Development Of Mutual Dragging Test And Test System Of Motorized Spindle Based On Direct Torque Control

Motorized spindle industry starts late in our country and the production technology is backward,both of these resulting in a poor reliability level and heavy reliance on imports.Motorized spindle is one of the main function unit of computer numerical control(CNC)machine tools,the development of CNC machine tools mach depends on the development of motorized spindle.Developing motorized spindle test and test system is one of the key parts of the development of motorized spindle industry.On the one hand,the test system can detect the spindle`s indicators before entering the market which means producers can expose fault early and improve the design and assembly.On the other hand,as one of the main functional units of CNC machine tool,the reliability of spindle can directly affect the reliability of CNC machine tool,the system can shorten the test cycle of reliability test and reduce the test cost.Therefore,the research of this test and test system is of vital importance.Combining with the current status of motorized spindle industry in our country,research hot spots and difficulties of the industry,based on the analysis of structure,working principle and test methods of motorized spindle,this paper focuses on the mutual dragging test system and it`s direct torque control(DTC)strategy.By applying the sliding mode control(SMC),effectively solves the problem of torque pulsation in DTC.This paper builds the mutual dragging test platform,and by using the sensors,builds the mutual dragging test systems.The main contents of this paper are as follows.1.Research of mutual dragging test of motorized spindle.On the basis of introducing the structure and working principle of the motorized spindle,this paper compares and analyzes different control strategies,shows that the DTC strategy has obvious advantages because of the direct control of flux linkage and torque.2.Direct torque control strategy and optimization.DTC queries the switch vector table which representing the working status of inverter,concludes the appropriate voltage space vector and directly controls the flux linkage and torque in stator coordinate system.This paper introduces the control principle of circular flux control and establishes the control block diagram of DTC.The traditional DTC may occur a huge torque pulsation because of the using of hysteresis comparator,by applying the SMC,this paper effectively solves the problem and builds the control diagram of this control strategy.In this paper,two kinds of DTC control strategies are simulated and analyzed in Matlab/Simulink simulation software.3.The construction of mutual dragging test platform and test system of motorized spindle.By applying the ACS-880 converter,dynamic torque speed sensor and other equipment,this paper builds the mutual dragging test platform.By using the Labview software,this paper builds the software control part of the platform.Then,this paper implements the monitor of three indicators including temperature,eccentricity and vibration.By analyzing the acquiring data from four kinds of working conditions,verifying the feasibility of the test system.In this paper,the development of mutual dragging test platform and test system of motorized spindle which can apply torque load to spindle in the reliability test and measure key indicators in the process,has practical significance.The platform and system not only provides the equipment for the reliability and comprehensive performance test of motorized spindle,but also provides a basic platform for further expanding test like applying axial and radial load,state identification and monitoring,motorized spindle fault mechanism identification and analying and so on.