Integrated modeling of an electro-hydraulic servo manipulator using linear graphs

Analysis and design of mechatronic systems require integrated and concurrent tools. This paper presents an integrated mechatronic modeling tool using linear graphs (LG) theory. To demonstrate the capabilities of the presented framework, an integrated model of a complex electro-hydraulic servo manipulator and its governing motion equations in the state space form are presented. It includes a hydraulic power supply unit, a two-stage flapper-nozzle servovalve, a double-acting single-ended hydraulic cylinder, a position transducer (embedded in the cylinder), a controller circuit, and a servo amplifier. The LG model of each subsystem is generated, and the full integrated dynamic model of the system is obtained by assembling the LG model of the subsystems. The control elements, information pathways and modulated source elements (amplifier and position transducer) are also incorporated.