Research On Fault Diagnosis And Fault-tolerant Control Of The Servo System In Unmanned Aerial Vehicle

The rapid development of UAV flight control system requires high reliability of servo system. Therefore, the reliability index of servo system is increasing. The traditional single-loop system is difficult to have new breakthroughs in mission reliability. The construction process of redundancy actuator servo system with core of TMS320F28335 is expounded in this paper.Firstly,the fault tree analysis method which belongs to the reliability engineering field is adopted to find the weakest link of the system.Through comparing different redundant model, an appropriate redundancy configuration scheme is selected. Then the working mechanism of its important component is analyzed, and the mathematical model is built. Thus, the mathematical model of the servo system is obtained. A three closed loop position servo system using the classic control theory is designed for the established model. And the waveform based on simulink is presented, which prove the designed controller is adapted to the control requirements.The influence of several fault forms on the servo system is studied. And a fault detection method based on the judgement of threshold is adopted in the redundancy servo system. The digital simulation demonstrate the effectiveness of the proposed method. In order to get a more accurate fault location, a fault diagnosis method based on wavelet transform and neural network is explored, and to some particular fault, it is effective. And the method for fault isolation and disposal is presented.Finally, the principle prototype and all the monitor circuit is designed, the adaptive parameters of the capacity and resistor is selected, the hardware is tested to make the servo system work normally. The software of the fault diagnosis modular is compiled and tested. The monitoring interface of the host computer is designed to observe the data when the servo system is in error state.