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Slip Indicator Maths

PostPosted: Sat May 30, 2020 10:03 am
by JordonMusser
I have setup an SLM to display acceleration wheel slip, but now I want to do braking (a bit more complex). I am new to the motec world. This is for an ADL3.

I need to first find the fastest wheel
- Math channel I assume, can I use nested "choose" or is there a better way to do it?

I then need to find the slowest wheel
- same Q as above


Then i will divide slowest by fastest, and display using user conditions a number of lights related to that slip %. This obviously picks the wheel with the most slip at any given time.

I only want this to occur during deceleration obviously. It seems I may need to setup an alarm to do that.

Has anyone implemented something similar? The Pseudo code is easy I am just not sure the right strategy for implementing it here. I can think of a few different ways. My assumption is this has been done many times and a strategy fine tuned :)

Re: Slip Indicator Maths

PostPosted: Thu Jun 04, 2020 12:11 pm
by adrian
I've seen this done a few ways. Most of the time it works similar to this:

Use channel maths to divide each of the wheel speeds with "ground speed" (generated in Calculations>Speed and Distance). This gives you a ratio of the wheel speed to the actual vehicle speed. This will be 1 when the particular wheel is at the same speed as the vehicle and 0 when completely locked.

Now create User Conditions to determine how much slip will turn the lights on. Typically you would add either Brake Pressure or Longitudinal G into the condition so that it only comes on when you are actually braking hard on the track.