Several scene analysis methods [1, 2] such as location fingerprinting have been proposed to execute room-level localization with high accuracy. However, these methods estimate locations wrongly when received signal strength (RSS) observed at a target user's current position is similar to RSS in another place. By utilizing the heuristic of passing through a passable boundary point (for example, an entrance door) when moving between rooms, we introduce a technique for evaluating the distance between the current position of the target user and the boundary point by comparing RSS around the boundary point with RSS at the user in order to reduce the number of erroneous judgments. Experiments conducted in office environments confirmed that our proposed technique achieved an accuracy rate of 97.1% in localizing the target user.

In this paper, we describe a power assist method for a nonholonomic mobile robot designed to carry out office-oriented services. We developed a new mechanism for obtaining an approximate measurement of the zero moment point (ZMP) using three single-axis force sensors so that a robot pushed from any direction by a human can detect the direction and magnitude of the external force. We also propose impedance control to generate translational and rotational motion in accordance with ZMP displacement. This control method achieves a function whereby a robot that has been given an external force from a direction differing from its translation direction will follow the direction of the external force while rotating. The robot can also return automatically to its initial pose once the external force has been released. We show though experiments that our power assist method is effective in improving the operability and usability of an office-oriented robot.

The intelligent home service robotic system has been developed in order to assist the aged or the disabled people in the population-aging society. The developed robotic system was demonstrated from June 9 to June 19 at the 2005 World Exposition, Aichi, Japan. The purpose of our research is developing robotic system to provide daily services such as bringing some objects to the elderly or disabled wheelchair users. Network distributed monitoring system was also developed in order to monitor the state of robotic system working and the state of the aged or disabled. The developed system uses robot technology middleware (RTM), which was developed by AIST (Agency of Industrial Science and Technology, Japan) to promote application of robot technology (RT) in various fields. RTM is based on CORBA, so has high scaling and inter-operating ability and facilitates network distributed software and sharing. Using RT middleware, we can develop robotic functional elements as "RT software component", which makes application and system integration easier. This paper introduces the architecture of the developed demonstration robotic system and the results of a demonstration conducted at the exhibition

Delivery is an essential task for a mobile robot. Automatically guided vehicles play a crucial role in many factories by performing delivery tasks. The next step involves having mobile robots work in populated environments, such as offices, hospitals, and health care facilities. This paper proposes a service robot that can deliver parcels, letters or documents in such an environment. The design policy, architecture, methodology and implementation of this system are presented.

We have induced a quadruped robot to walk with medium walking speed on irregular terrain based on biological concepts. The PD-controller at joints constructs the virtual spring-damper system as the visco-elasticity model of a muscle. The neural system model consists of a CPG (central pattern generator) and reflexes. A CPG receives sensory input and changes the period of its own active phase. The desired angle and P-gain of each joint in the virtual spring-damper system is switched based on the phase signal of the CPG. CPGs, the motion of the virtual spring-damper system of each leg and the rolling motion of the body are mutually entrained through the rolling motion feedback to CPGs, and can generate adaptive walking. We report our experimental results of dynamic walking on terrains of medium degrees of irregularity in order to verify the effectiveness of the designed neuro-mechanical system.

This paper proposes a novel method to integrate Internet distributed robotic systems using Common Object Request Broker Architecture for implementing telecare robotic system to aid the aged or disabled. The proposed method makes system have low cost and wide availability, high scaling and inter-operating ability to allow the clients and server objects, written in different languages, run in different operating system, and connected in different network to inter-operate. It also makes it easier for system to be extended and integrated with the other technologies and applications distributed over the Internet. Using CORBA as a communication architecture, we developed hardware base, Web user management server, task-level robot arm control server, live image feedback server, mobile robot control server and iGPS server, which can provide some basic care services to aid the aged and disabled.

A delivery service system employing multiple mobile robots, which enables many users to use the delivery service simultaneously, needs the capability to reliably direct robots to their destinations in an office-like environment. In the preliminary stages of our work, we achieved deadlock-free navigation of such a multi-robot system in a static environment, where obstacles did not move. The next stage, which is presented in this paper, progressed to the robust navigation of a multirobot system in a dynamic environment, where obstacles, such as chairs or people, are moving. To do this, we used two methods. The first method recognizes obstacles by a mark-based vision technique and updates the environmental map with iGPS. The second method is a conventional one that detects unknown obstacles by an onboard laser range finder. To test our navigation methods, we conducted actual multi-robot experiments in an office-like environment.

