Research On Active Balancing Control System Of High-Speed Spindle

High-speed spindle is one of the functional parts of high-grade CNC machine tool,whose whole machine function depends on its performance to a large extent.The unbalance is the main factor leading to the vibration of high-speed spindle as a result of typical rotor-bearing dynamic system structure.As the core technology to solve vibration problem of machine tools,the active balancing control technology of highspeed spindle has become the focus of domestic and foreign scholars' research.Considering the inevitable time-delay in active balancing control of high-speed spindle.Therefore,this paper focuses on the unbalanced vibration of high-speed spindle and the time-delay of system.The main research contents are as follows:1.Constructing dynamic model based on time-delay rotor system with imbalance.Based on the strict positivity of transfer function and Lyapunov-Krasovskii function,the adaptive control law and the relevant stability theoretical criterion of the rotor system with time-delay are solved.2.The dynamic model of a single disk rotor system with time-delay is established.Based on the dynamic model,a strictly positive real system is built to satisfy the stability conditions of adaptive control system.Furthermore,a feedforward gain adaptive controller is successfully designed.Aiming at the balance control of rotor system under variable speed and constant speed,an improved active control method combining with adaptive control and PID control is proposed.3.In view of the complexity of high-speed spindle system,a dynamic model of flexible time-delay rotor system with unbalance is constructed.The vibration response expression of the high-speed spindle system with time-delay represented by multi-order mode superposition is derived by the standard modal analysis method.Then,the stability conditions of high-speed spindle system are proposed and the active balance controller is designed.Finally,the validity of the controller is verified by numerical simulation.4.According to the control principle of motor driven balancing head,a set of control system is designed using TMS320f2812 as main control chip.And a balancing control test-bed for high-speed spindle is built to debug hardware and software of the active balancing controller.