Graphical Integration Of Robot Programming And Sequence Planning For Mechanical Assembly

Some twenty years have elapsed since the first attempts at planning were made by researchers in artificial intelligence. These early programs concentrated on the development of plans for the solution of puzzles or toy problems, like the rearrangement of stacks of blocks. These early programs provided the foundation for the work described in this book, the automatic generation of plans for industrial assembly. As one reads about the complex and sophisticated planners in the current gen eration, it is important to keep in mind that they are addressing real-world problems. Although these systems may become the "toy" systems of tomor row, they are providing a solid foundation for future, more general and more advanced planning tools. As demonstrated by the papers in this book, the field of computer-aided mechanical assembly planning is maturing. It now may include: • geometric descriptions of parts extracted from or compatible with CAD programs; • constraints related to part interference and the use of tools; • fixtures and jigs required for the assembly; • the nature of connectors, matings and other relations between parts; • number of turnovers required during the assembly; • handling and gripping requirements for various parts; • automatic identification of subassemblies. This is not an exhaustive list, but it serves to illustrate the complexity of some of the issues which are discussed in this book. Such issues must be considered in the design of the modern planners, as they produce desirable assembly sequences and precedence relations for assembly.

Although parallel robots are known to offer many advantages with respect to accuracy, dynamics, and stiffness, major breakthroughs in industrial applications have not yet taken place. This is due to a knowledge gap preventing fast and precise execution of industrial handling and assembly tasks. This book focuses on the design, modeling, and control of innovative parallel structures as well as the integration of novel machine elements. Special attention is paid to the integration of active components into lightweight links and passive joints. In addition, new control concepts are introduced to minimize structural vibrations. Although the optimization of robot systems itself allows a reduction of cycle times, these can be further decreased by improved path planning, robot programming, and automated assembly planning concepts described by 25 contributions within this book. The content of this volume is subdivided into four main parts dealing with Modeling and Design, System Implementation, Control and Programming as well as Adaptronics and Components. This book is aimed at researchers and postgraduates working in the field of parallel robots as well as practicing engineers dealing with industrial robot development and robotic applications.

Machines will gradually become programmed using computers which have the knowledge of how the objects in the world relate to one another. This book capitalizes on the fact that products which are manufactured can be designed on the computer and that information about the product such as its physical shape provide powerful information to reason about how to develop the process plan for their manufacture. This book explores the whole aspect of using the principles of how parts behave naturally to automatically generate programs that govern how to produce them. The last decade saw tremendous work on how machines can be programmed to perform a variety of tasks automatically. Robotics has witnessed the most work on programming techniques. But it was not until the emergence of the advanced CAD system as a proper source of information representation about objects which are to be manipulated by the robot that it became viable for automated processors to generate robot programs without human interface. It became possible for objects to be described and for principles about how they interact in the world to be developed. The functions which the features designed into the objects serve for the objects can be adequately represented and used in reasoning about the manufacturing of the parts using the robot. This book describes the necessary principles which must be developed for a robot to generate its own programs with the knowledge of the world in the CAD system.

BASYS conferences were initially organized to promote the development of balanced automation systems. The first BASYS conference was successfully launched in Victoria, Brazil, in 1995. BASYS'06 is the 7th edition in this series. This book comprises three invited keynote papers and forty-nine regular papers accepted for presentation at the conference. All together, these papers will make significant contributions to the literature of Intelligent Technology for Balanced Manufacturing Systems.

The Eighth International Symposium of Robotics Research was held in Kanagawa, Japan, on October 4-7 1997; Robotics Research presents the findings of this symposium. The papers, written by international specialists in the field, cover the many topics concerning advanced robotics today, ranging from practical system design to theoretical reasoning and planning. They assess the state of the field and discuss all the current and emerging trends dealing with, amongst many other topics, mobile robotics, manufacturing, learning from humans, autonomous land vehicles, humanoid robots, future robots, and new components. The reader will share with the attendees the meaningful steps forward in building the emerging body of concepts, methods, scientific and technical knowledge that shape modern day robotics.

The assembly sector is one of the least automated in the manufacturing industry. Automation is essential if industrial companies are to be competitive in the future. In assembly, an integrated and flexible approach is needed because 75% of the applications are produced in small and medium batches. The methodologies developed in this book deal with the integration of the assembly process from the initial design of the product to its production. In such an integrated system, assembly planning is one of the most important features. A well-chosen assembly plan will reduce both the number of tool changes and the fixtures within the assembly cell. It will prevent the handling of unstable subassemblies, simplify the design of the robot grippers and reduce production costs. An automatic generator of assembly sequences can be an efficient aid to the designer. Whenever he or she modifies features of the product, the influence of these modifications can immediately be checked on the sequences. For small batch production, the automatic generation of assembly sequences is faster, more reliable and more cost-effective than manual generation. By using this latter method interesting sequences could be missed because of the combinatorial explosion of solutions. The main subjects treated in this book are as follows. 1. Presentation and classification of existing systems of automatic generation of assembly sequences. Automatic assembly planning is, indeed, a very recent research area and, in my experience, no systematic study has been carried out up to now.

A mechanical assembly is a composition of parts interconnected to form a stable unit. The mechanical assembly sequence problem is to find a feasible, cost-effective sequence of tasks to perform the assembly. This problem has recently been recognised as significant by the manufacturing industries, since this plan will help mechanical designers to analyse the assembly tasks off-line and justify the cost involved in the process. Homen de Mello and Sanderson proposed the AND/OR graph notation to represent all feasible assembly sequences for a given assembly in one graph and also provide an algorithm to generate the AND/OR graph. Recently, object-oriented approach to software design becomes popular in the computer science community, mainly because of its advantages over the functional approach towards softwar reuse and maintenance. The object-oriented approach asserts that enhancement and adaptation of the software to the environment are easier to do, compared to the functional approach. In thesis, we have usedthe object-oriented approach to redesign the AND/OR graph generation algorithm for assembly sequence generation. This approach inherits the advantages of the object-oriented paradigm. The main contributions of this thesis are the following: (1) An object-oriented version of the assembly sequence algorithm to generate AND/OR graph notation is given. (2) This version eliminates some of the redundant steps in the functional algorithm. (3) The object-oriented design described in this thesis is easy-to-understand, easy-to-enhance and inherits the advantages of the object-oriented paradigm. (4) A formal model of the object-oriented design is also included in the thesis.

Containing 88 papers, the emphasis of this volume is on the control of advanced robots. These robots may be self-contained or part of a system. The applications of such robots vary from manufacturing, assembly and material handling to space work and rescue operations. Topics presented at the Symposium included sensors and robot vision systems as well as the planning and control of robot actions. Main topics covered include the design of control systems and their implementation; advanced sensors and multisensor systems; explicit robot programming; implicit (task-orientated) robot programming; interaction between programming and control systems; simulation as a programming aid; AI techniques for advanced robot systems and autonomous robots.