Method of correcting steering of a road driven vehicle

Claim 1

A method for automatically correcting steering of a road vehicle by a driver, the driver controlling a steering wheel of the vehicle by an angle δ H (in radian), the vehicle having a wheelbase l(in m), a center of gravity (CG) disposed a distance l F (in m) from the front axle and a distance l R (in m) from the rear axle, a mass m (in kg), a moment of inertia J (in kg m 3 ) around a vertical axis through the center of gravity, and a steering gear ratio i L ; the method comprising: providing a controller and sensors; measuring a yaw velocity r (in radian/s) around the vertical axis with the yaw rate sensor; determining a driving speed v x (in m/s) via the ABS sensor; measuring an acceleration a x (in m/s 2 ) in the driving direction with an accelerometer; measuring a lateral acceleration, the acceleration being counted as positive to the left, with two accelerometers mounted at two convenient locations at a distance l a in the longitudinal vehicle direction as a y1 , (in m/s 2 , front) and a y2 (m/s 2 , rear); measuring a steering wheel angle δ H with a potentiometer or a capacitive sensor on a steering column of the vehicle, the angle being measured in radians counting positive to the left; computing a vehicle wheel angle δ L =δ H /i L controlled by the driver; computing a variable angle β F at the front axle according to a the known observer method; and computing in a microprocessor of the controller according to the differential equation ##EQU48## where δ C denotes a supplemental steering angle which, when added to the vehicle wheel angle δ L controlled by the driver results in the overall wheel angle δ F =δ L +δ C ; where δ 1 , denotes a computer-internal controller state; where u 1 denotes a first input for further feedback signals and u 2 denotes a second input for further feedback signals; and where F 1 (δ L ) and F 2 (δ L ) denote prefilters which are functions of the vehicle wheel angle δ L .

Claim 2

A method for automatically correcting steering of a road vehicle by a driver, the driver controlling a steering wheel of the vehicle by an angle δ H (in radian), the vehicle having a wheelbase l(in m), a center of gravity (CG) disposed a distance l F (in m) from the front axle and a distance l R (in m) from the rear axle, a mass m (in kg), a moment of inertia J (in kg m 3 ) around a vertical axis through the center of gravity, and a steering gear ratio i L ; the method comprising: providing a controller and sensors; measuring a yaw velocity r (in radian/s) around the vertical axis with the yaw rate sensor; determining a driving speed v x (in m/s) via the ABS sensor; measuring an acceleration a x (in m/s 2 ) in the driving direction with an accelerometer; measuring a lateral acceleration, the acceleration being counted as positive to the left, with two accelerometers mounted at two convenient locations at a distance l a in the longitudinal vehicle direction as a y1 , (in m/s 2 , front) and a y2 (m/s 2 , rear); measuring a steering wheel angle δ H with a potentiometer or a capacitive sensor on a steering column of the vehicle, the angle being measured in radians counting positive to the left; computing a vehicle wheel angle δ L =δ H /i L controlled by the driver; computing a variable angle β F at the front axle according to a the known observer method; and computing in a microprocessor of the controller according to the differential equation ##EQU48## where δ C denotes a supplemental steering angle which, when added to the vehicle wheel angle δ L controlled by the driver results in the overall wheel angle δ F =δ L +δ C ; where δ 1 , denotes a computer-internal controller state; where u 1 denotes a first input for further feedback signals and u 2 denotes a second input for further feedback signals; and where F 1 (δ L ) and F 2 (δ L ) denote prefilters which are functions of the vehicle wheel angle δ L .