In recent years, the aging of pipelines has been severe and has caused fatal accidents. The pipe diameters are small, and the layouts are complex. Pneumatically driven mobile robots have become popular as inspection methods. Various types of robots have been studied, like earthworm-type robots, inchworm-type robots, and spiral-tube-type robots. Typically, they make periodic movements; however, they have challenges because they are driven by existing pneumatic valve technologies, which are limited to small mobile robots. Small pneumatic valves have low flow rates and limit the performance of pneumatic actuators. Therefore, we focused on the structure of the ball valve and periodic motion. Furthermore, in this paper, we developed the Compact Rotary Valve Mechanism for pneumatic mobile robots in pipe inspection, which generates periodic air pressure.
This paper proposes a design method of robots with high specific stiffness for dynamic jumping motions. In the proposed method, we regard drive-trains as part of structures supporting frame loads. Particularly in the case of rotary joints driven by linear actuators, we resolve joint moments into actuator's tensile forces and frame's compressive forces and reduce loads exerted on a frame. Though this effect is already known, our method is novel in terms of utilizing this effect for designing robot structures systematically and for saving robot weights. In addition, we introduce a set of the wrenches which would be exerted on a frame (the frame load region) and evaluate the lightness of several robots' structures by using the frame load region. As a resultant of the proposed method, we developed a new life-size humanoid robot prototype JAXON3-P. Then we demonstrate the high motion performance of JAXON3-P and the effectiveness of the proposed design method through jumping motion experiments.
The purpose of this study is to propose a real-time footstep adaptation mechanism for humanoid robots that can be integrated into a conventional bipedal walking planner and increase the robustness of walking against disturbances. One of the main advantages of the proposed methods is that it can take into consideration restrictions such as allowable landing region and relationship between foot movement distance and step duration. In order to meet the strict real-time constraint of humanoid robot control, the proposed method computes viable capture basins in the design phase. This pre-computed data can be used at run-time to modify foot placement and center-of-mass movement in response to applied disturbances with small computation cost. The performance of the proposed method is evaluated in simulation experiments.