Path following algorithm for skid-steering mobile robot based on adaptive discontinuous posture control

The kinematic model of a skid-steering mobile robot (SSMR) is manipulated using signed polar transformation which represents a discontinuous state transformation. The influence of relative position between the instantaneous center of rotation (ICR) and SSMR center of mass is considered. Then, adaptive state feedback controller is designed and stability regions are studied. Subsequently, a point-to-point tracking algorithm is introduced to track a trajectory that is defined by a set of way-points, which is the more realistic case of dangerous exploration or landmine detection purposes. The closed-loop system is simulated using MATLAB environment and experimentally validated using a modified TURTLEBOT3 Burger. Results show that the proposed controller reaches almost zero steady state error with smooth paths for point stabilization, moreover, good tracking capabilities are demonstrated. The proposed control system integrates both posture and tracking algorithm, thus achieve trajectory tacking which is defined by a set of way-points.

针对滑移转向移动机器人（skid-steering mobile robot, SSMR）的运动学模型，采用表征不连续状态变换（discontinuous state transformation）的符号极坐标变换（signed polar transformation）进行建模推导。研究中充分考虑了瞬时旋转中心（instantaneous center of rotation, ICR）与SSMR质心之间的相对位置影响。随后设计了自适应状态反馈控制器，并对其稳定域开展了系统性研究。进一步提出了一种点对点跟踪算法，用于跟踪由一组航路点定义的轨迹，该场景更贴合危险勘探或地雷探测这类实际应用场景。在MATLAB环境下对闭环系统进行了仿真实验，并通过改装型TURTLEBOT3 Burger完成了实物验证。实验结果表明，所提控制器可实现近乎为零的稳态误差，点位镇定过程中路径平滑；同时展现出优异的跟踪性能。所提出的控制系统整合了位姿调节与跟踪算法，最终实现了由一组航路点定义的轨迹跟踪。