Soft contraction actuator has always been an important research field in soft robotics. This paper presents a novel soft contraction actuator which can realize high-ratio contraction when pressurized by pneumatic power. This actuator can be easily made by soft materials including rubber tube, one-way extensible cloth, inextensible cloth and wire. 2 types of structures are presented based on different working circumstances. When pressurized, the actuator can curve and then coil to a helical shape due to the different extensibilities of its opposite sides, a high contraction length and large contraction force can be achieved synchronously. Experiments are conducted to show the relationship between contraction force and contraction ratio of this actuator. The high contraction ratio of this actuator is revealed by comparing with McKibben actuator under the same condition, the maximal contraction ratio reaches 78% and the actuation stress is 8.36kPa.

This paper discusses the design method of a self-propelled catheter with thin diameter of 2.6mm, aimed for moving and steering in the bronchi. As the basic configuration, the proposed catheter is composed of an inner tube and McKibben artificial muscles. It can propel by generating travelling waves by a single supply line driven by pneumatics. Since the inner tube equips with orifices of different size, several McKibben chambers can deform with the time delay. We also propose the method to steer the direction at the branch pipe, whose angle can be adjusted by PWM control of pressuring. Besides, we also introduce the design method of how to deal with the pipes with different diameters. The validity of these proposed methods are verified by the prototype through the experiments in the bronchial model.

In this paper, we propose an epoch-making soft sheet actuator called “Wavy-sheet”. Inspired by gastropod's locomotion, Wavy-sheet can generate continuous traveling waves on the whole soft body. It aims to be applied to a mobile soft mat capable of moving and transporting without damaging the object and the ground. The actuator, driven by pneumatics, is mainly composed of a couple of flexible rubber tubes and fabrics. The advantages are: i) many traveling waves can be generated by just three tubes, ii) the whole structure can adapt its own shape to the outer environment passively, and iii) only 10 mm in thickness and can generate waves with larger than 10mm in amplitude. In this paper, first, we describe the basic concept of Wavy-sheet, and then show the configuration and the principle of wave propagation. Next, fabrication methods are illustrated and the design methods are addressed. By using a prototype actuator, several experiments are conducted. Finally, we verify the effectiveness of the proposed actuator and its design methods.

This paper presents the design and implementation of a lightweight and powerful fingers actuator capable of grasping various shaped objects. The proposed fingers actuator is designed on the underactuated structure formed by a thumb and an index finger, which are composed of a zigzag tube with one chamber and a soft polyurethane foam with notch. When the inside of the tube is pressurized by pneumatics, each finger joint can be bent simultaneously performing one degree of freedom motion. Due to the compliance of pneumatic and the softness of the structure, it can automatically hold various types of objects. The design parameter of each joint is illustrated in order to base on distributed grasping force evenly against the objects. The developed fingers could not only perform wide range of grasping but also realize two and half times larger force/weight ratio than general fingers actuator with electric servo motor. Lastly, as the application of the proposed fingers, it is mounted on an aerial manipulator for the door opening mission, and its validity is experimentally verified.

This paper presents an aerial robot with a manipulator to implement door opening mission. Although general aerial robots have advantages of flying in the three-dimensional space freely, they don't have any capability of moving to another room when the door is closed. To overcome this problem, we propose a new configuration of an aerial manipulator with perching function, knob-twisting function, and door-pushing function. Perching function can be achieved by integration of door-approach control, the mechanism for perching and attitude-change control. With regard to knob-twisting function, the design concept of a light-weight manipulator generating large enough force to twist the knob is introduced, which is composed of a soft-bag actuator with variable restriction to perform the arbitrary curved trajectory. On the other hand, the door pushing force is aimed to be generated by the lift of the propeller, which is helpful to avoid gaining the additional weight. The validity of the proposed methods is experimentally verified by using the developed prototype.

