The academic world is continuing to undergo an extensive, in-depth evolution.
What view does a Toyo University faculty member devoted to education and research have on the contemporary world?
We interviewed Professor Sho Yokota of the Faculty of Science and Engineering, who is researching and developing assistive casters to allow wheelchairs to easily climb steps. We discussed his research assisting human activities with addressing the needs of the times.
Professor, Department of Mechanical Engineering, Faculty of Science and Engineering
Sho Yokota
Profile
Professor, Department of Mechanical Engineering, Faculty of Science and Engineering Doctor of Engineering. Docteur en Robotique. Completed a doctoral program in robotics at the Université de Versailles Saint-Quentin-en-Yvelines (UVSQ). Subsequently, Yokota worked as a university lecturer and researcher before joining Toyo University as a professor in 2014. He specializes in designing human interfaces through manufacturing.
Understanding People Is at the Root of My Research
I have majored in robotics since I was a university student. I had been researching the mechanisms and control of robots that travel on uneven terrain. Still, I began to feel a desire to engage more directly with society through my research. This led me to research and development of robotic technologies to support human activities. People and society constantly change, and with each era comes problems that people face. I am researching day and night, hoping that we can alleviate some of these challenges using robotics and engineering. I seek to uncover needs and contemplate solutions through the daily news, social issues I hear about, and discussions with students and fellow researchers in my lab. However, people are at the root of all social issues. That is why I base my research around the three pillars of understanding people, human-oriented design, and developing core robotics technology. As a specialist in building interfaces between humans and machines, it's crucial that machines can be operated intuitively as one would anticipate. That is why understanding people is always at the root of my research. I consider the mechanisms of machine interfaces based on information about how human senses and actions are interconnected and how they relate to perception.
I Want to Create Simple Robots that Can be Easily Operated by Anyone
In my research, I place emphasis on ease of use and simplicity. While we can solve problems to a certain extent with current technology using high-performance devices or complex mechanisms, these solutions lack practicality due to their cost and difficulty in operating. I believe the best systems are those that can be used by anyone, regardless of age or gender. The step-climbing caster I am currently working on also has a simple mechanism. I heard that wheelchair users have difficulty climbing steps, so I developed a mechanism to enable steps to be climbed easily. This caster uses the four-bar linkage, which is well-known in mechanical engineering. Its structure is made with a combination of plates and springs and does not need a power source. No special wheelchair techniques are required, and users can climb steps using their wheelchair as they ordinarily would. It can be easily attached with a single spanner, and there is no need to modify the wheelchair. Thanks to its simple mechanism, it can be applied to a wide range of equipment, such as trolleys and chairs. The design stage requires delicate digital technology, so we collect data using many sensors. However, I find that the fun of making things lies in figuring out how to implement these designs in the simplest possible manner.
Simplicity Makes it Difficult to Find the Optimal Solution
Simple structures can also be said to be without a margin for error. Changes of only a few millimeters can have a significant impact. It's always a continuous struggle to derive optimal values from the data we've collected. Even in the development of the wheelchair caster, there are many design conditions, such as the length of the links that make up the caster and the positions of the joints. For example, the front-to-back mounting position of the caster differs depending on the model of the wheelchair. Meaning that the same design may not work as the load on the wheels will differ. Also, the force on the wheels differs for electric and manual wheelchairs. While electric wheelchairs constantly transmit power to the wheels through a motors, manual wheelchairs have moments when force is released after a push, which changes the force needed to climb a step due to inertia. Even if it seems possible in mathematical models, there are matters that cannot be understood unless the caster is actually put into use. This includes factors that cannot be modeled, such as friction and collisions, in addition to comfort, such as physical sensation and touch. That is why we have no choice but to create prototypes, continuously conduct experiments, and implement improvements. The sense of achievement when I overcome this process, my ideas take shape, and are returned to society is rewarding as a researcher. It also reminds me of why I enjoy making things.
The importance of committing to one thing
I enjoyed making things with my hands since I was young. There was even a photo of me with wire cutters and plyers when I was three. As a middle school student, I dreamed of becoming an engineer. Since then, I was also interested in environmental issues and wanted to create hydrogen engines. I believe it was at this time that my desire to make things beneficial for people and society started to develop. As a university student, I worked hard at my part-time job to save money and bought a car I liked. I was obsessed with tinkering with that car. The feeling of interacting with the car as it was a full-sized plastic model allowed me to gain a tactile understanding of the workings of mechanisms, electricity, and information; those experiences have led me to where I am now. That's why I hope that students can find something they can dedicate themselves to, whether related to their studies or something entirely different. The questions and curiosity that develop from this dedication will lead to the joy of study and research. Some people hesitate to start something new because they have no confidence, but it's impossible to be confident doing something you’ve never done before. Confidence comes from starting something and gaining experience through success and failure. I hope that students take on challenges in their lives.