Research On Multi-rotor UAV Stabilized Platform Control System

Multi-rotor UAV stabilization platforms are widely used.In the military field,they can perform reconnaissance tasks.In the agricultural field,they can record the color of the rice to determine the growth of the rice.In the transportation field,they can conduct on-site surveys of congested road sections.Remote control and more.Science and technology are the primary productive forces.Science and technology are strong and the country is strong.Improve the overall national strength to improve the international status.Therefore,military,agriculture,and transportation must be improved.Therefore,higher accuracy requirements for stable platforms are required.In this paper,a three-axis stable platform is used as the controlled object,and a multirotor UAV is used as the carrier.The following research work has been done on the dynamic model coupling,the carrier vibration affecting the boresight stability,and the missed target delay affecting the tracking accuracy:First,the servo system index parameters are formulated according to the target characteristics of the tracking target,and the appropriate mechanical structure frame is selected according to the characteristics of the carrier movement form and the consideration of accuracy and complexity.Combining servo system indicators,component error factors,and structural characteristics to select major components such as gyroscopes,magnetic encoders,and torque motors.Secondly,the mathematical model of the actuator is established,and the dynamic models of the three frames are established according to the principle of conservation of angular momentum.For the three-axis coupling system,the control is complex,the parameter adjustment is difficult,and it is difficult to achieve the desired accuracy.Therefore,a nonlinear feedback decoupling control strategy is adopted.After decoupling,it is equivalent to three single-input and single-output systems to achieve three frames The output of the axis is only related to the control amount of its own frame and has nothing to do with the control amount of other frames,and the feasibility of the decoupling method is verified by simulation.Then analyze the motion form of the multi-rotor drone.The forward movement,yaw,and elevation of the drone will generate corresponding disturbance forms,which will cause a variety of attitude disturbances.In order to compensate for the disturbances,an adaptive disturbance rejection control algorithm is adopted.The ADRC controller is designed and simulation experiments are performed to verify the effectiveness of the ADRC algorithm and compare it with the traditional PID algorithm.It shows that the ADRC algorithm has certain advantages in disturbance suppression and can effectively isolate the body.Disturb to achieve the stability of the boresight to meet the requirements of stable accuracy.Then analyze the impact of the off-target amount delay on the tracking accuracy.The delay will reduce the system bandwidth,reduce the phase margin,and even affect the stability of the system.Therefore,the current statistical model of the singer is used to establish the target characteristics.The H~∞ prediction filtering method compensates for the delay and compares it with the kalman prediction filtering algorithm based on the average acceleration model.By designing time-invariant delay and time-varying delay simulation,it shows that H~∞ prediction makes the system have higher tracking accuracy and can Effectively compensate for the missed target amount delay to meet the tracking accuracy index requirements.Finally,the hardware,software and algorithm implementation of the servo system are introduced.The test conditions are introduced.The disturbance amplitude and frequency of the carrier are analyzed,and the five-axis swing platform is used to simulate the motion characteristics of the carrier and the target.The swaying platform moves at a sine angle of 2 ° 3Hz,and the target moves at a sine angle of 10 ° 0.2Hz to simulate the tracking accuracy test conditions.After the test,the tracking accuracy is calculated to reach 1.0327 mrad.The target is stationary to simulate the stability accuracy test conditions.After the test,the three-axis gyroscope data is used to calculate the stability accuracy to 1.1468 mrad.