The Research Of Semi-physical Flight Simulation System Of UAV Based On RTX

The flight control system is one of the core subsystems of the Unmanned Aircraft Vehicle(UAV).It consists of a sensor subsystem,a flight control computer and an actuator subsystem.The sensor subsystem is used to sense the real-time flight state of the UAV,and it also provides the source of information for flight control calculation;the flight control computer calculates the control command,based on the output of the flight state information from the sensor subsystem;the actuator subsystem converts the flight control computer output command into the rudder deflection(or position)of the face or other steering mechanism.Both the sensor and the actuator subsystem contain non-ideal factors,which could cause errors and increase the possibility of failure.These errors and faults seriously affect the control quality and even the function of the flight control system,posing a major risk to the flight safety of the drone.To study the effects of sensors and actuators on UAV flight,based on a typical UAV modal and the typical errors and faults of the sensor subsystem and the actuator subsystem,a set of RTX-based semi-physical flight simulation system based on RTX was built in the thesis.The impacts of the flight safety of the study was achieved by implementing errors to sensor and actuator,and injecting errors in the flight simulation system.The main research work of the thesis was as follows:At the begining,based on analyzing the research results of the flight simulation technology at China and abroad,a six-degree-of-freedom mathematical model of a certain type of UAV was established according to a certain UAV system which was studied;the data of the aerodynamics coefficients of the UAV was established based on the aerodynamics and aerodynamic torque calculated by the certain aerodynamics database of the UAV which was studied;the rigid body motion model of the UAV was established according to the dynamics principle and kinematics principle.The commonly used numerical solution methods were analyzed.The fourth-order Runge-Kutta method was used to solve the differential equation of the UAV's mathematical model,which layed a foundation for the flight simulation system.Furthermore,research on a certain type of UAV demand sensor was done.The GPS,accelerometer,gyroscope,airflow angle sensor and atmospheric sensor were studied,and the corresponding mathematical models were established.The non-ideal factors of the respective sensors were analyzed,and the model of the corresponding to the error was established.At the same time,research on a certain type of UAV actuator was done.The mechanism model of the actuator was obtained through the theoretical analysis;the transfer function of the actuator was obtained by the sweep test method;the non-ideal factors of the actuator were studied;the typical error and fault pattern of the actuator were analyzed and the corresponding model of the error and fault of the actuator was established.Moreover,the application method of RTX real-time system in real-time simulation system was studied.Designed and developed flight simulation software under RTX real-time system to realize sensor characteristics,actuator characteristics and simulation of a certain UAV model;completed the development of the control and display software under the Windows operating system;completed the real-time communication with RTX system and Windows system,and the semi-physical flight simulation system is set up.Finally,the function and performance of a certain kind of UAV's semi-physical flight simulation system were verified by flight simulation experiments.The results showed that a certain type of semi-physical flight simulation system contains normal functions and meets the design requirements in real time.The effects of sensor error,actuator error,and actuator failure on flight performance and flight safety of a UAV are determined by error and fault injection functions.