Front Wheel Skidding Compensation System in Snow Ploughing

Tractor based snow ploughing with front mounted blade is steered by using front steering wheels of the tractor, but in slippery conditions the front wheels tend to slide sideways remarkably. Normally the driver compensates the skidding by steering the front wheels to opposite direction. If the skidding is not compensated, the tractor eventually drifts to the oncoming lane or spins around.In this paper, an automated method to estimate and to compensate the slipping is proposed. The estimation is based on a simple kinematic model of tractor-plough system with some additions. The estimation relies on an angular velocity measurement (Fiber Optic Gyro) of the heading that is able to recognize small changes of the driving direction that indicates the presence of slipping. The indicated slipping is compensated by a feedback law in a drive-by-wire steering system.The results show that the proposed system is able to measure fairly realistic values for the slipping angle and to compensate the slipping. Driver experiences confirm that less steering corrections are needed to keep the tractor on the desired trajectory.