带扩张观测器的虚拟轴并联机构滑模控制  

Sliding Mode Control with a Extended State Observer for a Virtual Axis Parallel Mechanism

作　　者：江道根[1] 潘世华[1] 张慧[1] 朱蓉[1] JIANG Dao-gen;PAN Shi-hua;ZHANG Hui;ZHU Rong(School of Information and Intelligent Engineering,Ningbo City College of Vocational Technology,Ningbo 315100,China)

机构地区：[1]宁波城市职业技术学院信息与智能工程学院,浙江宁波315100

出　　处：《控制工程》2020年第4期733-740,共8页Control Engineering of China

摘　　要：针对多自由度虚拟轴并联机构动力学方程高度非线性、强耦合及运动过程中各种干扰而难以精密控制的障碍,在基于运动学名义模型基础上,运用扩张观测器光滑滑模控制算法,在关节空间中运用PVT轨迹插补策略,实现机构未建模动态与扰动信号补偿控制。为抑制滑模控制所固有的抖振缺陷,将一种非线性幂函数fal(s,α,δ)用于滑模趋近律的设计中,并将传统滑模切换面(s)改造成高增益连续滑模面s/(|s|+δ)。机构轨迹跟踪实验表明,该控制策略增强了系统鲁棒性,并且具有良好的稳态性能和动态品质。Aiaming at avoiding the obstacle on the the highly nonlinear and strong coupling as well as dynamic disturbance in the process of the movement of the multi degree freedom of virtural axis mechanism,this paper proposes the algorithm of smooth sliding mode control with a extended state observer based on the nominal kinematics model,which realizes the compensation control of the unmodeled dynamics and inhibition of disturbance signal.In order to decline the inherent trembling of the sliding mode control,the nonlinear power function such as fal(s,α,δ)is used in the approching law design and a new sliding mode surface s/(|s|+δ)is applied,which replaces the traditional sliding mode sruface(s).Simulation of the trajectory tracing shows that the algorithm can improve the robust performance,which achives the aim of the accurate steady-state performance and the good dynamic tracing performance.

关 键 词：并联机构 光滑滑模控制 扰动补偿 PVT插补 

分 类 号：TP241.3[自动化与计算机技术—检测技术与自动化装置]