Application And Implementation Of Position And Attitude Controller For UAV Flight Control System Based On Real-time Operating System

With the progress of science and technology in China in recent years,the application of UAV in various industries is expanding rapidly.Therefore,UAV ascends the stage of China's science and technology industry development quietly whether it's military level or civilian consumption level.The in-depth study of UAV flight control system has arisen with the growth of demand for UAVs in all walks of life in today's Society.In such an environment of development.In this paper,Four-rotor UAV is taken as the research object to achieve position and attitude controller of Four-Rotor UAV Using Cascade PID Control Based on Real-time Operating System.Therefore,this paper describes the implementation steps as follows: Firstly,the dynamics model of UAV is built based on Newton-Euler method,and the feasibility of the scheme is explained theoretically for the follow-up implementation.Secondly,the realization principle of UAV position and attitude controller based on cascade PID control is explained theoretically.Because the essence of attitude change of UAV is attitude angle change of UAV,and angle change will inevitably accompany angular velocity change.Therefore,angular velocity loop is added to the single-stage PID control of angle control to stabilize the direct control quantity.The controlling of position control is divided into two categories: vertical and horizontal control loops.Vertical control is a cascade PID position controller based on height and vertical speed loop.Besides the horizontal position is composed of a cascade PID position controller composed of horizontal position and horizontal speed loop.Then,the nonlinear equations of UAV dynamics need to be linearized by the LPV method In order to get the transfer function of UAV power system.And constructing simulation of the attitude controller of UAV Based on cascade PID control model with linearized system transfer function after that.The Matlab/Sinmulink based simulation experiment is used to compare the single level PID used in traditional UAV attitude control.And the attitude controler of this algorithm is verified by comparing the control response time with the steady-state error.In the end,software design and flight datameasurement for attitude and position controller of "Flight F450" UAV with "cursor" flight control board should be done after the design and Simulation of attitude and position controller.So we can further summary of cascade PID control algorithm applied to UAV attitude and position controller's actual effect and advantages and disadvantages analysis.Finally,it is found that the control effect of cascade PID control algorithm has good data performance in response sensitivity and steady-state error of the controlled object.For example the angle and angular velocity are stable near the expected value in 0.5 seconds from the beginning of error.And the error of roll and pitch angle is less than 0.05 degrees,and the yaw angle error is less than 0.1 degrees.Beside,in the position controller,the height control effect of UAV achieves a maximum overshoot of 0.1M and an average response time of 0.2s which means it has good control effect for the UAV with the fastest speed of 60Km/h.Thus we can see that the position and attitude controller of UAV based on cascade PID control algorithm can produce good control effect for basic flight operations such as hovering and directional movement of consumer UAV,and it has high value of research significance and broad application prospects.