This paper presents an adjustable knee mechanism for walking assistance devices for the elderly to provide physical gait assistance. The adjustable knee mechanism can assist in flexion/extension motions of the knee joint and compensate for the transitional movements of the knee in the sagittal plane as well as aligning the frontal plane. In order to compensate for the center of rotation, the proposed adjustable knee mechanism is implemented by connecting several rolling cams with unique and precisely calculated contact geometries. The key idea of the proposed mechanism is to realize linear motion and accurate torque transmission by a pulley method using the rolling joint in which the distance of the center between the rolling cams is changed. The proposed articulated joint can effectively deliver the torque required for assistance while adapting to the joint motion of the wearer. This paper describes the mechanical design of this knee mechanism and its implementation on a wearable robot and in preliminary experiments. The performance of the proposed mechanism was verified by simulations and experiments.

This paper proposes a new concept called “a flexible exoskeleton” and presents the design of a wearable walking assistance device to provide physical gait assistance for the elderly. To overcome some limitations of previous wearable walking assistance devices, 3 novel mechanisms are proposed: 1) flexible thigh frames that withstand the designated load direction, 2) an adjustable flexible hip brace surrounding the wearer's body, and 3) slim and backdrivable actuators that minimize the maximum height and resistance. The proposed walking assistance device has reduced metabolic energy consumption by 13.2±4% compared with a free condition.

In this paper, tension propagation analysis of a newly designed multi-DOF robotic platform for single-port access surgery (SPS) is presented. The analysis is based on instantaneous kinematics of the proposed 6-DOF surgical instrument, and provides the decision criteria for estimating the payload of a surgical instrument according to its pose changes and specifications of a driving-wire. Also, the wire-tension and the number of reduction ratio to manage such a payload can be estimated, quantitatively. The analysis begins with derivation of the power transmission efficiency through wire-interfaces from each instrument joint to an actuator. Based on the energy conservation law and the capstan equation, we modeled the degradation of power transmission efficiency due to 1) the reducer called wire-reduction mechanism, 2) bending of proximal instrument joints, and 3) bending of hyper-redundant guide tube. Based on the analysis, the tension of driving-wires was computed according to various manipulation poses and loading conditions. In our experiment, a newly designed surgical instrument successfully managed the external load of 1kgf, which was applied to the end effector of a surgical manipulator.

The differential drive mechanism, which is one of the mechanisms of wheeled mobile robots, is simple and useful for the motion of the mobile robot. The mechanism, however, has typical disadvantages of losing mobility, falling down, etc. when the robot moves over obstacles or uneven terrains. A novel suspension mechanism presented in this paper was designed to help the robot to overcome these problems. In particular, this mechanism is very suitable for a tall robot, which is susceptible to overturning because of the disturbance caused by acceleration, deceleration, and collision. The proposed mechanism called a Multilayered Suspension Mechanism is composed of the effective and well-directed combination of springs and dampers. It is very simple and cost-effective since it has no actuator for suspension. In this paper, mechanical construction and characteristics of the mechanism are described. Then, excellence and performance of the proposed mechanism are demonstrated by simulations and experiments.

In recent decades, the devastating earthquakes, which can damage a lot of houses and buildings, have frequently happened. To slow down or prevent the disastrous damages of the earthquake, the various technologies have been required. Of these technologies, the ground motion simulator of the earthquake can be used to alert people to the dangers of the earthquake. This paper introduces a potable earthquake simulator, called a Jishin-The-Vuton 3D, which realizes the up-and-down motion with the holonomic omni-directional motions in order to simulate three-dimensional ground motion of the earthquake. Focusing on the design concept, structure, and feature of this new simulator, the authors discuss its implementation and verify its feasibility with preliminary experimental results.

