In this paper, we present a data acquisition method to realize a distributed tactile sensor system that can provide wide-range, and high-sensitivity with a small data size for communication. Since the data size is proportional to the number of acquired data and the resolution of the data, we propose systems to increase the resolution of the sensor output values without increasing the amount of data and to reduce the sampling frequency without reducing the time resolution. The system to increase the data resolution is based on a mechanism to dynamically change the gain of an amplifier circuit for a tactile sensor depending on the input value in the local controller. The system to reduce the number of data acquisitions consists of an analog circuit to judge the amount of change in the tactile sensor output based on a threshold at the hardware level. We demonstrate that the system reduces the data size for communication on a sensor system in our robotic hand. The experimental results indicate that the tactile sensor systems could sense high-resolution data with a small data size for communication.

Previous studies suggest that bipedal robots that have prismatic compliance in the legs can achieve efficient walking. However, how this efficiency can be achieved still remains an open research problem. In this study, we developed a 2-degree-of-freedom planar bipedal robot comprising Neidhart springs and five-bar parallel mechanisms. The five-bar parallel mechanism allows the robot to achieve prismatic compliance. In addition, a lightweight torque limiter function is achieved by Neidhart springs with an original design. We implemented a simple controller and conducted walking experiments. Experimental results showed that the robot walked effectively using the regenerative energy stored in the prismatic springs.

Humans can walk stably and adaptively in the presence of various environmental changes. Their bodies have very complex musculoskeletal structures that contribute to their walking stability and adaptability. In this paper, we focus on the gluteus medius, one of muscles contributing to the support of the pelvis. The gluteus medius supports the pelvis when the leg is in a standing position, but it should not inhibit its smooth swing motion. This mechanism is assumed to be realized by the musculoskeletal structure. This paper is devoted to explaining the mechanism by reproducing it using artificial pneumatic muscles. We developed a musculoskeletal robot with a gluteus medius, and showed that the mechanism is well-designed for realizing two seemingly contradictory functions: being stiff to support the pelvis while standing and being smooth to allow swinging. This finding can be utilized for adaptive walking of musculoskeletal humanoid robots.