Sorry for making my first (I think?) thread a question.
I've been working on a 2D car physics simulation as a hobby project, and old threads on these boards have been a great help.
I've got the tire modelling working great, as well as the car body and handling phsyics.
Up until now, I've had the tires represented as a regular 2d entity (handled with positional verlet), which is extended to include direction and rotation. The rotation is integrated using positional verlet as well (where forces are accumulated and the "position" is the amount of rotation). The front tires rotate naturally when they are pushed along the road by the rear tires.
I've been testing the system by just having the accelerator apply a force to the rear tires' rotation, which works very nicely, but I'd now like to add engine, clutch and gearbox modelling.
I've modelled an engine and flywheel, and the RPMs and throttle response look very convincing when it's not attached to anything, but getting the force from the engine to the road is confusing me, and it seems to be the point where most discussions on this topic reverse to kludgery.
For example, many people advocate getting the engine speed from the car's longitudinal velocity, and then calculating the engine torque via a lookup table, but in a dead sideways slide, that would cause the engine to bog down into antistall even if you had your foot flat on the throttle. It would also make it impossible to get wheelspin with many engine configurations.
Another issue with deriving engine speed from heading velocity is what happens when the engine is declutched? And how do you handle damage and wear at an arbitrary point in the driveline without explicitly hardcoding every kind of damage response?
Ideally, I would like to model each component in the driveline separately, but I'm having trouble understanding the way force goes from the engine to the tire and then the resistance make its way back to the engine.
For example, 30%(ish) of the engine's rotation is lost in the transmission due ot efficiency issues, yes? So does that mean that 30% of the resistance coming back from the wheel is also lost?
This has ended up being a very meandering thread, but I guess my main questions are:
-Can anyone point me at resources for realistically modelling the drive line?
or, failing that
-Can anyone explain to me the math I should be learning to simulate a system of gears including mass, friction and inefficiency?
and alse
-Can anyone speak to their own experiences on driveline simulation? I'd love to hear anyone's thoughts.