Slot car racing control with the TI 99/4A

[+Vorticon]

It wouldn't work. When the accelerometer senses sideways acceleration too high, it's too late to do anything about it. The car's inertia will keep the speed above the acceptable level for too long. If you apply dynamic braking in any magnitude that's likely to make a difference in that case, then you'll lose tire grip.

 

 

But one could set the acceleration limit to a somewhat lower level than the critical one, thus creating a buffer zone to account for inertia and keeping the car on the track. However, that would sacrifice some speed but I believe it would still beat most human operators...

[apersson850]

To beat most human operators you only need to run at the same "safe speed" all the time. Most human operators run too fast and derail frequently, which gives an average speed below the safe speed.

 

The problem with the accelerometer approach is that to run at optimized speed, you must start slowing down before entering into the curve. You can't detect that with an accelerometer reporting centrifugal force only.

[Sinphaltimus]

An accelerometer can be used to collect data for the track to allow fine tuning of the tables.

Edited October 21, 2016 by Sinphaltimus

[+jedimatt42]

It would be interesting to be able to record speed tables of a hot lap, and be able to replay it, to compete against yourself or even share for others to compete against.

 

-M@

[+Schmitzi]

Maybe this is the right track

 

(hope you can see it on FB)

[+Vorticon]

 

The problem with the accelerometer approach is that to run at optimized speed, you must start slowing down before entering into the curve. You can't detect that with an accelerometer reporting centrifugal force only.

 

I'm still not 100% convinced about that. With fast enough sampling one should be able to detect a **rise** in the centrifugal force early enough to effect deceleration on the car before the critical centrifugal force limit is reached and with enough margin to account for inertia. Whether the TI will be able to handle this fast enough is unknown. This could actually be modeled in software if one is so inclined. I guess the only way to find out for sure is to implement the idea and see what comes out of it...

[Omega-TI]

I dunno... the processing time of the TI is one thing, add lag time sending the data from the sensor device itself... all while factoring the speed the car is travelling at full tilt... not much leeway for reaction time...

 

... I agree implementation is the best test.

[apersson850]

The problem isn't the processing time of the TI, the problem is that the approach is flawed. Anyone who has spent some time on a real race track knows that you need your brake markers a bit before the curve, or it will not work. Not if you are going at max possible speed between the curves, that is. If you aren't, then nothing really matters here.

But I agree that having accelerometer data could be used to optimized the tables. That's kind of what you do in real racing, when you keep trying the same curve, with adjustments of the braker marker position in between attempts. Brake later and later until you can't take the curve any longer.

[+Vorticon]

I see your point if the car is going full speed prior to the curve. I have actually experienced that with my setup as I was unable to slow the car quickly enough at the start of the curve to prevent it from flying off the track if it was going too fast on the straight section just prior. So the trick here would be to run the car at less than maximum prior to the curve, but then make up for it by letting the accelerometer data guide the speed to push it as close to the edge as possible on the curve. So the car would enter the curve at a relatively safe speed to stay on track, but then gradually accelerate while on the curve within the limits set by the accelerometer. This would be best noted on long curves.

Interesting problem...