Study On A Kind Of Robust Control For Vibration Suppression Of Spray Boom Of Spray Boom Sprayer

As a kind of important plant protection machinery,spray boom sprayer has been widely used in agricultural production.Due to uneven ground farmland will seriously affect the spraying uniformity of spray boom and in order to make the spray boom operate more effectively and spray uniformly in the uneven farmland,the control of spray boom is an important research problem.In this thesis,the cable suspension and twin link suspension are chosen to be studied and the robust controllers are designed to achieve the goal of improving the spraying uniformity of spray boom.In this thesis,the structure and working principle of cable suspension and twin link suspension are studied firstly,and then the transfer functions of two kinds of spray boom suspensions are considered.For these transfer functions are established based on the actual data they are more suitable to be sued to design the controller for the suspension.The cable suspension transfer function and position control servo motor transfer function are combined,and then be transferred to the state space model.Considering existence of the uncertainty and external interference in the model,the controller is designed to satisfy the performance constraint.After that,the transfer functions of the twin link suspension and the electric actuator are combined,and also be transferred to the state space model.In addition to the model uncertainty and external interference are considered,the failure of the actuator is also considered.Then,the controller is designed by applying the robust fault-tolerant control theory.The two kinds of controllers designed in this thesis are respectively tested by simulation in MATLAB.The simulation results show that angle and angular velocity of the cable suspension under the action of the robust guaranteed cost controller are significantly improved compared with that of the passive suspension.Under the action of the robust controller,the angular velocity of the spray boom of the twin link suspension can converge rapidly even the actuator fault occurring.It can be seen that the two robust controllers designed in this thesis are effective for restraining the harmful vibration of the spray boom of the sprayer and can improve the uniformity of spray effectively.