Many serious accidents are reported about the manual window cleaning task, and it is needed to automate the task for the majority of windows having no special guide frames for window cleaning machines. This paper proposes a novel tethered window cleaning robot named a “SkyScraper-I” and discusses its design. The SkyScraper-I has the functions to approach all the windows located on one side of a building by controlling the lengths of a pair of suspending tethers from the top of the building and to clean the whole surface of the windows. The robot consists of the vertically suspended sliding rod, a pair of clamping arms with clamping suction rollers on both ends, and a squeegee sliding mechanism to wipe the window. The clamping suction rollers have three functions: to fix the Sky-Scraper between the upper and lower frames of the window, to produce a suction force without touching the window, and to drive sideways for wiping all the window. From the several preliminary experiments, the SkyScraper-I demonstrated good mobility to move from window to window and to clean the surface of each window.

In this paper, we present an autonomous in-pipe robot navigating system using vision-based landmark recognition. We propose to use special features of the pipelines (such as elbows or branches) as landmarks by recognizing the shadows of the elbows and branches. To obtain consistent shadow images, the in-pipe robot equips with specially designed illuminator. By analyzing the shadow, the robot can easily identify these landmarks, detect the direction of the passage, and adaptively traverse through while continuously updating the map. The effectiveness of the proposed method is verified by real experiments using the in-pipe robot MRINSPECT V for inspecting inside of the miniature urban 8-inch gas pipeline structure.

Improvement of the adaptability of a quadruped robot in rough terrain is studied in this paper. First, the position and posture of the body of the robot are adjusted to maximize the number of choices for foot placement of the next swing leg. The more choices the robot has to select the next suitable foothold, the better it will be to cope with rough terrain. Second, an effective foothold search algorithm is developed. The foothold search algorithm not only tries to find a valid foothold but also tries to maintain high adaptability of the robot. For implementing the algorithm, some new concepts such as potential swing direction, complementary kinematic margin and elliptical set of candidate footholds are also proposed. The effectiveness of this procedure in improving the adaptability of a quadruped robot moving in challenging terrain is verified in both simulation and experiment.

Aiming to real easy application in several quadruped robot platforms, this paper introduces a new method of modeling central pattern generators (CPG) to control quadruped locomotion. Not only can this new model generate all the primary gaits of quadrupeds stably with limit cycle effect, but it also has the ability of tuning the periodic outputs with arbitrary waveforms. The core idea is to combine strong points of two mathematical tools: Fourier series and Recurrent neural networks. In addition, a new biomimetic controller is also introduced using the proposed CPG model and several reflex modules. Finally, dynamic simulations are performed to validate the efficiency of the proposed controller.

Generally, object recognition in robotics has used vision, sonar, laser range sensors, etc. In this paper, the authors propose a new sensing technology based on radio frequency identification (RFID) to facilitate the autonomous recognition of objects. This technology uses a novel tag, named the 3-D tag, with which an object can be identified and its orientation together with location can be estimated. This paper presents the method for object recognition by analyzing the characteristics of the 3-D tag, and then validates the 3-D tag through several demonstrations showing its usefulness as an independent sensor for recognizing objects.

In this paper, we investigate comprehensive issues of modularized robot systems and present architecture for effective development of personal robots. The proposed architecture includes the interface and interaction methodology of the hardware modules and the software among the modules. Based on the architecture, we present a fully modularized personal robot dynamically reconfigurable personal robot I. Its hardware modules are easily added to or removed from the original system, and also the distributed software functions of the modules are rearrangeable accordingly. We focus on how to effectively build up the robot, and discuss the dynamically reconfigurable features of it for evaluating the proposed idea and approach.

In this paper we present an in-pipe robot, called MRINSPECT V (Multifunctional Robotic crawler for In-pipe inSPECTion V), which is under development for the inspection of pipelines with a nominal 8-inch inside diameter. To travel freely in every pipeline element, the robot adopts a differential driving mechanism that we have developed. Furthermore, by introducing clutches in transmitting driving power to the wheels, MRINSPECT V is able to select the suitable driving method according to the shape of the pipeline and save the energy to drive in pipelines. The robot aiming for autonomous navigation is configured with four modules serially connected. Two active driving modules are located in front and rear of the system, respectively. Passive modules are linked between the driving modules. This module-based robot can fit to narrow and winding pipelines by using the novel mechanism such as the specially designed module-joints. In this paper, the critical points in the design and construction of the proposed robot are described with the preliminary results of experiments that yield good mobility and increased efficiency.

