Showing papers in "Robotics and Computer-integrated Manufacturing in 1990"

Object-instead of function-oriented data management for tool management as an example application

Abstract: Today's situation in data processing in production shows substantial heterogeneity. All data processing systems implemented usually maintain their own databases. CIM strategies often turn out to be bilateral connections between systems. In this way transparency of events as well as the possiblity of reacting quickly cannot surely be enforced. The “transit times for information” are still unsatisfactory, and organization stays slow. The importance of data management as a strategic problem becomes more and more apparent. A common database can serve as an integration kernel for a CIM concept. This database should be generated and maintained independently from specific applications. The internal representation of data in the database system is of fundamental importance. On one hand it should comply with the requirements of the user programs and should be a comprehensive picture of reality; on the other hand it should be easy to survey and render possible safe data maintenance. A suitable approach for modelling data is to orient the model to the objects of the real world. This way a system for data maintenance can be created which supplies all users with comprehensive information. Fast access to information that is always up to date guarantees the ability to react quickly and is a fundamental prerequisite for the application of highly developed data processing systems. Computer-aided production will remain but a wish for many enterprises unless due attention is paid to data management.

Automation technology—on the way to an open system architecture

Abstract: This contribution describes some basic rules for the construction of complex automation systems. It structures the factory from a control-technological view into functional blocks which are related to a 7-layer model of manufacturing technology. Thus, it becomes clear that the present MMS protocols end in the cell control layer in the functional unit of machine control. This unit, however, consists of functional blocks which, for flexible adaptation of future control tasks, should also be configurable and open. The function and communication structure of a factory are shown with a cube model.

A new concept of the SCARA robot

Abstract: Based on the SCARA concept, accepted worldwide, this paper considers the possibility of realizing SCARA with a full circle working area. The basis of the approach is a mechanism with two eccentrically positioned rotating discs instead several tools (hands) is also facilitated. This paper analyzes the advantages of the proposed solution and the possibilities of its realization.

Knowledge processing for concurrent engineering: An evolving challenge in CIM research

Abstract: As technological tasks in CIM environments become more complicated, the level of intelligence required to automate and integrate these tasks also evolves with increasing complexity. This paper classifies CIM tasks and their required intelligence into facility, data and decision levels, and discusses the automation and integration of those knowledge-intensive CIM tasks at their decision level. Since decision-level tasks are often more abstract than those at the facility and data levels, a systematic approach is necessary to build research programs for the automation of these tasks. This paper will use the decision-level task of concurrent engineering as an example to explain the five-step approach that we have adapted to form our research programs in this evolving area of CIM research. These five steps are: (1) perform analysis of the task and its needed decision-level supports, (2) conceptualize these analysis results into a concise framework, (3) propose a software paradigm for the conceptual framework, (4) identify functional requirements from this paradigm to guide software implementations, and (5) correlate implementation results to identify a fundamental technology. More specifically, the analysis of concurrent engineering tasks in CIM can be found in Section 2. Section 3 explains the conceptualization process which views decision making activities as mappings and loops between a control and performance space. In Section 4, concurrent engineering is modeled as a team problem-solving process participated in by multiple cooperating knowledge sources (MCKS) with overlapping expertise to perform those loops. Several functional requirements are identified from this MCKS model of concurrent engineering and example research activities to address these challenges are described in Section 5. The correlations in Section 6 indicate that the knowledge processing technology, evolved from applied artificial intelligence research, is a fundamental technology for building intelligent systems to support various knowledge-intensive CIM tasks at their decision level.

Development of a system for robotic deburring

Abstract: Relatively crude robotic deburring has been accomplished through the detailed programming of the edge contour and the provision of significant passive compliance to compensate for positional errors. In precision deburring, the uncertainties in edge position relative to the tool location may be too great to allow a sufficiently uniform chamfer to be obtained using passive compliance alone. In addition, the costs associated with the detailed path programming can represent a significant fraction of the cost of deburring. This paper discusses the development of a robotic deburring system which provides for simultaneous edge following and force control. An AdeptOne robotic manipulator has been interfaced with an instrumented remote center of compliance manipulator to provide a system which tracks an edge at a controlled force level which can be specified by the operator.

