Intelligent design approach for vacuum suction cup units in aircraft flexible assembly

Vacuum suction cups are key subassembly used in flexible fixture for aircraft flexible assembly system; it becomes an important issue in intelligent design to rapid design and automatic location of vacuum cups. In this paper, typical structure and properties of vacuum suction cups used in aircraft flexible assembly are analyzed; A general definition model-semantic model employed in developed Flexible Fixture CAD (FFixCAD) to support and implement automatic selection, rapid modeling and automatic location of standard/typified components is also introduced; Integrated with FFixCAD, an intelligent design approach based on process-conditions for vacuum suction cups is presented accordingly. Based on 3D semantic model definition, a typical components database of vacuum suction cups is built firstly; by establishing a "process reasoning mechanism" and introducing "geometric formula" to build up the relationship between external parameters and process conditions, vacuum suction cups can be automatically designed and installed; consequently, the design efficiency of flexible fixture is increased. This approach can also be spread to other general modular fixture design.