Research On Attitude Control Strategy Of Spray Boom Of Plant Protection Machinery

Plant protection machinery can reduce the workload of workers and is widely used in large-scale crop management operations worldwide.Plant protection machinery is affected by factors such as complex field pavement environment,chemical liquid sloshing,and its own uncertain mechanical movement status,the spray boom is prone to undesirable tilting movements during the operation,which adversely affects the uniformity of pesticide spraying.This is especially serious for plant protection machines with long spray booms.Sometimes spray booms can even collide with the ground or crops and break,seriously affecting the operating efficiency.Therefore,studying the precise control of the spray boom attitude of plant protection machinery is conducive to improving the quality of pesticide spraying,and is of great significance for improving the modernization of plant protection machinery.In this thesis,a widely used pendulum boom active suspension system of plant protection machinery is studied in depth.Based on the analysis of the existing dynamic model,the inclination angle,angular velocity of the spray boom and the length change of the hydraulic cylinder are selected as the state variables of the system,and the state space model of the pendulum spray boom active suspension system is established.Taking into account factors such as modeling errors and changes in operating characteristics of the active and passive components in the spray boom suspension system in practice,a spray boom attitude tracking controller based on indirect adaptive fuzzy control method is designed for the uncertainties and time-varying parameters of the system.The input-output linearization transformation of the system’s state space model is carried out,and a fuzzy logic system is designed to approximate the suspension system model with uncertainties.The Lyapunov synthesis method is used to design the adaptive law for the adjusting parameters in the controller.The simulation proves that under the action of the designed indirect adaptive fuzzy controller,the pendulum spray boom active suspension system has excellent ground slope tracking performance and high tracking accuracy with good stability,adaptability and robustness.Considering that the indirect adaptive fuzzy controller may have inaccurate model approximation and the problem of slow convergence of adaptive adjustment caused by complex fuzzy logic system,the stochastic configuration network is used to take advantage of its fast and accurate learning approximation ability,and the mathematical model of the pendulum spray boom active suspension system is established.Then apply it to the controller to replace the original fuzzy logic system,and realize the offline learning and online application of the indirect adaptive fuzzy control method.The simulation verifies that the method makes the control process have smaller overshoot,less adjustment time and less error while retaining the performance of the indirect adaptive fuzzy controller.And the effect of the boom attitude tracking control of the plant protection machinery pendulum active suspension system is further improved.