Sensors and interfacing in robotics and manufacturing

Abstract: Sensing is one of the most essential aspects of any robotic application, be it manufacturing or any automated process. Robotic sensors can be divided into two classes of “internal” and “external”. Examples of the first group are position or velocity, while the second group includes proximity, touch, or vision to name a few. The other important problem in manufacturing is interfacing with the environment within a cell. The object of this tutorial paper is to survey the two issues of “sensing” and “interfacing” in robotics and manufacturing.

Advances in the design of autonomous dextrous hands

Abstract: Intelligent robots, with multifingered end-effectors and control relying on real-time processing of huge amounts of visual and tactile sensory information, belong, no doubt, to the class of large dynamical systems. The essential feature of such systems is the multilevel organization of control. Due to the great amount of data processing in large systems, the state space approach, which id efficient in less complex problems, does not always provide the most efficient solution. Rather, a mixture of numerical and non-numerical control methods leads in many instances to an optimal solution in terms of the response of the large system. This paper describes advances in the design of autonomous dextrous hands.

Application of optimal control theory to flexible robotic manipulations

Abstract: The dynamic equatios of a single link flexible robotic manipulator and the measurements are formulated. The observer and the control law are derived based on optimal control theory. The numerical results of several cases obtained through computer simulation are presented here. The issues of nonlinearity and sampling rate, and the effects of gravity, white noises, and damping are investigated. The feasibility of real-time control of flexible robotic manipulators is discussed.

Dynamic stability in bipedal motion: Adaptive control strategies for balance and controlled motion

Abstract: The exploration of dynamic stability in bidedal machines requires a great deal of knowledge about the science of balancing, both equilibrium and motion. Recent work in robotic legged locomotion has concentrated on systems that require three or more legs on the ground at any given time. This research focuses on adaptive control strategies for a bipedal machine that will allow balance and controlled motion with one leg and, if not walking, on two legs on the ground at any given time. Our approach is to optimize a set of balance and motion profiles through extensive simulation and to validate the profiles on an experimental testbed. Once validated as capable of providing dynamic stability, the adaptive control model uses these profiles as nominal control. The sensory input is then used to modify the nominal control to allow precise control at each sampling period. Simply stated, our control model continuously measures the rate of fall of the biped, and adjusts torques at the knees and hips to constrain this fall to dynamic balance and controlled motion. As should be suspected at this time, our control model is sensor driven and does not require a solution to the Lagrangian equations of motion. The result is a faster, less complex, adaptive control process. Our experimental bipedal testbed currently, and repeatedly, exhibits 25 + stable steps on a flat but slightly varied terrain. Current technology could not provide the kind of actuation and measurements necessary to implement our control model; therefore, our team has developed new low pressure, servoed hydraulic systems and sensory devices. Our most recent experimentation has used parallel computing methods and devices in the C + + programming language on a transputer (parallel computer) based Cogent XTM parallel computing workstation. A new dimension to our research is the translation of our knowledge to manufacturing systems and machines. We are currently investigating how our knowledge of limb coordination and reflex can be applied to the coordination of multiple jointed appendages. In addition, we will explore the use of our positioning and balancing technology in the work cell.

World trends of importance to intelligent robotic CIM systems

Abstract: The reduction to practice of the concept of computer-integrated manufacturing (CIM) has moved painfully slowly in the more than 20 years since it came into being. However, within the past five years a very important world trend has emerged, namely a major commitment on the part of industry toward realistic and substantial accomplishment , in practice, of full computer-based integration of the overall system of manufacturing. With the emergence of the goal of accomplishing fully robotic operation of the technological system of manufacturing, and of the concept of the intelligent manufacturing system, the overall trend has now become one toward realization, in practice, of the computer-integrated intelligent robotic manufacturing system. That trend has generated important corollary trends which fall into two main categories, namely, enabling technologies for integration of the system of manufacturing and enabling technologies for imparting artificial intelligence to that system, both of which are required for accomplishing fully robotic operation of the technological system of manufacturing.

