Research On Robustness Of Autonomous Flight Control Of Rotor Type Plant Protection UAV

The Rotor-Type Plant Protection UAV(RPP-UAV)has a wide range of application value and prospect in crop pest control because of its flexible maneuverability,high safety of operators,high operation efficiency and good terrain adaptability.However,due to the uncertainty of its own parameters,nonlinear and vulnerable to interference,the high stability,robustness and anti-interference of the control system of the RPP-UAV have become a hot and difficult research topic.In this paper,the robustness of autonomous flight control of FRPP-UAV is studied.The main contents are as follows:(1)Research on robustness of attitude Control of Four-Rotor UAV(FR-UAV).In order to enhance the robustness and immunity of FR-UAV control in actual flight,a attitude ADRC Algorithm(ADRCA)with real-time feedback compensation for time-varying parameters and external disturbances is designed.The algorithm simulation model is established by using Matlab/Simulink toolbox,and the digital simulation experiments of attitude stability,height tracking and control robustness are designed,and the simulation experiments are compared with those of Cascade PID(CPID).The results show that the convergence of each channel controlled by ADRC is stable within 1.5 s,which meets the control requirements of stable flight of FR-UAV,and the dynamics of altitude tracking experiment.The tracking effect is stable and there is no overshoot,which is superior to CPID.in the control robustness experiment,ADRCA has strong robustness to the dynamic change of its own parameters.(2)Research on robustness of attitude Control of FRPP-UAV.Firstly,the structural characteristics of FRPP-UAV are analyzed,and the liquid-filled drug box model of FRPP-UAV is analyzed in detail.On this basis,the nonlinear dynamic time-varying model of FRPP-UAV is constructed.The differences and control difficulties between FRPP-UAV and FR-UAV are analyzed.The CPID and ADRCA are designed for the constructed model.Thealgorithm simulation model is constructed by Matlab/Simulink,and the digital simulation experiment is designed and compared.The results show that both control algorithms can stabilize the flight attitude of FRPP-UAV.There is no overshoot control,and the convergence speed of CPID is faster than that of ADRCA,but ADRCA has better dynamic tracking and robustness than CPID for large range parameter variation of FRPP-UAV.(3)Research on robustness of autonomous flight trajectory tracking control for FRPP-UAV.In this paper,the common spiral trajectory and cattle track of FRPP-UAV are analyzed,and the total trajectory length,variable frequency,coverage leakage rate and repetition rate of spraying between the two flight operations are compared in detail.Aiming at the trajectory control of FRPP-UAV,a Cascade ADRC Algorithm(CADRCA)is designed,and the trajectory tracking control experiment is carried out for the efficient cattle farming trajectory,and the simulation experiment is compared with the CPID.The results show that when the parameters of the FRPP-UAV remain unchanged,the two control algorithms can realize the FRPP-UAV without the change of the parameters of the FRPP-UAV.The tracking control of man-machine job trajectory,and the tracking speed of CPID is faster than that of CADRCA,but the control stability is worse than that of CADRCA.When the parameters of FRPP-UAV change,the CADRCA has better stability and stronger robustness.In this paper,the robustness of attitude and trajectory control of FRPP-UAV is studied,and the effectiveness and robustness of CADRCA are verified.It provides a certain reference for the study of control robustness of FRPP-UAV autonomous flight.