Path Tracking Control for Crawler Robots With Track Slippage and Signal Time Delay Based on Pure Pursuit and Look‐Ahead Heading Error Compensation

ABSTRACT

Crawler robots represent a vital subclass of mobile robots, widely deployed in unstructured field environments. On complex, uneven terrain, track slippage (TS) is almost unavoidable. In addition, signal time delay (STD) is common in sensing and actuation processes, further increasing control complexity. As a result, the coupling of TS and STD poses significant challenges to the accuracy and smoothness of path tracking control (PTC) in crawler robots. Recognizing the strengths of pure pursuit (PP), notably its robustness and straightforward structure, we set out to address the above challenges by improving the pure pursuit method. We propose a PTC method that incorporates a look‐ahead heading error compensation (LHEC) algorithm and a PP controller, achieving real‐time adjustment of the control inputs by calculating the heading deviation between the look‐ahead point and the crawler robot and feeding it back to the control loop as a dynamic compensation signal. This method provides a robust solution to the challenges posed by TS and STD without requiring exhaustive systemic modeling, effectively leveraging the inherent ability of these factors to mitigate oscillations under specific conditions, as we found, thereby enhancing both tracking accuracy and smoothness simultaneously. According to the real‐world experiment results, our control method has high accuracy, with the maximum absolute displacement error of 0.0762 m across all experiments. The proposed method can reduce the maximum absolute displacement error by at least 41.34% compared to state‐of‐the‐art yaw‐rate‐compensated methods, including pure pursuit, nonlinear model predictive control, and Stanley control. Moreover, the proposed method also exhibits superior smoothness. The average yaw jerk did not exceed 13.95 rad/s ³ . Compared with state‐of‐the‐art yaw rate compensation methods based on pure pursuit or Stanley control, the proposed method can reduce the average absolute yaw jerk by at least 19.55%. Furthermore, 15 sets of repeated trials on continuous curve paths in plowed dry land demonstrate that the controller maintains high consistency. By the way, this study clarifies the inherent limitations of look‐ahead distance adjustment and yaw rate compensation strategies under the coupled influence of TS and STD, providing new insights for the development of robust field‐robotic control.