Graduation Research

Research on passive walking robots
Modern walking robots are the culmination of state-of-the-art technology consisting of precision sensors, high-performance motors and advanced control. The walking of humanoid robots has reached the stage of completion in a sense. Even in such a situation, a walking robot called a "passive walking robot" has become a presence that cannot be ignored. Passive walking robots can walk gently downhill without any actuators, sensors and controls. In passive gait, the leg trajectory is not predetermined, it is generated only by the interaction between the dynamics of the pedestrian and the environment. Passive walking is also known for its natural and energy-efficient, and is said to be similar to human walking. In our laboratory, we develop a walking robot based on the principle of passive walking. In addition, we analyze the mechanism of human walking from the principle of passive walking.

Research on automotic driving personal mobility
"Walking" is very important for maintaining and improving the health of the elderly. We research and develop "automatic driving personal mobility" that supports "walking" by utilizing autonomous driving technology. This mobility allows elderly people who are not confident in walking with weak legs to walk freely depends on their conditions such as walking together when they are healthy, pulling when they are a little tired, and riding when they are tired. We aim to become a "walking partner" that allows you to go out. The experiment is based on a commercially available electric wheelchair, and is equipped with sensors such as laser scanners and cameras and a computer to enable to drive automatically. Furthermore, we measure how much it will be easier to walk with the support of this wheelchair from the viewpoint of biomechanics. Ultimately, we are aiming to realize new mobility by fusing autonomous driving biomechanics technology.

Study on fatigue resistant reliability of heat-resistant materials under combined stress
The main part of high temperature equipment is made of heat resistant "heat resistant material", but each component is exposed to various mechanical conditions depends on the actual usage of the equipment. For example, in an aircraft jet engine, a repetitive force is applied to components due to fluctuations in engine speed and vibration during operation, but the loads receive not only one-way tension and compression, but also complicated forces (combination stress) such as bending and twisting. To ensure the reliability of this type of material, it is important to check the durability of the material under the usage conditions. In this research, we will conduct an experiment (fatigue test) in which combined stress is repeatedly applied to a heat-resistant material at high temperature to investigate under what conditions cracks are generated and how they grow and lead to fracture. Furthermore, by observing the fracture surface with an electron microscope, students study the mechanism of fatigue crack growth at high temperatures in the case of combined stress.

Research on high-frequency in-vehicle noise prediction technology for automobiles
Various noises such as engine, tire, and wind noises come into the inside of a car. We study technologies for predicting these in-vehicle noise. Specifically, using commercially available hybrid SEA (statistical energy analysis) software, students study about creating an analysis model, comparing experimental measurement calculation results, and investigating the relationship between changes in acoustic characteristics and changes in vehicle interior sound due to component changes.

Study of vibration and acoustic characteristics of stringed instruments (violin)
Stringed instruments are produced by craftsmen and factories, but these production rely on past experience and intuition of craftsmen. We research what kind of sound (vibration) will be produced if the structure (shape) and material are changed by conducting experiments and using CAE.

Study on hot water flow in evaporative pattern casting process of aluminum alloy
 Evaporative pattern casting process is the way that a foamed styrol model is buried in dry sand, molten metal is injected as it is, and the molten metal flows into the cavity due to thermal decomposition of the model. In our laboratory, we experimentally examine how the flow rate of molten aluminum alloy changes depending on the air permeability of the coating mold coated on the foam model using a touch sensor, and also examine how the motel metal tempreture is during the water flow by using a thermocouple and research effects of the heat insulation of the coating mold and the flow rate of the molten metal due to decreasing in the temperature of the molten metal in the direction of the flow of the molten metal(upper figure). Furthermore, we will theoretically study by comparing the calculated values using the hot water flow model proposed in our laboratory. (Lower figure).

