A graph-based approach for hydraulic system automated conceptual design

This paper presents a new conceptual design method that is capable of generating abundant possible design concepts of hydraulic systems automatically by means of graph operations. The design process in this paper begins with a set of obtained subsystem circuits each fulfilling a particular mechanical action. Basic combination units are defined to describe the connectional functions of the directional control valves, and represented by connection state graphs. The circuit diagram for every subsystem is abstracted to a directed topological graph that describes the connectional relationships of the components contained in it. The directed topological graph of system is then formed by merging the graphs of the subsystems. After a series of simplification operations, the simplified topological graph of system is expanded by subsystem sequences. For each expanding sub-graph, the connection state graphs of basic combination units which have the same structures are identified. The directional control valves can be formed by the obtained basic combination units, and the mapping relationships between the system components and the valve ports on the directional control valve are also established. Thus, the entire circuit of the system is formed. The associated matrix operations are also proposed. The proposed method is illustrated by examples.