bluuebunny/crossref_metadata_2025 huggingface dataset:
Reflective Collision Avoidance for Mobile Service Robot in Person Coexistence Environment
Authors: Sonoura Takafumi ,   Corporate Research & Development Center, Toshiba Corporation, 1 Komukai-Toshiba-cho, Saiwai-ku, Kawasaki 212-8582, Japan, Tokura Seiji , Tasaki Tsuyoshi , Ozaki Fumio , Matsuhira Nobuto
Published: April 2016

A person coexistence environment is always changing. For example, people in the environment move around, someone changes the arrangement of the furniture, and someone puts something on the floor. Tasks of a service robot to support people include many scenes that the robot should move around in this environment. Without sensing the objects in the environment, it is difficult for an autonomous robot to move in the person coexistence environment protecting a people’s safety. Thus, an advanced ability to avoid collisions by adapting to the environment is required for a robot. From the viewpoint of robustness, a reflective collision avoidance algorithm has been used with predefined map-based path planning. However, because the algorithm is composed of simple operation rules, a robot depending on the reflective collision avoidance algorithm may often moves inefficiently. To ensure efficient collision avoidance, we propose a reflective collision avoidance technique that corrects direction and magnitude of robot velocity independently using 1-dimensional potential-like functions ruled by a pseudo distance that modifies its own distance in proportion to an angle from the robot traveling direction to the obstacle direction. We verify the effectiveness of the proposed technique for a robot developed to serve persons in a retail store.
Passively Adaptable Wall Climbing Robot in Narrow Space
Authors: Ariga Anna ,   Department of Applied Physics, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan, Yamaguchi Tomoyuki , Hashimoto Shuji
Published: April 2016

This paper presents a novel wall climbing robot for a narrow space that is not accessible for humans, such as a sewer pipe and small gaps between buildings. The proposed robot consists of two driving parts and a pantograph between them that generates a pushing force against the walls to prevent the robot from falling down. Two different kinds of springs are installed on the pantograph in order to provide certain amount of the pushing force. The proposed mechanism can passively adapt to the changes in the interwall distance with a constant pushing force to achieve a smooth movement. The experimental results show that the proposed robot can work reliably and safely in different types of narrow spaces between walls.
Sorting System for Recycling of Construction Byproducts with Bayes’ Theorem-Based Robot Vision
Authors: Gokyuu Takuya ,   Tokyu Construction co., Ltd., 3062-1 Tana, Chuo-ku, Sagamihara, Kanagawa 252-0244, Japan, Nakamura Satoru , Ueno Takao , Nakamura Munetaka , Inoue Daisuke , Yanagihara Yoshitaka
Published: April 2016

To further the proper and high-quality disposal of construction wastes (construction byproducts) and to improve safety in sorting operations, we have developed a system, which uses robot vision to determine materials based on the Bayes’ theorem, to sort construction byproducts of a wide variety of sizes and shapes that are discharged from building demolition sites. We have conducted, using construction byproducts discharged from actual demolition sites, sorting experiments with the developed sorting system. These experiments have demonstrated sorting accuracies of not less than 60%. These results prove the system’s effectiveness in sorting construction byproducts.
Bio-Inspired Omnidirectional Multilink Propulsion Mechanism in Fluid
Authors: Kobayashi Shunichi ,   Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan, Fujii Kyota , Yamaura Taiga , Morikawa Hirohisa ,   Mitsubishi Electric Engineering Co., Ltd., Japan,   Minebea Co., Ltd., Japan
Published: April 2016

Since most organisms are fairly autonomic, functional and efficient, the study of machines modeled on the movements of organisms has become significant in the engineering field. From this point of view, we observed organisms that swim in water by bending motions and noticed that the direction in which polychaetes swim differs from that of nematodes. This is explained by fleshy protrusions, called parapodia, that increase the worm’s tangential drag component during its movement in water. In this study, we have developed a bio-inspired omnidirectional in fluid propulsion mechanism that changes the angle of these protrusions.
Improved Stability Using Environmental Adaptive Yaw Control for Autonomous Unmanned Helicopter and Bifurcation of Maneuvering in Turning
Authors: Nakanishi Hiroaki ,   Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Yoshidahonmachi, Sakyo-ku, Kyoto 606-8501, Japan, Kanata Sayaka , Sawaragi Tetsuo ,   Department of Aerospace Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
Published: April 2016

Adaptation to environmental changes, such as wind, plays a very important role in improving the reliability of autonomous unmanned helicopters. Adaptive yaw (heading) control for an autonomous helicopter is discussed in this paper. The control structure is based on a hierarchal scheme that utilizes an inner yaw feedback control loop plus an outer feedback loop. The outer loop estimates the direction of the airspeed using roll angle and roll angular rate. Stable coupling in yaw and roll motion is induced by the proposed controller to improve the stability of the helicopter’s flight. Turning utilizing the proposed adaptive control system is discussed in particular. Results of flight experiments show that bifurcation of the helicopter’smaneuvering in turning occurs depending on airspeed. The results indicate that the autonomous unmanned helicopter can select a turning maneuver that is suitable for the environmental conditions, thus stabilizing its flight.
Probabilistic Planning for Predictive Condition Monitoring and Adaptation Within the Self-Optimizing Energy Management of an Autonomous Railway Vehicle
Authors: Klöpper Benjamin ,   National Institute of Informatics, Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan, Sondermann-Wölke Christoph , Romaus Christoph ,   University of Paderborn, Germany
Published: April 2016

