National Institute of Technology, Matsue College

Pneumatic artificial muscles (PAMs) are soft actuators that generate tension via contraction when supplied with compressed air. Although PAMs have been widely used in robots mimicking endoskeletal organisms, recent advancements in millimeter-scale thin PAMs have enabled a more precise replication of complex musculoskeletal systems. In contrast, exoskeletal organisms, such as crustaceans and insects actuate their joints using pennate muscles embedded within their exoskeletons. However, integrating actuators into the exoskeletons of exoskeletal-inspired robots is challenging owing to spatial constraints. Consequently, wire and servo-driven mechanisms are predominantly employed, and studies on exoskeletal robots incorporating the muscle-apodeme structures of exoskeletal organisms remain largely unexplored. To address this gap, this paper presents the development of a crab-inspired robotic walking leg featuring an exoskeletal structure with embedded pneumatic artificial pennate muscles, modeled after the muscle-apodeme structures of snow crabs. The experimental evaluations demonstrated that the robot successfully performed joint opening and closing motions, achieving a range of motion comparable to that of a snow crab.

This paper proposes a low-code development framework for Internet of Things (IoT) applications, integrating a visual data flow programming interface with the lightweight scripting language–mruby. The aim is to reduce the complexity and technical barriers traditionally associated with embedded programming, particularly in environments with resource-constrained microcontrollers.The system enables users to design application logic visually with Node-RED, a popular data-flow implementation tool. The generated data flow is exported as a JSON file, which is then parsed by a custom mruby code generator. This generator translates the data flow into executable Ruby code, then compiles it into compact bytecode using the compiler. The resulting bytecode is then deployed to microcontrollers running a minimal mruby virtual machine (VM), enabling the efficient execution of application logic without the need for a full interpreter or operating system. To validate the system, a prototype was implemented and evaluated on an RBoard — a development board based on a PIC microcontroller with limited memory and computing resources. A simple IoT application was designed to read temperature sensor data and control an LED based on a threshold. The experimental results confirmed that the system could handle sensor input, control logic and hardware-level output in real time using only the automatically generated code.This framework significantly reduces development time and programming effort, making embedded development accessible to non-experts and facilitating rapid prototyping. Combining visual programming with mruby bytecode execution ensures ease of use and runtime efficiency. Future work will focus on extending node types, enhancing debugging and simulation capabilities, facilitating wireless deployment and expanding support for a wider range of microcontrollers. This approach demonstrates a practical path towards scalable, maintainable and user-friendly IoT development.

To investigate the improvement in skill of rookie through training and the difference in skill between rookie and expert, the steering wheel steering angle and bank angle during straight narrow driving were measured. After training, rookie increased their steering effort, steering range, and appropriate corrective steering to the tilt of the vehicle. Expert corrected the vehicle to the left and made faster corrective maneuvers to vehicle lean.

Recently, soft actuators have gained considerable attention owing to their flexibility and high output-to-weight ratios. The McKibben pneumatic actuator (MPA), a type of soft artificial muscle, is an actuator that generates force by inflating a rubber tube with compressed air. Conventional MPAs, such as linear actuators, generate force along straight lines; hence, achieving complex movements, such as bending using a single muscle, can be challenging. In this study, we enabled bending movements in MPA by applying an elastic adhesive coating to MPA. Experimental results demonstrated that the coated MPA successfully performed bending movements. Furthermore, we confirmed that the curvature and fiber angles of the coated and uncoated surfaces changed with applied pressure, thereby indicating that the adhesive can be used to control the fiber angles and achieve the desired curvature.

In recent years, with the importance of cross-disciplinary educational programs such as STEAM education, it has become necessary to provide mathematical education at the early stages of elementary and junior high school to prevent the increase in the number of students who have dropped out of science.As a result, educational institutions are also becoming more active in efforts such as robot-themed education as part of their contribution to the local community.In this study, we propose a method for students to decide their own theme about mechanics, obtain a production budget, and engage in cross-disciplinary learning through extracurricular activities.with support outside and inside the school.

