Safety is important to a robot that is used in a way that can impact on the wellbeing of people. However, understanding and managing the safety information of a robot is not a trivial task. The quantity of this information is large, and it is usually stored in text-based formats. These factors mean that maintaining safety information when it changes is error prone, and understanding it requires manually searching through lengthy reports. In this paper, we demonstrate that a robot's safety information can be stored in a model-based format. We use the SafeML modelling language to model the results of a safety analysis performed on a semi-autonomous wheelchair. We then illustrate and discuss the benefits of storing and managing safety information using a model, both to maintainability of the information and to understanding the safety of the robot.

This paper reports the results of a survey on introducing robots and other new technologies to care services, such as care for older adults. Demographic data show that the ratio of older adults in Japan has already exceeded 23.3%. Japan also is facing a severe shortage of the working-age population, which could lead to a reduction in the quality of care services for older adults; therefore, robots and the provision of new forms of information technologies are expected to be utilized in such care services. The purpose of this study is to help facilitate the introduction of novel technologies in care services, such as in long-term care facilities. We focus on information-related costs that are incurred prior to the purchase of technologies such as attending exhibitions and conducting Internet searches. This report shows the results of an investigation into such information-related costs for three different products, and discusses the importance of the appropriate management of information costs from the development phase through to the introduction phase of such products.

The 4C's of software, computation, communication, configuration and coordination, indicate that the deployment and configuration of software components is an important part of using a component-based software system. This applies as much to robotics as anywhere else, where how to easily deploy the complex web of software components that make up a complete robot system is a well-known problem. We have developed an experimental tool for the deployment and configuration of components using RT-Middleware. It is based on the supervision tree concept. Components are organised into a hierarchy of sub-systems and managed in these groups. The use of a supervision tree ensures that dependencies between components are managed when errors occur, and that errors will propagate up the tree to a supervisor that is capable of handling them.

Within the larger task of renovating an office building, there are many repetitive tasks that are suitable for automation. With the decreasing availability of skilled labour and increasing emphasis on reuse of materials, there is an opportunity to introduce robots that can replace labour for the simpler tasks. This paper describes a robot to perform the task of removing tile screws from suspended ceiling beams. The robot uses a specially-designed tool mounted at the end of an arm. This tool removes screws by turning them between two rollers. The tool is moved down the beam in a single motion, allowing it to remove many screws fast with little operator interaction. RT-Middleware is used as the implementation architecture, which facilitated development by simplifying testing of individual components.

In this paper, we propose RT-middleware for robot system integration. "RT" means "robot technology", which is applied not only to industrial field but also to nonindustrial field such as human daily life support systems. RT-middleware which is proposed in this paper is a software platform for RT systems. We have studied modularization of RT elements and have developed RT-middleware, which promotes application of RT in various fields. Robotic system development methodology and our RT-middleware concepts are discussed. The RT-component, which is a basic software unit of RT-middleware based system integration, is derived from this discussion. A methodology of system development by using RT-components, and a framework for component development are proposed. Evaluations of some RT-component based systems are performed. Finally, conclusions and future work is described.

The Intelligent Systems Laboratory (ISL) has been developing coordinated control technologies for multitelerobot collaboration, in a common environment remotely controlled from multiple operators physically at a distance from each other. We have built a test bed and conducted a series of experiments, where we learned more about how the transmission delay over the network deteriorates the performance of telerobots. Previously, to overcome the problems arising from the throughput of the network such as the operator's delayed visual perception, we have suggested several coordination approaches in the local operator site. Likewise, this paper discusses the use of virtual repulsive force field in the online predictive simulator to assist the operator to cope with the collision between telerobots in remote environments. In the test bed, the operators control their master robot to get remote telerobots to work cooperatively with the other telerobots in a task. Specifically, the operator detects a priori the possibility of collision in the predictive simulator that runs in near real-time and the use of virtual force field prevents the telerobots from coming into collision. We have demonstrated various tasks by two telerobots and two operators via an Ethernet local area network (LAN) subject to simulated communication delays and evaluated the validity of the virtual force field guided approach in multi-operator-multi-robot (MOMR) tele-collaboration.

