Takafumi Matsumaru

Design and control of the modular robot system: TOMMS

The Toshiba Modular Manipulator System, TOMMS, consists of joint modules, link modules, and a control unit with a joystick. A manipulator with 3-DOF is assembled using three joint modules and optional link modules into any desired configuration and shape, for example, a horizontal type and vertical type. The assembled manipulator is connected to the control unit, and the position of the end tip of the manipulator is controlled using the joystick without special handling. There is only one kind of joint module and link module. There are three input ports and two output ports on the joint module. The distance between the fore side and the back side of the link module is adjustable. The Jacobian matrix is applied to the control software. Control experiments were carried out and the efficiency of the design concept for mechanical hardware and control software was confirmed.

Remote collaboration through time delay in multiple teleoperation

In this paper, remote robot collaboration using a network with communication time delay is discussed in multi-operator-multi-robot (MOMR) teleoperation. Recently, collaboration tasks have rapidly emerged in many possible applications such as plant maintenance, construction, and surgery, because multi-robot collaboration would have a significant advantage over a single robot in such cases. Problems and several noticeable results have been reported in a single-operator-single-robot (SOSR) teleoperation system. 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, some of the constraints on performance in MOMR teleoperation applications are examined. Then, the time-delay effects on tele-collaboration are investigated through several experimental studies. Finally, a method to cope with the time-delay in MOMR teleoperation systems is proposed exploiting the virtual thickness modification scheme.

Mobile Robot with Preliminary-announcement and Display Function of Forthcoming Motion using Projection Equipment

This paper discusses the mobile robot PMR-5 with the preliminary-announcement and display function which indicates the forthcoming operations to the people near the robot by using a projector. The projector is set on a mobile robot and a 2D frame is projected on a running surface. In the frame, not only the scheduled course but also the states of operation can be clearly announced as the information about movement. We examine the presentation of the states of operation such as stop or going back including the time information of the scheduled course on the developed robot. Scheduled course is expressed as the arrows considering the intelligibility at sight. Arrow expresses the direction of motion directly and the length of arrow can announce the speed of motion. Operation until 3-second-later is indicated and three arrows classified by color for each second are connected and displayed so these might show the changing of speed during 3-second period. The sign for spot revolution and the characters for stop and going back are also displayed. We exhibited the robot and about 200 visitors did the questionnaire evaluation. The average of 5-stage evaluation is 3.9 points and 4.5 points for the direction of motion and the speed of motion respectively. So we obtained the evaluation that it is intelligible in general

Task-based data exchange for remote operation system through a communication network

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.

Mobile Robot with Eyeball Expression as the Preliminary-Announcement and Display of the Robot’s Following Motion

This paper explains the PMR-2R (prototype mobile robot –2 revised), the mobile robot with the eyeball expression as the preliminary-announcement and display of the robot’s following motion. Firstly, we indicate the importance of the preliminary-announcement and display function of the mobile robot’s following motion for the informational affinity between human being and a robot, with explaining the conventional methods and the related works. We show the proposed four methods which are categorized into two types: one type which indicates a state just after the moment and the other type which displays from the present to some future time continuously. Then we introduce the PMR-2R, which has the omni-directional display, the magicball, on which the eyeball expresses the robot’s following direction of motion and the speed of motion at the same time. From the evaluation experiment, we confirmed the efficiency of the eyeball expression to transfer the information. We also obtained the announcement at around one or two second before the actual motion may be appropriate. And finally we compare the four types of eyeball expression: the one-eyeball type, the two-eyeball type, the will-o’-the-wisp type, and the armor-helmet type. From the evaluation experiment, we have declared the importance to make the robot’s front more intelligible especially to announce the robot’s direction of motion.

