Research On The Mechanism Of Two-axis Stabilized Platform Based On MEMS Gyroscope

Stabilized platform system, which is used for isolating the airborne movement and external disturbance, eliminating the image jitter, ensuring the stability and the legibility of image, is a significant component of optoelectronic pod.This paper studies the construction of one kind of airborne optoelectronic pod which functions on the gyro stabilized platform, and a control model for the gyro stabilized sighting system is proposed later. The pod adopts a classical two axis closed loop servo system, which consist of speed loop as the inner loop and position loop the outer. The position loop uses a high-resolution optical encoder to sense the movement of the DC motor while a MEMS gyroscope gets the angular velocity correspondingly.The pod demands high standard for the controller design, due to its characteristic of great delay, nonlinear and requirement of high-precision tracking. Therefore, a PID controller is put forward to improve the control performance, then the Fuzzy control rules raised to adjust the parameters of the PID controller in real-time according to the working condition. The model simulation and experimental test show that the next one has a better performance.The control accuracy of the servo system depends on the accuracy of the MEMS gyroscope, which is the core component for the feedback control loop. This paper studies the error model of the gyroscope and analysis the main factor of the model. The environment temperature is one of the main error as it effects zero bias of the gyro and nonlinearity of the scale factor. So we make a compensation equation based on the temperature gradient and test proves its effectiveness. Another measurement error is the drift error. We put forward a Kalman filter and the result shows that it is effective feasible in filtering the gyroscope random drift error.