Presents the utilization of inertial effect in damping-based posture control of a mobile manipulator. As a measure for redundancy resolution of a mobile manipulator, an effective inertia at the end effector in the operational space is proposed and investigated. By changing the effective inertia property via null-motion, we can get the reduced inertial property of the mobile manipulator. The reduced effective inertia has a significant effect on reducing the impulse force in collision with the environment. To find a posture satisfying both the reduced inertia and joint limit constraints, we propose a combined potential function method which can deal with multiple constraints. The proposed reduced inertia property algorithm is integrated into a damping controller to reduce the impulse force at collision and to regulate the contact force in mobile manipulation.

Deals with the reduced inertial effect in damping-based posture control of a mobile manipulator. As a measure for redundancy resolution of a mobile manipulator, an effective inertia at the end effector in the operational space is proposed and investigated. The reduced effective inertia has a significant effect on reducing the impulse force in collision with environment. To find a posture satisfying both the reduced inertia and joint limit constraints, we propose a combined potential function method that can deal with multiple constraints. The proposed reduced inertia property algorithm is integrated into a damping controller to reduce the impulse force at collision and to regulate the contact force in mobile manipulation. The experimental results show that the reduced inertial effect of the mobile manipulator alleviates the impact force at collision.

Various coordinated control schemes are explored in the multi-operator-multi-robot (MOMR) tele-collaborative system through a network with time delay. Multi-robot cooperation has rapidly emerged in many possible applications such as the plant maintenance, construction, and surgery, because it would have a significant advantage over a single robot in such cases. Thus, time-delayed control of a multi-robot system is expected to play an important role in remote operations, too. However, the effect of time-delay would pose a more difficult problem to the MOMR teleoperation systems and seriously affect their performance. In this work, first, we have built an experimental system to investigate the remote cooperation in MOMR teleoperation. Then, different coordinated control methods are proposed to cope with the collision, arising from the time delay over the network. To verify the validity of the proposed schemes, we have carried out various experiments on a planar block arrangement by two slave arms employing graphic simulators and a LAN subject to a significant communication delay.

Since a biped robot tends to tip over easily, stable and reliable biped walking is a very important achievement. In this paper, we propose a balance control method based on an off-line planned walking pattern with real-time modification. First, a method of generating a highly stable, smooth walking pattern is presented. Then, a method of real-time modification consisting of body posture control, actual zero moment point control and landing time control based sensor information is proposed. By combining the proposed off-line walking pattern with real-time modification, the biped robot can walk smoothly and adapt to unknown environments. The effectiveness of the proposed method is confirmed by dynamic simulator such as walking on unexpected irregular rough terrain, soft ground and in environments in the presence of disturbances.

The Mechanical Engineering Laboratory (MEL) is developing technologies for multi-robot collaboration in remote environments with the Toshiba Mechanical Systems Laboratory (TMSL). Human operators' delayed visual perception due to the communication delay over the network seriously affects the collaboration performance in the multi-operator-multi-robot tele-manipulation. We have built an experimental tele-manipulation test bed connecting the MEL and the TMSL to study the time-delayed remote tele-collaboration between two places. In the test bed, one operator controls her master robot nearby two slave robots in the work site and another from a distance. A local online graphics simulator without time delay is developed to cope with the communication delay and several multi-robot coordinated control strategies are devised to avoid the collision. To verify the validity of this simulator assisted approach, we demonstrated a maintenance work on a plant mock-up in the TMSL by two different slave robots and two distant operators in the MEL and TMSL respectively through an ISDN.

