Research On Cnc System Of Finishing Machine Toolfor Hemispherical Resonator Based On UMAC

Hemispherical Resonator Gyro (HRG), invented in1960s, is a new type ofvibration gyro based on the principle of Coriolis Effects. As a hot academicresearch subject not only in China but also throughout the world, HRG is widelyapplied in the fields of aeronautics and astronautics, national defense andmilitary, geochemical prospection and so on, with the advantages of highprecision, long service life and steady working condition. Hemisphericalresonator is the core component of HRG, its machining precision and surfacequality directly determines whether the technology of HRG in our nation coulddevelop towards the goal of high precision, inertial stage and practicalapplication. Therefore, to develop the numerical control system for the finishingmachine tool for hemispherical resonator which can realize the function ofmachine tool and satisfy the requirement of machining, has a significant meaningin realizing HRG ultra-precision machining in order to improve domestic HRGperformance.This thesis studied relative parameters, online command and secondarydevelopment theory of UMAC motion controller, which has established thefoundation of numerical control software design. Based on numerical controlsystem hardware platform, the communication principle of the host and slavecomputers in open numerical control system was studied. According to thepractical machining requirements, system software functions were mapped out.Under the Visual C++language compilation environment, the host computercontrols software was developed, with functions of motor condition display,control command input, motion program control and manual feed adjustment. Asimple and friendly user interface was also designed accordingly.Via study of the adjustment principle of servo system PID parameter,experimental adjustment and determination of relative control parameter of servosystem based on step signal response and parabolic signal response, the controlperformance of individual axial motor was improved and the following errors ofthe system was also reduced. The system positioning error of each motor wasachieved via laser interferometer. According to the theory of softwarecompensation, the compensation value of positioning error was computed and therelative compensation table in UMAC was established, resulting in theaccomplishment of positioning error compensation. Where, the initial positioningerror of X axial is±15μm, which became into±0.6μm after compensation.Via comparison, the tool path of the finishing for hemispherical resonator was analyzed. With UG NX numerical control machining software, the tool pathwas designed in combination by plotting, moreover, the numerical control G codefor practical polishing machining was also generated. Through machiningsimulation with VERICUT, the machining simulation of numerical program wasrealized after the machine tool model was constructed. Thus the possibility andvalidity of the code were proved. Circle, curved surface and hemisphericalresonator was finished following with the validity proof of numerical controlmachining performance, at the same time, the validity of the tool path wasfurther tested and confirmed.This thesis mainly aims at the numerical control system software design offinishing machine tool for hemispherical resonator, PID parameter adjustment ofservo system, positioning error compensation of motors, design of tool path ofhemispherical resonator and simulation and validity confirmation experiment,which has important referential significance in the research of open numericalcontrol system as well as practical significance to the ultra-precision machiningof HRG.