This paper proposes a pneumatic gripper that allows gripping of the human body aimed for the transfer support, whether the body is lying down or leaning against the back support on the chair. To grip the body safely and comfortably under any conditions, two functions are newly introduced. One of them is “shape adaptive joints” which enable every gripping force to be equally distributed at each contact point regardless of body shape. The other is “slip in tip” which helps to reduce both the risk of injury and the uncomfortable friction between the body and the gripper, realized by a new pneumatic actuator to draw out the inner chambers without rubbing against the contact surface. It allows to bend following to the body shape and can also retract the chamber to release the patient safely. The validity of these functions are verified by a developed prototype called “Big-hand”, and its effectiveness for the transfer support is experimentally confirmed by lifting a mannequin and a human being.

This paper discusses a method of locomotion called the “fluid powered ropeway”. It aims to collect information in dangerous buildings as rapidly and safely as possible. The device is mainly composed of a flexible flat tube and a gondola probe driven by fluid power using the buckling phenomenon of the tube. The big advantage is the gondola has the potential to traverse rocky terrains that wheeled and crawler-type vehicles have difficulty in crossing over. This is because the drive force of the gondola is not against the ground but against the tube. In this paper, first, how to operate fluid powered ropeway in a disaster site is illustrated. Next, how to increase the drive force, how to enhance the ability of the gondola to travel over obstacles, and an analysis of the performance are discussed. Finally, the feasibility of the proposed method is verified through an experiment that uses the prototype developed.

This paper discusses a casting device for search and rescue operation to aid higher and faster access for mobile robots. To realize higher performance, the design concept of the device is examined from the following three aspects. First, after the arrangements of the stored tether are categorized, the method of selecting the optimal one is considered to maximize the kinetic energy on the tether. Second, to minimize the resistance caused by the tether, a tapered case for the storage is proposed, expected to mitigate the friction between the tether and the case and to prevent the twist on the tether. Third, the way of anchoring the end of the cast tube is proposed. Finally, experimental results show the validity of the device designed on the proposed concepts, after the device is combined with an unmanned vehicle and a ropeway type robot.

This paper proposes a novel flexible fluid actuator with a long cylindrical structure, aimed at creeping smoothly even on rugged and narrow terrain. Since only the tip goes forward by drawing out the outer skin from its inside, the actuator creeps without moving against the outer environment, just like the plant's growing process. The actuator is composed of the plural flexible flat tubes, placed around the cylindrical slippery cloth in parallel, whose tips are bent to cut off the fluid passage. Moreover, it is designed to be capable of steering the direction actively by curving its tip, while the outer shape formed before remains constant. The developed prototype named "Grow-hose-I" creeps at the maximized speed of 500mm/s with generating the driving force of 40N in linear motion. Finally, its feasibility for search and rescue operation is discussed, aiming to make it carry small cameras and microphones as smoothly as possible at the disastrous site.

This paper proposes a novel flexible sliding actuator driven by fluid power. The actuator called Λ-drive is basically composed of a flat tube and a slider. In the slider the tube is bent, then the buckling point occurs, which helps to cut off the fluid passage in order to provide the driving force to the slider when pressurizing one side of the tube. The proposed actuator is applicable to not only the straight path but the spiral and the curved one as well. Moreover, the design method to drive stably and the analysis of the output force are discussed in this paper. Finally, “Fluid Ropeway” is also proposed as the application of Λ-drive aiming to search and rescue survivors in the half collapsed houses, and its feasibility is verified through the experiment.

An epoch-making handy sized sticky mobile robot has been developed, aiming to search and rescue survivors inside the half collapsed buildings caused by big earthquakes. After the robot is tossed through small spaces, it moves around the rugged or bumpy wall and ceiling to overlook the floor by the installed camera. To generate large enough adhesive force even on the rugged wall, a gel mat made of urethane is introduced, whose force can be recovered by the washing function. Developed sticky robot based on the above method could realize the 3D mobile performance on the rugged wall and ceiling with the function of washing of the gel mat and monitoring the scene of the inside of the building. The validity of the application to the rescue inspector is also verified.