Adaptive thresholding in 3-D scene description

Abstract: This paper describes the procedure for extraction of scene information required for recognition of 3-D objects Only one monochrome image with 256 gray levels is required, and the scene description obtained permits matching with wire frame models of objects previously designed by the aid of a CAD program package Adaptive thresholding is used for extraction of objects from the background and from each other, which is required in scene description, and for a reliable extraction of external edges and vertices

Solution principles for a new generation of precision self-correcting multi-axis machines

Abstract: Based on the premise that machinery cannot be built perfectly, this paper formulates plausible solutions for the active correction of the inherent inaccuracies of “less-than-perfect” machines in order to achieve or exceed the performance of precision machinery built by conventional methods which typically aim to build a “perfect machine”. Three problem areas central to the attainment of active or self-correcting capabilities are addressed. First of all, error correcting strategies based on mathematical models of error propagation are addressed through the development of a generalized first order volumetric error model of a multi-axis machine. Second, examples of real-time in-process error sensing methods are analyzed. Finally, strategies based on adaptive and conventional control approaches by which corrections can be fed back and executed by the machine's controller are introduced. For all three elements above, examples of developed systems are presented. It has been shown that the development of self-correcting machines is within the realm of current technology and that significant improvements in precision can be achieved at a relatively modest cost.

Knowledge processing for computer-aided product gestaltung

Abstract: Knowledge processing is of considerable interest for all tasks in computer-aided design and technological planning. The reasons are the possibilities of utilizing experiences and automatic decisions in addition to the capabilities of conventional data processing. This paper outlines the benefits and different technical solutions and describes stages of development towards knowledge integrated product modelling.

Robot accuracy and stiffness—An experimental study

Abstract: Investigations in robotics have been mainly directed toward the design of robots with a significant degress of intelligence, capable of high adaptability. However, very little research has been done on the design of a robot manipulator as an executive mechanism of the intelligent control system, whose high quality design will allow the sophisticated functions imposed by the control system. Experimental investigations of robot accuracy show unacceptable results which limit their future wider application. This is the reason why the off-life programming of robots has not been widely used, without which it is impossible to imagine a more significant integrationof robots in the CIM environment. The object of our study has been to find out the causes of low degreee of robot accuracy, emphasizing the non-corresponding choice of the robot coordinate system, algorithmic and computational errors and drive and transmission element design. Comparison with corresponding results gained from investigations of CNC machine tools cannot be avoided because of the fact that robots are also machines from which accuracy is required. What is missing in robotics today, but which inevitably is required, is the establishment of a standard methodology for testing robot accuracy and other performance.

University-industry interaction for the innovation of new products and processes: A U.S. model

Abstract: In addition to supplying highly educated personnel to industry, research universities in the United States have played an important role in innovating new products and processes, advancing the scientific and technological frontiers, and creating new venture firms. However, in the 1970s and early 1980s, it becase increasingly apparent that in order to take its technological leadership into the 21st century, the U.S. must make all of its institutional and industrial resources more effective. This required a realignment and strengthening of university-industry interactions and relationships, a revision of the curricula of engineering schools, and a reassessment of the role of the Federal government in strengthening the infrastructure of universities, national laboratories and industrial firms. This resulted in the establishment of the Engineering Research Centers (ERC), the Science and Technology Centers (STC), and the Industry-University Cooperative Centers by the National Science Foundation, and the enactment of a legislation that requires all National and Federal laboratories to take an active posture in transferring new technologies to industry. In the paper, the role of the NSF-funded Centers and their expected contributions to technological innovation are presented.

Management of new technologies in production and logistics

Abstract: The increase of a company's competitiveness can be compared with the acceleration of a train. In this idea the product is represented by the tractive power of the locomotive and the production system by the waggons. Until now, a powerful locomotive was considered to be the most important condition of success, which means an excellent product, leading all waggons: production, logistics and organization. Worlwide, it can be observed that even feeble locomotives (products) with easily running waggons are overtaking powerful locomotives with heavily running waggons. This requires a concentration on the speed of the whole train, taking all influencing parameters into account. The enterprise's investment strategy demonstrates an almost equal percentage of its investable funds, namely about 5% of the return for research and development and about 6% for new technologies. The share of new technologies in production is increased from 62 to 68%. The strategic potential of new technologies in production and logistics can be judged by their effects on critical factors for success like costs, quality, flexibility and time. The achievable advantages in competition depend on the level of experience and on the duration of protection against imitation, as well as on the turnover and market shares of the products involved. To align an enterprise with the critical factors of success, the exclusive use of new technologies for automation is not sufficient. The combination of productive factors has to be rearranged frequently. Existing organizational structures, potential of employees, systems of logistics and technologies of production have to be improved considering these circumstances. They should be integratively controlled in a long-term strategy through the systematic management of technology.

