Assembly planning for modular fixtures

Fixtures are devices used in manufacturing to immobilize a part for operations such as assembly, inspection or machining. Modular fixtures are configurations of standard components. The goal of a automatic modular fracture design is to find algorithms to determine a set of fixturing contact points automatically given a set of modular components and the fixturing requirements. This paper considers the problem of generating valid assembly sequences for a given modular fixture configuration. This is called assembly planning for modular fixtures. Because the application domain is known, we can devise an efficient assembly planning system, taking advantage of the characterstics of the fixture domain. In this paper we propose a fastener-based approach which considers the functionality of fasteners (to hold the fixture components together) to achieve both the efficiency in assembly planning and the stability of the generated assembly sequences. We also describe an accessibility measure that can be used to select preferred assembly sequences. This work complements automatic fixture design such that complete automation can be achieved from the design of a fixture to its assembly, which can be performed manually or with the aid of robots.