Research And Real-time Simulation Of Quadrotor Based On VxWorks Operating System

Because of its small size,able to hover,flexible,easy to operate,the quadrotor has become a hot spot.The quadrotor is a non-linear,strongly coupled and underactuated system,and its precise control is a difficult problem.As the core component of the quadrotor,the flight control system has a decisive influence on the flight quality.At present,the verification of the flight control system is mainly carried out under MATLAB / Simulink numerical simulation with the lack of hardware environment simulation,which is different with the actual flight.In the development process,the debugging is easily influenced by the weather,environmental constraints,so it's not easy to quickly change the control algorithm and parameters.This paper designs and realizes a semi-physical simulation platform for the quadrotor.The platform is based on the embedded real-time operating system Vx Works.The host computer,the simulation computer and the four-rotor flight controller are designed,and the flight controller is added as a part of the simulation circuit to improve the confidence of the simulation.Firstly,in order to realize the object of the semi-physical simulation,this paper deeply studies the control mode of the quadrotor,and establishes the nonlinear model of the quadrotor from the six degrees of freedom.A series of experiments were designed to identify the parameters in the nonlinear model.Using the graphic modeling tool Simulink,the quadrotor model is built in MATLAB,which provides the theoretical basis for the semi-physical simulation.Secondly,this paper analyzes the hardware and software platform and designs the overall structure of the semi-physical simulation platform of the quadrotor.The host computer is used in the simulation process control and the result showing.The quadrotor controller is used in the simulation circuit.The simulation computer adopts the VxWorks operating system to improve the real time of the object model solution.After linearization of the quadrotor object model,a cascade PID controller is designed.Furthermore,the Vx Works operating system is transplanted,and the simulation application is realized through modular design.The network communication between the simulation computer and the host computer is realized.The serial port communication is realized between the simulation computer and the quadrotor flight controller,then all the quadrotor semi-physical simulation platform is achieved.Finally,the quadrotor tracking static target is designed through vector field control.The basic performance simulation and surround tracking control simulation of the quadrotor are completed under MATLAB,and the controller is transplanted into the actual quadrotor.These simulations verified the effectiveness of the control algorithm.The algorithm is finally applied to the actual flight.The experimental results show that the hardware-in-the-loop simulation platform can be used in the design of the quadrotor flight controller.