Check your units - some engines use angles for rotations instead of radians a second. When car is just rolling your reaction force should produce exactly enough torque to rotate wheels with exactly the same velocity as car is moving. You need to get this right before doing anything with the drive train.
Engine RPM and wheel angular velocity
Author
Oh... That, of course, applies to non-drive wheels? I'll see if I can get it work;)
Author
OK! I'll tell you honestly - I have no any idea how to achieve this. Is it even possible?!
To all of them. If we ignore engine, like when de-clutched completely, without brakes car will roll, both front and back wheels will have the same rotation. Technically gearbox might slowdown drive wheel but this is just detail.
Simple way to check is to calculate angular velocity from linear velocity. Take linear velocity of car in m/s divide by radius of wheel in meters, this is your angular velocity in radians/second. To get car moving just push it with force or place on a slope.
Your reaction force should be producing exactly enough torque to accelerate wheel to the same linear velocity as car is moving.
When wheel moves with the same velocity reaction force would be zero.
Your reaction force should be producing exactly enough torque to accelerate wheel to the same linear velocity as car is moving.
When wheel moves with the same velocity reaction force would be zero.
Author
Yes, it would be zero. However, let's say, if the wheel is turning a bit faster, the reaction torque tends to be stronger than needed to get it free-rolling. Way stronger. How to fix this?
Check your units first. If you are using some realistic curve for a tire I would expect that you need a realistic mass and moment of inertia for the wheel. I haven't done car simulation, I'm doing this for tanks. In case of tanks I calculate friction force from local velocity and mass of the tank, plus friction coefficients and so on. When it comes to reaction force it is scaled down. I divide friction force by the mass of the vehicle and then multiple by the mass of tracks and sprocket. This seams to produce pretty accurate results.
Author
Hm... What I do is just use Pacejka Magical Formula. The slip definition is
(w * r - V) / |V|I really don't know how to find out correct mass of the wheel. I think that I need to find exact wheel example, but I have no where to look.
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