Vibration Suppression Method For High Speed Direct Drive Feeding System Based On Active Eddy Current Damping Control

The manufacturing industry is the cornerstone of the modern industry and the pillar of the national economy.The computer numerical control performance determines the level of manufacturing industry as the working platform.The linear motor is often used as the driver for high-speed and high-precision feeding.The direct drive has the advantages of fast response,high tracking performance and so on,which is the essential demands in high speed feed motion.However,the direct drive system is sensitive for disturbances due to lack of damping in the feed motion direction,which will affect the accuracy of the workpiece surface.In view of the above problem,an active variable damping vibration suppression method for feeding system is researched in this thesis.It will improve the performances of the direct drive feeding system,which is meaningful for the application of direct drive feeding system.Firstly,the double-sided active eddy current damper used as the vibration suppression actuator for the direct feeding system is developed.Analyses of the proposed damper are conducted with the analytical method and finite element analysis method,which are all feasible for analyzing the characteristics of the active eddy current damper.Secondly,the factor that impacts the performance of the eddy current damper is investigated based on the proposed analyses.The optimization method of the damper based on the Taguchi method and permanent magnet redistribution is proposed to improve the amplitude or the linearity of the damper force.It is validated that the active eddy current damper functions well for suppressing the vibration of the feeding system based on the force-hammer excitation method.Then,an experiment platform and theoretical model of the direct drive feeding system based on the eddy current damper is established.It provides a platform for the design and verification for active damper vibration suppression method.The control strategy for the systems based on PID control is proposed.An active subsection damper controller is designed according to the feeding motion process,which can suppress the overshoot effectively.In order to achieve good adaptability control,an active sliding mode variable structure damper controller is proposed.For saking of improving the performances of the direct drive system based on the eddy current damper,the variable structure controller is combined with subsection controller.The active subsection sliding mode variable structure damper controller is put forward,and its feasibility validated via simulation and experiment.