This paper proposes a novel type of rescue robot which is aimed to open narrow spaces, move under heavy debris, and search and save out survivors at disastrous site. Unlike most of the conventional mobile robots to move through opened spaces, the proposed robot has the ability of cultivating spaces by its own so as to be able to pass through. The key of the robot is the step structure on its head which enables it to open 10 mm gap up to 250 mm gradually under 600kg load by oil hydraulic power, synchronizing with the mobile behavior to go forward. Such kind of mobile method with jack-up function can be realized by switching two modes alternately discussed in this paper. The validity of the proposed design and behavior is experimentally verified by the developed model named Bari-bari-II.

A novel fluid power actuator called flat ring tube (FRT) is introduced in this paper. The mechanism of FRT is so simple that it only needs a urethane flat tube and some water pressure. No valves or switches are required. Applying constant water pressure results in periodic oscillation of the tube. The frequency is proportional to the flow rate of the water and inversely proportional to the tube length. By contacting the tube with a motor shaft, the motor rotates due to the periodic tube oscillation. Thus, we succeeded in rotating the motor without using any electricity. There are many possible applications with FRT, and we are developing a wearable massage device which makes people feel comfortable and improves their circulation of the blood.

In order to search survivors in half-collapsed buildings at disastrous sites, the authors have developed the throw & collect rescue inspector. It is composed of a throwing and a drawing mechanisms and a child machine equipped with camera. The parent robot is inserted to the site and starts the inspection of the area. If an obstacle is in the way, it throws out a child machine with its magnetic brake pneumatic cylinder, and the inspection can be performed beyond the obstacle while the child machine is drawn back. This report shows the details of the structure of the robot.

This paper discussed an Internet-based telerehabilitation sharing system, which aims to achieve the situation where multiple stay home patients in different places can share rehabilitation instruction of one physical therapist at the same time. After the introduction, three main problems are described in this paper. Firstly the stability problem of the master-slave system with variable time delay which is the biggest problem of the tele-control system is focused on, the time delay and its effect to the system is described and the control architecture is proposed; then the operation method of the whole system with single-master and multi-slave is described; After that, the wound-tube actuator and tail-wrist which will be used as slave in the tele-rehabilitation system is introduced

This paper describes the numerical analysis and design for a higher jumping rescue robot using a pneumatic cylinder. First, the basic equations for jumping are derived and the simulation is performed. Then, the relationship between the jumping height and the pressure-receiving area of the cylinder is considered when the volume or the stroke of the cylinder is kept constant. This allows calculation of the optimal cross sectional area. In addition, the jumping height is also affected by the weight ratio between the rod and the cylinder tube. Based on these results, a robot equipped with a cylinder of the appropriate dimensions controlled by a well-selected valve is re-engineered and demonstrated. Experimental results show that the improved robot can jump considerably higher than the former design with the same energy efficiency, as shown in the following video. http://www.cm.ctrl.titech.ac.jp/study/jump/home.html.

This paper discusses the design and motion experiments of the newly constructed jumping & rolling inspector Leg-in-rotor-II. The features of Leg-in-rotor-II are as follow; (i) The driving method of 3-D jumping & rolling by the reduced degrees of freedom on the separated drive. (ii) The introduction of the passively stored leg. (iii) The introduction of the wheel with the light anisotropy elasticity of the high changing ratio. (iv) The pneumatic jumping control method and its energy saving, (v) The sensing method to estimate the desired jumping start point. (vi) The structure of the sideway tumble prevention and the shock buffer. Finally, the motion experiments of Leg-in-rotor-II to roll, jump and land on debris are shown and the validity of the introduced design methods is verified.

This paper presents a novel approach of driving the human joints by means of a fluid control system with flexibility just like clothes, which leads to a cyborg amplifying the human motor function. Former actuators for body mounting were not always designed from the point of clothing comfort. Thus, in the first part of this paper, a clothing comfort index is introduced so as to evaluate the desirability of the actuator mounted on the body. Then, pneumatic tube actuators with a novel structure are systematically proposed to increase the comfort index. By using the actuators, an efficient driving method of both the arm and the leg is shown to realize "Wearable Fluid Power" so as to assist the disabled to walk or to improve their sporting skill.

