Objective-based driver

[josefl9]

Hello,

I want to test a vehicle on a specific road profile by requsting an objective (e.g. minimize travel time). Does the Adams SmartDriver support this feature and, if not, are there any alternatives?

Thanks in advance,

Josef

 

[GregLocock]

I have had little success ( or need to get involved ) with ADAMS various 'smart drivers' but yes, I believe there is a laptime optimiser, possibly in ADAMS/Racecar?

Yes there are many alternatives, starting from the free and adequate OptimumLap, through things like the excellent Bosch Lapsim, and the the MBD simulators such as ADAMS. It would be easy and possibly sensible to drive ADAMS via an external driver, such as a Simulink model, and do your optimisation outside of ADAMS.

If your circuit is very simple then you may be able to model it as a series of open loop commands, for instance ISO lane change A can be modelled as very small sequence of 4 steering inputs.

Another option would be to use a real time simulator and put the human driver in the loop. Playstation time.

More generally, ADAMS models are inherently complex. They are slow to run and finicky. To make them worth using they need to be filled with ACCURATE non linear component properties. If you run your ADAMS models with a lot of plug or default numbers, then the answers you get will be no more valid than if you'd run a simpler model that ignores the complexities. Specifically with laptimes, you need a good tire model that correlates well with real world conditions at the limit of traction. One of my jobs was to correlate a model for rollover under 2 loading conditions and at 8 different steering wheel angles. That took 3 months running 5 models in parallel.

Simpler models like CarSim or CarModeller (apparently) will run much faster and are quicker to build and are more robust, all for good reasons. We had a semi automated way of building CarSim models from any mixture of rig results and ADAMS models. These would run in real time.


Cheers

Greg Locock


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