System for controlling behavior of vehicle during braking and during a steering maneuver

A control system for a wheeled vehicle, comprising:

• a brake system for braking said vehicle;
• a steering system for steering said vehicle;
• a brake actuating means for controlling a behavior of the vehicle during braking by developing a left and right braking force difference between left and right wheels of the vehicle in accordance with a braking force difference control signal representing a brake control input;
• a sensing means for sensing an actual steering input applied to said steering system by a driver of the vehicle, and an actual vehicle motion variable of the vehicle, said sensing means comprising a steering angle sensing means for determining said actual steering input by sensing a displacement of a movable element of said steering system and a vehicle motion sensing means for determining said actual vehicle motion variable representing a vehicle planar motion including a vehicle yawing motion and a vehicle side translational motion;
• and
• a controlling means for determining an estimated vehicle motion variable from said actual steering input and said brake control input by using a first predetermined estimator transfer function for determining a theoretical vehicle steering response from said actual steering input and a second predetermined estimator transfer function for determining a theoretical vehicle response due to braking from said brake control input, further determining a deviation of said actual vehicle motion variable from said estimated vehicle motion variable, and further determining said brake control input of said brake control signal in accordance with said deviation by using a predetermined compensator transfer function, and a predetermined filter transfer function, said controlling means including a means for determining said brake control input, by using said compensator transfer function which is in an inverse form of said second estimator transfer characteristic and said filter transfer function, and causing said brake actuating means to increase said left and right brake force difference by increasing said brake control input.