摘要
针对传统滑模观测器在执行器故障重构中出现的精度低、抖振大及渐进收敛等问题,将准连续高阶滑模控制思想应用于滑模观测器的设计中,提出了机械臂执行器故障重构方法。利用RBF神经网络逼近建模不确定部分和未知干扰部分,构建准连续高阶滑模观测器保证状态估计误差有界稳定,采用等效输出误差注入方法,在有限时间内完成对执行器故障的重构。选取双关节机械臂进行仿真验证,结果表明,准连续高阶滑模观测器能够使滑模运动在有限时间内到达滑模面,使状态估计误差和输出估计误差分别稳定在0.002 rad和0.004 rad/s范围内,进而重构执行器故障,执行器1和2的故障重构误差分别小于0.05 rad和0.02 rad,同时有效消除了抖振,提高了机械臂在实际应用中的精度和安全性。
This paper intends to propose a fault reconstruction method based on the quasi-continuous high-order sliding mode observer for the manipulator actuator system. As is known,in the traditional sliding mode observers,the estimation errors of the unmeasured state used to come about due to the low asymptotic convergence and some other corresponding defects,like the low accuracy or high chattering in the reconstructed actuator. In response to the above problems,we have first of all established a mathematical model of the rigid manipulator and analyzed the faults types of the actuator. Secondly,we have adopted a RBF neural network model to approximate its uncertainties and the unknown disturbances. Thirdly,taking advantage of the sliding surface of quasi-continuous high-order sliding mode observer,we have designed the observer gain so as to ensure that all of the state estimation errors can converge in the boundary of stability. Finally,we have also chosen a double-jointed manipulator and validated the method proposed via simulation. The results of our research and simulation prove that the quasi-continuous high-order sliding mode observer is in a position to make the sliding mode move and reach the sliding surface in a limited designated time. The state estimation error and the output estimation error can be made stabilized in a sphere of 0. 002 rad and 0. 004 rad/s,respectively.Thus,the method we have developed can promote the robustness of the system and improve the precision and safety of the manipulator in the actual application.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第6期2114-2118,共5页
Journal of Safety and Environment
关键词
安全工程
准连续高阶滑模观测器
等效输出误差注入原理
机械臂执行器
故障重构
safety engineering
quasi-continuous higher ordersliding mode observer
the equivalent output errorinjection method
manipulators actuator
fault re-construction
作者简介
米根锁，教授，从事计算机系统测控技术与应用研究，mgs643@126．com。
