Vehicle wheel-to-road real-time drive force control system

摘要

A brake controller reacts to the output signals from a pair of wheel speed sensors to trigger one of the pairs of brakes (40) for the respective drive wheel (10) at the lower critical drive speed relative the road so as to raise the apparent drive force of this wheel to that of the other wheel in the pair. The vehicle has left and right front and rear wheels in a four-wheel drive system sourced (24) via a front wheel speed differential (12) as well as a rear differential for the rear wheels speed. A central differential (18) is connected to front (20) and rear shafts (22) for speed differentiation and shaft-transmitted (20,22) torque distribution. The brake controller controls three of the four wheel brakes in the event of wheel displaying minimum road speed. This wheel gives the reference value to which the brake controller zeroes the difference between the respective drive wheels assisted by a system in the controller which summates the speed error for all four wheels by the first error component obtained by subtracting half the average speed of the rear wheel from that of the front wheels and a second error component composed of the difference calculated by subtracting half the average speed of the two front wheels from their respective wheel speeds.