In order to realize performance gain of a robot or an artificial arm, the end-effector which exhibits the same function as human beings and can respond to various objects and environment needs to be realized. Then, we developed the new hand which paid its attention to the structure of human being's hand which realize operation in human-like manipulation (called TUAT/Karlsruhe Humanoid Hand). Since this humanoid hand has the structure of adjusting grasp shape and grasp force automatically, it does not need a touch sensor and feedback control. It is designed for the humanoid robot which has to work autonomously or interactively in cooperation with humans and for an artificial arm for handicapped persons. The ideal end-effectors for such an artificial arm or a humanoid would be able to use the tools and objects that a person uses when working in the same environment. If this humanoid hand can operate the same tools, a machine and furniture, it may be possible to work under the same environment as human beings. As a result of adopting a new function of a palm and the thumb, the robot hand could do the operation which was impossible until now. The humanoid hand realized operations which hold a kitchen knife, grasping a fan, a stick, uses the scissors and uses chopsticks.

In this paper, a traveling wave type miniature ultrasonic motor using a foil type stator is proposed. The developed motor has a simple mechanism without being a piezoelectric vibrator in itself. Traveling waves from the vibrator source propagate to the foil type stator through the long-length waveguide. Unlike an ordinary ultrasonic motor, the developed motor rotates in the same direction as the traveling wave. To clarify the reverse rotational phenomenon, transient response analysis was executed. The result showed that the foil type motor driving principal was different from that of the general ultrasonic motor which was driven by elliptical motion of the elastic body surface, the main driving force was the generated symmetric lamb wave which rotates the coil surface forward direction. A rotation experiment using the developed prototype motor was executed. Rotational speed was found to be 6,380 rpm and starting torque was 698.8 µNm when the ideal gap between rotor and stator was realized.

In this paper, we investigate the position control of spherical ultrasonic motor (SUSM). The generated torque of SUSM is influenced by the phase difference and the driving frequency of applied AC voltages. Therefore, the control strategy is classified into three types: (a) variable phase and fixed frequency, (b) fixed phase and variable frequency, and (c) variable phase and frequency. We formulate the position control rules for SUSM based on the above three types of control variables, and investigate the performances experimentally.

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°.

Recently, It has become a rapidly aging society. Coupled with a decrease in the number of farmers, this has becomes a serious problem in agriculture. Agricultural work includes a great deal of heavy work and special work postures, imposing a large physical strain on farmers. Therefore, we developed the Wearable Agri-Robot, which was designed as an exoskeletal mechanism to assist in the wearer's work. This study evaluates the degree of freedom realized by forcusing on the range of motion of the joints. Using this method, we evaluated the articular structure of the Wearable Agri-Robot. We investigated the possibility of using it to assist in agricultural work by analyzing the motion required for thie type of work. In this work, we narrowed down the intended operations to the harvesting of Japanese radishes, and validated the effect of the Wearable Agri-Robot on the wearer using myoelectric potential measurement. As a result, it was ascertained that wearing the Wearable Agri-Robot could alleviate the burden on wearer by assisting with agricultural work.

We present a micro ultrasonic motor having rotary and linear motions (rotary-linear motor) suitable for endovascular diagnosis and surgery. The rotary-linear motor is miniaturized to the size needed to function in a blood vessel. The stator prototype is a cube of side 3.5 mm, and the main body is fabricated as a single metallic cube with a through-hole. Four piezoelectric elements are bonded to the sides of the stator. When AC voltage at each resonant frequency is applied to the piezoelectric elements, the circumference of the stator generates elliptical motions at each natural frequency. We can obtain the output from a shaft inserted through the hole. We developed the first prototype of the stator using the finite element method (FEM), and experimentally determined the output of the rotary-linear motor. In the rotary sense, approximately 260 rpm and 0.1 mNm were attained at a resonant frequency of 270 kHz, and in the linear sense about 50 mm/s and 0.01 mN was attained at 306 kHz by driving the system at applied voltages of 42 Vrms.

