Improving assembly precedence constraint generation by utilizing motion planning and part interaction clusters

Improving assembly precedence constraint generation by utilizing motion planning and part interaction clusters

In this paper, we present a technique that combines motion planning and part interaction clusters to improve generation of assembly precedence constraints. In particular, this technique automatically finds, and clusters, parts that can mutually affect each other’s accessibility, and hence may impose assembly constraints. This enables generation of accurate precedence constraints without needing...

Constraint-based interactive assembly planning

Constraints on assembly plans vary depending on product, assembly facility, assembly volume, and many other factors. This paper describes the principles and implementation of a framework that supports a wide variety of user-speci ed constraints for interactive assembly planning. Constraints from many sources can be expressed on a sequencing level, specifying orders and conditions on part mating...

Complexity of Precedence Graphs for Assembly and Task Planning

This paper deals with a complete and correct method to compute how many plans exist for an assembly or processing task. Planning is a NP-hard problem and then, in some situations, the application of time consuming search methods must be avoided. However, up to now the computation of the exact number of alternative plans for any situation was not reported elsewhere. Notice that the complexity of...

Part II Motion Planning

Minimum Constraint Displacement Motion Planning

This paper formulates a new minimum constraint displacement (MCD) motion planning problem in which the goal is to minimize the amount by which constraints must be displaced in order to yield a feasible path. It presents a sampling-based planner that asymptotically approaches the globally optimal solution as more time is spent planning. Key developments are efficient data structures that allow t...