Make Do-It-Yourself Sideslip Sensor.

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11-12-2016, 05:16 PM
BillCobb

Make Do-It-Yourself Sideslip Sensor.

Then you can design a car's tire, chassis and steering performance, validate your design with direct measurements and turn your Wrench hat in for a Engineer's cap.

https://pixhawk.org/modules/px4flow

This can also settle the noisy discussions about Understeer, Moment Methods, Tire Size and Testing Best Practise Methods. And it just might get you invited to work for a real race team instead of an old school one.
11-15-2016, 12:15 PM
MCoach

Quote:

Originally Posted by BillCobb

Then you can design a car's tire, chassis and steering performance, validate your design with direct measurements and turn your Wrench hat in for a Engineer's cap.

https://pixhawk.org/modules/px4flow

This can also settle the noisy discussions about Understeer, Moment Methods, Tire Size and Testing Best Practise Methods. And it just might get you invited to work for a real race team instead of an old school one.

Bill,

The only real problem that I see with this set up is the required focal distance above the ground and the limitation it brings with max velocity.

Max velocities for different focal length lenses and ground distances:

Grounddistance 1m 3m 10m
16mm lens 2.4m/s 7.2m/s 24m/s
8mm lens 4.8m/s 14.4m/s 48m/s
6mm lens 6.4m/s 19.2m/s 64m/s
4mm lens 9.6m/s 28.8m/s 96m/s
11-15-2016, 03:52 PM
rory.gover

Can't speak to the accuracy of all the content, but: http://journals.sfu.ca/vte-j/index.p...icle/view/6/11
11-16-2016, 10:22 AM
Pennyman

Pretty crippling deadband they've got there
11-16-2016, 06:44 PM
Swiftus

I like the stick-a-wire-on-a-potentiometer-and-drag-it-on-the-ground method. Simple to implement and pretty cheap. Probably not as responsive as a visual sensor, but that would just take a bit of testing.
11-17-2016, 11:05 AM
apalrd

Quote:

Originally Posted by Pennyman

Pretty crippling deadband they've got there

They mentioned that the mouse sensor has a +-5deg deadband when the motion is aligned to an axis (X or Y), so they rotated the sensor by 45deg relative to the car (so the sensor sees 45deg at 0 slip angle). This gives them +-40deg of slip angle measurement before they hit the deadband. So no deadband in practice.
11-17-2016, 01:42 PM
MCoach

Quote:

Originally Posted by rory.gover

Can't speak to the accuracy of all the content, but: http://journals.sfu.ca/vte-j/index.p...icle/view/6/11

I've been waiting for that article to be published, and completely forgotten about it. Thanks for bringing it up.
The interesting part is that mouse technology has advanced fair enough just in the development of that project that those sensors are now obsolete and replaced by even better candidates.
It does address the one thing issue I see with Bill's suggestion by applying a new lens to the sensor.

Neat.
11-26-2016, 12:39 AM
MileyCyrus

Quote:

Originally Posted by MCoach

I've been waiting for that article to be published, and completely forgotten about it. Thanks for bringing it up.
The interesting part is that mouse technology has advanced fair enough just in the development of that project that those sensors are now obsolete and replaced by even better candidates.
It does address the one thing issue I see with Bill's suggestion by applying a new lens to the sensor.

Neat.

Sorry for also forgetting to post it here once it was published. It's kinda nice to see my paper being read and spread around.

MCoach, you are correct, and the current design I am playing with, amongst a bunch of other improvements, is now based around a PWM3310, and I'd say that there would be better once again since designing that board early this year.