Self-optimizing mechatronic systems are a new class of technical systems. On the one hand, new challenges regarding dependability arise from their additional complexity and adaptivity. On the other hand, their abilities enable new concepts and methods to improve the dependability of mechatronic systems. This paper introduces a multi-level dependability concept for selfoptimizing mechatronic systems and shows how probabilistic planning can be used to improve the availability and reliability of systems in the operating phase. The general idea to improve the availability of autonomous systems by applying probabilistic planning methods to avoid energy shortages is exemplified on the example of an innovative railway vehicle.
Placing Motion of an Object by a Robot Hand with a Flexible Sensor
Authors: Saito Naoki ,   Akita Prefectural University, 84-4 Tsuchiya Ebinokuchi, Yurihonjo, Akita 015-0055, Japan, Satoh Toshiyuki , Suzuki Yoshinao , Okano Hideharu ,   Futaba Industrial Co., Ltd., 1 Azaochaya, Hashime-cho, Okazaki-shi, Aichi 444-8558, Japan
Published: April 2016

We examine a placing motion of a grasped object by a robot hand equipped with a flexible sensor on the finger. The aim of this study is to realize a quick placing motion with a small impulse force between the object and the floor. To derive a dynamic model of the motion, we consider the deformation of the flexible sensor occurring when the hand grasps the object. The dynamic model represents the relation between the impulse force and an approaching trajectory of the robot hand to the floor. From this model, we can obtain the trajectory of the hand that ensures that the impact force is less than the object’s mass. The validity of the model and the effect of the sensor’s flexibility are examined through simulation. We then confirm experimentally that the robot hand puts down the object without an excessive impact force using the obtained trajectory.
GPU Acceleration in a Visual Servo System
Authors: Zang Chuantao ,   Graduate School of Information Science, Tohoku University, 6-6-01 Aramaki-Aza Aoba, Aoba-ku, Sendai 980-8579, Japan, Hashimoto Koichi
Published: April 2016

In this paper we present our novel work of using the Graphic Processing Unit (GPU) to improve the performance of a homography-based visual servo system. We propose a GPU accelerated Efficient Second-order Minimization (GPU-ESM) algorithm to ensure a fast and stable homography solution, approximately 20 times faster than its CPU implementation. To enhance the system stability, we adopt a GPU accelerated Scale Invariant Feature Transform (SIFT) algorithm to deal with those cases where GPU-ESM algorithm performs poor, such as large image differences, occlusion and so on. The combination of both GPU accelerated algorithms is described in detail. The effectiveness of our GPU accelerated system is evaluated with experimental data. The key optimization techniques in our GPU applications are presented as a reference for other researchers.
Proposal of an Energy Saving Control Method for SCARA Robots
Authors: Lu Guangqiang ,   Department of Robotics, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, Japan, Kawamura Sadao , Uemura Mitunori
Published: April 2016

The energy-saving method for SCARA robots proposed in this paper utilizes elastic elements effectively in order to save energy for periodic motion. In other words, our method is based on resonance. Mechanically linearized robot dynamics with nondiagonal elastic-matrix elements are considered to save SCARA robot energy significantly. An adaptive elastic method and an adaptive viscosity compensation method are proposed. It is mathematically proven that robot motion controlled by the proposed method converges at the desired periodic motion and elasticity and viscosity parameters converge at ideal values. Several simulation results demonstrate the feasibility and robustness of the proposed method.
Multi-Leg System for Aerial Vehicles
Authors: Doi Takahiro ,   Department of Robotics, Kanazawa Institute of Technology, 3-1 Yatsukaho, Hakusan, Ishikawa 924-0838, Japan, Miyata Kazunori , Sasagawa Takamasa , Tadakuma Kenjiro ,   Hirata Corporation, 3-9-20 Togoshi, Sinagawa, Tokyo 142-0041, Japan,   Department of Mechanical Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
Published: April 2016

The multi-leg system concept for aerial vehicles proposed here is a novel alternative to conventional landing gear and realizes adaptation to undulating terrain, shock absorption, ground-surface gripping, and chassis support after landing. The sections that follow discuss multi-leg system concept, mechanical shock absorption design, simulation, and experimental results.
Calculation of 6-DOF Pose of Arbitrary Inclined Nuts for a Grasping Task by Dual-Arm Robot
Authors: Shauri Ruhizan Liza Ahmad ,   Department of Mechanical Engineering, Division of Artificial Systems Science, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan, Nonami Kenzo
Published: April 2016

