Research On Position Control And Algorithm Of Multi-cylinder Synchronous System

Multi-cylinder synchronization control system is a typical mechanical and electrical hydraulic coupling system,synchronous control precision by hydraulic components manufacturing error,installation error,friction resistance,partial load and other factors.Therefore,how to ensure that the hydraulic cylinder position has always been to meet the requirements of the system of quickness,stability and accuracy,realize the hydraulic cylinder synchronization control system of automatic correction is very important.Based on the theory of multi-cylinder synchronous system,control algorithm and actual research results,the position control and algorithm of six-cylinder synchronous system are studied in this paper.Based on the research status of multi-cylinder synchronous control system,this paper first defines the specific design requirements of the hydraulic synchronous system.The main performance parameters of the six cylinder synchronous control system are given.Secondly,the factors that may cause the position error of the multi-cylinder synchronous system are analyzed.Based on the analysis of various control strategies,the mean coupling control strategy is selected to compensate for the synchronous error of the hydraulic cylinder.Then the six cylinder synchronous control circuit design,determine the use of solenoid directional valve,two-way hydraulic lock and sequence valve in the hydraulic circuit combined with the balance circuit,and combined with the design requirements of the system,the synchronous system in part of the components of the design calculation and selection.Finally,the static analysis of the six-cylinder synchronous control platform shows that there is often coupling between the hydraulic cylinders.To realize the high-precision synchronous control of the hydraulic cylinders,it is necessary not only to adjust several hydraulic cylinders at the same time,but also to ensure that a single hydraulic cylinder does not overload,so as to avoid safety problems.The six-cylinder synchronous system designed in this paper adopts the structure form of one valve controlled one cylinder.Considering the asymmetry of the hydraulic cylinder structure,the mathematical model of the single-cylinder control system is established through the analysis of the stretching and retracting state of the hydraulic cylinder.Then the load and pressure characteristics of the hydraulic cylinder are analyzed and the mathematical model of the six-cylinder synchronous system is determined.Finally,according to the design requirements of the hydraulic synchronous system,the parameters of the hydraulic system are determined.As a nonlinear control strategy,the sliding mode variable structure control algorithm not only has fast response speed,but also has little influence on the system by parameter changes and interference signals,so it is widely used in the synchronous control system of motor.However,since discontinuous switching in the control process is easy to cause high frequency flutter and reduce the stability of the system and the precision of synchronous control,this paper will use fuzzy control rules to adjust the switching gain in the sliding mode variable structure,weaken the effect of buffeting and vibration,and further improve the stability of the system and the precision of synchronous control.The physical model of the hydraulic system is built by AMESim component library,and the control algorithm model is built by Simulink module.The co-simulation research of the six-cylinder synchronous control system is carried out.First of all,the traditional integral sliding mode surface and the nonlinear integral sliding mode surface are compared and analyzed.It is shown that the nonlinear integral sliding mode surface designed in this paper can control the synchronization error and the hydraulic cylinder force change in a small range,and meet the design requirements of the system.Secondly,a Simulink model of the adjacent cross-coupling control strategy was established and compared with the mean coupling control strategy.The simulation results show that the mean coupling control strategy can reduce the position error of each hydraulic cylinder and improve the precision of synchronous control.Finally,the control algorithm is applied to the biased load system,which shows that the control algorithm designed in this paper has certain adaptive ability under the condition of load disturbance,and meets the requirements of synchronous control precision.