The methodology for design of effective computer-integrated manufacturing systems

Abstract: This paper the combines group technology and the simulation approach to the design of an effective material flow system in production processes of a discrete nature. The GT method shows how to find operational groups using a classification system, and how to design GT cells to achieve their maximal effectiveness. Dynamic modelling and simulation of the designed system are emphasized as the tools for checking the behavior of the designed structure and measuring its effectiveness. An example of an application of the suggested approach in the case of a textile machine factory is discussed.

Marketing advantages via new manufacturing technologies

Abstract: Computer-integrated manufacturing (CIM) is generally seen as the manufacturing technology of the future. Within the scope of discussion concerning the chances and risks of CIM it is always pointed out that a company can also strengthen its market position by the improvements following the implementation of CIM at the factory floor. These competitive advantages do not arise automatically. It rather requires an effective marketing orientation to transform those technological innovations into competitive advantages.

Design management in the face of growing product complexity

Abstract: Increasing requirements towards function, further integration of data processing systems and the use of new technologies have led to an enormous extension of product complexity. In order to face these new requirements it is necessary to reconsider design management profiles and to find a more effective organization of the design process. Against this background the existing methodological aids should be reconsidered. On the other hand, improved knowledge acquisition and better communication between the individual departments of an enterprise are of great importance. Nevertheless, design management has to react to these new requirements of the design process with clear management principles to create and maintain a high level of motivation.

Factory environment and CIM

Abstract: This contribution on the topic of factory environment and CIM is divided into two parts. The first part deals with some fundamental aspects of intelligent manufacturing systems for the new generation factories. This subject is divided into three blocks: intelligent manufacturing systems, expert systems and intelligent CAE/CAD/CAM. Based on the input-output approach, some basic requirements for IMS definition are given. The second part deals with the problem of the factory environment and CIM, more specifically from historical aspects to the contemporary factory and some conceptual designs aspects of FMS. At the end, an example of structural pattern recognition of FMS is given.

Development of passive sensing as a key to the solution of mechanical integration in CIM by autonomous mobile robots

Abstract: The autonomous mobile robots involved in material handling in a CIM are expected to operate in a well structured environment. The system that is being developed is based on a variety of autonomous cycles. The development of the part of an autonomous module in an on-board controller of the vehicle together with an appropriate communication and interpretation mechanism is the objective of this project. This paper presents an organization of the reflective controller with a world model based on the coded space. This is followed by a brief description of the mechanism based on error protecting codes. This mechanism belongs to the operation layer of the controller. The layer responsible for local map updating is assumed to be a distributed agent able to close the control of the autonomous cycle. This paper presents some comparative advantages of the solution that is being developed.

The barriers to widespread use of intelligent robots and manufacturing machines

Abstract: The theme of this presentation is that technical barriers exist that have prevented widespread industrial use of intelligent robots and manufacturing machines. These barriers must be successfully addressed for major progress to occur in these fields. Each barrier is identified and discussed, current research projects addressing each barrier in that area are presented, and opinions expressed as to how that barrier will be removed. This paper presents some current industry/university cooperative research results that reinforce the author's view; nine selected projects will be highlighted. Areas of special interest are presented including intelligent robots, intelligent machines, adaptive control structures, the potential of neural nets, the influence of cognitive processes, and the potential for autonomous machine operation in the factory of the future. Some comments on the mechanisms needed for successful industry/university cooperative research are offered.

Computer-integrated mechanical engineering (CIME)

Abstract: Companies can only survive the rigors of international competition if they can bring telling advantages to bear in markets that are subject to vigorous change. New information technologies hold the key. An unbroken flow of data intermeshing with business management systems can support the development of a product from basic concept to design, manufacture and assembly. As tasks become more complex, the development of mechanical products requires assured mastery of high-performance computational techniques in an environment marked by constantly changing parameters. The potential of new engineering materials, e.g. in the fields of ceramics, powder metallurgy and fiber-reinforced plastics, have to be taken into account. Product quality can be enhanced using integrated computer-aided systems, e.g. for optimizing the geometry of machine components. Machining times and hence costs can be appreciably reduced. Tool optimization is achieved using CAD in conjunction with on-line CAM facilities. To increase availability and enhance product quality and user-friendliness, mechanical engineers will increasingly use computer-aided simulation and diagnosis systems to improve products, methods and techniques. Apart from product quality, a flexible response to customer's wishes and short development and delivery times will be decisive factors in future competitive scenarios. CAD support and the use of expert systems will substantially reduce the lead time from receipt of customer enquiry to submission of an offer. These trends in the development of mechanical products within the framework of an integrated information system will have increasing impact on organizational structures, managerial approaches and personnel requirements.