The capability to manipulate small objects is one of the important requirements for producing assembly work robots. Moreover, a robot that exhibits humanlike skills could be used to reduce the high labor cost for complex tasks. Therefore, we propose a seven-link dual-arm robot with three-fingered hands for cooperative tasks to manipulate small parts such as nuts and bolts in an unstructured environment. As an initial experiment, we need to obtain the six degrees of freedom (DOF) posture of a hexagonal M10 nut (diameter, 19.6 mm), which is small and possesses an indistinguishable color. These constraints have made it difficult to recognize such a target by current available methods where a higher order of posture data is necessary for robot operation. Hence, we propose a technique that we have labeled as Confirm-Estimate-Rotate (CER), which employs integration between the image and robot algorithms in consecutive iteration loops via a visual servoing structure. Real-time experimental results indicate the capability of our method to change the seven-link arm robot posture safely to match the posture of a target in an inclined position. Furthermore, a statistical grasping result by this method has shown a moderate performance for nuts in arbitrary poses. Thus, this shows that the method could be applied to solve the problem of aligning nuts and bolts from the previous screwing task performed by the dual-arm robot in the next future work.
A Study on Position Measurement System Using Laser Range Finder and its Application for Construction Work
Authors: Inoue Fumihiro ,   Technical Research Institute, Obayashi Corporation, 4-640 Shimokiyoto, Kiyose-shi, Tokyo 204-8558, Japan, Sasaki Takeshi , Huang Xiangqi , Hashimoto Hideki ,   College of Engineering and Design, Shibaura Institute of Technology, Japan,   Institute of Industrial Science, Tokyo University, Japan,   Faculty of Science and Engineering, Chuo University, Japan
Published: April 2016

This paper describes a study of high accuracy and low cost position measurement system using Laser Range Finder (LRF), and its application for construction pile work. Since the LRF is a sensor which can measure distance to surfaces of objects by radiating laser beams from itself and receiving the reflected ones, an obtained data from the LRF are nothing more than the contours of objects. In proposed system, the obtained data from LRF assumed the arc-shaped contours of the bar, the center position was analyzed introducing the least square method and maximum likelihood estimation. The error between the analysis and the measurement corresponds enough to the allowable accurate range. Additionally, improving the angular resolution of the LRF by using a pan unit, the highest accurate center position was able to be acquired. Applying this system to the construction work, the high accurate pile marking and the pile drive positioning were recognized. Since this measurement was achieved by only a worker and the position and direction of the worker was easily found, the high efficient and short term works were surely performed.
Simulation Analysis of a Miniature Shutter Unit Using an Electromagnet for Digital Still Cameras and Video Cameras
Authors: Sugasawa Masayuki ,   Department of Intelligent Interaction Technologies, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan, Ohba Kohtaro
Published: April 2016

Customers require that camera shutter and diaphragm size and power consumption are minimized but shutter speed maximized for the electromagnetic shutter units used in digital still-camera and video cameras. This paper describes the problems with past shutter and diaphragm units and proposes a new shutter unit based on simulation analysis. We compare the prototype model with simulated shutter speed data. Experimental results ascertain the effectiveness of this approach. Simulation results agreed quite well with experimental results.
Multi-Material Anisotropic Friction Wheels for Omnidirectional Ground Vehicles
Authors: Ishigami Genya ,   Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 252-5210, Japan, Overholt Jim , Iagnemma Karl ,   United States Army TARDEC, 6501 E. 11 Mile Road, Warren, MI 48397, USA,   Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA
Published: April 2016

In this paper, a novel wheel design utilizing the anisotropic friction property for omnidirectional vehicles is presented. The proposed wheel has a series of bendable “nodes” on its circumference, each of which is made of two materials with differing friction properties: one material exhibits high friction, and the other exhibits low friction. The high friction section of the node generates a high traction force, while the low friction section enables the wheel to passively skid. The wheels are arranged such that the robot wheel exhibits high traction in its drive direction (much like a conventional tire), but low traction when sliding laterally. Exploiting this “anisotropic friction” property, the proposed wheel enables a vehicle to realize omnidirectional motion (i.e., the vehicle can move any direction within the plane - forward, back, or laterally). While many other omnidirectional wheel drives exist, the proposed wheel is simpler than any other existing design because the wheel is composed of a single, moldable element. This paper summarizes the design of the proposed wheel and presents experimental comparisons between an omnidirectional robot using the proposed wheel and an omnidirectional robot using conventional wheels.
Development of an Active Walker and its Effect
Authors: Kobayashi Hiroshi ,   Department of Mechanical Engineering, Tokyo University of Science, 1-14-6 Kudankita, Chiyoda-ku, Tokyo 102-0073, Japan, Hashimoto Takuya , Nakayama So , Irie Kazutaka ,   Hart Walker Japan, Co. Ltd., 75-41 Mitusawa Ogori City, Fukuoka 838-0106, Japan
Published: April 2016

