Akihiko Takahashi

A system for simultaneously measuring grasping posture and pressure distribution

This paper describes a measurement system that can simultaneously measure the distribution of grasping pressure, grasping posture and wrist position synchronously with grasping action video image data. A sensor designed to measure the distribution of grasping pressure was developed, for use with this system, and when employed, it is slipped onto the hand the same way as an ordinary glove. It has 15 load detection points on each finger and a total of 81 such points for a single hand. A sensor that can detect finger movements at 18 joints was used, for the measurement of the grasping posture and wrist position. This paper discusses the configuration of the system and presents an experimental result.

Measuring system for grasping

A measuring system for grasping function is developed. The purpose of this system is to measure and analyze the grasping function of human hands. In this report, the structure of the system is introduced. The sensor glove which is the main device of the system, developed by the authors to measure the operation force distribution in hands, is also explained in detail. Using this system, the operation force distribution, joint angles of hands and fingers, wrist position and direction in the operation space and the view of the operation can be simultaneously measured and recorded in real time. The system consists of 5 subsystems: 1) the sensor glove for operation force distribution; 2) the Cyber Glove (by Virtual Technologies) for 18 joint angles in hand; 3) a magnetic sensor to detect the wrist position and direction; 4) a video equipment for the observation of the operation view; and 5) a personal computer to control the system.

Development of a New Hand-Grasp Measurement System

Summary We have developed a system which can synchronously record and reproduce data of four different types: hand position and angle, individual finger joint angles, image data on hand operation, and the distribution of grasping pressure, combining position and angle sensors, finger joint angle sensors, video, and the Sensor Glove. Since this system can synchronously record multiple physical variables involved in the hand and finger operation (recording mode), synchronous reproduction (playing mode) and/or the multiphase evaluation of data (data processing software), previously not possible, have been made possible. We expect this system to contribute to the establishment of a method for designing comfortable man-machine interfaces.

Influence of Repeated Experience on Unsignalized Intersection Crossing Behavior of Drivers without Right-of-Way

The change of start position, where drivers step on the gas pedal just before entering unsignalized intersection within a residential area, through repeated experience was examined. The relationship with Driving Style Questionnaire (DSQ) was discussed. The results showed that subjects who decrease the distance from the edge of a cross lane to start position through experience had tendency to step on the gas pedal only just before entering intersections. The opposition was also true. These subjects had high scores in the following scales of DSQ: Methodical driving, and Preparatory maneuvers at traffic signals. The change of start position through experience also correlated with start position. For instance, start positions of these subjects were relatively small, and they were negative for some intersections.

Sequence of Visual Behavior during Parking

The change of a driver’s viewing direction during parking was investigated by studying the driver’s focus points in each parking phase. Skilled drivers tend to observe the parking place to prepare the next motion even when the vehicle is not approaching the place; unskilled drivers look a long time in the vehicle’s direction of travel to avoid contacting obstacles. This result suggests that helping a driver recognize the location of a parking place and a future position of the vehicle in the preparatory phase can be an effective parking assistance system.