Proposes task-based data exchange for teleoperation systems through a communication network as an efficient method of transmitting data between an operation device and a remote robot. On the task-based data exchange, the more important information according to the contents and conditions of the task which the robot performs is given transmission priority, for example, by altering the contents of the transmitted data. We have built an experimental system in which the master arm in Tsukuba and the slave arm in Kawasaki, separated by, about 100 km, are connected through N-ISDN and the standard techniques are utilized, such as TCP/IP, socket, JPEG, etc. A series of experimental tasks has been effectively carried out by the task-based data exchange, that is, crank operation which consists of grasping and revolution. The communication network with capacity limitations was used effectively, and the high maneuverability in real-time with bilateral servo control has been realized. The effectiveness of the task-based data exchange has been confirmed.

Since most conventional robots cannot easily be adapted to environments designed for humans, a human-size biped robot is expected to be able to play an important role in assisting human activities. The selection of suitable joint actuators is an important point when developing a human-size biped robot. In order to select suitable actuators and effectively utilize the selected actuators, it is necessary to clarify the relationship between walking patterns and the specifications of each joint actuator, and this is the issue tackled in the paper. First, a method of generating a high stability, smooth walking pattern is presented, and it is shown how various walking patterns can be produced by setting a series of defined walking parameters. Then, the dynamics of the robot, including the reaction force between the feet and the ground, are formulated. Finally, by simulation studies, the correlation found between actuator specifications and walking patterns is described, and the effectiveness of the proposed method is suggested.

Facial expression communication is considered, mainly focusing on achieving smooth telecommunications. Gesture and facial expressions are considered to be significant factors in telecommunications, such as tele-services. To realize a real time communication system for facial expression, we proposed the facial expression space (FES) and a correspondence technique between each personal facial expression space. Then, a real time facial expression communication system is developed, which transports the facial expressions but not the images themselves. This final system is able to synthesize the facial expressions with two persons, further more in cartoon characters. The experimental results show the validity of these criteria.

We have been developing a casting manipulator which includes a flexible string in the link mechanism in order to enlarge the work space of the manipulator. Like the casting motion of fly fishing, the necessary motion of the gripper, which is attached at the end of the string, is generated by swinging a rigid link The gripper is thrown to the target by releasing the string at the suitable time. In this paper we deal with the basic swing motion control of the casting manipulator. We describe a method of oscillating the casting manipulator by considering it as a two-degrees-of-freedom nonholonomic system By planning a time-periodic reference for the second joint while controlling the first joint, the desired swing motion of the system can be generated. The method was evaluated by comparing the results of numerical simulation and those of experiments using the casting manipulator hardware.

We have been developing a casting manipulator which includes a flexible string in the link mechanism in order to enlarge the work space of the manipulator. Like the casting motion of fly fishing, the necessary motion of the gripper, which is attached at the end of the string, is generated by swinging a rigid link. The gripper is thrown to the target by releasing the string at the suitable time. We deal with the swing motion and throwing motion of the casting manipulation. First, we describe a method of oscillating the casting manipulator by considering it as a two degrees of freedom nonholonomic system. The method of the swing motion generation is investigated through experiments. Next we propose a method of planning of throwing the gripper considering the time delay of releasing the gripper and frictional force which disturbs the flying motion of the gripper. The evaluation by comparing the results of numerical simulation with those of experiments using the casting manipulator hardware has shown the effectiveness of the proposed methods.

In this paper, the gesture and facial expression is mainly focused to achieve the smooth communication on telerobot systems. The facial expressions has been considered as a most significant factor in telecommunications, such as teleservices. To realize the real-time facial expression transportation system, we proposed the facial expression space (FES) and a correspondence technique between each personal facial expression spaces. Then, real time facial expression transportation system is developed, which transport the facial expression but not the image itself. This final system is able to display the same facial expressions in other persons, and in cartoon characters. The experimental results show the validity of these criteria.

