Aircraft Dynamic Derivative Test System Research Based On MEMS Gyroscope

Stability and control problem is one of the key technology of aircraft design,dynamic derivative is an important parameter used to measure the stability of the aircraft. Wind tunnel free flight test can avoid the strut influence on dynamic derivative measurements; therefore, no interference effect of wind tunnel free flying derivative test technology is still in the exploration development.The purpose of this paper is to improve the current start with high-speed photography to obtain original attitude angle data, and then based on the model plane motion equation by using the method of maximum likelihood criterion to identify dynamic derivative. This paper designs an embedded test system based on MEMS gyroscope measure attitude angle movement, this paper researches the use of phase plane method to determine the derivative.First, on the basis of aircraft dynamic derivative test and its related techniques,using high-speed MEMS gyroscope and ARM micro controller as the processing core,the measurement precision, conversion rate and bandwidth, volume and power consumption have been completed, meeting the requirements of wind tunnel free flying derivative measuring overall scheme of testing system and hardware and software design of attitude. System adopts modular design technology, according to the functional test system hardware can be divided into angular velocity testing module, the automatic gain control module, the collection and processing module, wireless transceiver module, power management module, etc. The system uses assembly language mixed with high-level language programming to complete the system main function modules of software design. The test system hardware processing and the joint debugging of software and hardware have been completed.Second, the debugging and calibration of aircraft dynamic derivative test system has been completed. The test system uses of MEMS gyro servo turntable motor under the condition of multiple sets of different static calibration to collect different rotational speed gyro output and fits out of the gyro output motion model based on the least square method; Various error sources that affect the precision of gyro measurement are analyzed; According to the blank of inertia rate electromechanical system which could provide high frequency angular motion excitation, the system uses the linear servo motor speed way and gyro self-test function to test the frequency response of thegyroscope. Fading factor adaptive kalman filter is adopted to improve the gyroscope and accelerometer data fusion, obtain ideal attitude Angle of the dynamic response,ensure that the test system can be measured reliably used in wind tunnel free flying derivative.Finally, an angle/angular speed phase plane method which is different from the maximum likelihood method has been studied to identify dynamic derivative, using attitude angle movement data of aircraft dynamic derivative test to validate the method,the results show that, compared with the traditional maximum likelihood method,Angle/Angle speed dynamic derivative of phase plane method can quickly judge the polarity of the aircraft dynamic stability.