Design Of Precision Platform Based On Double Closed-loop Feedback

In the modern industrial production, precision platform is applied to theaerospace, telecommunications, medicine, astronomy, military, wildlife researchand high-precision measurement technology. Precision positioning platform isessential for precision machining and production of precision instruments,precision platform determines the precision of measurements and accuracy in theproduction. It can be seen that precision positioning platform has a decisiveposition in high-precision instruments and sophisticated measurements. Thetechnical indicators of precision platform represent the national developmentslevel in the field of precision, is also an important gauge of national high-techdevelopment. From this practical problems in production, this study is based ondouble closed-loop feedback control method.it uses grating measurement andpiezoelectric ceramic actuator which makes the precision platform accomplishnanometer positioning.This design will use the ball screw with a wide range as the rail platform,step-motor as the driver, grating sensors for feedback, to build a macro-driveplatform. Entering the appropriate signal, the step-motor will drive ball screw,then the grate will detect actual displacement and send feedback signal to correctthe motor displacement accuracy. So that it can achieve a wide range and highaccuracy.The micro-drive platform use the piezoelectric ceramic actuator as the drivedevice, the signal processing circuit as the feedback device of piezoelectricceramic actuator. Using the converse piezoelectric effect of Piezoelectric ceramic,input signal can be converted to the corresponding actual displacement.Piezoelectric ceramics actuator tend to have higher accuracy, so that can improveaccuracy of the system. When the displacement signal is transmitted to thepiezoelectric ceramics actuator, a corresponding actual displacement will be made out. Then the signal processing circuit will send a feedback signal back tothe piezoelectric ceramic actuator until reaching the same displacement. Thencombine the two-tier stage system to achieve the design requirements of widerange and high precision of measurement and positioning.