Wang Aojie, Gao Guoqin, Li Xue
School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China.
Sensors (Basel). 2025 Mar 5;25(5):1584. doi: 10.3390/s25051584.
A fixed-time global sliding mode control with prescribed performance is proposed for the varying center of mass parallel robot mobile platform with model uncertainties and external disturbances to improve the global robustness and convergence performance of the model, and reduce overshoots. Firstly, kinematic and dynamic models of the parallel robot mobile platform with a varying center of mass are established. A reference velocity controller for the mobile platform system's outer loop is designed using the back-stepping method, which provides the expected reference velocity for the inner loop controller. Secondly, to improve the global robustness and convergence performance of the system, a fixed-time global sliding mode control algorithm in the inner loop of the system is designed to eliminate the reaching phase of sliding mode control and ensure that the system converges quickly within a fixed time. Meanwhile, by designing a performance function to constrain the system errors within the performance boundary further, the fixed-time global sliding mode control with prescribed performance is implemented to reduce overshoots of the system. Then, the Lyapunov stability of the proposed method is proved theoretically. Finally, the effectiveness and superiority of the proposed control method are verified by simulation experiments.
针对具有模型不确定性和外部干扰的变质心并联机器人移动平台，提出了一种具有规定性能的固定时间全局滑模控制方法，以提高模型的全局鲁棒性和收敛性能，并减少超调量。首先，建立了具有变质心的并联机器人移动平台的运动学和动力学模型。采用反步法设计了移动平台系统外环的参考速度控制器，为内环控制器提供期望的参考速度。其次，为了提高系统的全局鲁棒性和收敛性能，在系统内环设计了一种固定时间全局滑模控制算法，以消除滑模控制的到达阶段，并确保系统在固定时间内快速收敛。同时，通过设计性能函数将系统误差进一步约束在性能边界内，实现了具有规定性能的固定时间全局滑模控制，以减少系统的超调量。然后，从理论上证明了所提方法的李雅普诺夫稳定性。最后，通过仿真实验验证了所提控制方法的有效性和优越性。