We propose a new type of manipulator, a casting manipulator, which includes flexible parts, such as a string, in the link mechanism. A gripper is attached at the end of the string. In order to let the gripper reach a target, the rigid link is swung until the necessary motion of the gripper is generated. The gripper is then thrown to the target by releasing the string at the suitable time. In this paper we describe the manipulation of a casting manipulator. We present a method of oscillating a casting manipulator by considering it as a two-degrees-of-freedom nonholonomic system. First, we propose a method to swing the manipulator for casting motion, and then discuss the selection of swing motion and decision of the timing for releasing the string.

A sequence replanning/control method is proposed to overcome geometric uncertainties of the slave environment in our a priori knowledge of a discrete-event-based tele-task model. A class of controlled Petri net (CPN) is adopted as a modeling tool of tele-robotic part-mating process and the discrete-event control policy of the process is formulated on the basis of the CPN model. In the case when an unexpected state transition occurs due to the uncertainty of the slave environment, recovery paths and their costs are extracted from the a priori knowledge and one of them to minimize the given cost is chosen as the replanned sequence in order for the slave process to escape from the unexpected state and resume the nominal plan.

This paper presents a new planning/control method to integrate the master and slave site in a teleprogramming system in the framework of a discrete-event dynamic system model. Specifically, a simple telerobotic part-mating task environment is modelled based on a class of controlled Petri net (CPN) by associating contact states between objects with state places, and the model is used as the source of a priori knowledge for successful accomplishment of the given task in the slave site. The a priori knowledge is transmitted from the master to the slave site and interpreted into the a priori knowledge base before the teleprogramming starts. Referring to the a priori knowledge base, the slave site interprets the succeeding symbolic commands from the master side and successfully executes the sequential commands to reach the final goal even in the case when an unexpected state transition occurs due to geometric uncertainties in the actual environment.

This paper presents an algorithm for estimating the interaction forces between model objects contacting at multiple points. The authors' previous work addressed the interaction forces that arise between two convex polyhedra, and the development of an efficient algorithm for detecting the interaction and for estimating the interaction forces. To deal with the general case of multiple contacts, the authors consider the non-convex objects as a set of convex polyhedral parts. The problem of calculating the interaction forces with multiple contacts can be divided into multiple problems involving the calculation of the interaction forces arising between two convex objects making a single contact. By implementing this algorithm on a parallel processing system, the authors constructed a real-time operating simulator. Preliminary experiments, involving the placement of a cube in a corner, were performed to evaluate the effectiveness of the system.>

This paper discusses the design of a predictive display system with force feedback and its application to a remote manipulation system with transmission time delay. In the field of telerobotics, it has been found that an operator's performance is enhanced by the ability to obtain the information of remote environment with high fidelity. However, the transmission time delay produces one of the most crucial problems in space telerobotics. It is not practical to feed back force data continuously to the operator's hands because the delayed feedback may cause instability. In order to improve the manipulability, a system that presents the information of environments pre- cisely to the operator without time delay is re- quired. In this paper, a method for virtual genera- tion of the constraining forces in the model world is proposed. As a first step, a simple robot and its environment model are constructed. It is assumed that the environment model consists of several polyhedral objects without friction on the surface and that the slave robot is a point object. The spring effects are assumed at the surface of the ob- jects and then the constraining forces are produced in the direction normal to the surface, and those magnitudes are in proportion to the amount of the penetrations. A predictive display remote manipu- lation system with a force generation function is implemented. Some experiments were performed to confirm the effectiveness of the proposed method.

Discusses a method of calculating the interaction forces produced between objects which will contact in model space. Recently, needs of robotic simulators are increasing to provide efficient off-line teaching tools, effective human-robot interfaces for telerobotic systems and so on. In almost simulators, currently operators can see good images of the environments to be manipulated by introducing computer graphics techniques. However, such simulators only can display the environments unilaterally without feeling any constraint force which will occur during teaching tasks. In some applications of the simulators, the lack of force feedback causes low efficiency of the system. In order to overcome this problem, a method which can generate constraint forces in a model world is proposed, which will be called the EMID (environment modeling for the interactive display) system. After the method is formulated, using the EMID method will be confirmed.>