This paper presents a mechanism for an in-pipe robot, called MRINSPECT VI (Multifunctional Robotic crawler for In-pipe inspection VI), which is under development for the inspection of gas pipelines with 150mm inside diameter. The mechanism is composed of multi-axial differential gear mechanism, wall pressing one, and driven by single motor. It is designed to adapt to the varying inside geometries of pipelines such as elbows by modulating the velocities of active wheels mechanically without any control effort. In this paper, the design features of the mechanism are detailed and its effectiveness is experimentally validated.

In this paper a new soft actuator based on dielectric elastomer is proposed. The actuator, called an antagonistically-driven linear actuator (ANTLA), has the muscle-like characteristics capable of performing the motions such as forward/backward/controllable compliance. Due to its simplicity of configuration and ease of fabrication, it has the advantage to be scale-independently implemented in meso- or micro-scale robotic applications. Its basic concepts are introduced and a quasi-static analysis is performed with experimental verifications.

In this paper a new soft actuator based on dielectric elastomer is proposed. The actuator, called an antagonistically-driven linear actuator (ANTLA), has the muscle-like characteristics capable of performing the motions such as forward/backward/controllable compliance. In this paper, its dynamic analysis is performed with experimental verifications, and applications for robotic actuating devices are introduced.

In this paper a microrobot, mimicking annelid animals like the earthworm, is presented. The robot is composed of several ring-like segments. Each segment is able to generate three degree-of-freedom motions such as pan/tilt/up-down respectively, and it is actuated by three soft actuators located equidistantly along the circumferential direction. The soft actuator, called antagonistically-driven linear actuator (ANTLA), is based on polymer dielectrics and has muscle-like characteristics capable of performing motions such as forward/backward/controllable compliance. In this paper, the basic concept of the actuator is briefly reviewed and the robot, including the ring-like segment, is explained in detail with demonstrations.

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.

A self-contained wall-climbing robot called MRWALLSPECT-II, is presented. The robot has characteristic features in the kinematic design of the leg with closed link mechanism. It reduces the number of actuators compared to the previous ones and makes it possible to have high force-to-weight ratio. Those are enabled by adopting a simple and robust gait pattern mimicking a living creature. Also, as the robot is designed to be a self-contained one, it includes all the components such as air compressors, vacuum generators, an embedded controller, batteries, a CCD camera, sensors, motors and electronics in itself without any tether cable. Its communication with the operating site in the ground is conducted through wireless LAN. In the paper, its principles of design and configuration of the robot are introduced.

We present a robotic joint mechanism that makes it possible to mimic the human-like motions. The proposed robotic joint, called the double active universal joint (DAUJ), generates a two-degree of freedom motion suppressing rolling by the coupled motions of two independent motors. The mechanism design and kinematics are mentioned. Two application examples are outlined: an anthropomorphic finger and an in-pipe inspection robot. The results of basic experiments are reported to confirm the effectiveness of the proposed mechanism. Also, we briefly introduce the advantage that the compliance of the proposed mechanism can be easily controlled by modulating the engagement period of the magnetic clutch.

We present a new 2-DOF anthropomorphic joint mechanism that makes it possible to mimic the human-like motion completely. The proposed joint, called double active universal joint (DAUJ), generates the 2-DOF motion free of rolling by the coupled motions of two independent motor-clutch pairs. Also, it has the advantage that the compliance of the mechanism can be easily controlled by modulating the engagement period of the magnetic clutch. The mechanism design and kinematics are described and two application examples, an in-pipe inspection robot and an anthropomorphic finger, are outlined. In addition, basic experiments are performed to confirm the effectiveness of the proposed mechanism.

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.