TRAJECTORY TRACKING METHOD AND SYSTEM FOR FOUR-WHEEL INDEPENDENT STEERING AND INDEPENDENT DRIVE VEHICLE

摘要

The present invention provides a trajectory tracking method and system for a four-wheel independent steering and independent drive vehicle. The method comprises: on a target trajectory, selecting a point that satisfies both a foresight distance constraint and a radial distance constraint as a foresight point, the radial distance constraint being the product of a radial distance coefficient and a lateral error; the lateral error being the shortest distance between the target trajectory and a vehicle body reference point; according to the current position relation between the foresight point and the vehicle body, fitting a circular arc trajectory passing through the foresight point and the vehicle body reference point, and calculating the radius of the circular arc trajectory; calculating an angular velocity at the vehicle body reference point according to the set vehicle speed and the radius of the circular arc trajectory; and obtaining a rotational speed control amount and a rotation angle control amount of a wheel according to the angular velocity at the vehicle body reference point and the linear velocity to control a vehicle to travel along the target trajectory. The method and system in the present invention improve the accuracy of trajectory tracking, the error convergence rate, and the ride comfort of the vehicle body during tracking.