Research Of Microscope Observed Living Organisms Based On Adaptive Fretting Platform

When microscopically observed on living organisms, since living organisms breathing, heartbeat, muscle vibration and other factors, often produce inaccurate focus. This requires microscopic living organisms as breathing, heartbeat and muscle tremor and micro displacement.Because of the depthof field in general biological microscope between0.5μm-100μm, so I can not manually controlled by an optical microscope fast and accurate adjustment. Here the differential astigmatic method is designed based on four-quadrant photodetector defocus detection system, and quick focus by LPMSM Fuzzy PID Control.Designed a differential astigmatic method defocus detection system, and analyzes the causes laser, cylindrical lens, and a four-quadrant detector error, the error made by the simulation analysis solutions.Focus on the fuzzy PID controller, through the input of fuzzy, build membership functions, establishment of fuzzy rules and fuzzy inference rules. Through the establishment of linear motor control system Matlab simulation model of fuzzy PID controller with PID controller performance for comparison, the fuzzy PID control strategy has better anti-interference ability and better dynamic and static characteristics.Designed to have the speed, the amount of defocus and the current loop of the DSP program, in which the amount of defocus and current closed-loop PID control belong, belong to fuzzy PID closed loop speed control, and through digital filter reduces the amount of defocus random white noise and interference, generate three-phase voltage PWM wave linear motor control.The experiment proved that, at40times magnification, the depth of focus of the microscope objective under0.91μmobtained accuracy of±0.8μmdefocus detection signal, the sampling frequency of120Hz. Experiment to achieve the intended goals, get a better experimental results.