喷砂除锈并联机器人无模型自适应实数幂非奇异终端滑模控制

Model-free Adaptive Real Power Nonsingular Terminal Sliding Mode Control of Sandblasting and Rust Removal Parallel Robot

为获取既能全面反映动力学特性,又能实现实时控制的Stewart并联机构动力学模型,设计一种Stewart并联机构动力学模型的时延估计方法,在线获取其动力学模型;为解决喷砂除锈并联机器人系统中存在的不确定性问题,设计一种Stewart并联机构无模型自适应实数幂非奇异终端滑模控制算法,通过将终端滑模面参数的指数幂由分数幂推广到实数幂,放宽滑模面参数取值范围,并且实现在有限时间内收敛,以提升Stewart并联机构控制的鲁棒性。通过设计一种基于滑模变量实时快速调节切换增益的自适应律,以提升系统对主动关节伸缩运动和负载作用力变化的自适应性,同时削弱滑模控制抖振。采用Lyapunov稳定性理论证明该控制方法的稳定性,并通过仿真实验证明了该控制方法的有效性。

To acquire the dynamic model of Stewart parallel mechanism,which can fully reflect its dynamic characteristics und fulfill realtime control,a time-delay estimation technique of the dynamic model of Steward parallel mechanism is designed to acquire its online dynamic model. To solve the uncertainty in the system of sandblasting and rust removal parallel robot,a model-free adaptive real power nonsingular terminal sliding mode control method of Stewart parallel mechanism is designed,the range of sliding surface parameters are broadened,by extending the exponential power of terminal sliding mode surface parameters from fractional power to real power,und realize the finite-time convergence,to improve the robustness of Stewart parallel mechanism. Furthermore,an adaptive law based on the sliding mode variables is designed to adjust the switch gain quickly in the real time to improve the adaptability of the system for the retraction of the active joints and the change of the load force,und weak the chattering caused by sliding mode control. The stability of the proposed control method is proved by Lyapunov stability theory. Simulation and experimental results show the effectiveness of the proposed control method.