RFID (radio frequency identification) technology has been rapidly and widely applied to various applications. Recently, RFID has been suggested as technology that supports object recognition. This paper introduces the advanced RFID-based recognition. The proposed RFID system not only identifies the existence of the object, but also estimates object's orientation and location. These characteristics considerably reduce the dependence on other sensors which are required for recognizing objects. In this paper, we analyze the characteristics of our system and present a novel tag named a 3D tag. The estimation methods of location and orientation using the system are discussed

Pipelines for the urban gas-supply system require a robot possessing outstanding mobility and advanced control algorithms, since they are configured with various pipeline elements, such as straight pipelines, elbows, and branches. We present a comprehensive work for moving inside underground urban gas pipelines with a miniature differential-drive in-pipe robot, called the Multifunctional Robot for IN-pipe inSPECTion (MRINSPECT) IV. MRINSPECT IV has been developed for the inspection of urban gas pipelines with a nominal 4-in inside diameter. The mechanism for steering with differential-drive wheels, arranged three-dimensionally, allows it to easily adapt to most of the existing configurations of pipelines, as well as providing excellent mobility during navigation. After carrying out analysis for fittings in pipelines, mathematical descriptions of their geometries are presented, which make it possible to estimate the movement patterns of the robot while passing through the fittings. Also, we propose a method of controlling the robot by modulating speeds of driving wheels that is applicable without sophisticated sensory information. To confirm the effectiveness of the proposed method, experiments are performed, and supplementary considerations on the design of the in-pipe robot are discussed.

Architecture and method for accelerating the development of personal robots are presented. It includes the technology such as modularization with its own processing and standardization open to other developers. We mainly focus on the effective ways for integrating the various robotic components and interfacing among them. The architecture is implemented by developing the fully modularized personal robot DRP I (Dynamically Reconfigurable Personal robot). Its hardware component is easily attached to and detached from the whole system but also each software of the components is functionally distributed. As methodology for interfacing and integration of DRP I, we introduce Module-D (Module of DRP I) characterized functionally, VM-D (Virtual Machine of DRP I) and RPL(Robot Programming Languages) for supporting compatibility of each Module-D. As experimental work, the dynamically reconfigurable feature of the robot is introduced.

In the previous reports (2001), we presented a miniature inpipe robot called MRINSPECT (Multifunctional Robotic crawler for INpipe inSPECTion) IV which has been developed for the inspection of urban gas pipelines with a nominal 4-inch inside diameter. Its steering capability with three-dimensional differentially driven method provides the outstanding mobility for navigation and the new mechanism for steering can easily adjust itself to most of pipelines or fitting, in which other former inpipe robots can hardly travel as ever. In this paper, we present the strategy and the critical points established on using the speed modulation for the navigation in elbows and branches. The analysis for the navigation inside fittings and curved pipelines is given in detail and it is addressed how to compute the speeds of the independent wheels for the differential drive in elbows and branches.

We introduce the robots called MRINSPECT (multifunctional robotic crawler for inpipe inspection) III and IV which are under development for the inspection of urban gas pipelines. The proposed robots can freely move along the basic configuration of pipelines, such as horizontal or vertical pipelines. Moreover, it can travel along reducers, elbows, and steer in the branches by using steering mechanisms. Especially, their three dimensional steering capability provides outstanding mobility in navigation that is a prerequisite characteristic in urban gas pipelines. Their critical points in the design and construction are introduced with preliminary results of experiments.

We present a robot system for in-pipe inspection of underground urban gas pipelines. The robot is configured as an articulated structure like a snake with a tether cable. Two active driving vehicles are located in front and rear of the system, and passive modules such as a control module are chained between the active vehicles. The proposed robot has outstanding mobility offered by a new steering mechanism, called double active universal joint, which makes it possible to cope with complicated configurations of underground pipelines. Characteristic features of the system are described and the construction of the system is briefly outlined.