4WID-4WIS智能车阿克曼转向轨迹规划及位置估算

针对四轮独立驱动与四轮独立转向(four-wheel independent drive and four-wheel independent steering,4WID-4WIS)智能车的转向行驶工况,基于阿克曼转向原理,提出一种利用三阶贝塞尔曲线进行轨迹规划的新方法.首先,采用最优函数获取一条满足智能车初始状态约束...

Ackerman steering trajectory planning and position estimation of 4WID-4WIS intelligent vehicle

Aiming at the steering driving conditions of four-wheel independent drive and four-wheel independent steering (4WID-4WIS) intelligent vehicles, a new method for trajectory planning using third-order Bézier curve was proposed based on the Ackerman steering principle. Firstly, an optimal trajectory with minimum curvature difference was obtained by using the optimal function, which met the initial state constraints and target state constraints of intelligent vehicle and the curvature continuity constraints. Then, a position estimation algorithm was proposed, which calculated the position increment of intelligent vehicle based on the navigation angle measured by the inertial navigation system and the pulse number of encoder, so as to estimate its position during driving and calculate the driving trajectory length. Finally, the planned intelligent vehicle trajectory was simulated in the MATLAB software, and the rationality and feasibility of the trajectory planning method and position estimation algorithm were verified on the real vehicle test platform. The results showed that the 4WID-4WIS intelligent vehicle could drive to the given end point according to the planned trajectory, and its lateral position estimation error was 0.19%, the longitudinal position estimation error was 0.20% and the driving trajectory length calculation error was 0.22%; compared with other single algorithms such as mileage calculation method and ranging method, the proposed position estimation algorithm had high precision, which can provide reference for trajectory planning and position estimation of other mobile robots.