The branching in the musculotendinous structures is crucial to control complex, nonlinear musculoskeletal systems in vertebrate bodies. Although common, their functional impact remains unclear. Here, we present a dynamical model of musculoskeletal networks that explicitly incorporates branching points as mass points, representing geometric constraints and internal force distribution. Applying this model to the crocodilian hindlimb with branching musculotendinous structures, we validate results against robotic and anatomical studies. We find that branching reduces required muscle force, enhances joint coordination, and enables stable standing and propulsion with minimal input. These insights can guide biomechanical research and bio-inspired robotic designs.

Seven species of galatheoid crustaceans, including five new species, are reported from the southeastern Arabian Sea, southwestern Bay of Bengal, and western Andaman Sea, India, based on material collected from 56 to 113 m depths. Distinctions between the five new species (Galathea bharata sp. nov., G. kalingasagara sp. nov., G. quadrangularis sp. nov., Nanogalathea longispina sp. nov., and Sadayoshia brevirostrum sp. nov.) and their morphological close congeners are given in detail. The genus Nanogalathea Tirmizi & Javed, 1980 is rediagnosed to include N. longispina sp. nov. Trapezionida latior Baba, 2005 is recorded for the first time from Indian waters, indicating northward extension of its known geographical range. A specimen tentatively referred to Galathea aff. nasimae Karasawa, 2019 is also reported from the Andaman Sea.

A liquid piston Stirling engine is an external combustion engine that uses air and water under atmospheric pressure as its working fluids. Resulting from its uncomplicated design and the capacity to operate under relatively low temperature differentials of less than 100 °C, it has attracted considerable attention in recent years. This paper presents the fundamental characteristics of the liquid piston engine combined with a self-rectifying turbine for the advancement of thermal generators. When the turbine is installed in the water region rather than in the air region, it exhibits unidirectional rotation with a rotational speed directly proportional to the velocity amplitude of the reciprocating axial flow. Additionally, the acoustic impedance within the duct section containing the turbine is determined, demonstrating that the real part of impedance rises with increasing axial velocity, indicating a loss mechanism similar to the minor loss. Furthermore, the installation of the turbine results in a breakdown of symmetry in the engine oscillation mode. To maintain symmetry and improve system design, future developments must consider the installation of a turbine in each unit. These findings can pave the way to the design of liquid piston Stirling engines and their applications in thermal energy conversion.

We revised the previous records of Clorida japonica Manning, 1978 and conducted extensive field and museum material surveys in Japan. The material examined included five species of the genus Clorida Eydoux & Souleyet, 1842 as follows: C. japonica; C. albolitura Ahyong & Naiyanetr, 2000; C. denticauda (Chhapgar & Sane, 1967); C. rotundicauda (Miers, 1880); and C. seversi Moosa, 1973. Among them, C. albolitura, C. denticauda, C. rotundicauda, and C. seversi are new to the Japanese stomatopod fauna. Re-examination of the Japanese specimens previously reported as C. japonica has shown that they partially belong to Cloridina ichneumon (Fabricius, 1798), a new record from Japan as well. A key to the Japanese species of Clorida and Cloridina reported in this study is also provided.

With the extensive use of robots in recent years, an age of co-existence between humans and robots is expected to arrive in the future. Therefore, providing robot education in the early stages of elementary and junior high school is necessary to stimulate students' interest in robots. Furthermore, educational institutions are becoming more active in robot education as a part of their contribution to the local community. For elementary school students, a Beauto Racer (Vstone) has been adopted as a teaching material for robot education, and teaching materials have been developed for teaching line tracing. In this study, we will develop educational materials for junior high school students on maze exploration using a Beauto Rover (Vstone). The students of Matsue National College of Technology took the initiative in this activity. The purpose is to improve their teaching skills.