next up previous
Next: Plan Evaluation Up: Generative Process Planning Previous: Identifying Precedences Constraints.

Fixturability and Setup Planning.

To ensure successful machining, each intermediate workpiece shape should be fixturable. This requires consideration of fixturing devices and formulating the conditions that are needed to insure proper fixturing. Setup planning involves determining the various setups in which the part will be machined. While advances have been made in automated fixture design [161], existing research has mainly focused on designing new fixtures for a given geometry.

Chang [153] presented comprehensive conditions for holding the workpiece in a vise. These conditions are based on the intermediate workpiece geometry and are sufficient for successfully clamping the workpiece. He also presented an algorithm for setup planning that, while producing valid results, in certain cases may generate setup plans that are non-optimal.

Yue and Murray [162] presented a comprehensive set of fixturability and clamping conditions for vise clamping, machine table clamping, and frame bolting for manufacture of 2.5D prismatic parts. These conditions are based on intermediate workpiece geometry and consider friction forces.

For a review of fixture design automation, readers are referred to articles [163,164].

Generated by latex2html-95.1
Fri Apr 14 13:59:16 EDT 1995