面向复杂曲面力控抛光的变阻抗控制研究

Research on Variable Admittance Control for Force-Controlled Polishing of Complex Surfaces

针对复杂曲面的力控抛光任务中同时控制刀具进给速度与接触力困难的问题,分析了在刀具期望进给速度与接触力方向时变场景下基于经典力位混合方法的柔顺控制算法难以控制的原因,提出了一种新的基于时变力位混合框架及自适应导纳控制的柔顺控制算法。使用工件轮廓曲率实时修正力位混合框架,减小进给速度与接触力控制之间的耦合影响,并使用接触力误差与力位混合框架修正速度来自适应调整导纳控制的阻尼参数。仿真验证了所提算法可解决传统算法在时变力位跟踪时的接触力不收敛问题,且所提自适应策略可进一步降低超过80%的接触力跟踪误差。

Aiming at the difficulty of simultaneously controlling the tool feed rate and contact force in the force-controlled polishing task of complex surfaces,analyze the reason why the force control quantity and the position control quantity interact with each other in the compliance control algorithm based on the classic hybrid position/force framework under the condition that the expected feed rate of the tool and the direction of the contact force are time-varying.Therefore,a new compliance control algorithm based on time-varying hybrid position/force framework and adaptive admittance control is proposed.Use the contour curvature to correct the hybrid position/force framework in real time to reduce the coupling effect between the feed rate and the contact force control.And use the contact force error and the framework′correction rate to adaptively adjust the damping of the admittance control.Simulation results show that the proposed algorithm can solve the problem of non-convergence of contact force in time-varying force/position tracking of traditional algorithms,and the proposed adaptive strategy can reduce the error by more than 80%.