摘要
研究了全状态约束与输入饱和情况下的全向移动机器人轨迹跟踪控制问题.首先,针对一类三轮驱动的全向移动机器人,考虑系统存在模型参数不确定与外部扰动,建立了运动学与动力学模型;其次,利用障碍Lyapunov函数,结合反步设计方法,有效处理全向移动机器人跟踪过程中存在的状态约束,保证所有状态变量不会超出状态约束的限制区域;然后,针对系统参数不确定和未知有界扰动,设计相应的自适应律进行处理;同时,提出一种抗饱和补偿器保证机器人输入力矩满足饱和约束;并且利用Lyapunov理论分析证明了当选取合适的控制参数时闭环系统中的所有信号均能保证一致有界;最后,通过与未考虑状态约束和输入饱和的控制器以及经典比例-微分控制器进行仿真对比,验证了该方法的有效性和鲁棒性.
The omnidirectional mobile robot(OMR),which is different from the two-wheeled differential drive mobile robots,can achieve three-degree-of-freedom motion in a plane with no non-holonomic constraint.Therefore,this type of robot has been widely used in many fields owing to its superior maneuverability and controllability.In practical applications,the trajectory tracking problem of the OMRs is a key issue that requires an urgent solution.The challenges with respect to the tracking performance can be categorized into the following:first,the parameter uncertainty of the OMR model and external disturbances affect the accuracy of the control.Second,on account of the limited workspace and the security requirements,the positions,attitudes,and speeds of the OMRs are subject to state constraints during the tracking process.Finally,the limited capability of the actuators can lead to input saturation,which will further degrade the tracking performance or even result in failure to track the desired trajectory.Thus,this study investigates the trajectorytracking control problem of the OMRs with full-state constraints and input saturation.The kinematics and dynamics for a class of threewheeled omnidirectional mobile robots were presented with the model uncertainties and external disturbance.Moreover,the barrier Lyapunov method was applied to handle the state constraints using the backstepping technique so that none of the state variables violated the restrictions.Meanwhile,adaptive control laws were designed to deal with the parameter uncertainties and unknown bounded disturbance.Moreover,an anti-windup compensator was adopted to ensure the input torque of the robot met the input constraints.The Lyapunov theory was used to prove that all the signals in the closed-loop system were uniformly bounded when the control parameters were selected suitably.Finally,using numerical simulations,the proposed robust adaptive controller was compared with other controllers,and the results verify the effectiveness and robustness of the proposed method.
作者
郑文昊
贾英民
ZHENG Wen-hao;JIA Ying-min(School of Automation Science and Electrical Engineering,Beihang University,Beijing 100191,China)
出处
《工程科学学报》
EI
CSCD
北大核心
2019年第9期1176-1186,共11页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(61327807,61521091,61520106010,61134005)
国家重点基础研究发展规划资助项目(2012CB821200,2012CB821201)
关键词
全向移动机器人
跟踪控制
自适应控制
状态约束
输入饱和
omnidirectional mobile robot
tracking control
adaptive control
state constraints
input saturation