Because the elderly population is growing while the number of people to take care of them is declining, the aging problem is becoming an increasingly important social issue. Thus, developing an inexpensive support system for these elderly people staying alone at home or small-scale distributed facilities is becoming particularly important. The paper proposes a basic platform design of a network distributed telecare robotic systems using CORBA as communication architecture, which has high scaling and inter-operating ability that allows the different support groups to make their own independent computing decisions to develop their applications. It also has remote accessibility for caregivers, and the other helpers from any location where a Web browser is available. Using the developed platform, we implemented a task-level robot arm server, a mobile robot control server, and a live image feedback server, which realized some basic telecare services for the aged and disabled.

We attempt to induce a quadruped robot to walk dynamically on irregular terrain by using a neural system model consisting of a central pattern generator (CPG) and reflexes. In this paper, we report on a newly developed quadruped robot, which contains a mechanism designed to make adaptive 3D space walking (pitch, roll and yaw planes) on irregular terrain be performed more simply. In 3D walking, a rolling motion is naturally generated in most gaits. By having the rolling motion be the standard oscillation and making the CPGs of the legs be entrained with a rolling motion, we realized the stabilization of the gait at a constant walking speed, in spite of an unbalanced gravity load between the fore and hind legs. We also realized an autonomous gait transition in changing walking speeds, by utilizing such rolling motion feedback to CPGs, in order to reduce energy consumption. Rolling motion feedback to CPGs contributes to gait stabilization in walking on an irregular terrain as a tonic labyrinthine reflex for rolling. At present stage, the robot succeeded in walking over several 2D irregular terrains by using CPGs, a flexor reflex and tonic labyrinthine reflexes for pitching and rolling.

Tracking a target robustly by utilizing vision is very difficult for a mobile robot running over the irregular terrain of a natural environment, due to the image deformation caused by the rolling and pitching of the camera, as well as due to the relative movement between the target and the camera. One approach for coping with such problems is matching the target image with many affine-transformed candidate images while tracking. However, when the number of candidate images increases significantly, such an approach is not practical to real-time tasks due to the high computational cost involved. In the present paper, we propose a new system called robustness analysis for tracking (RAT) that improves tracking ability. RAT is an analysis based on the features of the object image, in which three parameters - detectability, robustness for depth and robustness for rotation - are defined. Many more robust templates can be found by analyzing the object image using RAT before the tracking task is performed. The experimental results are shown to verify the effectiveness of this method.

We propose a practical method of multiple mobile robot navigation aimed at the realization of service robots that deliver letters, parcels and documents in an office building. For robust execution of delivery tasks by mobile robots, navigation is important, and localization of robots is a key function for designing robust navigation. We developed a global positioning system for indoor mobile robots by using cameras distributed in the robots' working domain. This system can execute fast and accurate localization of mobile robots. By integrating the positioning system with a deadlock free navigation algorithm for multiple mobile robots, we implemented a successful autonomous service robot system.

We are trying to induce a quadruped robot to walk dynamically on irregular terrain by using a neural system model. In our previous study, we integrated several reflexes into a CPG (central pattern generator) and realized adaptive 2D walking on terrain of medium degree of irregularity. In this paper, in order to make the role of a CPG be clear, we investigate the relation between parameters of a CPG and the mechanical system by simulations and experiments. In addition, we show a newly developed quadruped robot, of which mechanism is designed to make adaptive 3D walking on irregular terrain be realized more simply. At this moment, 3D walking on flat terrain is realized by using a neural system model consisting of CPG and reflexes.

Introduces a methodology that will allow robots to execute tasks autonomously and with a high degree of success. Taking as an example the mobility of a robot without collision in a dynamic environment, a task-level feedback control system is proposed. The key idea is to incorporate the real-time recognition and motion planning functions into the task control loop. For real-time recognition of the environment, mark-based vision is used. In addition, algorithm to do a global motion planning in the environment where movable obstacles exist is proposed. By integrating the real-time recognition and motion planning, we succeed in forming a control loop, for a robust and deadlock free navigation.