Development of intelligent McKibben actuator

The aim of this study is to develop an intelligent McKibben actuator with an integrated soft displacement sensor inside, so that displacement of this actuator can be controlled without having any extra devices attached. In addition, the high compliance which is a positive feature of the McKibben actuator is still conserved. This paper consists of four main parts. First of all, different types of soft displacement sensors made out of rubber were composed, and tested for their functional characteristics. Secondly, the intelligent McKibben actuator was developed with the soft displacement sensor incorporated within. Then, experiments of the position servo control with a single intelligent McKibben actuator were carried out. At last a robot arm mechanism was designed with two intelligent McKibben actuators, and those experimental results showed a great potential for its future applications.</p

Development of intelligent McKibben actuator with built-in soft conductive rubber sensor

This study aims at the development of an intelligent McKibben actuator, in which a soft rubber displacement sensor is integrated. Recently, the McKibben actuator has attracted engineers because of light weight, high output power and high compliance. But in the case of using it for servo control at present, the systems need encoders or potentiometers, therefore the systems tend to grow in size and take away from compliance which is an important advantage for a safe and secure mechanism. We have developed a soft displacement sensor and incorporated it in a McKibben actuator, named it the intelligent McKibben actuator, and proved its potential.</p

A miniature inspection robot negotiating pipes of widely varying diameter

The purpose of this research is to realize a small robot which can negotiate pipes whose diameter varies widely during the robot's course. A new in-pipe locomotion mechanism named &#34;snaking drive&#34; is proposed in this paper and its potential and fundamental characteristics are shown with experimental data of the prototype model. First, in the sections 2 to 5, the basic traveling characteristics of the snaking drive mechanism are discussed: a theoretical formula of the fundamental characteristics and control algorithm are derived, the motions of the robot are simulated on a PC, and the prototype model was designed, developed, and tested. Next, in the sections 6 and 7, additional control algorithms for the front link are derived. They are necessary for steering at T-branches and L-bends of pipes, and also for camera view stabilization. Their performances are also shown by software simulation and experiments. The prototype robots moved in pipes whose diameter varies between 55 mm to 331 mm with the maximum speed of 22 mm/s. The paper also shows that the prototype negotiates T-branches and L-bends of pipes with inspection capability through a camera mounted on the robot.</p

A miniature inspection robot negotiating pipes of widely varying diameter

Abstract The purpose of this research is to realize a small robot which can negotiate pipes whose diameter varies widely during the robot&apos;s course. A new in-pipe locomotion mechanism named &quot;snaking drive&quot; is proposed in this paper and its potential and fundamental characteristics are shown with experimental data of the prototype model. First, in the sections 2 to 5, the basic traveling characteristics of the snaking drive mechanism are discussed: a theoretical formula of the fundamental characteristics and control algorithm are derived, the motions of the robot are simulated on a PC, and the prototype model was designed, developed, and tested. Next, in the sections 6 and 7, additional control algorithms for the front link are derived. They are necessary for steering at T-branches and L-bends of pipes, and also for camera view stabilization. Their performances are also shown by software simulation and experiments. The prototype robots moved in pipes whose diameter varies between 5 5 m m to 331mm with the maximum speed of 22 d s . The paper also shows that the prototype negotiates T-branches and L-bends of pipes with inspection capability through a camera mounted on the robot

Displacement Sensing of an Active String Actuator Using a Step-Index Multimode Optical Fiber Sensor

A thin McKibben artificial muscle is a pneumatic actuator with an outer diameter of only 1.8 mm. We fabricated a string-shaped actuator called an "active string actuator," which achieves a high contractile displacement by accumulating thin McKibben artificial muscles. To control the displacement, the length of the active string actuator should be estimated. However, this is difficult because bulky and rigid sensors are unsuitable for the sensor element of the active string actuator. Therefore, in this study, we propose a new sensing method for estimating the length of an active string actuator. The proposed sensing system is simple and comprises only three components: a step-index multimode optical fiber, a light emitter, and a light receiver. A step-index multimode optical fiber was combined with the active string actuator, and the length was estimated from the change in the amount of light propagating in the optical fiber when the active string actuator was driven. Fundamental experiments were conducted in this study, and the results demonstrated that the optical fiber sensor value changed with the actuator length. This suggests that it is possible to estimate the displacement of an active string actuator using an optical fiber sensor

A micro snake-like robot for small pipe inspection

The goal of this research is development of a micro robot which can negotiate pipes whose diameter varies widely. The robot mechanism is based on &#34;snaking drive&#34;. First, in section 1 to 4, basic characteristics of the snaking drive are discussed: the principle of the snaking drive is shown, theoretical fundamental formulas are derived, and the motions of the robot are simulated. Second, in section 5, a micro robot was designed, fabricated and tested. And fundamental experiments of the robot are shown. Third, in section 6, two application experiments are shown: one is a stabilization of camera image, and the other is a robot steering at branches. The robot moved in pipes whose diameter varies between 18 mm to 100 mm with the maximum speed of 36 mm/s. And the robot could negotiate T-branches and L-bends of pipes.</p

Core-Shell Droplet Generation Device Using a Flexural Bolt-Clamped Langevin-Type Ultrasonic Transducer

Droplets with a core-shell structure formed from two immiscible liquids are used in various industrial field owing to their useful physical and chemical characteristics. Efficient generation of uniform core-shell droplets plays an important role in terms of productivity. In this study, monodisperse core-shell droplets were efficiently generated using a flexural bolt-clamped Langevin-type transducer and two micropore plates. Water and silicone oil were used as core and shell phases, respectively, to form core-shell droplets in air. When the applied pressure of the core phase, the applied pressure of the shell phase, and the vibration velocity in the micropore were 200 kPa, 150 kPa, and 8.2 mm/s, respectively, the average diameter and coefficient of variation of the droplets were 207.7 mu m and 1.6%, respectively. A production rate of 29,000 core-shell droplets per second was achieved. This result shows that the developed device is effective for generating monodisperse core-shell droplets

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