| Hydraulic climbing formwork technology can realize the mutual crawling of frame and rail by using hydraulic synchronization system as the main driving device,and it can be used in combination with multiple pieces formwork for a wide range of applications.In the field of hydraulic mold climbing technology,the hydraulic synchronization system is not only required to have high tracking accuracy and synchronization accuracy,but also is used to deal with the influence of various time-varying factors such as mechanical coupling,external disturbance and bias load,etc.It is difficult to obtain high control performance by conventional control methods,so it is important to design and control the hydraulic synchronization system for the hydraulic climbing formwork machine.In this paper,a variable speed pump-controlled cylinder synchronization control system was innovatively designed with the desynchronization factors of the hydraulic climbing formwork machine hydraulic synchronization system.The proposed system adopts coupled synchronization control strategy to compensate the position control law and to ensure the displacement synchronization of each pump-controlled cylinder system.The main research contents are as follows:(1)The workflow and technical parameters of the hydraulic climbing formwork machine was analyzed,and the overall synchronization control scheme was propoesd for the desynchronization factors and structural characteristics while segmental climbing and overall climbing.The variable speed pump-controlled cylinder synchronization system was designed with the working load,and the hydraulic components were calculated and selected.The multi-body dynamics model and hydraulic system simulation model of the hydraulic climbing formwork machine were establish in MATLAB.(2)The force analysis of the climbing formwork was carried out.The mathematical models of the permanent magnet synchronous motor and pump-controlled cylinder system were establish.The state space equation of the pump-controlled cylinder system was derived,and its nonlinear characteristics was analyzed to provide theoretical basis for the design of the extended state observer and the position control algorithm.(3)The extended state observer was designed to estimate the unknown state,unmatched disturbance and matched disturbance for the nonlinear characteristics of the pump-controlled cylinder system.The integral sliding mode backstepping control algorithm was proposed to compensate for the system disturbance.The effectiveness of the proposed control algorithm was verified by simulation.(4)A simulation model of the variable speed pump-controlled cylinder synchronization system of the hydraulic climbing formwork machine was established in MATLAB.Multiple control combinations were used for synchronization control simulation by setting the climbing conditions with the segmented climbing and overall climbing stages,respectively.The simulation results show that the synchronization control combination of integral sliding mode backstepping control algorithm with cross-coupling and adjacent deviation coupling has the best control performance in all aspects compared with other control combinations.The overall synchronization error can be controlled within 0.01 mm and the tracking error within 1.5mm under any working condition,and the synchronization difference between two adjacent hydraulic cylinders with mutual mechanical coupling is less than 1/200,which meets the control performance requirements of the hydraulic climbing formwork machine.It can provide reference for related research and application fields. |
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