In Japan alone, more than one million people have walking difficulties. The many kinds of walker being developed thus far for gait training are used by grasping the front and/or back in order to balance the body. This requires tilting the upper half of the body forward or backward, making it difficult to keep the right posture for walking. There are moreover few examples of an active walker that is used if people have no muscular strength for walking. In order to deal with these issues, we have been developing an active walker using the HartWalker which consists of a double upright knee-ankle-foot orthosis and a 4-wheeled carriage with a stem located in the center of the carriage. Since the waist of the orthosis is attached to the top of the stem, there is no risk of falling, it is possible to keep the right posture, and both hands become completely free. McKibben artificial muscles are attached to the Hart Walker in order to control the gait as an active walker. In walking experiments using a child-size doll with the same kinds of joints and weight that a human child has, we confirmed that a humanlike gait is realized by the active walker we developed. Many patients who have different kinds of disease are using it and we have confirmed that all of them can walk by using the active walker. The active walker is now commercially available.
Improvement of the Needle-Type Dispenser for Precise Micro-Droplet Dispensation – Gap Measurement Between the Needle Tip and the Target Surface Based on Needle Vibration –
Authors: Hirata Shinnosuke ,   Department of Mechanical Engineering and Intelligent Systems, The University of Electro-Communications, E4-329, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan, Hirose Kazuki , Irie Yuuka , Aoyama Hisayuki
Published: April 2016

Micro-droplet dispensation is required in current systems or industrial equipments. However, drop-ondemand inkjet technologies are difficult to use in dispensing micro droplets from high-viscosity liquids. Therefore, the needle-type dispenser using a thin needle and a glass capillary has been developed for microdroplet dispensation. When the needle passes through the capillary with a sample liquid, a droplet of the liquid adheres to the needle tip. The micro droplet can be transcribed to the target surface by bringing the needle-tip droplet into contact with the target surface. The needle-type dispenser can dispense sub-pico-liter amounts of droplets from liquids of several hundred Pa?s. When a micro droplet is dispensed, a gap is formed between the needle tip and the target surface. Amounts of droplets are unstable, as the dispensing gaps fluctuate. Therefore, a contact-detection method of the needle-tip droplet and the target surface is proposed. The needle is vibrated by a piezoelectric actuator through a leaf spring in the proposed method. The needle-vibration characteristic is made variable by the differences in conditions between the needle-tip droplet and the target surface. Therefore, contact of the needle-tip droplet with the target surface can be detected by needle-vibration characteristics. Then, the dispensing gap can be kept constant by contact detection for dispensing accurate amounts of droplets.
A Yank-Based Variable Coefficient Method for a Low-Powered Semi-Active Power Assist System
Authors: Rosendo Andre ,   Department of System Science and Informatics, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0814, Japan, Tanaka Takayuki , Kaneko Shun’ichi
Published: April 2016

In this paper, we developed a power assist system to help users on carrying heavy loads. This system uses the user input force and position to generate an aiding force, reducing the burden on carrying heavy loads. We adopted a semi-active methodology, combining an active with a passive element, aiming to match the best traits from both, and also considering a lighter motor, which makes the system reach its limit force. To control this lightly actuated semi-active system we proposed a proportional controller which has its gain tuned accordingly to the yank value; this is calculated by the derivative of the force. The controller method herein amplifies the system response whenever the user intends to change his movement, producing a better handling of the system and saving actuator power for either periodical or non-periodical movements. Future applications may involve creating a light assist system for portable applications or assist in heavy industrial environments.
High Speed and High Sensitivity Slip Sensor for Dexterous Grasping
Authors: Teshigawara Seiichi ,   Department of Mechanical Engineering and Intelligent Systems, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan, Tsutsumi Takahiro , Suzuki Yosuke , Shimojo Makoto ,   Yokogawa DCS Hardware Development, 2-9-32 Nakacho, Musashino-shi, Tokyo 180-8750, Japan
Published: April 2016

Slip-detecting tactile sensors are essential if robot hands are ever to achieve the gripping motions of human hands. In our previous research, we developed a flexible, thin, and lightweight slip sensor that exploits resistance changes in pressure conductive rubber. However, using this sensor, it was difficult to distinguish between object slip and changes in normal force. Therefore, in this research, we investigate a method of identifying object slip by analyzing the frequency components of the output signal from the sensor. As a result, we find that high-frequency components of several kilohertz or more are included in the complex voltage signal immediately before object slip. Therefore, using this high-frequency component, we develop a simple structure sensor that distinguishes between both contact and a state of immediately before slip with high sensitivity. Moreover, we design a slip sensor for a robot hand and examine the effects of noise by manipulation. Finally, we describe an experiment involving the adjustment of the gripping force of a robot hand.
Numerical Solution Using Nonlinear Least-Squares Method for Inverse Kinematics Calculation of Redundant Manipulators
Authors: Toritani Shunsuke ,   Department of Mechanical Engineering, Division of Artificial Systems Science, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi, Chiba 263-8522, Japan, Shauri Ruhizan Liza Ahmad , Nonami Kenzo , Fujiwara Daigo
Published: April 2016

