考虑绕障时耗的四轮全向移动机器人轨迹跟踪控制

Trajectory tracking control of four-wheeled omnidirectional mobile robot considering time consumption in obstacle bypass

为保证移动机器人动态环境下的运行安全性,须结合轨迹重规划实现实时绕障;针对路径重规划会带来额外的计算负担、难以保证控制系统实时性的问题,为实现高效高精移动机器人运动控制,提出考虑绕障时耗的四轮全向移动机器人轨迹跟踪控制器.首先,将参考曲率引入四轮全向移动机器人的跟随误差模型,对控制时域和预测时域进行动态优化,提高弯曲复杂路径的跟踪精度;在此基础上,分析控制时域与重规划时耗的映射关联,设计自适应步长的调节策略,提升绕障模式下的控制实时性.测试结果表明:与比例-微分(PD)控制和传统滚动时域控制相比,所提出算法考虑绕障过程的跟踪控制性能更好,实时性更优.

To ensure the working safety of mobile robot in dynamic environment,it is necessary to realize real-time obstacle avoidance using trajectory replanning.However,path replanning leads to extra computational burden,which makes it difficult to ensure the real-time control performance.To achieve high-efficiency and high-precision motion control of the considered mobile robot,a trajectory tracking controller considering the time consumption around obstacles was proposed for the four-wheel omnidirectional mobile robot.Firstly,the reference curvature was integrated into the error model of four-wheel omnidirectional mobile robot,and the control horizon and prediction horizon were dynamically optimized to improve the control accuracy when tracking complex curved paths.Then,the correlation between control time domain and replanning time was analyzed,and the adaptive step adjustment strategy was designed to improve the real-time control performance in the obstacle avoidance mode.The test results show that,compared with proportional-derivative(PD)control and traditional rolling time domain control methods,the proposed one has better control and real-time performance when considering obstacle avoidance.