基于模糊PID的力/位混合控制机器人自动化叶片磨削加工

Hybrid Force/Position Control Method for Robot Automatic Grinding Blades Based on Fuzzy PID

针对机器人自动化航空发动机叶片磨削加工质量不高的问题,提出了一种基于模糊PID的力/位混合主动力柔顺控制。基于外部固定工具坐标的重力补偿算法解决了叶片重力对接触力求解的影响,根据坐标变换,完成接触力的精确感知。将机器人、工件和砂带轮简化成弹簧-阻尼二阶系统模型,利用最小二乘参数辨识方法建立系统模型。基于模糊PID的力/位混合力控制策略根据实际接触力与参考力的差值对离线编程轨迹进行在线修正,实现恒力控制。实验表明,相对于经典PID控制,基于模糊PID力/位主动柔顺控制算法可提高系统响应性能,降低稳态误差,改善系统鲁棒性,实现机器人自动化磨削加工过程的主动力柔顺控制。

The hybrid force/position active compliance control method based on fuzzy PID is proposed aiming at the problem of low grinding quality of robotic automatic polishing aero-engine blades.In order to solve the influence of blade gravity for the solution of contact force,a gravity compensation algorithm is proposed based on external fixed tool coordinate system.The contact force can be sensed by coordinate transformation.The system is simplified to a second order spring-damper system model by analysis of robot,workpiece and abrasive wheel.And the system model is established by least squares parameter identification method.Based on the proposed control strategy,the off-line programming trajectory is corrected by the deviation between contact force and reference force to achieve constant force control.The Experiments show that the force/position active compliance control algorithm based on fuzzy PID can improve system response performance,reduce steady-state error and improve robustness compared with traditional PID control to realize the active compliance force control for robot automatic grinding.