Design of a variable-stiffness robotic hand using pneumatic soft rubber actuators

In recent years, Japanese society has been ageing, engendering a labor shortage of young workers. Robots are therefore expected to be useful in performing tasks such as day-to-day support for elderly people. In particular, robots that are intended for use in the field of medical care and welfare are expected to be safe when operating in a human environment because they often come into contact with people. Furthermore, robots must perform various tasks such as regrasping, grasping of soft objects, and tasks using frictional force. Given these demands and circumstances, a tendon-driven robot hand with a stiffness changing finger has been developed. The finger surface stiffness can be altered by adjusting the input pressure depending on the task. Additionally, the coefficient of static friction can be altered by changing the surface stiffness merely by adjusting the input air pressure. This report describes the basic structure, driving mechanism, and basic properties of the proposed robot hand

Design of Cylindrical Crawler Robot Inspired by Amoeba Locomotion

Recently, the need of colonoscopy is increasing because of the rise of colonic disorder including cancer of the colon. However, current colonoscopy depends on doctor's skill strongly. Therefore, a large intestine endoscope that does not depend on the techniques of a doctor with high safety is required. In this research, we aim at development a novel large intestine endoscope that can realize safe insertion without specific techniques. A wheel movement type robot, a snake-like robot and an earthworm-like robot are all described in the relevant literature as endoscope robots that are currently studied. Among them, the tracked crawler robot can travel by traversing uneven ground flexibly with a crawler belt attached firmly to the ground surface. Although conventional crawler robots have high efficiency and/or high ground-covering ability, they require a comparatively large space to move. In this study, a small cylindrical crawler robot inspired by amoeba locomotion, which does not need large space to move and which has high ground-covering ability, is proposed. In addition, we developed a prototype of the large intestine endoscope using the proposed crawler mechanism. Experiments have demonstrated smooth operation and a forward movement of the robot by application of voltage to the motor. This paper reports the structure, drive mechanism, prototype, and experimental evaluation

Development of a steering mechanism for a cylindrical elastic crawler

There are many pipes in factories, chemical plants and houses, whose insides are inaccessible by human. These pipes must be continuously inspected and repaired to prevent severe accidents. To realize robots which can inspect inside of such pipes, we have developed a simple and compact cylindrical crawler robot based on amoeba locomotion. In this study, we propose a steering mechanism that enables the robot to pass through T-shaped curves in pipes. Many of conventional steering mechanisms for crawler robots use single geared motor per single crawler belt to drive the crawler belts. On the contrary, the proposed mechanism can use a much larger geared motor than conventional steering mechanisms to drive all the crawler belts. Therefore, the crawler robot using the proposed steering mechanism can generate higher torque than one using conventional steering mechanism. This paper presents descriptions of the proposed steering mechanism design, comparison between proposed and conventional steering mechanisms with respect to the torque of the geared motor, and experiments using a 75A pipe with a T-shaped curve. In the experiments, the proposed steering mechanism was evaluated steering performance in a T-shaped pipe of 75A with three routes. The results demonstrated that the robot could pass through all the routes

Smart Pneumatic Artificial Muscle Using a Bend Sensor like a Human Muscle with a Muscle Spindle

Shortage of labor and increased work of young people are causing problems in terms of care and welfare of a growing proportion of elderly people. This is a looming social problem because people of advanced ages are increasing. Necessary in the fields of care and welfare, pneumatic artificial muscles in actuators of robots are being examined. Pneumatic artificial muscles have a high output per unit of weight, and they are soft, similarly to human muscles. However, in previous research of robots using pneumatic artificial muscles, rigid sensors were often installed at joints and other locations due to the robots’ structures. Therefore, we developed a smart actuator that integrates a bending sensor that functions as a human muscle spindle; it can be externally attached to the pneumatic artificial muscle. This paper reports a smart artificial muscle actuator that can sense contraction, which can be applied to developed self-monitoring and robot posture control