer, i will try to explain better what i would like to do:  
The holygrail of the vehicle dynamics if the evaluation of the Beta angle (or setup angle) that gives you a direct measuremente of the amount of understeer or oversteer that the car is having during a corder.  
Do do so you can do an indirect meaurement with an IMU and a GPS or you can make a direct measurement with radar o optical XY speed sensors, this is he sensor that is a de facto standard in the automotive  
[http://www.dynatech-jp.com/product/CORRSYS-DATRON/cds-d\_S-350\_e.pdf](http://www.dynatech-jp.com/product/CORRSYS-DATRON/cds-d_S-350_e.pdf)

This thing is extremely expensive and i was thinking if with the OpenMV cam is possible to develop something simila at a fraction of the cost, with a 56 fps what is the minimum overlap between the frames i need to have a accurate measurement ? Is it the asphalt grain suitable for such measurement ?