Model solving type vehicle steering control system with parameter identification

Claim 1

A control system for steering a controlled vehicle having first and second wheels, comprising: (i) means for sensing a steering wheel angle of said controlled vehicle, and determining a sensed value of said steering wheel angle, means for sensing a vehicle speed of said controlled vehicle, and determining a sensed value of said vehicle speed, (iii) means for sensing a turning behavior of said controlled vehicle by sensing a first vehicle motion variable representing the turning behavior, and determining a sensed value of said first vehicle motion variable, (iv) actuating, means for steering said controlled vehicle by altering a first wheel steer angle of said first wheels in accordance with a desired value of said first wheel steer angle, and (v) controlling means for determining said desired value of said first wheel steer angle, said controlling means comprising at least; (v-i) target turning behavior determining means connected with said steering wheel angle sensing means and said vehicle speed sensing means for determining a desired value of a second vehicle motion variable corresponding to a vehicle steering response with respect to said sensed value of said steering wheel angle and said sensed value of said vehicle speed by solving a desired vehicle model simulating a motion of a desired vehicle defined by values of vehicle parameters, (v-ii) steer angle determining means connected with said target turning behavior determining means for determining said desired value of said first wheel steer angle required to achieve said desired value of said second motion variable in said controlled vehicle by solving a first actual vehicle model representing said controlled vehicle by use of values of said vehicle parameters inclusive of a first vehicle parameter, (v-iii) actual turning behavior estimating means connected with said steer angle determining means for determining an estimated value of said first motion variable resulting from said desired value of said first wheel steer angle by solving a second actual vehicle model simulating a motion of said controlled vehicle by use of values of said vehicle parameters inclusive of said first vehicle parameter, (v-iv) parameter identifying means connected with said turning behavior sensing means for modifying only said second actual vehicle model by adjusting the value of said first vehicle parameter of said second actual vehicle model so that said estimated value of said first motion variable determined according to said second actual vehicle model approaches to said sensed value of said first motion variable, and thereby determining a desired value of said first vehicle parameter, and (v-v) parameter adjusting means for modifying said first actual vehicle model by adjusting the value of said first vehicle parameter of said first actual vehicle model so as to approach said desired value of said first vehicle parameter.