We aimed to develop an active catheter that could be used safely in human blood vessels. We proposed and developed a micro valve for a water pressure-driven system with multi-degrees of freedom, to produce an active catheter that is compact and not driven electrically. In this paper, we proposed a new method that uses pressure pulses to control the bending angle of the active segment. We experimentally verified this control method using the new valve design.

A lightweight wall climbing robot with reduced degrees of freedom (DOF) is under development. This robot consists of three main components. The first component is a quadruped walking robot with reduced-DOF. Since lightweight is an important feature for wall-climbing robots, the DOF of this robot were reduced until three, without hampering its ability as a walking robot. The second one is a sucker using a blower. The adhesion force with a blower is weaker than with a vacuum pump, but the blower can deal better with air leakage. The sucker developed in this research can adhere to walls with many slits and uneven ceiling. Finally, the last component is an ankle joint with wide movable range. This mechanism is indispensable for walking freely in any environment and transferring from wall to wall, wall to ceiling and ground to wall. Moreover, the appropriate compensated motion for wall climbing is considered. The structure of the wall climbing robot has been deformed by the gravity effects. Therefore, the compensated motion should be indispensable for its smooth climbing motion. Wall climbing experiments using the walker developed in this research have been performed with the proposed compensated motion

At present, robots are demanded not only for stationary use but also for tasks that require high mobility. The important abilities for such robots are both moving and task performing abilities. However, in order to perform tasks and move using separate mechanisms, robots are required to have many degrees of freedom (DOF). As a result, robots become heavy and lose mobility. In this paper, an effective design of robots with reduced-DOF is described. Besides, an 8-DOF bipedal configuration robot with high tasking and moving performance was developed. In this robot, the DOF have been reduced as much as possible without hampering its mobility, finding a balance between the increase in weight with additional DOF and the loss of manipulability with reduction of DOF. Moreover, applying this concept to the locomotion using the same DOF for differential purpose, it is possible to use the sane mechanism for the legged locomotion and wheeled locomotion. In this paper, this concept and maneuvers for locomotion are described. New experimental model is designed and experiment results for proposed locomotive maneuvers are expressed.

This paper proposes a new walking and jumping robot, that is expected to get over large debris in the disaster area which is difficult to move around by ordinary walking robot and to find out the victims efficiently as the rescue operation. To acquire stability on uneven terrain in landing, the robot is designed by legs which widely spread like spiders. The legs are consists of 4-bar linkage and driven by a pair of pneumatic cylinders which momentarily produce high power and speed. At this time, basic performance of the pneumatic cylinder is verified for the jumping use. Moreover the one leg model is developed and examined its jumping and landing performances.

In order to perform tasks and move using separate mechanisms, robots are required to have many degrees of freedom (DOF). If robots can perform both wheeled locomotion on flat ground and legged locomotion on uneven terrain, they can achieve much higher mobility. We have already proposed an effective design method with both mobility and manipulability, that is a method of combining each mechanism. The designed robot uses the same mechanism for locomotion and manipulation. By applying this concept to locomotion, it is possible to use the same mechanism for legged locomotion and wheeled locomotion. In this paper, this concept and maneuvers for locomotion are described and an experimental model and experiment results are reported.

In order to perform tasks and move using separate mechanisms, robots are required to have many degrees of freedom (DOF). As a result, robots become heavy and lose their mobility. In this paper, an effective design of robots with reduced DOF is described. An 8-DOF bipedal configuration robot with high tasking and moving performance was developed. In this robot, the DOF are reduced as much as possible without hampering the its mobility, by finding a balance between the increase in weight with additional DOF and the loss of manipulability with a reduction of DOF.

To introduce the force control for an uneven terrain walking robot such that it effectively sets the suitable contact pressure of its supporting legs and is able to change from support to swing legs smoothly, the force control for ParaWalker-II, serial/parallel hybrid mechanism that is connected between two frames and contacts ground at three points, is proposed. With this method, the entire leg-drive mechanism acts as a 6-axis force sensor; and the force and moment can be calculated from the changes of each joint angle such that sensors at the ends of the leg are not necessary. Furthermore in the paper; force control and position control can be chosen for each direction in order to smoothly walk on uneven terrain. Smooth contact with the ground by the swing-leg and the changing from swing to support leg is verified through experiments using this force control and measurement method.

A walking robot that has high ground adaptability and the ability to perform various tasks would be extremely desirable in many fields. It can move efficiently in an outdoor environment and on uneven terrain such as stairs, as well as perform tasks. In this paper, for a six-legged uneven terrain walking robot with two body segments, we examine the number of degrees of freedom, movement performance, stability on uneven terrain, and work performance. In addition, we examine the arrangement of the degrees of freedom suitable for practical uneven terrain work by this type of robot. We also propose that a walking robot with an extra leg extension mechanism and a 6-DOF between the body segments is effective. We adopt this design to ParaWalker-II, which we had previously developed, and verify the effectiveness.

A new lightweight six-legged robot is developed which uses a simple mechanism and can move and work with high efficiency. This robot consists of two leg-bases with three legs each and walks by moving each leg-base alternately. These leg-bases are connected to each other through a 6-DOF mechanism. Thus, when the robot stands on three legs, or one leg-base is placed on the ground, the other leg-base can be used as a 6-DOF manipulator or active working platform. The output force, velocity, and movable range of various mechanisms for connecting the two leg-bases were compared and the results showed that good performance could be achieved with a serial-parallel hybrid mechanism consisting of three 6-DOF serial linked arms positioned with radial symmetry about the center of each leg-base, each composed of two active and four passive joints. Walking experiments with this robot confirm that this mechanism has satisfactory performance not only as a walking robot but also as an active walking platform.