自适应阻抗控制在广义主动加载中的应用

 以并联六自由度机构为对象，研究了阻抗控制在广义主动加载中的应用。推导了并联六自由度机构广义力、单缸力和单缸位移之间的阻抗控制数学模型，并分析了稳态误差影响因素；设计了符合现有实验条件的模型参考自适应阻抗控制器(MRAC)，该控制器仅通过广义力反馈、单缸力反馈即可实现控制参数的在线修正,并由六自由度机构单缸位移反馈构成闭环控制系统。比较自适应阻抗力控制器和经典力控制器进行了广义主动加载仿真，结果表明所设计的控制器提高了系统动态响应能力，对环境刚度变化鲁棒性强，可以实现实验室条件下广义力的精确稳定跟踪。

Application of MRAC Based Impedance Control in Active Generalized Loading

The application of impedance control theory with 6 degrees of freedom (6-DOF) parallel manipulator is investigated for the purpose of generalized loading. The linearized impedance control model is derived, which explains the relationships among generalized force, cylinder force and cylinder displacement, and also helps to analyse the influencing factors of steady-state error. A model reference adaptive control (MRAC) based impedance controller is developed; and the related parameters can be adjusted according to the actual generalized force and cylinder force. Simulation of dynamic generalized loading are carried out to compare the performance of impedance controller with that of the classical PID controller, and the results indicate that the MRAC based impedance controller improves the response capability and robustness of loading system, and is capable to realize accurate and steady loading under laboratory condition.