Closed loop vehicle control comprising of the driver, the vehicle and the environment is now achieved by the automatic wheel slip control combination of ABS and ASR.
To improve directional control during acceleration, the Robert Bosch Corporation has introduced five ASR-Systems into series production. In one system, the electronic control unit works exclusively with the engine management system to assure directional control. In two other systems, brake intervention works in concert with throttle intervention.
For this task, it was necessary to develop different highly sophisticated hydraulic units. The other systems improve traction by controlling limited slip differentials. The safety concept for all five systems includes two redundant micro controllers which crosscheck and compare input and output signals.
A Traction Control System can be achieved through a number of torque intervention methods. The most important are the ability to:
adjust throttle angle
interrupt fuel injection
brake the drive wheels.
Within future traction control concepts priorities of traction, directional control, comfort and cost objectives will be influenced by the individual drivetrain (FWD, RWD, 4WD).