ANALYSIS OF MECHANICAL ASSEMBLIES BASED ON COMPONENT SPECIFIC ATTRIBUTES

Abstract

A major obstacle for assembly process automation and its integration with other processes such as design and scheduling is the assembly sequence planning (ASP) problem. It can be simply stated as how to find the best or optimal sequence to assemble a product, given its design characteristics and CAD data. The automation of this problem proved to be very complicated, and is still performed manually in most assembly firms, thus consuming more human power and time. Assembly planning consists of two major activities: assembly modeling and assembly sequence planning. Assembly modeling starts with the CAD design model of a product, and generates the geometrical data (like weight, dimension etc.). Assembly sequence planning on the other hand is the procedure of generating an optimal or a best sequence to assemble the product, given its modeling information. One investigation found that on average, current products have around 50% more parts and assembly content and undergo more complex assembly procedures than is necessary. The objective of this dissertation work is to determine an optimized assembly sequence for an assembly. In order to find optimized assembly sequence plan, Contact and precedence relations or matrices first determined, Contact relations can be determined from Directional Accessibility Indices (DAI). Then possible assembly sequences are determined using hierarchical tree structure and geometrically non feasible sequences are eliminated using precedence relations. After that we calculate the cost of each feasible sequence by optimizing criteria, so that we get the least assembling cost of an assembly In these work, User Interface software is developed which should have the capability to analyze the various sequences on basis of various attributes and determine its relative cost. The User Interface developed gives the full flexibility to user to perform assembly analysis of any desired assembly