Automobile driving torque control system for controlling torque distribution between front and rear road wheels

A driving-torque distribution control system of an automotive vehicle for controlling a torque distribution between front and rear road wheels, one being a main drive wheel and the other being an auxiliary drive wheel, said system comprising:

• a torque-distribution adjustment means responsive to a target torque distribution command value for adjusting a distribution of driving torque between said main and auxiliary drive wheels;
• a first detection means for detecting a first physical quantity indicative of a rotational condition of said main drive wheel;
• a second detection means for detecting a second physical quantity indicative of a rotational condition of said auxiliary drive wheel;
• and
• a torque-distribution control means for producing said target torque distribution command value at predetermined sampling time intervals, said torque-distribution control means including a calculating means for calculating a reference torque-distribution command value based on a difference between said first and second physical quantities, and for calculating a torque-distribution limiting value based on a lateral acceleration exerted on the vehicle and a vehicle speed;
• wherein said torque-distribution control means selects said torque-distribution limiting value as said target torque-distribution command value when satisfying both a first condition in which said difference decreases to a value below said torque-distribution limiting value and a second condition in which an elapsed time, calculated from a time when said first condition has been satisfied, is less than a predetermined time period.

A driving-torque distribution control system of a four-wheel drive vehicle with a variable torque transfer for controlling a torque distribution between front and rear road wheels, one being a main drive wheel and the other being an auxiliary drive wheel, said system comprising:

• a transfer clutch mechanism responsive to a control signal for adjusting a distribution of driving torque between said main and auxiliary drive wheels;
• a main drive wheel speed sensor for detecting a revolution speed of said main drive wheel;
• an auxiliary drive wheel speed sensor for detecting a revolution speed of said auxiliary drive wheel;
• and
• a controller for producing said control signal based on an absolute value of a wheel speed difference between said main and auxiliary drive wheels,
• wherein said controller includes a correction means for correcting a value of said control signal, by decreasingly compensating a rate of change in said control signal value when satisfying both a first condition in which said wheel speed difference decreases to a value below a predetermined threshold and a second condition in which an elapsed time, calculated from a time when said first condition has been satisfied, is less than a predetermined time period.