In this paper we present a control method for robotic finger that uses twisted strings actuator called Twist Drive. A five fingered robotic hand prototype was developed by using Twist Drive actuators to control 14 active degrees-of-freedom. This paper focuses on control of a thumb's CM joint, which is the only joint in the robotic hand prototype that uses two Twist Drive actuators configured in an antagonistic pair of actuators. Positioning accuracy and smoothness of the joint's motion is influenced by nonlinear characteristics of the actuators and by friction in the mechanism. To compensate for the disturbances, we used disturbance observer, and additionally enhance smoothness of motion by controlling the unwinding torque of opposing actuator. The robotic hand and the proposed control algorithm are explained in the paper, experimental results of CM joint positioning control are presented.

A goal of our research is to produce a light-weight, low-cost five fingered robotic hand that has similar degrees of freedom as a human hand. The joints in the fingers of the developed robotic hand are powered by a newly proposed strings transmission named “Twist Drive”. The transmission converts torque into a pulling force by using a pair of strings that twist on each other. The basic characteristics of the transmission are given in the paper. A robotic hand prototype with 18 joints of which 14 are independently powered by Twist Drives was produced. The size of the hand is equal to the size of an adult human's hand and its weight including the power circuits is approximately 800 grams. The mechanical and the control systems of the hand are presented in the paper. Fingers position control and simple pinching and grasping tasks by using open loop force control are presented in the video.

A goal of our research is to produce a light-weight, low-cost five fingered robotic hand that has similar degrees of freedom as a human hand. The joints in the fingers of the developed robotic hand are powered by a newly proposed strings transmission named “Twist Drive”. The transmission converts torque into a pulling force by using a pair of strings that twist on each other. The basic characteristics of the transmission are given in the paper. A robotic hand prototype with 18 joints of which 14 are independently powered by Twist Drives was produced. The size of the hand is equal to the size of an adult human's hand and its weight including the power circuits is approximately 800 grams. The mechanical and the control systems of the hand are presented in the paper.

In this paper, we describe the concept, design and implementation of a series of autonomous mobile soccer robots, named ldquoMusashirdquo robot, which have safety design which is based on ISO and a mechatronics modular architecture, to participate in the RoboCup middle-size league. In modularity design methodology, we show that the selection of a proper moving mechanism, a suitable vision system and a mechatronics modular architecture design can lead to realize a reliable, simple, and low cost robot comparing with most of car-like robots including many kinds of sensors and a complex design structure.

We have proposed practical torque sensing which utilizes a flexible part of a harmonic drive gear. The sensing technique provides joint torque sensing without reducing stiffness of the robot and changing the mechanical structure of the joints. The characteristics of the torque sensing have been studied under an immovable condition. The dependence of characteristics on the rotational velocity have not been discussed. We describe the characteristics under rotational conditions of the harmonic drive. The experimental results show that the accuracy of the torque sensing under high velocity rotation is 2% of the gear torque capacity.

Torque sensing built into harmonic drives has advantages in its size and stiffness comparing to the torque sensors added to the robot joints. A relatively high fluctuation signal of a built-in torque sensor is a drawback in its practical applications. However, we present a simple and effective method to compensate the fluctuation signal and thus improve an overall accuracy of the harmonic drive built-in torque sensing. The method does not require precise positioning of the strain gauges, does not require online-estimations of the fluctuation signal, and does not increase the number of applied strain gauges. It requires initial tuning of the gains. For the signals of the separate strain gauges, two techniques to define the gains are presented: one is based on a mathematical model of the fluctuation signal, and the other employs a heuristic approach. Practical results show the effectiveness and usefulness of the proposed method.