Research On The Control System Of Large Scale KDP Crystal Polisher

Laser crystal is the core part of laser and ICF reactor.At present,KDP and YAG are widely used in laser crystal.With the rapid development of technology,new generation of optical components put forward higher requirements for laser crystals,and continuous polishing is considered as one of the effective means to solve the problem of polishing crystals with high quality and efficiency.Ultra-precision continuous polisher becomes the key factor of polishing laser crystals.The precision of main axle and the surface shape of polishing lap determine the quality of large-scale KDP crystal.Therefore,it is necessary to study the main axle with high smooth operation and evaluate the surface shape of polishing lap precisely.In this paper,integrated control system of measurement and machining is developed for the large scale KDP crystal polisher.The hardware structure is built and the software is compiled based on the software structure of LabVIEW enviroN·ment and Advantech application programming interface(API).Furthermore,the interface of the software is designed independently.It is aimed to design and realize the main axle control system and lap measurement control system based on actual engineering.The main research contents are as follows:(1)Combined with the actual situation of mechanical structure of the polisher,the hardware structure and software level of the control system are designed.It is based on investigation and comparison of similar ultra-precision polishing equipment at home and abroad.Moreover,design of the electrical control cabinet and the selection of key electrical components are completed,and the control system software is compiled with the UI interface designed.(2)Based on the three-loop control theory,the control level of the main axle system is designed,and the system is simulated and verified by the Simulink module embedded in MATLAB.The analysis and experiment results show that the speed rising time increases with the increase of velocity command,and the maximum fluctuation range of actual velocity is 0.54%,which meets the design requirements.In the process of CMP,results show that the maximum velocity fluctuation of the main axle motion unit is 0.64%,which can meet design requirements.(3)The lap measurement control system is designed.Mathematical model of the touchtrigger probe is established and the measurement error is analyzed.The best measurement parameters under the system are the velocity of 35 mm / min and the probe inclination of 30 °.The plan of lap measurement system is optimized,and the data processing system based on LabVIEW is used to process the measurement data.(4)The error compensation of the lap measurement system is carried out,and the results are compared with those of CMM.Results show that the error accuracy of the system is 6 ?m,which can meet the design requirements,and the flatness of the lap is 22 ?m.The developed control system of the large scale KDP crystal polisher has the ability of continuous polishing.