Design for Assembly (DFA) can have a significant influence on the cost of a product. DFA is especially beneficial for products that are robotically assembled, due to the limitations placed on the product design by the automated assembly equipment. Automated assembly analysis systems have been developed to assess the assemblability of a product but, many lack an interface to the product CAD database. The lack of a CAD interface requires the user to examine every part in the assembly to determine the characteristics and features that promote efficient assembly. This is a time consuming and tedious process.
An automated assembly analysis system is described that will automatically analyze a product design to determine if it can be assembled on a particular assembly system and suggest improvements in the design. Three main stages of the system are identified. The first stage determines if the individual parts of the assembly can be presented to the work station. The second stage determines if the individual parts of the assembly can be grasped and manipulated by the end effectors. The third stage determines if every part in the assembly can be positioned and inserted into the assembly to complete the assembly process.
A prototype system was developed that addresses the second stage of the proposed automated assembly analysis system and is described herein. The Robotic Grip Determining (RGD) program examines a B-Rep solid model of a part to determine if it can be grasped by a modeled end effector. If the RGD program determines that the part can be grasped, a list of gripping positions are generated that describe how the end effector can grasp the part. These gripping positions can then be passed to the third stage of the proposed automated assembly-system.