Research On Control System Of Large-tonnage Hydrodynamic Deep Drawing Equipment

As the manned launching vehicle goes to a light-weighting, heavy-duty, high-reliable, and low-cost one, increasing number of all-in-one large thin parts are designed for the rockets to reduce the cost and increase the efficiency. Because these parts are made by light materials with high strength, they are hard to produce, which significantly limits the behavior and usage of the parts. Therefore, this situation limits the vehicle technology progress of our country seriously.Hydro-mechanical deep drawing(HDD) is one of the most effective way to promote the forming limit of those large thin parts, most of the large thin parts used by space powers’ launching vehicle are composed by large-tonnage HDD machine. This paper mainly concerns the liquid chamber of large-tonnage HDD machine. First, it concludes the worldwide researches of the liquid chamber. Based on that, five pressurizing cylinders are chosen to control the pressure in the liquid chamber. For proper operation, the five cylinders should control the pressure and the synchronization of the displacements concurrently.According to this scheme, key components design and components selections are finished based on actual needs. Then the system mathematical model is set up and the variable gain PID controller is built up to eliminate the asymmetry of movement.Concerning the load of liquid chamber system is widely changed, a fuzzy self-adaptive PID controller is designed to improve the robustness and adaptation of the system. By comparing the simulation results, the fuzzy PID controller controls the hydraulic system more efficiently.MATLAB and AMESim are used to establish a mathematical model of the whole HDD machine system. Based on this model, “equalizing control mode”, “master-slave control mode” and “compensation control mode” are come up with to complete the pressure control and synchronization of the displacement concurrently. The simulation results display that equalizing control mode can complete the press control excellently, but it can’t reduce the displacement deviation. The master-slave mode and compensation mode can significantly improve the synchronization of cylinders. what’s more, the master-slave mode get a much better control results than the other two. So this mode is used to design the controller of the liquid chamber system.The final process is converting the experiment platform in the laboratory to test the effective of the controller. The Advantech industrial computer is introduced as the carrier, and C++ Builder as the programmer. Frist of all, Obtaining the transfer function of the system by system identification, which is used to design the PID controller. Secondly, the first cylinder is used to control the system pressure and the second cylinder tracks the displacement of the first cylinder. The test results show that the concurrent control of pressure and displacements synchronization can be applied by the controller, and the pressure mistake and displacements deviations are both acceptable. This controller based on master-slave mode can satisfy the request of hydraulic system...