Intelligent robots and manufacturing automation

Abstract: Intelligent robots have been classified as the third generation of robots, able to solve strategic goals. However, if a robot is conceived as an automaton which replaces the intellectual activities of a human being, a rather different approach can be proposed, with a broader meaning of the concept “intelligent”.

Criteria for selecting control systems in flexible manufacturing

Abstract: Industry in Europe has been undergoing major structural changes during the last twenty years or so. Against the background of high demand for consumer and capital goods with corresponding, mostly fixed production capacities, it was necessary to build flexible and, at the same time, efficient production plants in order to cope with the increasing variety of products and shorter innovation cycles. Flexible manufacturing is inconceivable without information technology. Thus, the word “information” has rightly taken its place in the list of primary factors associated with modern production technology. The “gating” of data into production planning and quality assurance, combined with concepts of logistics and control, keeps the flow of materials on the move and helps to shorten lead times. The organization of production and the plant equipment itself have to be matched to the size of the plant, the product range and the market. In large-batch production, for example, a customized vehicle is required; in small-batch or unit production it is often necessary to manufacture a machine to specific customer requirements. Despite such great variations in the type of requirement, it is still possible to distinguish a number of common factors—one of them being the hierarchical structure of the automation landscape with objective and transparent distribution of information across all levels; from the control level for pre-production, assembly and transport up to the planning level for capacity planning and materials management. Hierarchical levels enable particular tasks to be assigned to specific automation equipment. Mainframes and minicomputers are used at the planning level. Dedicated systems such as numerical controls and programmable controllers are now used almost exclusively on the shopfloor control level. Local area networks connect the automation systems of different manufactures without the need for any adaptation. Protocols must be unified for this purpose. Since stable standards are not yet in existence, Siemens has decided to follow the strategy of standard harmonized development. Programmable controllers are part of all production, transport and storage systems. The main requirements are for control, operator communication, monitoring, counting and positioning. A comprehensive production family is a very important factor. Excellent hardware compatibility, easy interlinking and a uniform programming language are all characteristic of the family philosophy. Industrial robots are used mainly in the automobile industry. Largely thaks to them it is possible to produce economically and rationally any mix of model variants and to automate assembly. Programming facilities such as teach-in, on-line or off-line are therefore an important selection criterion for robot control. The majority of numerical controls in use today are used for controlling single machines in heavy-duty and special-purpose machinery manufacture. In networked applications, numerical controls form part of flexible manufacturing systems. In addition to machine control and management, the capacity for communication is an important criterion for selection in this case. In many controls for individual machines the priority is for quick and easy programming. “Shopfloor programming” has assumed considerable importance in such applications. Shopfloor programming requires controls with a sophisticated, user-friendly, graphics interface. Examples show how dedicated automation subsystems have been finding widespread application in the automation of manufacturing, transport and warehouse equipment. They are designed specially to perform certain tasks, both in programming and operation, in order to provide an economic solution to a problems in terms of matched performance and functionality.

A contribution to the organization of an expert system for process control of FMC

Abstract: The distributed processes control model was investigated. A discussion of the automated acquisition of knowledge for process control is presented. The logical solution concept and basic details for implementing an interpreter are described. How it functions was considered, as well as the language for the control of expressions in base rules. A set of rules from the rule base are presented to show a simplified method of organizing a knowledge base by Petri net models of robots and machines.

Market-oriented quality management—a strategy with regard to the single European market

Abstract: Market-oriented quality management commences with the recognition of the changes that have taken place in quality in industry over recent decades. Quality assurance has become a comprehensive task, going far beyond the measurement and inspection of characteristics. The single European market will change some of the conditions of competition. Recognizing this fact and adjusting to it will be a requirement for success.

Corporate management in the industrial society of the future

Abstract: Technology embodies the changes in industrial society. New production technologies and the integration of information technology in companies result in far-reaching developments in industrial production. Knowledge technology assumes a major position in this development. The productive resources in management evolve into an integrated, galvanizing force for qualification and work, research and technology, production and the market. The further development of company management gives rise to a progressive corporate identity. Initiatives at all corporate levels, competent decision-making in a context of risk, leadership through motivation, authority through expertise, strategic investments, quality, education and technology are all characteristics of successful companies.