基于干扰观测器的级联气动肌肉肘关节滑模控制

摘要

The design and control of elbow joint are the research priorities of humanoid arm.To obtain the elbow joint model,a test platform is constructed for static modeling of a single pneumatic muscle,and then a nominal model of cascade elbow joint is established.The least square parameter identification is used to obtain the parameters of model.A sliding mode control law is designed based on Luenberger disturbance observer.The elbow joint location tracking with proportion integration differentiation (PID) control,sliding mode control (SMC) and sliding mode control based on disturbance observer (SMCDO) are simulated.Three control algorithms are tested by taking half a bottle of mineral water held at the end of humanoid arm as a load and uncertain outside disturbance.The simulated and experimental results show that the location tracking accuracy and robustness of sliding mode control based on disturbance observer are better than those of sliding mode control and PID control.%肘关节的设计和控制是仿人手臂的研究重点.为了得到肘关节的模型,首先搭建测试平台对单根气动肌肉进行静态建模,再建立级联式肘关节的名义模型,采用最小二乘参数辨识得到模型的参数.基于Luenberger干扰观测器设计了滑模控制律.分别采用PID控制、滑模控制和基于干扰观测器的滑模控制对肘关节位置跟踪进行仿真和实验,在仿人手臂末端夹持半瓶矿泉水作为负载和外界不确定性干扰,测试3种控制算法的性能.仿真和实验结果表明,基于干扰观测器的滑模控制位置跟踪精度和鲁棒性均优于滑模控制和PID控制.