In this paper, we present an Inverse Kinematics (IK) algorithm based on the nonlinear least-squares method for redundant manipulators. The Newton-Raphson (NR) method is a commonmethod for IK calculation of redundant manipulators. The NR method, however, causes many problems in terms of joint angle limits, singularity, and solvability. Severalmethods have therefore been proposed to solve these problems. Most, however, focus only on IK calculation performance when a desired trajectory moves outside of the workspace. A manipulator is required to move continuously, even after a desired trajectory moves outside of the workspace. It is thus also necessary to implement the IK calculation method for bringing a desired trajectory back into the workspace. In this study, we propose a user-friendly method for robotic manipulation that is capable of implementing accurate IK calculation when a desired trajectorymust be returned to the workspace.
Development of a Passive Turn Type Skiing Robot with Variable Height Mechanism of Gravitational Center
Authors: Kono Kengo ,   Faculty of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan, Saga Norihiko
Published: April 2016

In recent years, sports engineering has become an active area of research. It has produced important contributions of many kinds in the development of sports. Ski turns have been investigated from various viewpoints such as the motion analysis of skiers and ski robots and dynamic simulation. Nevertheless, despite considerable research, the mechanisms of ski turns remain to be completely elucidated. Mechanical models derived using approximate expressions do not, furthermore, match alpine ski turns and results are therefore not reflected concretely. To facilitate theoretical considerations, a passive skiing robot was developed. Influences on ski turns, such as the position of the center-of-gravity, can be examined easily using this robot. In a passive turn type of ski robot, a difference in the turn cycle appeared in a difference in leg height. We noticed the influence of turning in the difference in the center-of-gravity height and appended mechanism to change the height of the legs to a passive turn type of ski robot in order to verify whether turns can be controlled by changing the position of the gravitational center. As described here, we examined ski turn dynamics to help skiers improve their athletic performance.
Development of Portable Energy-Saving Type Air Supply System – 1st Report: Effect of Variable Volume Tank –
Authors: Iwawaki Tatsuyuki ,   Graduate School of Natural Science of Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan, Sasaki Daisuke , Noritsugu Toshiro , Takaiwa Masahiro
Published: April 2016

The purpose of this study is to develop a portable energy-saving type air supply system. A variable volume tank is developed in order to drive a pneumatic actuator with a low discharge pressure in a tank. The developed tank composed of flexible materials can store pneumatic energy by converting it to elastic energy. In this paper, the composition of the system, the structure and characteristic of a variable volume tank and experiment of driving actuator with constant and variable volume tanks are discussed. As a result, the variable volume tank can drive the actuator at a lower supply pressure than with the constant volume tank.
Curved Type Pneumatic Artificial Rubber Muscle Using Shape-Memory Polymer
Authors: Takashima Kazuto ,   Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan, Noritsugu Toshiro , Rossiter Jonathan , Guo Shijie , Mukai Toshiharu ,   Advanced Science Institute, RIKEN, 2271-130 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-0003, Japan,   Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan,   Department of Engineering Mathematics, University of Bristol, Bristol BS8 1TH, UK,   SR Laboratory, Tokai Rubber Industries, Ltd., 1 Higashi 3-chome, Komaki 485-8550, Japan
Published: April 2016

A novel pneumatic artificial muscle actuator is presented which is based on the design of a conventional curved type pneumatic bellows actuator. By inhibiting the extension of one side with fiber reinforcement, bending motion can be induced when air is supplied to the internal bladder. In this study, we developed a new actuator by replacing the fiber reinforcement with a Shape-Memory Polymer (SMP). The SMP can be deformed above its glass transition temperature (Tg) and maintains a rigid shape after it is cooled below Tg. When next heated above Tg, it returns to its initial shape. When only part of our actuator is warmed above Tg, only that portion of the SMP is soft and can actuate. Therefore, the direction of the motion can be controlled by heating. Moreover, our actuator can be deformed by an external force above Tg and fixed by cooling it below Tg.
High-Efficient Biped Walking Based on Flat-Footed Passive Dynamic Walking with Mechanical Impedance at Ankles
Authors: Hanazawa Yuta ,   Department of Mechanical and Control Engineering, Tokyo Institute of Technology, 2-12-1 Oh-okayama, Meguro-ku, Tokyo 152-8552, Japan, Yamakita Masaki
Published: April 2016

In this paper, we present novel biped walking based on flat-footed Passive Dynamic Walking (PDW) with mechanical impedance at the ankles. To realize biped robot achieving high-efficient walking, PDW has attracted attention. Recently, flat-footed passive dynamic walkers with mechanical impedance at the ankles have been proposed. We show that this passive walker achieves fast, energy-efficient walking using ankle springs and inerters. For this reason, we propose novel biped walking control that mimics PDW to realize biped robots achieving fast, energy-efficient walking on level ground. First, we design a flat-footed biped robot that achieves fast, energy-efficient PDW. To achieve walking based on PDW, the biped robot then takes advantage of a virtual gravitational field that is generated by actuators. The biped robot also pushes off with the foot in the double-support phase to restore energy. By walking simulation, we show that a flat-footed biped robot achieves fast, energy-efficient walking on level ground by the proposed method.
Image Information Added Map Making Interface for Compensating Image Resolution
Authors: Kawakami Shinya ,   Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan, Takubo Tomohito , Ohara Kenichi , Mae Yasushi , Arai Tatsuo ,   Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
Published: April 2016