Study on the flow phenomenon in the tuyere combustion zone of a blast furnace for steelmaking
This research examine changes in the phenomenon at the tip of the tuyere, assuming that natural gas or biomass is blown in place of pulverized coal in order to reduce CO2 emitted by the iron-making blast furnace that burns pulverized coal as a heat source. Raceway when gas or powder is blown into a solid particle (assuming coke) packed bed using a reduced model (cold model) experimental device of a blast furnace (solid particles are blown off by a blast and circulate, and the void ratio is high. We will investigate the formation of (creating space) and the flow behavior of solid particles, and experiment how the difference in the blowing diameter, wind velocity, and physical properties of the blowing material affects the shape and size of the raceway. In addition, we use a 2D model that allows observation of the cross-sectional shape of the tuyere and a 3D model that has multiple tuyere in the circumferential direction, similar to the actual blast furnace, to understand the difference between 2D and 3D experimental characteristics.

Research on improving reliability of motors / generators
The mechanism that supplies electricity while rubbing from a stationary object to a moving object is called an electric sliding contact mechanism. This mechanism is used as a brush / slip ring (commutator) in motors and generators, and is an important part for rotating motors and generating electricity. In other words, improving the electrical conductivity and wear resistance of the brush leads to the high reliability of motors and generators. Therefore, in order to clarify the sliding energization phenomenon of the brush, we conduct tests and analyzes using a sliding test device. We also consider high-efficiency operation of motors using power electronics, with a view to research on control for energy-saving and smooth operation of motors.

A study to clarify the physical characteristics of the elderly in driving a car
From now on, Japan has been becoming an aging society unlike any other countries in the world. In order to revitalize the economy sustainably in a super-aging society that is said to be the age of 100 years of life, the elderly are also required to play the role of labor force. For that purpose, it is also necessary to create technologies such as mobility (vehicles) to prepare for the arrival of a new era in Japan. From the viewpoint of ergonomics, this research clarifies the characteristics of the physical characteristics of the elderly through collaboration between the medical and the engineering field, and creates a technology that can realize the same driving operation ability as younger people even if the elderly become old. Computer simulation is used to extract the characteristics of the physical characteristics of the elderly during the research process.

Research on DX of daily activities using AR technology
Although the SDGs ^*1 are calling for DX ^*2, it is surprisingly difficult to use Office software or 3D CG/CAD software using a keyboard and mouse.
In this research, we will use AR ^*3 technology to create a file that simulates PowerPoint and Excel operations in Microsoft Office applications using only block placement and audio, and to create a 3DCG model as desired by directly drawing in an empty space. We conduct research using machine learning to create and predict.

※1 Sustainable Development Goals

※2 Digital Transformation

※3 Augmented Reality

Research on interlock systems to avoid human errors
Many tragic accidents occur in the world due to human error. In this research, we proposed a simple interlock system that combines modular robots, AR technology, and image processing technology from previous research. Afterwards, we are investigating the operation of the interlock system when assuming tidying work.

Motion characteristic evaluation system for NC machine tools
Molds are used in the production process of many products around us, especially cars and plastic products. The manufacturing process of this mold includes ``design'', ``processing with NC machine tools'', and ``polishing'', but the ``polishing'' work, which occupies most of the process, is not influenced by the results of machining with NC machine tools. I receive it greatly. Therefore, in order to reduce the number of man-hours required for this "polishing process," research and development has been actively conducted to improve the speed and precision of NC machine tools. In this research, we are focusing on the high speed and high precision of the feed axis, which greatly contributes to the demands for these NC machine tools, and are working on research and development of measurement equipment and measurement technology to evaluate the motion characteristics.

Transfer characteristics of motion error to machined surface
In this research, we are investigating how the feed axis movement error of NC machine tools affects the machined surface, focusing on its transfer characteristics. Here, we focused on the motion error when the direction of motion of the feed axis is reversed, and investigated the transfer characteristics to the machined surface. As a result, it was found that motion errors with a convex shape are less likely to be transferred to the machined surface, compared to motion errors with a concave shape. By investigating the motion characteristics of these various feed axes and the transfer characteristics to the machined surface, we are working to develop a function that efficiently corrects machining errors caused by motion errors.