Research On Trajectory Tracking Control Of Folding-boom Aerial Work Platform Based On Observer

Folding boom aerial platform vehicle is a kind of system which is installed on the chassis of the vehicle,using the vehicle as the carrier.It has unique advantages such as mobility and flexibility.The hydraulic cylinder is used as the driving force to achieve the lifting of the robotic arm,hence folding boom aerial platform vehicles can transport personnel to the designated location for installation and maintenance operations,and are widely used in construction,municipal,fire protection and other industries and in the production process of factories.Due to the use of the lightweight long boom in the boom system,there will be instability during the movement of the working platform of the aerial platform vehicle.The aerial platform vehicle is used for manned high-altitude operations which requires for high safety.Therefore,the elastic deformation of the manipulator arm of the aerial platform vehicle cannot be ignored.To ensure the stability of the working platform,it is necessary to establish a more reasonable boom system model and achieve stable and accurate control of the working platform.Therefore,it has farreaching theoretical significance and application value to study the vibration suppression and trajectory tracking control of the flexible arm in the boom structure of the aerial work vehicle.In this paper,a control method combining observer and neural network sliding mode controller is designed for the trajectory tracking control of the knuckle boom aerial vehicle under the influence of factors such as unmeasurable flexible modal variables and external interference.This control method combines the robustness of sliding mode control with the function approximation ability of neural network.The main research contents of this paper are as follows:1.The development status of aerial work vehicles at home and abroad is summarized the development status of aerial platform vehicles at home and abroad,and are summarized the modeling method of flexible multi-body dynamics system and the trajectory tracking control method of flexible manipulator.The flexibility of the boom is incorporated into the model,the deformation of the flexible body is described by using the hypothetical modal method,and the dynamic model of the boom system of the knuckle boom aerial operating vehicle is established by using the Lagrangian method.2.Aiming at the dynamic model of the boom system,the neural network sliding mode control method is studied.The output of the neural network is used to approximate the system uncertainty,and the output of the neural network is introduced into the control rate to compensate for the system uncertainty.Aiming at the problem that the flexible modal variables of the arm cannot be measured in reality,a state observer is designed to observe the modal variables,and the observed values ??of the modal variables are applied to the designed controller.Theoretical and simulation experiments prove that when the model has uncertainty and the flexible modal variables of the arm are unmeasurable,the observer can quickly and accurately calculate the estimated value of the unmeasurable state of the system,and the designed control method which be able to realize tracking control of platform motion trajectory and i vibration suppression can work.3.Aiming at the problem of unmeasurable flexible modal variables of the boom and external disturbances in real situations,an expanded state observer is designed to observe the modal variables of the system,and the external disturbances are observed as system state variables,and the observed values ??are applied in the designed controller,which can compensate the interference so as to enhance the control performance of the controller.Theory and simulation experiments prove that the designed control method can effectively track the desired signal when the model has uncertainties,the flexible modal variables of the arm cannot be measured,and the external disturbances.The expanded state observer can quickly and accurately calculate the unmeasurable state of the system and the estimated value of external disturbance,which has a good effect restraining system chattering and constringes the elastic deformation variable to a small value.Finally,this paper summarizes the research results and analyzes the limitations of this paper and problems that are needed to make further research.