Research On Control Method Of Hydraulic Forging Machine System

As aerospace technology and automobile industry developing rapidly, China demands for more large-tonnage hydraulic forging presses, which have good forged precision, high working speed and high level of automation. Give the principle of the current large-tonnage hydraulic forging machine is many cylinders drive a slid to press the billet for forging, so during the design process of the control system, it is bound to face more cylinders simultaneously and coupling problems. In recent years, the consensus control problems of multi-agents attracts more attention, which provides a new idea to solve the problem of multi-cylinders synchronization. In this paper, the back-stepping method was used to design the pressure loop as the inner loop. A consensus control algorithm was introduced and improved from the research of multi-agent , which has double-integrate characteristics. This algorithm was made as the outer loop-synchronization loop. The inner loop and the outer loop constitute a double-loop. Then the design of synchronization control loop was completed and applied to the actual control system.The oil providing system was designed independent. But there were many hydraulic components in the hydraulic system. There were hydraulic valves non-linear, pipe lagging, and the coupling of four driving cylinders’forces, which increased the difficulty of system modeling. Without considering the coupling force in the case of four-cylinder, this paper established a single-cylinder hydraulic system model, which established a four-cylinder hydraulic system model. Second, the driving force to establish a four-cylinder coupled model under the conditions of the slider movement. Finally, the four-cylinder hydraulic system integration model and slide motion model established forging hydraulic mathematical model, verified and analyzed.80MN forging hydraulic press for the mathematical model, this paper designed for the pressure of the inner loop, outer loop for the simultaneous dual-loop control circuit. The purpose of the design pressure closed-loop circuit is the use of hydraulic cylinders, deputy driving force of rapid adjustment, the proportional valve to overcome the non-linear factors. Established based on single-cylinder model, we construct the Lyapunov function of the system, using the reverse recursive method for solving nonlinear control law to maintain the function derivative negative definite, thus ensuring system stability. To compensate for the uncertainty of model parameters, using the Lyapunov function-based adaptive method to estimate the parameters of structural parameters of the system. Motion model in the analysis of the slider with dual integral characteristics of the situation, this paper introduces a multi-agent coordination and control algorithms. Considering the requirements of synchronization error precision , improved coordination control algorithms was used in the outer loop.To verify the design effectiveness of the synchronization and stability control systems, a control system simulation model was built in Matlab-Simulink environment. Simulation .Results show that partial load power in case of a certain size, forging hydraulic model has better synchronization performance, and changes in the parameters for the model has strong adaptive ability.In the actual implementation of the project, the synchronization control algorithm has been applied and practice and have achieved good results. This article describes the actual control system hardware platform structure-bit machine, the control algorithm flowchart. Finally, the paper shows the actual system operation in the collection of experimental data and curve-fitting. The results show that the accuracy can meet the system requirements.