Robust Control Of Spray Boom Suspension System With Pendulum Of Plant Protection Machinery

Agricultural production,as the cornerstone of social development and progress,has been playing an important role.And plant protection is one of the most vital parts in agriculture.To cope with the technical requirements such as the scale and precision of modern plant protection technology,large-sized plant protection machinery are widely applied.However,due to the serious lag in the research of large-scale plant protection machinery in China,it has greatly restricted the development process of modern plant protection.Thus,it is imperative to focus on large-sized plant protection machinery to promote agriculture plant protection technology stable and fast in the new era.During the use of the machinery,due to the complexity and variety of the condition in the field,the spray boom is liable to roll,jolt,and yaw,which will cause the boom to vibrate and deviate from the optimal application position and even collide with the ground.And the spray quality of application can be decreased sharply and also caused over-dose,under-dose,and even the machinery can be broken and cause bad effectsIn order to weaken the influences above,the standard of performance of the large-sized plant protection machinery is more and more stringent.In this thesis output angle control of the pendulum boom suspension system of plant protection machinery is mainly studied.In this thesis,a com plant protection pendulum suspension system used widely is selected and the its mathematical model is established based on Lagrange's second equation is studied.Taking the actual work requirements into consideration,the linearization processing in the modeling process and the losses changing of the parameters during the use of the machinery are fully considered.A robust output stabilization stabilizing controller based on optimal control is designed,and the quadratic stability of the closed-loop system is proved by Lyapunov stability theory.The robust controller designed can effectively control the boom angle of the plant protection machine on the MATLAB simulation experiment.In order to make the model description more accurate,the model is improved by introducing a first-order dynamic system to present the electro-hydraulic servo and the work requirements are changed.The spray boom is needed to track the slope of the field.Therefore,a robust output tracking controller is designed.In order to verify the performance of the controller in different conditions,the different slopes and boom angles are sufficiently selected to investigate the ability of the plant protection machine in the tracking track the slope of theroad.After MATLAB simulation,the performance of tracking the designated slope of the ground is good under the action of the robust controller.Even if there are certain uncertain parameters emerged in the system,the system stability can still be guaranteed and the controller designed had an excellent performance of robustness.