Path Tracking Based on Improved Pure Pursuit Model and PID

In the path tracking algorithm of unmanned vehicles, pure pursuit algorithm is widely used in low-speed application scenarios because of its simple model and easy implementation. In the pure pursuit algorithm, it is difficult to choose a suitable look-ahead distance for the unmanned vehicle. And there is a problem of outputting discontinuous steering angle under two continuous control cycle. Therefore, large heading and lateral error exist and make the tracking unstable. To solve these problems, firstly the look-ahead distance can be calculated by using the vehicle speed and the path information. Secondly, the PID controller is used to optimize the target steering angle which is calculated by the pure pursuit algorithm and then output stable angle to implement path tracking. In the golf course environment, a golf unmanned vehicle is used to track the predefined path. The results of optimized method show that the lateral error is reduced by 15.13 cm and the heading angle error is reduced by 1.88 degrees.