Development of Spherical Ultrasonic Motor for Critical Environment

In recent years, due to advances in science technology, space satellites have made progress. So, the presence of space debris has become problem in the world because they may collide each other. In our study, we have developed Spherical Ultrasonic Motor (SUSM) for space use with 3 DOF to drive the satellite thruster and resolve it. We aim that the satellites enter the atmosphere when the satellites reached the end of life, and SUSM controls thrusters when they inject for the directional control. We have made experiments of measuring torque, durability and lifetime. It shows that the torque and lifetime meets target value. But durability does not meet target value. To resolve it, we have applied stator lining materials and shifted frequency with 0.4kHz from resonant frequency and we have shown that it meets durability required specifications

Development of spherical ultrasonic motor for pipe inspection robot

We present a pipe inspection robot using a newly developed spherical ultrasonic motor (SUSM) as a camera actuator. The novel SUSM has improved the range of movement compared to previous SUSMs, and the robot can point a camera in any direction. In this study, we determined a method for controlling the rotational direction and strategic control from the kinematics and characteristics of ultrasonic motors. The rotational directions were defined by the phase differences of the applied voltages, and the rotational speeds were changed with the frequencies. Additionally, we developed a very small position sensing system using rotary potentiometers. In the control experiment performed using the sensing system, the SUSM showed the returnability to the default position from several specified points, within an accuracy of 1°

A study for safety design of electrical machines considering human behavior

Manufacturers have to design machinery considering not only the intended use, but also a reasonably foreseeable misuse, which can lead to product-related accidents. However, manufacturers cannot predict everything the users might do for the machinery. In this study, we have focused on one type of misuse: when the users put their hands inside machinery. Safety mechanisms that deter users from putting their hands inside machinery are required to prevent such accidents. Therefore, in this study we have tried to understand what promotes this action. In this initial stage of our research, we experimented with the visibility and accessibility of an object, and evaluated whether there are related instructions that can affect human behavior

Development of deep-sea drone by spherical ultrasonic motor

The world ocean occupies 70 % on the earth and the average sea depth is about 4,000 m. More than 80 percent of it has not been investigated precisely and the bottom shape of the sea has not been mapped. When doing resource-searching in the future, the precise maps must be required. So, the authors have developed a drone movable around 4,000 m deep sea to measure the bottom of the ocean. It is based on spheres, which includes cameras, batteries, some sensors and controllers. It can rotate a spherical rotor sensing widely to obtain the information about the bottom of the sea. At the first step of the research, the authors have made basic experiments of the motor’s performance in water. The authors have obtained the excellent results in maneuverability, temperature durability, and shock resistance of the motor