Research And Design Of The Flight Control System For A Subminiature Unmanned Helicopter XZ03

In this paper, the flight control system for sub-mini unmanned helicopter was discussed. The key technologies were introduced and some research work of Shanghai University about unmanned helicopter was presented. Sub-Mini Unmanned Helicopters with the flight control system can perform aggressive maneuvers, its good performance and action as a flying robot and can be used in some particular circumstance.Before designing the FCS, the Model Analysis of vibration for subminiature unmanned helicopter should be researched. The software named CATIA is used to modeling and analysis for the subminiature unmanned helicopter. Some vibration experiments are also engaged to amend the result of the analysis. Comparing the result of vibration experiment with the data of CATIA modeling analysis; the values of nature frequency were accordant. From these results, it could be found that amplitudes of vibration on the bottom, main shaft and the upside of the helicopter are larger than other positions. For this reason, the frame of the helicopter had been strengthened, which improved the working condition of the sensors on the helicopter.To accomplish a control algorithm, a settles of dynamic equations must be modeled. As to work accurately out the dynamics model, the interference of wind could be taken into account.Then the amendatory ARX modeling based system identification algorithm should be used. Accordingly, the circuit for sampling to the manipulating channel and the response of pitch/ roll /yaw was made. Based on the experimental data of the test flight of the rotorcraft, the mathematical model structure, the identify model parameters were calculated finally. The result would be precise.Unmanned helicopter flight control system must have the ability to ensure attitude and altitude controlled. Based on the result of system identification, some amendatory PID and fuzzy algorithm were used for FCS. And the results of these research show that the it reached desired control effects.Unmanned helicopter have a planned reference trajectory and a feedback controller to accomplish the task of traveling from a launch point to a goal point. Differential GPS and IMU had been used, and a general methodology for finding feasible and approximately optimal trajectory without violating the state and input bounds equally was researched.On the basis of the above research, the hardware of the FCS is designed. The analog and digital signal interface circuits and remotely control / automatic control switch circuits are worked out, and the resources of MCUs in the hardware system are configured. The flight control system consists of sensor unit, flight control unit board, and wireless modem. Sensor unit includes 2 axis tilt sensor and 3 axis angular velocity gy- roscope which ensures flight stability in all phases of flight, and it also contains altimeter, compass, and is combined with a GPS (globe positioning system), which work for navigation. Wireless modem continuously transmits navigation and operational data between the Ground Control Station and FCU.Compared to some other hardwares of unmanned helicopter FCS, this hardware developped in papers has some advantages in configuration of sensors, performance of processors, low power asumption, small size and low weight.Ground Control Station (GCS) is mounted in a shelf and consists of a notebook computer, 7-inch monitor, a joystick, antenna, and interface circuit. Then the human-machine interface of the GCS is also developed in VB environment.Finally, the flight experiments are carried out; the results of the test proved that the autonomous flight of subminiature unmanned helicopter has been achieved.