We propose an image information added map to create an intuitive interface to explore unknown environments using pictures. The proposed map contains a good picture for each mapped object. The shooting angle and position for the picture are defined by the required resolution of the image, the camera specifications and the object’s shape. The appearance from a desired direction can be confirmed intuitively by referring to the shooting vector for the object. To make the proposed map, high quality image information should be acquired on its definition. We developed a tool for making the map and tested its effectiveness in an experiment.
Virtual Reality Simulators Based on a Novel Robotic Catheter Operating System for Training in Minimally Invasive Surgery
Authors: Guo Jin ,   Graduate School of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Japan, Guo Shuxiang , Xiao Nan , Gao Baofeng ,   Intelligent Mechanical Systems Engineering Department, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Japan,   Harbin Engineering University, Harbin, Heilongjiang Province, China
Published: April 2016

Minimally invasive surgery is a specialized surgical technique that permits vascular interventions through very small incisions. This minimizes patients’ trauma and permits faster recovery compared to conventional surgery. The significant disadvantage of this surgical technique is, however, its complexity; therefore, it requires extensive training before surgery. In this paper, we presented virtual reality simulators for training with force feedback in minimally invasive surgery. This application allows generating realistic physicalbased models of catheters and blood vessels, and enables surgeons to touch, feel and manipulate virtual catheter inside a vascularmodel through the same surgical operation mode as is used in actual MIS. Experimental results show that the error rate is in an acceptable range and that simulators can be used for surgery training.
Feasibility Check of an Assist System Through the Simulation of Bipedal Walking Using a CPG
Authors: Takubo Tomohito ,   Department of Physical Electronics and Informatics, Graduate School of Engineering Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan, Fukano Yohei , Ohara Kenichi , Mae Yasushi , Arai Tatsuo ,   Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
Published: April 2016

A wearable mobile-base Walking Assist System (WAS) is simulated in this paper with the bipedal simulator we developed. The simulator employs a Central Pattern Generator (CPG) for bipedal walking pattern generation. The CPG-based walking pattern is one of the candidates for simulating human walking. Average Japanese body dimension data is applied to the bipedal model so that walking efficiency can be evaluated using the simulator. The effectiveness of the proposed simulator is confirmed by comparing real human walking and simulated walking in terms of the shape of the swing leg trajectory, data from the pressure sensor, and the feasibility of the prototype WAS. A prototype is developed and experimental results show the effectiveness of the bipedal simulator.
3D Measurement Using a Fish-Eye Camera Based on EPI Analysis
Authors: Terabayashi Kenji ,   Department of Mechanical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Hamamatsu, Shizuoka 432-8561, Japan, Morita Toru , Okamoto Hiroya , Umeda Kazunori ,   Sony Corporation, 2-15-3 Konan, Minato-ku, Tokyo 108-6201, Japan,   Department of Precision Mechanics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
Published: April 2016

In car driving support systems and mobile robots, it is important to understand three-dimensional environment widely at once. In this paper, we use a fish-eye camera as a sensor to measure three-dimensional (3D) environments. This camera can take a wide-range and distortional image and can be easily mounted on cars. We propose a method for reconstructing 3D environment using fish-eye images based on Epipolar-Plane Image (EPI) analysis. This method enables easy and stable matching of feature points. The effectiveness of the proposed method is verified by experiments.
2-D Force Display System with Redundant ER Fluid Brake Aimed at Rehabilitation Support System for Upper Limbs
Authors: Haraguchi Makoto ,   Department of Mechanical Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan, Furusho Junji , Kawatani Ryoji ,   Department of Mechanical Engineering, Faculty of Engineering, Fukui University of Technology, 3-6-1 Gakuen, Fukui 910-8505, Japan,   Department of Mechanical Engineering, Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui, Fukui 910-8507, Japan
Published: April 2016

These days, there aremany patients with ataxia, which is paralysis caused by a brain stroke or asynergia. Early detection of functional deterioration and sufficient rehabilitative training are necessary for these patients. Rehabilitation support systems for upper limbs using force display systems are expected to quantify the effects of rehabilitative training and enhance the motivation of patients. The application of a passivetype force display system is especially desirable for its high safety. There are, however, some directions and positions for which it is difficult to display force in a passive-type force display systemusing only passive elements. To solve this problem, a method for the improvement of controllability using redundant brakes had been suggested. This method made it possible to display more various force power and directions than could be done with previous systems. In this study, we have developed a redundant-brake rehabilitation system for the upper limbs: Redundant-PLEMO-1.
Life Pattern Estimation of the Elderly Based on Accumulated Activity Data and its Application to Anomaly Detection
Authors: Mori Taketoshi ,   The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Ishino Takahito , Noguchi Hiroshi , Sato Tomomasa , Miura Yuka , Nakagami Gojiro , Oe Makoto , Sanada Hiromi
Published: April 2016

