Research On Parallel Drive Vibration Assisted Swing Turning Device And Its Key Technologies

Elliptic vibration cutting(EVC)technology has made great progress in recent years,but the residue-height of the tool between adjacent tracks cannot be eliminated,which limits the further advance of machining accuracy.The residual-height can be reduced by increasing the vibration frequency of the cutting but brings additional motion and the increased control difficulty.Thus,it is necessary to propose a method that the accord with the advantages of EVC,and meantime overcome the disadvantage of EVC.We presented a new vibration assisted swing cutting(VASC)method in this paper,which the main research contents are as follows:1)A new two-degree-of-freedom motion decoupling VASC device was designed,which is an L-shaped symmetrical parallel flexure hinge with decoupled drive and decoupled output motion.Meanwhile,in order to meet the practical application of VASC,considering the decoupling effect,kinematics,stiffness and dynamic performance,the optimal design was carried out.To obtain better structural performance,Pseudo-rigid-body model(PRBM),Matrix-based compliance modeling(MCM)and Lagrange method was applied to kinematics,stiffness and dynamic performance of the theoretical model,respectively.Then,the structural parameters were optimized by differential evolution(DE),and the theoretical modeling was verified by Finite Element Analysis(FEA).2)The related performance test was carried out on the developed VASC device.The VASC system was fixed on the optical air-floating vibration isolation platform Newport RS4000.The experimental system was mainly composed of VASC device,Capacitive displacement sensor,Power PMAC controller,Power amplifier and two parallel Piezoelectric actuators(PZTs).The main features of the test include sinusoidal response test,natural frequency test,hysteresis test,resolution test,maximum travel test and crosstalk test,ect.3)A newly improved differential evolution(IDE)algorithm was proposed to identify and optimize the Hammerstein-Wiener model parameters in VASC system.The IDE algorithm was used to transform the identification problem of the model into the optimization problem in the parameter space,and the optimal solution of the model parameters in the parameter space was obtained.4)VASC online processing experiment and verification.To avoid the influence of the internal microstructure of the material on the vibration marks.For typical aluminum alloy and brass materials,residual height test was carried out respectively to verify the proposed VASC turning method.Finally,by comparing the surface quality of EVC and VASC,it is verified that VASC effectively mitigates the residual-height during EVC processing.