In this paper, we develop a force display system using parallel wire mechanism for virtual sports training with high speed motion. We firstly point out a control issue of the force display system driven by parallel wire mechanism. Based on the analysis, control laws are proposed to improve performance of the force display system. It is experimentally demonstrated that the proposed control laws realize higher acceleration and lower reaction force than other force display systems. Using the experimental result, the performance of the system is evaluated quantitatively.

JAPAN

New challenges face the robot industry of tomorrow. ‘It is estimated that the Japanese robot industry increased its production to Yen550billion in 1997,’ writes Seiuemon Inaba, Chairman of the Japan Robot Association in his New Year message . ‘This is 17% up over the preceding year, due chiefly to the rapid recovery of exports, in addition to the active domestic demand that has continued since 1996. The figures also reflect a firm trend of capital investment. ’ Although rec ent economic conditions have led to some uncertainties about future developments of the business climate, the industry's production in 1998 is likely to regain the Yen600billion level, an all-time high which was reached in the previous peak period,' he adds. ‘In respect of the fundamental economic and social needs for robots in Japan, we believe it is essential to further development of the nation's manufacturing industry-based economy that steps are taken to meet the requirements of industry, particularly in the strengthening of its international competitive abilities through the improvement of productivity and the establishment of a more efficient production system, ' writes Mr Inaba. ’In addition, the industry is called on to meet various other requirements, including measures to compensate for the shortage of skilled workers, the development of an intellectual, comfortable working environment to arrest the tendency of young workers to defect from the manufacturing sector , the release of workers from the so-called ‘three-D (dangerous, dirty and difficult) jobs, and the reduction of working hours,' declares Mr Inaba. ‘These requirements are expected to bring about mid-to-long-term active demand for automat ion equipment, especially robots and factory automation systems,’ writes Mr Inaba. ‘At present robots are used mostly in the conventional manufacturing industy, but in the years ahead, their application will be expanded to the personal sector, covering household uses and support systems for the daily life of the elderly and handicapped, as well as to non-manufacturing industries, including construction, nuclear power, ocean development, medical care and services.’ Mr Inaba adds: ‘St renuous research and development efforts for high technologies are essential to meeting such a wide range of economic and social needs in Japan. Among 15 new and growth sectors covered by a government programme for economic restructuring and creation, pre-arrangements are being made for a research and development project on ‘human co-operating and coexi sting robots’ for which the programme calls on interested parties to immediately set about development and commercialisation tasks. The robot industry intends to participate actively in the project when it comes to the implementation stage. “Thus the Japan Robot Association intends to carry out actively on various operations aimed at further development of the industry. For this purpose, we request the competent government agencies and other interested parties for continued guidance, assistance and co-operation” concludes Mr Inaba.

The WESTEC exhibition, held on March 24–27, 1997, at the Los Angeles Convention Center attracted 683 exhibitors and nearly 30,000 manufacturing professionals, the biggest ever event. A wide selection of manufacturing equipment and technologies was displayed in an area of over 250,000 square feet, including machine tools of every description, plastics and integrated design and manufacturing . . . . Over 1000 international equipment lines were exhibited by leading international machine tool builders, and the technology categories included machining, milling, grinding and deburring, cutting tools, drilling and tapping, CAD/CAM, EDM, machine control finishing, laser systems, etc . . . .

The goal of this paper is to provide a critical review of the well-known resolved-acceleration technique for the tracking control problem of robot manipulators in the task space. Various control schemes are surveyed and classified according to the type of end-effector orientation error; namely, those based on Euler angles feedback, quaternion feedback, and angle/axis feedback. In addition to the assessed schemes in the literature, an alternative Euler angles feedback scheme is proposed which shows an advantage in terms of avoidance of representation singularities. An insight into the features of each scheme is given, with special concern to the stability properties of those schemes leading to nonlinear closed-loop dynamic equations. A comparison is carried out in terms of computational burden. Experiments on an industrial robot with open control architecture have been carried out, and the tracking performance of the resolved-acceleration control schemes in a case study involving the occurrence of a representation singularity is evaluated. The pros and cons of each scheme are evidenced in a final discussion focused on practical implementation issues.

This note briefly summarizes the successful ICAR'97 Conference at Hyatt Regency in Monterey, CA on July 7–9 1997.

A genetic algorithm for the path planning problem of a mobile robot which is moving and picking up loads on its way is presented. Assuming a findpath problem in a graph, the proposed algorithm determines a near-optimal path solution using a bit-string encoding of selected graph vertices. Several simulation results of specific task-oriented variants of the basic path planning problem using the proposed genetic algorithm are provided. The results obtained are compared with ones yielded by hill-climbing and simulated annealing techniques, showing a higher or at least equally well performance for the genetic algorithm.

The Second International Conference in Genetic Programming (GP-97), like the first, was held on the beautiful Stanford University campus in California under the chairmanship of John Koza. More than 350 people from all over the world gathered together for four days to see presentations, posters, tutorials and trade presentations on a range of topics. In addition to GP and related topics in Genetic Algorithms (GAs) and classifier systems, the up and coming fields of evolvable hardware (EHW) and biocomputing (also called DNA computing) were also represented.

This paper describes an automated procedure for analysing the significance of each of the many terms in the equations of motion for a serial-link robot manipulator. Significance analysis provides insight into the rigid-body dynamic effects that are significant locally or globally in the manipulator's state space. Deleting those terms that do not contribute significantly to the total joint torque can greatly reduce the computational burden for online control, and a Monte-Carlo style simulation is used to investigate the errors thus introduced. The procedures, freely available, are a hybrid of symbolic and numeric techniques implemented using a standard computer algebra package.

SIXTH ANNUAL SYMPOSIUM ON HAPTIC INTERFACES

The Sixth Annual Symposium for Haptic Interfaces for Virtual Environment and Teleoperator Systems was held on Nov. 17–18, 1997 in Dallas, Texas. Haptic interfaces are devices that allow human–machine interaction through force and touch. Areas of application include, but are by no means limited, to telemanipulation (for work in hazardous or challenging environments such as space exploration, undersea operations, microsurgery and minimally-invasive surgery, and hazardous waste clean-up) and virtual environments (for realistic interactions with computer simulations in critical procedure training, architectural design, product prototyping, and data visualization).