Development of Lane Keeping Assist System Using Lateral-Position-Error Control at Forward Gaze Point 2016-01-0116
Mitsubishi Electric has been developing a lane keeping assist system (LKAS). This system consists of our products such as an electric power steering (EPS), a camera, and an electronic control unit (ECU) for ADAS. In this system, the camera detects a lane marker, the ECU estimates reference path and vehicle position, and calculates reference steering wheel angle, and the EPS controls a steering wheel angle based on reference steering wheel angle. In this paper, we explain the calculation method of reference steering wheel angle for path tracking control. We derive a formula of reference steering wheel angle calculation that converges lateral position deviation in desired time by using lateral position deviation change rate control on forward gaze point as path tracking control algorithm. Since the formula is obtained from the vehicle model, we can easily design a controller depending on the vehicle type, by using known vehicle specifications. In addition, we confirmed that the algorithm can be used for LKAS by simulation and examination. The algorithms uses just the lateral position deviation, yaw angle deviation on the forward gaze point and the yaw rate. Since, the algorithm doesn’t need the road curvature information, it can be used for applications such as path tracking control with global navigation satellite system.