四舵轮移动机器人分段预测路径跟踪系统研究

Exploring Piecewise Predictive Path Tracking Control of Four Steering Wheel Mobile Robot

针对四舵轮移动机器人路径跟踪特点,使用工控机、运动控制卡,基于Visual C++平台开发了一种移动机器人路径跟踪系统。针对四舵轮移动机器人构型,采用速度-几何法建立了机器人运动学控制模型。提出了一种基于最优控制的分段预测路径跟踪算法,避免了对所需参数进行试凑的同时,降低了车体远离目标路径情况下的距离偏差最大超调与纠偏总步数。路径跟踪实验表明,应用所提出的分段预测路径跟踪算法的移动机器人可以较好地跟踪目标路径,相比未使用分段预测路径跟踪算法的多步预测控制,其位置偏差最大超调降低了29.81%,达到35.563 mm,纠偏用时降低了38.10%,达到13 s,且定位精度达到11.292 mm、0.51°,可以较好地满足四舵轮移动机器人定位需求。

According to the path trackingcharacteristics of a four steering wheel mobile robot,themobile robot’s path tracking system was developed based on the Visual C++platform with an industrial computer and a motion control card.Based on the configuration of the four steering wheel mobile robot,its kinematics control model was established with the velocity geometry method.On this basis,a piecewise predictive path tracking algorithm based on optimal control was proposed.It not only avoids the trial of required parameters but also reduces the maximum overshoot of distance deviation and the total number of deviation correctionsteps when the vehicle body was away from its target path.The experimental results on path tracking show that the mobile robot using thepiecewise predictive path tracking algorithm can well track the target path.Compared with the multi-step predictive control that does not usethe piecewise predictive path tracking algorithm,the piecewise predictive path tracking algorithm reduces the maximum overshoot of position deviationby 29.81%,reaching 35.563 mm,the time for deviation correction by 38.10%,reaching 13 s,its positioning accuracy being 11.292 mm and 0.51°,better meeting the positioning requirements of a four steering wheel mobile robot.