The Research Of Piezoceramic Objective-lens Actuator Control System

Digital confocal microscopy technology is a new microscopy technology, which is based on ordinary optical microscopy, acquiring image slice sequence of biological cells, processing the images by mathematical deconvolution on the computer to get the high-resolution sequence images, and finally achieving the display of high-resolution of three-dimensional cell through three-dimensional reconstruction.In order to obtain precisely equal intervals of image slice sequence of the biological cells with the digital confocal microscopy techniques, we need to drive the tens nanometers of the relative micro-displacement between objective lens and the object stage to acquire the images. And driving the microscope objective lens by the use of control technology of piezoelectric ceramic can implement the relative micro-displacement between the microscope objective lens and the stage on high precision. Control technology is the core of the system for the sake of playing the characteristics of high precision and high response speed of the piezoceramic objective-lens actuator. This research focuses on the construct of the piezoceramic objective-lens actuator control system and its control technology. A piezoceramic objective-lens actuator control system which is applied to digital confocal microscopy system has been constructed, and a new control method based on the idea of offline optimization has been proposed.In this new control method, the optimization of the initial parameters is separated from the online real-time adjustment, and a genetic algorithm is used to complete the global optimization in the offline state in advance, thus reducing the online regulating time and the number of adjustment, and improving the response speed of the system. The initial parameters optimized are configured in fuzzy PID control to implement the in online and real-time adjustment and feedback control of the system. The experimental results in MATLAB environment show that this new control method can achieve the demand of control accuracy and response speed of the system. We carry out experimental testing on the hardware platform of the control system, the experimental results show that the control system can achieve high accurately and fast positioning control for piezoceramic objective-lens actuator, meet the control requirements of task.