Research On Optimizing Route Control Of Plant Protection UAV Mountain Operation

The area of hills and mountains in my country accounts for about 67%.The area of economic crops in the mountains is vast.Traditional machinery is difficult to work in the mountain environment due to topographical restrictions.The plant protection operation consumes a lot of manpower and material resources.In recent years,multi-rotor plant protection UAVs have gradually replaced human plant protection operations due to their high operational efficiency and flexibility.Plant protection UAVs need to ensure that they are flying at a stable altitude within 0.5 to 3 meters from the crops during work.To ensure a better spraying effect,but the mountain environment is complex and changeable,plant protection drones need to retain a large amount of safety redundancy in order to ensure safety,which leads to a large deviation in height control and reduces the spraying effect.Aiming at the pain points in the operation of plant protection drones in complex mountain environments,this thesis proposes a mountain operation system consisting of three parts: 3D mapping and model reconstruction,3D route planning,and plant protection drone control algorithms for complex mountain environments.The relevant key algorithms are deduced,and the reliability of the system scheme,the accuracy of the route optimization algorithm and the spraying effect of on-site mountain operations are verified through experiments.This article mainly conducts research from the following aspects:(1)Design of optimization algorithm for plant protection UAV mountain route controlThis thesis proposes a complete set of plant protection UAV mountain environment operation solutions based on 3D mapping and reconstruction to generate high-precision routes and highprecision positioning equipment,combined with the targeted upgrade of plant protection UAV control algorithms.In terms of 3D surveying and reconstruction,this thesis designs the mountain 3D surveying and mapping route generation algorithm and the mountain 3D reconstruction terrain correction algorithm for the mountainous complex terrain.In the 3D route generation,this article aims at the route planning algorithm in the irregular area with obstacles,and combines the 3D reconstruction model to extract the terrain height to realize the 3D route extraction algorithm.In terms of plant protection drone position control,this thesis combines high-precision positioning equipment to propose a mountain position estimation algorithm based on the Extended Kalman Filter algorithm,and proposes a cascade fuzzy PID height control algorithm based on slope and a real-time threedimensional space ladder for mountain undulating routes.Arrival criterion algorithm and route control algorithm of dynamic segment slope forward-looking algorithm.(2)Mountain operation system designBased on the overall plan of mountain operation,this thesis completes the construction of mountain operation platform and software design.The operating platform is divided into two parts:the surveying and mapping system and the plant protection drone platform.The DJI MARRICE 600 PRO flight platform is equipped with a Zenmuse X5 gimbal camera to complete the 3D surveying and mapping image collection.The Zhonghaida i RTK high-precision positioning system is used to provide high-precision position data.AG-1 plant protection drone platform for plant protection operations.For the special operating environment in mountainous areas,the software design of mountain surveying and mapping route and image reconstruction software,the software design of the extraction software of irregular 3D route with obstacles,the real-time height estimation based on the extended Kalman filter algorithm combined with RTK data and the software design of cascade fuzzy PID height control software have been completed.,And designed a position control failure protection software that may occur in an emergency state to ensure the safety of plant protection drones,and build a complete mountain operation system.(3)Carry out experiments to verify the accuracy of mountain route controlIn this thesis,six experiments have verified the accuracy of plant protection UAV mountain operation route control optimization.The RTK positioning accuracy experiment verifies that the RTK positioning accuracy in the mountainous terrain with obstacles and undulating environment meets the requirements of mountain operation accuracy and reliability under the condition of selecting a reasonable erection site.Designed 3D terrain reconstruction experiments to verify the reconstruction accuracy,and obtained 93.5% of the control points with height errors within the range of 0.3～0.6meters.Designed the route planning accuracy verification experiment,and detailed the process of extracting the 3D route from the 3D model.The route planning accuracy is absolute.The value is within 0.3 meters,and the accuracy of 3D mapping and route planning meets the requirements of mountain operations.Based on simulation technology,the slope-based cascade position fuzzy PID algorithm proposed in this thesis is simulated,and it is verified that the controller can improve the dynamic performance of the plant protection UAV and reduce the overshoot and response time.Next,this article simulates a typical route in a mountain environment,and conducts a large number of tests on plant protection drones at different operating speeds and different operating slopes.The data of more than 1,200 test waypoints are collected.The final data shows that the altitude control accuracy within ±0.3 meters is 97.05%,and the height accuracy control effect meets the operation requirements in the complex mountain environment.Finally,this article carried out a field plant protection drone operation effect verification for a typical mountain tea garden environment.The water-sensitive thesis test showed that the amount and coverage of the crop are evenly distributed,which meets the requirements of plant protection operations for the effect of the medicine.