A life pattern estimation method and its application to anomaly detection of a single elderly are proposed. Our observation system deploys some pyroelectric sensors in an elderly’s house and monitors and measures activities 24 hours a day to grasp residents’ life patterns. Activity data is successively forwarded to the nurse operation center and displayed to nurses at the center. The system reports status related to anomalies together with the basic activities of elderly residents to the nurses, who decide whether recent accumulated data expresses an anomaly or not based on suggestions from the system. In the system, residents whose lifestyle features resemble each other are categorized into the same group. Anomalies that occurred in the past are shared in the group and utilized in an anomaly detection algorithm. This algorithm is based on an “anomaly score.” The score is figured out by utilizing the activeness of the house’s elderly resident. This activeness is approximately proportional to the frequency of sensor response within one minute. The anomaly score is calculated from the difference between activeness in the present and in the past averaged over the long term. The score is thus positive if activeness in the present is greater than the average in the past, and the score is negative if the value in the present is less than average. If the score exceeds a certain threshold, it means that an anomaly event has occurred. An activity estimation algorithm is also developed that estimates the basic activities of residents such as getting up in the morning, or going out. The estimation is also shown to nurses with the anomaly score of residents. Nurses can understand the condition of elderly residents’ health by combining the information and planning the most appropriate way to respond.
Insole-Type Simultaneous Measurement System of Plantar Pressure and Shear Force During Gait for Diabetic Patients
Authors: Mori Taketoshi ,   Life Support Technology (Molten), Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, Hamatani Masako , Noguchi Hiroshi , Oe Makoto , Sanada Hiromi ,   Department of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Published: April 2016

Plantar foot ulceration is one diabetic complication shown to be associated with both pressure and shear force. There are plantar pressure measurement systems, but it is still difficult to measure plantar shear force while walking. The aim of this study is to establish a simultaneous in-shoe measurement system of plantar pressure and shear force during a gait. The design of the measurement system is based on F-scan pressure-distribution-sensor sheets and shear-sensor sheets. An insole with a shear-sensor sheet was arranged to be applicable for measurement of diabetic having neuropathy patients without damaging their skin. It was found that the system gets proper different shear force data in response to gait patterns, such as shuffle walking and flat-floored walking. We confirmed, moreover, the repeatability of the system for 5 healthy individuals. Experimental results show that weight-adjusted plantar shear stress during the pushoff phase of a gait increases in diabetic patients with calluses more than in patients without calluses. After a clinical study of diabetic patients, the system can be applied not only for the prevention of diabetic foot but also for the broad evaluation of gait posture.
A Portable Arthroscopic Diagnostic Probe to Measure the Viscoelasticity of Articular Cartilage
Authors: Sugita Naohiko ,   School of Engineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Kizaki Toru , Kanno Daisuke , Abe Nobuhiro , Yokoyama Yusuke , Ozaki Toshifumi , Mitsuishi Mamoru ,   Toyota Motor Corporation, 1 Toyota-cho, Toyota, Aichi 471-8571, Japan,   Department of Intelligent Orthopaedic System, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama-shi, Okayama 700-8558, Japan,   Department of Orthopaedic Surgery, Tottori Municipal Hospital, 1-1 Matoba, Tottori-shi, Tottori 680-0873, Japan
Published: April 2016

Tissue engineering has been increasingly applied to treat diseases of the joints that adversely affect components such as cartilage and ligaments. These components do not contain blood vessels and nerves; the risk of rejection during tissue transplantation is therefore less than that for other organs. Treatment of cartilage and ligaments requires highly skilled surgeons, however, and it is necessary to establish a quantitative evaluation method. It is difficult to measure the mechanical properties of cartilage because of its viscoelasticity. Sensing technology that enables uniform qualitative evaluation is therefore desired. In this study, a portable diagnostic probe was developed and the viscoelasticity of cartilage was measured quantitatively over a short period of time. The probe was designed based on the Voigt model and comprises a piezoelectric actuator, a force sensor, and a contact probe. Stiffness and viscosity coefficients of various samples such as silicone rubber and the bovine meniscus were measured, and the accuracy of the developed probe was evaluated. Finally, the mechanical properties of human articular cartilage were measured using the diagnostic probe.
Automatic Surgical Workflow Estimation Method for Brain Tumor Resection Using Surgical Navigation Information
Authors: Nakamura Ryoichi ,   Division of Artificial Systems Engineering, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan, Aizawa Tomoaki , Muragaki Yoshihiro , Maruyama Takashi , Iseki Hiroshi ,   Institute of Advanced Biomedical Engineering and Science, Tokyo Women’s Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo 163-8522, Japan,   Department of Neurosurgery, Tokyo Women’s Medical University, 8-1 Kawadacho, Shinjuku-ku, Tokyo 163-8522, Japan
Published: April 2016