This paper proposes both the design concept and the driving mechanism of a flexible robot with multiple degrees of freedom to dive into debris. Up to now, several kinds of pneumatic robots with flexibility have been developed, however they have been unable to perform multiple degrees of freedom with high bending moment. A new type of robot, called "Active Hose", is proposed here, which has multiple degrees of freedom by connecting units of two degrees of freedom in series and has a high bending moment by introducing a spine structure and using deformation of the spiral tubes. "Active Hose" can be expected to be applied to rescue operations such as searching for victims under debris just after an earthquake, supplying fresh air and drinking water for victims, and carrying air jacks so as to make room for victims to escape.

Some stability criteria for walking vehicles on rough terrain are discussed. Several criteria for stability margin have been proposed previously and they can be roughly divided into three categories. The paper compares them with each other and concludes that a stability criterion based on energy consideration is the most reasonable for practical use through simple experiments. The existing stability margin is apparently inadequate because it varies with weight of the vehicle with the same posture, while weight doesn't affect its resistance to a tumble. Therefore, an improved stability margin normalized by weight is proposed. At the same time, a helpful tool to derive the desirable posture for walking vehicles is described which can maximize the proposed stability margin on rough terrain.

Proposes both the design concept and the driving mechanism of a flexible robot with multiple degrees of freedom to dive into debris. Up to now, several kinds of pneumatic robots with flexibility have been developed, however, they could not perform multiple degrees of freedom with high bending moment. A new type of robot, called Active Hose, is proposed which has multiple degrees of freedom by connecting units of two degrees freedom in series and has high bending moment by introducing a spine structure and using the deformation of spiral tubes. Active Hose with this performance can be expected to be applied to rescue operations such as searching for victims under debris just after an earthquake, supplying fresh air and drinking water for victims, and carrying air jacks so as to make a room for the victims to escape.

This paper proposes new types of a water hydraulic motor and a valve to control its speed which will be applied to the robots soaked in water. The big advantage of this motor is that it can be driven by such low pressure as tap water with high performance. The key of their mechanism is that the working fluid is completely wrapped by the soft tube and their machine moving parts contact the fluid indirectly. In other words, the deformation of the tube drives the motor, and reversely the valve makes the tube deformed to control the motor, which removes the risk of leakage without also requiring a seal. In addition, the valve to control the rotational speed is designed which can be driven by fluid power signal without using electricity. The motors can be used in places where electricity cannot be used safely, such as bathroom, sink, workshop over water, under water, etc. The basic driving principle and characteristics of the theoretical torque, the rotational speed, and the efficiency are described here with the results of the experiment.

Design and control of a new quadruped walking and manipulating robot TITAN VII which can be operated on a steep slope is discussed. We first consider the optimal design of a driving system of legs consisting of prismatic actuators so as to produce large output power with minimum weight based on the concept of coupled drive. Secondly, we discuss the criteria for stability on a slope and introduce a new type of extensible leg to maintain high terrain adaptability on a sleep slope. Thirdly, we mention a passive terrain adaptive foot mechanism consisting of a "rocker bogie sole" based on the concept of a connected differential mechanism and including an ankle installed sensor mechanism. The validity of these newly introduced mechanisms has been investigated through walking experiments of the prototype model TITAN VII, including climbing a slope of about 30 degrees using the intermittent crawl gait.

On the assumption that a quadruped robot works on a slope, we discuss how to make it prevent tumbling over. The larger the difference becomes between the potential energy of the center of gravity of the initial position and that of the highest position after its rotating, the less the robot tumbles. So this difference can be regarded as stability margin, and a novel gait to obtain largest stability margin is mentioned here. It is an intermittent crawl gait. Its energy stability contour (consisting of equal stability points on the inclined plane) is helpful in the design of standard foot trajectories. An optimal posture on the slope, designed in this way, results in inverse trapezoid shape, which means that upper two legs are located wider than lower two ones. This form worked for the experimental machine, TITAN VII. Furthermore, if the standard trajectory for one direction is combined with another direction trajectory, the quadruped robot can easily switch its proceeding directions, keeping enough stability margin. This sequence is shown.