Modeling, Simulation, and Control Concepts for a Hydraulic Supply Unit to Control Pressure or Flow Rates

This summary discusses the development, implementation and investigation of a signal-processor based digital controller which interfaces with an existing hydraulic supply unit thus increasing its overall system performance. The major objective is to control pressure-level or flow-rate at a point of interest within a hydraulic system (normally outside of the supply unit). Conventional hydro-mechanical components, such as pressure limiting valves or proportional valves, do not achieve satisfactory results. Consequently, a mechatronic approach suggests the use of a digital controller to adjust the supply unit's state so that the desired pressure or flow-rate at this point of interest can be kept within reasonable limits. Investigations based onto the laboratory system have shown that pressure deviations were well within +/- 0.45 bar and flow-rate errors within +/- 0.45 l/min for given disturbances resulting in an significant increase of the overall system performance up to a factor of ten.