Research On A Quadrotor With Public Security Functions

There are many disadvantages in traditional manual patrol and rescue, such as low efficiency, easy to miss the best relief time, due to the limitations of the sight of human, large-scale patrol can not be done, during the rescue process, rescuers are vulnerable and so on.Quadrotor with Public Security Functions is a good solution for the questions above, a quadrotor is in a high level of automation, can be widely used, the vertical lift and stable hovering characteristics of which overcomes the disadvantage of helicopter who has lots of requirements for taking off and landing, and has technical difficulty for stable hovering. In addition, its advantage of low-cost and easy-to-operate, provide a possibility for the quadrotor to be used throughout the country. This paper design and produce a quadrotor with the functions of obstacle avoidance, coordinates calibration, aerial photography and other public security functions based on the relative studies at home and abroad. The following works has been done in this paper:(1) According to the characteristics of actual work condition of a quadrotor with public security functions, this paper determine the overall mechanical design principles which is light weight, high strength. Based on the design principle and refer to the relative research, this paper designs the mechanical structure of quadrotor, and produces an experimental product.(2) In the research of control algorithm, since the quadrotor is an underactuated system with six degrees of freedom and four control input which is multi-variable, nonlinear, strong coupling and interference-sensitive, which makes the design of the flight control system very difficult. To achieve effective control of the quadrotor, this paper establishes its precise flight dynamic model based on the characteristics of quadrotor. Then the PID control studies have been done based on the motion characteristics of quadrotor, and ultimately determine the control parameters of PID control through the boundary conditions obtained by the experimental product. Finally, simulation analysis has been done in use of Matlab/Simulink tools, simulation results show that the system overshoot is small, steady-state error is almost zero, the response speed is fast, system simulation verify the effectiveness of the PID control.(3) In the research of flight control system design, the paper design ATmega644-based flight control system. Hardware of flight control system contends power conversion modules, sensor modules, motor control module, the wireless communication module, synchronous serial communication modules and other parts. According to the characteristics of quadrotor, movement control procedures is designed, and the program flow chart of the movement control procedures, and main flight control is given.(4) In the research of public security, the paper design of the aerial photo capabilities, obstacle avoidance functions, navigation functions, software and hardware design of the modules are given.(5) In the research of actual flying test, results of flying test of six degrees of freedom and perpendicular flying test show that:PID control method can effectively complete the flight control of quadrotor. Also proved ATmega644-based flight control system has good stability. Functional test results show that the quadrotor can basically complete the public security requirements.