一种球形滚动机器人纵向运动的控制策略研究

Study on Control Strategy for the Longitudinal Motion of a Spherical Rolling Robot

针对一种球形滚动机器人纵向运动的位置控制问题,提出一种基于有限时间滑模干扰观测器和双幂次组合函数趋近律的解耦滑模控制策略。所提出的控制策略不仅可以保证球形机器人的滚动性能,并且能够保持解耦滑模控制律的连续性。设计有限时间滑模干扰观测器对复合不确定性进行在线估计,并在此基础上得出机器人系统平衡摆角的估计。基于所得平衡摆角的估计,分别定义系统的各级滑模变量。借助所设计的有限时间滑模干扰观测器,基于第二级滑模变量和双幂次组合函数趋近律构造解耦滑模控制律。从理论上证明了所提出的控制策略能够确保各级滑模变量收敛至0,仿真实验结果验证了所提出的控制策略的控制性能和鲁棒性。

A decoupled sliding mode control strategy based on finite-time sliding mode disturbance observer and double power combination function reaching law was proposed for the position control of a spherical rolling robot in longitudinal motion.The proposed control strategy can not only guarantee the rolling performance of the spherical robot,but also can keep the continuity of the decoupling sliding mode control law.A finite-time sliding mode disturbance observer was designed to estimate the system uncertainties on-line,and the estimation of the balance pendulum angle was obtained.Based on the estimation of the balance pendulum angle,the sliding mode variables of both levels were defined respectively.Using the designed finite-time sliding mode disturbance observers,the decoupled sliding mode control law was constructed based on the second level sliding mode variable and double power combination function reaching law.It is proved theoretically that the proposed control strategy can ensure the convergence of the sliding mode variables of both levels to 0.The simulation results verify the controllability and robustness of the proposed control strategy.