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Why not cap the motor speed via the IMU accelerometer?


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Wheels are cutting out because they hit a small bump, become airborne, and then the slightest forward tilt cause the wheels to freespin far beyond where they should be once they hit the ground again. Why not just use the accelerometer to cap off the max freespin speed (with a small buffer)? I'm thinking it also might eliminate the need for a lift button. 

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6 hours ago, BFE Duke said:

Wheels are cutting out because they hit a small bump, become airborne, and then the slightest forward tilt cause the wheels to freespin far beyond where they should be once they hit the ground again. Why not just use the accelerometer to cap off the max freespin speed (with a small buffer)? I'm thinking it also might eliminate the need for a lift button. 

 

5 hours ago, BFE Duke said:

Nevermind, I guess it's difficult to estimate speed by integrating acceleration and graphing it out. 

Take a look at 

for ideas in this direction. 

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  • 2 weeks later...

Unfortunately accelerometers are too noisy and imprecise to track absolute position in any direction.  If it were possible, game developers would've worked out how to do it in nintendo Wii games.

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they already do that...

Except rider ignore the beeps and tilt back warnings and push it until it cant physically go any faster...

 

50kph wheel being pushed to 55kph+ and then cutting out.

Do you suggest insta-cutout at 50kph? XD

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8 hours ago, musk said:

Unfortunately accelerometers are too noisy and imprecise to track absolute position in any direction.  If it were possible, game developers would've worked out how to do it in nintendo Wii games.

Some aircraft have inertial navigation systems, based on ring-laser or fiber optic type gyros, which are much more precise than the MEMS type IMUs in these EUCs and drones. I guess they are just too expensive for an EUC. 

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5 hours ago, BFE Duke said:

Some aircraft have inertial navigation systems, based on ring-laser or fiber optic type gyros, which are much more precise than the MEMS type IMUs in these EUCs and drones. I guess they are just too expensive for an EUC. 

Sounds cool!

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Next topic: Why not cap the motor speed via GPS or bluetooth doppler effect :D

If the purpose is to prevent cutoffs due to the wheel reaching max spinning speed in the air during brief loss of contact with the ground - then the wheel could be capped at its max rotation speed without cutoff for a limited period of time, few second should be enough to return to the ground from safe jump height.

In any case accelerometer during jump in the air will show zero acceleration, which could be used for jump detection, and on the ground you have the actual speed via wheel RPM.

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