Research On Double Side Polishing Control Technology Of Medium And Large Diameter Optical Components

Ultra-precision machining is the primary means of obtaining ultra-smooth surfaces for medium to large aperture optical components.Nowadays,the traditional planetary double-sided polishing technology has been relatively mature,but such a processing method is only suitable for small-diameter optical components,and cannot meet the processing requirements of medium and large caliber.The ultra-precision machining methods of traditional medium and large-diameter optical components are all in the form of single-sided polishing,which has the disadvantages of long processing cycle and low surface precision.Therefore,the development of a double-sided polishing apparatus suitable for medium and large-diameter optical components is of great significance for shortening the processing cycle of medium and large-diameter optical components,improving the surface precision of optical components,and realizing mass production of optical components.In this paper,through the research on the polishing mechanism of medium and large diameter double-sided polishing machine,the main factors affecting the machining accuracy are obtained: the hardware structure of the electrical control system,the loading pressure control of the pneumatic control system and the motor control of the servo system.First,the performance of hardware devices and the connection between hardware devices seriously affect the real-time and effective control of the control system.Therefore,the selection of hardware and the design of the system in the electrical control and control system are important guarantees for achieving high-precision polishing.Secondly,during the polishing process,different loading pressures will have different processing effects.Therefore,the high precision and stability control of the loading pressure in the pneumatic control system is the primary prerequisite for achieving high precision polishing.Finally,the double side polisher removes the optical surface material by the relative movement between the polishing disk and the workpiece.Therefore,the stable operation of the motor in the servo system is the most important for achieving high-precision polishing.The following are designed for these three factors:1)The overall scheme of the electrical control system is designed.The control system of the SIMOTION D controller + distributed I/O module ET200 M with human-computer interface is developed,which realizes the modular design of the system,namely SIMOTION D controller and SINAMICS S120 driver.,servo motor and man-machine interface and other modules.2)The polishing pressure controller based on self-tuning fuzzy PID control is designed.Compared with the traditional PID control AMESim and MATLAB joint simulation results,it is verified that the self-tuning fuzzy PID control can effectively improve the stability and loading of the polishing pressure of the pneumatic control system.Precision and speed.3)The self-tuning fuzzy PID controller of the servo control system speed loop is designed.Compared with the traditional PID control Simulink simulation experiment,the servo system based on self-tuning fuzzy PID control is proved to have fast response speed,overshoot and small oscillation,and strong anti-interference ability.It is more suitable for complex systems with large hysteresis,large moment of inertia and strong coupling,which better guarantees the stable operation and polishing efficiency of medium and large diameter double-sided polishing machine.