With the development of soft robotics, the number of soft robots equipped with flexible actuators or sensors is expected to increase. In this paper, I investigated the appropriate robotic hardness for developing a robot with psychological and physiological stress relief effects through experiments comparing the effects obtained by interacting with robots having the Asker C hardness of about 0, 3, and 6. As a result, I confirmed that psychological and physiological stress relief effects obtained by interaction with the robot having the Asker C hardness of about 6 were significantly lower than that obtained by interaction with robots having the hardness lower than that, especially in terms of reducing tension and depression, improving vigor, and increasing the percentage of alpha waves. On the other hand, there was no significant difference between psychological and physiological stress relief effects obtained by interaction with robots having the Asker C hardness of about 0 and 3. These results suggest that the higher robotic softness within the discriminable range of robotic softness, the higher psychological and physiological stress relief effects obtained by interaction with robots. In addition, I found that it is necessary to set the softness of robots to be below the range of the adaptation-level of softness expected by users.

In this paper, we investigate the effect of contact with other ants on exploratory behavior of ants. Japanese wood ants were placed inside ANTAM and their exploratory behavior was recorded for 5 minutes by contacting with other ants every 30 seconds. We found that ants that were allowed to be contacted with other ants maintained super-diffusive movements while presenting the Lévy walk. We also found that they frequently changed their movement directions.

The purpose of this study is to devise a Direction Comparison (DC) model that focuses on the agent's memory and investigate the relationship between the search pattern and the memory-related parameter. The DC model compares two directions, the previous one and the current one, and changes the way it moves. As a result, the Lévy walk appears when comparing with new memories, while the Levy walk does not appear when comparing with old memories. We also found that these results were related to the frequency of the rule change.

We are developing a robot system that can automatically fold “Orizuru,” a paper crane. It uses a cutting plotter to add creases on papers to make them easily-foldable. The development diagram of the paper crane for the crease pattern is generated by our origami simulator. Two robots grasp dedicated tools to fold the papers. The base on which a paper is placed has several suction pads to fix the papers, and the pads are selectively turned on and off to support each of the folding processes. Most of the processes of folding Orizuru, including techniques like “squash-folding” and “petal-folding” were achieved automatically using 150mm square origami papers.

This research proposes a method to estimate three-dimensional coordinates of glass using a polarization camera and LiDAR. A laser beam passes through glass. Therefore, it is impossible to acquire 3D point clouds of glass when performing 3D measurement of structures with LiDAR. On the other hand, the light reflected from the glass surface has a higher degree of linear polarization. Therefore, the direction in which the glass exists can be measured by using a polarization camera. In the proposed method, a polarized camera is used to determine the glass. After the determination, point cloud interpolation is performed on the point cloud measured from LiDAR, considering the positions of the surrounding window frames. In the indoor experiment, we successfully complemented the position of the glass that could not be measured by LiDAR.

This paper evaluates the performance of four open-source publication/subscription communication middlewares, Fast DDS, Cyclone DDS, iceoryx, and eCAL, on shared memory inter-process communication in a real-time execution environment. I set up two hypothetical robot systems and measured the communication latency and publication processing duration of these communication middlewares in the real-time execution environment. Experimental results for the first robot system (with a payload of 1kB and a publication interval of 1ms) showed that the communication middleware with the smallest communication latency is iceoryx. Apart from the quantitative evaluation of communication latency, qualitative aspects such as single point of failure, communication with other computers, and availability of GUI monitoring tools are also considered. The results show that eCAL is a well-balanced option with the second lowest maximum communication delay after iceoryx. In the second robot system, which is a mobile robot navigation robot system, iceoryx and eCAL, which performed well in the motion control robot system experiments, are evaluated in more detail with payloads up to 10MB. iceoryx and eCAL support the Zero-Copy function, which reads messages directly from shared memory when subscribing to a message. This function eliminates the need for copying by communication. However, the measured communication latency and publication processing duration show that iceoryx requires only one copy when publishing a message, while eCAL requires two copies. Accordingly, eCAL requires more communication latency and publication processing duration than iceoryx. The performance of eCAL is also measured for Byte-string and Protocol Buffers message formats, and the results show that serialization significantly impacts performance. For relatively large messages with payloads of 10MB, iceoryx performed 111 times better than eCAL regarding maximum communication delay and three times better in maximum publish processing duration. These results indicate that iceoryx is the most suitable for inter-process communication with large payloads.

Musculoskeletal robots using McKibben-type pneumatic muscles have been known to be capable of dynamic locomotion, such as walking, running, and jumping. However, most of these robots have been controlled by trial and error, such as adjusting the timing of opening and closing of pressure valves. We have focused on the antagonistic drive, a characteristic of musculoskeletal systems. Our previous study proposed “tension feedback cooperative control,” which generates periodic motion by utilizing autonomous coordination of antagonistic muscles. In this paper, we applied this control law to a two-degree-of-freedom leg model with antagonistic bi-articular muscles that mimic the hind legs of a four-legged walking animal. The autonomous coordination of the antagonistic bi-articular muscles and the generation of periodic motion were verified by simulation and experiment on a real machine. The simulation results confirmed that the antagonistic bi-articular muscles cooperate autonomously with the proposed control law. We also confirmed that by changing the feedback gain, five types of cooperative modes are generated, and periodic motions like walking, standing still, and running of animals are generated autonomously. Furthermore, experiments on an actual machine confirmed three cooperative modes of antagonistic bi-articular muscles. And periodic motions like walking, standing still, and running were generated autonomously.

In this study, we propose a locomotion mechanism with rotation of curved horns and vibration of elastic cilia of a mobile robot for pipe inspection. At first, the mobile robot with elastic cilia and a vibration motor was developed to examine the thrust with vibrating cilia. The cilium of this first prototype has a circular cross section. Second, the vibration motor was replaced with tilted horn that rotates around roll axis of the robot at its head. This second prototype selects a route in branching pipes by orienting its horn to the desired direction. It can also move forward and backward with continuous rotation of its horn and soft cilia with rectangle cross section. Fundamental running experiments were conducted to evaluate the effect of the rotating horn with the biased center of mass and elastic cilia of the pipe inspection robot.

The effects of transcranial direct current stimulation (tDCS) to the MT cortex on visuomotor responses were investigated using a visual motion direction discrimination task (MDD) generated by a random dot kinematogram. There was no change in the reaction rate before and after stimulation, but there was a region where the EEG coherence value increased between the measured electrode position and the MT region.

In this paper, we developed a fish-like robot featuring a large trapezoidal elastic sheet driven by wire and a continuous snap-through buckling mechanism. Swimming tests demonstrated the increased speed and fish-like movements.