Research On Position Tracking Robust Control Of Aerial Work Vehicle Electro Hydraulic Servo System

Aerial work vehicle is a kind of construction machinery, which is used to transport people and tools to the designated position. It is widely used in many fields of national modernization and has a broad development prospects. There are problems such as external disturbance and parameter perturbation in the high altitude operating vehicle hydraulic drive system, which makes the control effect of aerial work vehicle poor. In order to improve the control performance of Aerial work vehicle, This paper analyses the control strategy of the pitch mechanism of Aerial work vehicle, models the valve control cylinder part and designs the robust H-infinity controller, to realize the position tracking control of the pitch joint of vehicle.The main contents of this paper are as follows.1) The composition structure of aerial work vehicle and the working principle of its hydraulic drive system are introduced in this paper and taking the hydraulic system of pitching joint as an example. The simulation software SimulationX, which uses the integrated machine, electricity and liquid, provides the simulation platform and the 3-D model of the aerial working platform.2) For solving pitch joint of aerial work truck hydraulic drive system in the presence of variable load force and system model parameter perturbation problem, using the robust H-infinity control strategy. According to the requirements of the design of robust H-infinity controller, the valve control cylinder mechanism of aerial work vehicle is modeled. And using LMI method to design state feedback H-infinity controller and mixed sensitivity H-infinity controller to suppress the disturbance and parameter perturbation. Finally, the experiments in the simulation platform of aerial work truck were carried out. Simulation results show that the state feedback H-infinity controller and mixed sensitivity H-infinity controller have significant effect for inhibition the load disturbance and parameter perturbation of the Aerial work vehicle pitch joint hydraulic driving system.3) With the problem of external disturbance and parameter disturbance exists in the hydraulic drive system of the pitch joint of the aerial work vehicle, the paper use a scheme which contains the state feedback H-infinity control and mixed sensitivity H-infinity control and a simulation experiment was carried out. For the asymmetry of the pitch of the aerial vehicle in the different direction, using the adaptive control method and the method was tested on the simulation platform of aerial work truck. Simulation results show that the composite control strategy can also eliminate external disturbance and parameter disturbance effect on the hydraulic drive system and the positive and negative characteristics of motion of the system are consistent after adding the adaptive control.