It has been acknowledged as a problem in recent years that surgery has become complex due to medical system updating. To respond to the increasing demand for making surgery more optimal and efficient, studies on surgical process analysis have attracted attention. Automatic estimation technology is necessary for accurate and efficient process analysis. With a focus on this problem, we have studied technologies on the automatic estimation of surgical processes. In this study, we develop an automatic estimationmethod for a chosen surgical process on the basis of information obtained from a surgical navigation system, taking as an example image-guided brain tumor surgery. We found a significant correlation among five parameters – progress in enucleation, depth of surgical tool tip, displacement of surgical tool, volume of surgical tool position log data, and number of events detected during surgery – that are defined according to the anatomical information on patients and surgical procedure information on surgeons stored in the navigation system, and three stages in the brain tumor removal process: (1) incision of the surface cortex, (2) testing and blood vessel resection, (3) resection and removal of tumors. By using automatic Bayesian estimation of tumor removal processes in eight case examples using the five parameters, we estimated 73% of all processes correctly. This result indicates that surgical processes are automatically estimated with information in the surgical navigation system alone, which thus contributes to the accurate and efficient surgery analysis.
Development of Database of Children’s Fall Dynamics Using Daily Behavior Observing System
Authors: Kakara Hiroyuki ,   Department of Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan, Nishida Yoshifumi , Yoon Sang Min , Mizoguchi Hiroshi , Yamanaka Tatsuhiro ,   Digital Human Research Center, National Institute of Advanced Industrial Science and Technology, 2-3-26 Aomi, Koto-ku, Tokyo 135-0064, Japan,   School of Computer Science, Kookmin University, 861-1 Chungnung-dong, Songbuk-gu, Seoul 136-702, Korea,   Ryokuen Children’s Clinic, 2-1-6-201 Ryokuen, Midori-ku, Yokohama-shi, Kanagawa 245-0002, Japan
Published: April 2016

This paper describes the development of a fall database for biomechanical simulation. First, data on children’s daily activities were collected at a “sensor home,” which is a imitation daily living space. The sensor-based home comprises a video-surveillance system embedded into a daily-living environment and a wearable acceleration-gyro sensor. Falls were then detected from sensor data using a fall detection algorithm that we developed, and videos of detected falls were extracted from long-time recorded video. Extracted videos were used for fall motion analysis. A new Computer Vision (CV) algorithm was developed to automate fall motion analysis. Using the CV algorithm, fall motion data were accumulated into a database. The database allows a user to perform conditional searches for fall data by inputting search conditions, such as a child’s attributes, and fall situations.
Relation Between Blood Pressure Estimated by Pulse Wave Velocity and Directly Measured Arterial Pressure
Authors: Inajima Tsukasa ,   The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan, Imai Yasushi , Shuzo Masaki , Lopez Guillaume , Yanagimoto Shintaro , Iijima Katsuya , Morita Hiroyuki , Nagai Ryozo , Yahagi Naoki , Yamada Ichiro
Published: April 2016

Hypertension is the strongest risk factor in cardiac and cerebrovascular diseases among the Japanese. Even daily variations in blood pressure may become a risk, and repeated blood pressure measurement is recommended. Conventional Ambulatory Blood Pressure Monitoring (ABPM), however,may cause discomfort to examinees because they have to have their arms compressed and carry the monitor itself. The number of ABPMmeasurements is limited to about 1 every 15–30 minutes. We therefore attempted, working with medical and engineering teams, to develop a wearable blood pressure sensor that would place less burden on examinees, be less influenced by physical movement, and be usable for continuous blood pressure measurement. We then examined the clinical practicality of the sensor. We modified the existing Moens-Korteweg blood-pressure equation and developed a new systolic blood pressure calculation system that used electrocardiography and ear-lobe pulse waves because the ear lobe would receive little influence from physical movement. We chose three clinical cases from among intensive care unit subjects. We not only estimated their blood pressure using the systemwe developed but also measured arterial pressure directly with an intravascular catheter to see how estimated blood pressure followed actual changes in blood pressure and to evaluate the accuracy of estimated blood pressure. When systolic blood pressure estimated by using the pulse wave velocity method was compared with direct blood pressure measurement, we found that the method captured trends in blood pressure variations correctly. The difference was within ±10 mmHgfor all of the cases. In a comparison using the Bland-Altman method for the three clinical cases, the average difference was –0.4 mmHg, –1.0 mmHg, and –1.7 mmHg and standard deviation was 4.2 mmHg, 4.8 mmHg, and 4.3 mmHg, respectively, which indicated good agreement. Introducing such wearable blood pressure sensors into daily medical practice gets detailed information on continuous blood pressure variation while examinees move freely and the resulting information is used for better quality control of adult diseases. It is also expected that wearable blood pressure sensors can be used in emergency medical cases, in intensive care, and at remote sites.