TORQUE CONTROL METHOD FOR REDUCING VIBRATION AND NOISE IN FOUR WHEEL DRIVE VEHICLE

摘要

The present invention relates to a torque control method for reducing vibration and noise of a four-wheel drive vehicle under circling condition on a low friction road, and more specifically, to a torque control method in the four-wheel drive vehicle which reduces vibration and nose of the four-wheel drive vehicle by calculating speed difference of a front wheel and a rear wheel of the four-wheel drive vehicle in case the four-wheel drive vehicle circles on the low friction road, and maintaining the speed difference between the front wheel and the rear wheel of the four-wheel drive vehicle constantly by applying drive torque (constant torque) to a sub-driven wheel of the four-wheel drive vehicle in case the speed difference exceeds a fixed range in a positive direction and a negative direction. A first embodiment of the torque control method in the four-wheel drive vehicle by the present invention can include: a vehicle traveling state determining step of determining whether an angle of a steering wheel exceeds a fixed value; a TCB logic operation step of reducing four-wheel drive torque, in case the angle of the steering wheel exceeds the fixed value; a speed difference comparison and sleep logic operation step of determining whether speed difference (V1-V2) between a main driven wheel (V1) and the sub-driven wheel (V2) is within a fixed range, and increasing the four-wheel drive torque; and a torque control step of controlling the four-wheel drive torque with constant torque and performing the vehicle traveling state determining step again, in case the speed difference (V1-V2) exceeds the range.