Assembly Planning System Design For Industrial Robots

With the development of robotics, the robots are used as assembly tools in FMS. How to make robot work well in assembly and the assembly sequence planning will be the urgent problem to solve we face now. This paper mainly focuses on the development of a system for automatic planning of assembly sequences for industrial robots.First, a brief introduction to the structure, character, classify and control system of the industrial robot is presented in this paper. Based on the language RAPID of IRB?40 (produced by ABB), the compose and structure of industrial robot program language is described in detail. The precondition for using the robot in assembly task is presented. We classify the robot tasks by analyzing the symbolic spatial relations between the objects to be assembled, the depart-spaces and the necessary tools .We predefine a skill primitives. The tasks are decomposed into suitable elementary robot operations, skill primitives. The robot workcell will executable skill primitives. We give the 5-tuple to describe the robot task.Next, the assembly modeling technique is investigated in this paper. With the summary of current assembly modeling methods and the analysis of the geometric assembly functions furnished by 3 dimension CAD , a 3-tuple model is proposed to represent the assembly. Also a detection of subassembly is involved.At last, this paper discusses the content of assembly sequence planning. Based on the comparison of several typical assembly sequence generation algorithms, assembly state vector (ASV) method is introduced to this system. Meanwhile, this paper discuses the evaluation for assembly sequences too. This paper introduces an evaluation for assembly sequence of the products based on information entropy (IE), and specifies the evaluation criteria of the best sequence.