| Nowadays,information technology develops rapidly.The Internet and artificial intelligence are maturing.The uav(unmanned aerial vehicle)play an important role in agriculture,commerce and the military.The vast number of requirements associated with rotary-wing drones are increasingly complex.Therefore,the quadrotor has become a hot topic for many universities and companies to study.Quadrotor is a new type of unmanned aerial vehicle with low cost,good control and wide application.The core technology of the quadrotor is the flight control system.The flight control system with high stability and low coupling is the focus of the research of quadrotor.Simulation technology has developed rapidly in recent years.Simulation technology is an important means to analyze the system behavior and reveal the system motion law.Semi-physical simulation is more realistic than full-digital simulation.Semi-physical simulation is an important method to improve the efficiency of flight control system of quadrotor.The design of the quadrotor flight control system should consider not only the stability of quadrotor,but also the influence of the external environment.Because of its light weight,the quadrotor often deviates from its normal flight position and flight attitude under the action of natural wind.The natural wind even affects the safety of flight.The simulation of natural wind mostly adopts local area measurement method,which is not universal.The full digital simulation of quadrotor is not good for researchers to find problems,and the cost of physical simulation of quadrotor is high.Aiming at the above problems,this paper has obtained the following results:1.This paper proposes the construction method of the digital model of natural wind.After studying the characteristics of natural wind,the natural wind model was constructed by combining basic wind,gradient wind,gust wind and random wind with MATLAB/Simulink tool.The natural wind model is the disturbance factor of quadrotor flight control system.2.In this paper,genetic algorithm is used to optimize the PID(Proportion Integral Derivative)controller.After comparing the difference between expected data and actual data,the fuzzy rules are optimized.3.This paper presents a method to construct a semi-physical simulation platform for a quadrotor.In this paper,six degrees of freedom turntable and MPU6050 attitude measurement sensor are used as the core components.The classical PID controller,fuzzy PID controller and optimized fuzzy PID controller are compared and tested by semi-physical simulation platform.The experimental results show that the natural wind model established in this paper accords with the characteristics of natural wind.Under the disturbance of natural wind model,the quadrotor flight control system optimized by genetic algorithm can make the quadrotor flight attitude more stable than the classical PID controller and fuzzy PID controller.The flight control system of quadrotor developed based on semi-physical simulation platform can reduce the actual flight debugging time through flight software simulation.Semi-physical simulation flat lift through hardware simulation to enhance the authenticity of debugging.Therefore,the semi-physical simulation platform is a good method for the development of quadrotor flight control system. |