This paper presents the development of rotary and linear piezoelectric actuator (rotary-linear motor) for a surgical manipulator with MRI compatibility. The stator of the rotary-linear motor is fabricated as a single metallic cube with a through-hole and shaft is inserted to the through-hole. Four piezoelectric elements are bonded to the sides of the stator. When AC voltage at each resonant frequency is applied to the piezoelectric elements, the shaft can move to the rotary and linear directions. There are several control inputs such as the voltage, the frequency, and the phase difference of two AC voltages to control the motor. We have measured the characteristics of the control inputs. As the result, the control characteristics of voltages were linear and were better than those of the frequency and phase difference. On the other hand, the MRI compatibility test was conducted in 0.3 Tesla MRI. MRI image shows the practical quality of the image in the case of that the motor is placed at the center of the imaging volume of MRI while the motor is not driven.

We present a spherical ultrasonic motor (SUSM) and an attitude sensing system using optical fibers for the SUSM. The SUSM is constructed from three ring-shaped stators and a spherical rotor, and has three degrees of freedom (DOF). It has good responsiveness, high positioning accuracy, and strong magnetic field compatibility. In the attitude sensing system, a flat mirror is built in the spherical rotor. Light is emitted to the mirror, and the reflection is caught by optical fibers. The light intensities captured by the optical fibers are processed by a neural network and are converted to attitude information for the spherical rotor. We describe a system comprising the SUSM and the attitude sensing system with its design derived from mechanics and optics. The prototype SUSM is 26mm in diameter and was actuated by the attitude sensing system. Position errors with respect to x and y axes are less than 0.5deg.

MR compatible apparatus is essential to design new tasks for fMRI study. This paper described the development of an MR compatible manipulandum actuated by the ultrasonic motors, which was able to work within MRI scanner and to perform fMRI task continuously during finger movements. The prototype of manipulandum was able to produce two discriminable force fields: position dependent and velocity dependent force field. The control law was derived by the characteristic of velocity-phase difference-torque relationship of the ultrasonic motor. After MR compatibility was verified with signal noise ratio of the images, it was shown that the proposed prototype was able to use for fMRI study

Describes the development of an application of a traveling-wave-type ultrasonic motor as an orienting stage with the precision to cover the fine rotation of a tool at a submicrometer-level orienting system. The defined term of orienting here implies the micro positioning with a fine rotation motion. The proposed fine-orienting stage consists of a half spherical-type rotor and three pieces of ring-type stators. The fine rotation at the center of the rotor is determined by controlling friction forces, which generate rotation at the three contact points between the rotor and the stators. A method to rotate the rotor in fine rotation to attain a desired orientation is also proposed. Three different sizes of ultrasonic motors are presented to verify performance of the ultrasonic motor as a fine-orienting stage and to investigate an extreme of the ultrasonic motor motion. The results of the three models of the orienting stages are discussed and the validity of the ultrasonic motor as a fine-orienting stage is confirmed.

The increasing demand for robotic applications in dynamic unstructured environments is motivating the need for dextrous end-effectors which can cope with the wide variety of tasks and objects encountered in these environments. The human hand is a very complex grasping tool that can handle objects of different sizes and shapes. Many research activities have been carried out to develop artificial robot hands with capabilities similar to the human hand. In this paper the mechanism and design of a new humanoid-type hand (called TUAT/Karlsruhe Humanoid Hand) with human-like manipulation abilities is discussed. The new hand is designed for the humanoid robot ARMAR which has to work autonomously or interactively in cooperation with humans and for an artificial lightweight arm for handicapped persons. The arm is developed as close as possible to the human arm and is driven by spherical ultrasonic motors. The ideal end-effector for such an artificial arm or a humanoid would be able to use the tools and objects that a person uses when working in the same environment. Therefore a new hand is designed for anatomical consistency with the human hand. This includes the number of fingers and the placement and motion of the thumb, the proportions of the link lengths and the shape of the palm. It can also perform most part of human grasping types. The TUAT/Karlsruhe Humanoid Hand possesses 20 DOF and is driven by one actuator which can be placed into or around the hand.

We have successfully developed a new kind of spherical motor with two degree of freedom by ultrasonic vibration: it has o45 rotor; the maximum speed is 30 rpm, the maximum output torque reaches 0.7 kgf cm, the maximum positioning error is less than 0.3 mm. In order to control this new motor, we have developed a new dynamic model by the friction drive model. We demonstrated that the traction drive model explains the characteristics of the motor and this motor has good controllability of velocity and position. We can expect to apply this motor to robotics manipulator's joint and machine vision systems due to the small and simple mechanism of the motor.