A characteristics measurement of two-dimensional range scanner and its application

This paper shows the result of the characteristics measurement of a two-dimensional active range scanner, URG made by Hokuyo Automatic Co., Ltd. which was released in 2004 and is spreading widely as an external sensor for mobile robot. The following items were clarified from the characteristics measurement of URG-X002S in various condi- tions. (1) In the case that the object has a gloss surface or a black surface, the error rate (the frequency that the scanner judges to be impossible to measure and an error code is output) rises when the oblique angle of object becomes large and also the distance to object becomes long. (2) In the case that the object has a white surface or a rough surface, not only the error rate is zero but also the margin of error becomes dozens of millimeters and the varying is small, if the oblique angle is smaller than 60 deg and the distance is shorter than 1 m. (3) The lateral error is negligibly small if the distance to detect is shorter than 1 m. Moreover it shows the result of the examination to apply the range scanner in the Step-On Interface (SOI), in which the scanner is used for detection and measurement of the stepping of an operator. Based on the measured results, we designed the judgment method of the stepping, the installation position of the scanner, and the placement of buttons in the direction screen to apply the range scanner to the SOI for operation of a mobile robot.

Examination by software simulation on preliminary-announcement and display of mobile robot's following action by lamp or blowouts

This paper discusses the preliminary-announcement and display function of the robots following action and intention, especially about the direction of motion and the speed of motion for mobile robot which moves on a 2-dimensional plane. We started with a software simulation about the announcement method indicating a state just after the moment, with lighting lamps and with using blowouts (elastic arrow) on translation and rotation separately. As a result, the following three remarks have been obtained: not only the direction of motion but also the speed of motion is effective to estimate the following translation. Not the rotation speed but the rotation angle (the target direction) is efficient to understand the following revolution. Around 1-second before the actual motion is the optimal timing to recognize the robots following motion both on translation and rotation. Moreover we have verified the validity of the preliminary-announcement and display also for the general movement on a plane.

Preliminary-announcement and display for translation and rotation of human-friendly mobile robot

Discusses the preliminary-announcement and display method of action and intention which is carried with a robot which moves in a human-coexisting environment. It is pointed out that the speed of motion and the direction of motion are important to announce the action of a mobile robot. The method by using blowout is proposed to tell surrounding people about these two kinds of information. A method to announce the speed of motion in translation is examined using a software simulator concerning the case that a robot is equipped with blowout, lamp, or no apparatus. Consequently, the effectiveness of the preliminary-announcement and display using blowout and the importance of information about the speed of motion are confirmed Moreover a method to announce the direction of motion in rotation is examined concerning the case of announcing the target direction or the rotation speed. As a result, it is found that the target direction is efficient for announcing rotation of a mobile robot.

Calligraphy-stroke learning support system using projection

In this paper, a calligraphy learning support system is presented for supporting brushwork learning by using a projector. The system was designed to provide the three kinds of training according to the learners ability as followings: copying training, tracing training, and combination of them. In order to instruct the three-dimensional brushwork such as the writing speed, pressure, and orientation of the brush, we proposed the instruction method by presenting the information to only brush tip. This method can be visualized a brush position and the orientation. In addition, the copying experiment was performed using the proposed method. As a result, the efficiency of the proposed method was examined through experiment.

Laser spotlight detection and interpretation of its movement behavior in laser pointer interface

A laser pointer can be used as an input interface in human-machine interaction. Such utilization, however, can be problematic and one of the main issues is the lack of good reliability in the laser spotlight detection. Another problem is how to interpret the users movement of the spotlight into commands for the application. This paper proposes a method for a laser spotlight detection. The aim is to improve the practicality and reliability of the previous approaches. We use the maximum pixel value as a multiplier in determining the threshold. Maximum pixel value is obtained from environment brightness at a specified time. For the second problem we propose a simple interpretation of incidents that allows the user to use the application, with three main events: laser-move, hover, and single-click. There is no need for users and program to wait a specified time span to be able to interact with each other, and the user can directly give commands to the application after the single-click event. These approaches result in better reliability, easier operation of the application by the user, and allow opportunity for development of a system for rehabilitative, recreation, and input interface devices in the future.