Jun 30, 2012 at 11:45 AM
Edited Jun 30, 2012 at 11:54 AM
There is a VelocityLimitController that could be of use but it limits the speed of all objects.
You can use Linear and Angular Damping to some effect as they will decelerate the body proportionally to the speed.
In general what you probably really want is the body to move at constant speed. To that regard check this tutorial:
P.S: If you went with the circle at the bottom route and you attach it with a revolute joint you can enable the motor on the joint and by setting MaxMotorTorque it would actually limit the max speed of the motor. So you won't need to apply forces - just
set the MotorSpeed and the body will move accordingly. There is also a way to implement joint friction by setting MaxMotorTorque to a low value and MotorSpeed to 0. If you then ApplyTorque() to the circle the motor will actually oppose the movement. Very useful.
Rotational and Linear movement on a wheel are connected there are some formulae to go from one to another. It's a common problem in vehicle mechanics so you can find info easily if you need to convert form one to another.
Check this for some explanations: