Hironori Ogawa

Development of a system for experiencing tactile sensation from a robot hand by electrically stimulating sensory nerve fiber

Research attempting to merge human and mechanical systems through a nervous system is one of the most dynamic fields in interface technology. Recently, artificial cochlear and retinal nerves were connected via a nervous system. However, there has been no report concerning the replacement of human tactile sensation by artificial sensors connected to the tactile sensory nerve system. The present study reports the development of a system which enables the touch strength applied to a robot hand to be sensed and applied to the hand of a human operator via the microstimulation method. The operator controls the grasping action of a robot hand equipped with tactile sensors at a remote location via a network. The contact information between an object and the robot hand is transmitted via the network, and the tactile sensory nerve of the operator is stimulated by a microelectrode. The force applied to the robot hand can be sensed as an applied force to the hand of the human operator. Applications of the proposed system include the presentation of tactile perception in remote manipulation. In addition, the proposed system is an effective method for transmitting sensation from artificial limbs. The present paper describes the experimental system and results.

Hemispherical net-structure proximity sensor detecting azimuth and elevation for guide dog robot

We have developed a net-structure proximity sensor that detects the azimuth and elevation to a nearby object. This information can be used by robots to avoid obstacles or to respond to human behavior. We propose detection principles where the azimuth is detected by arranging two one-dimensional net-structure proximity sensors along orthogonal axes, and the elevation is detected by arranging two one-dimensional net-structure proximity sensors in a stacked ring. We also experimentally demonstrate the feasibility of these detection principles. The experimental result shows the sensor can detect azimuth at all peripheral angles and elevation from side to top up.

A guidance robot for the visually impaired: System description and velocity reference generation

This paper presents a guidance robot for the visually impaired along with generation of velocity reference signals. The guidance robot has an interface grip with a force sensor on the top. The robot can be operated intuitively through the interface grip, and at the same time, the position and the behavior of the robot can be provided to the user. An underactuated mobile mechanism is used. It can be moved in X and Y directions and is unconstrained in turning direction. The rotation center of the robot is determined by the users position. Environmental sensors are equipped for avoiding obstacles and hazards. In addition, the robot has redundant anti-falling systems for safety. The systems work independently from the environmental sensors. The robot is lightweight, foldable, and easy to carry. A versatile time-optimal reference generation algorithm is proposed for the robots velocity reference. The algorithm can set the bounds for the acceleration, jerk, and snap. Moreover, initial conditions and final conditions of the velocity, acceleration, and jerk can be specified. The switching surfaces are obtained with these parameters in the three-dimensional phase space, which allows the determination of the snap command for easy motion pattern generation. These parameters are changeable online.