Optimal Control of Force Couple Leveling System in Heavy Hydraulic Forging Presses

摘要

Force couple leveling system is a leveling structure used in heavy hydraulic presses to keep the slider moving horizontally. This paper develops a hierarchical synchronous motion control method for this system. We transfer the model of the leveling system into motion control subsystem and pressure control subsystems and design a hierarchical control structure based on them. In the outer loop, we use an optimal control method with disturbance estimation to minimize synchronization error and get desired pressure difference. In the middle loop we use a pressure allocation method to transfer the desired pressure difference to desired cylinder pressure. In the inner loop each cylinder is controlled by PD method to follow the given pressure. Simulation experiments show that the hierarchical optimal control method has a good synchronization effect.