Seiji Chonan

Development of a Sensor System for Measuring Tactile Sensation

This paper presents the development of a sensor system for measuring tactile sensation. First, various tactile feelings of fabrics are collected through questionnaires and the factor analysis is introduced to classify the feelings. Next, an active sensing system using the piezoelectric effect and the pyroelectric effect of a PVDF (polyvinylidene fluoride) film is assembled. The sensors surface is heated and two kinds of active sensing, contact and slide, are introduced to collect tactile information. Measurement is done on the sample fabrics and features of the collected data are extracted as the sensor outputs. Comparison with tactile feelings shows that the sensor system well describes human tactile perception.

Development of an endoscopic tactile sensor using PVDF films

In this work, a prototype Polyvinylidene Fluoride (PVDF) tactile sensor for endoscopic application has been developed. The sensor aims to measure hardness, which is one of the information of tactile perceptions, of biomedical tissue. This sensor is composed of two PVDF films, a silicone cylindrical column, and an aluminum cylinder. And the classification of hardness is concerned with the ratio of these PVDF outputs. In this paper, two sensors are fabricated using two silicone cylindrical columns with different Youngs modulus. The performance evaluation of each sensor is conducted using 6 silicone rubbers as measuring object. The experimental results correspond with the simplified theoretical analysis and the proposed sensor can distinguish a difference of elastic property.

Visualization of short-term HRV as an index for mental stress evaluation

This paper proposes a new method for visualization of the Heart Rate Variability (HRV) as a visual presentation for mental stress evaluation using the Symmetrized Dot Patterns (SDP) presentation. With this method, time series of the R-R intervals of the electrocardiogram (ECG) are mapped into a polar space and plot out as a scatter plot on the polar graph. The proposed method is testified with the ECG data of fourteen subjects during the mental work-load experiments. Mental arithmetic tasks were used for applying mental work load to the subjects. Experimental results show significant difference of the SDP of the R-R intervals between the mental workload phase and the rest phase, and the difference can be easily recognized. This fact verifies that the proposed method can serve as a visual presentation for the real-time evaluation of mental stress.

Prediction of Disease Infection of Welsh Onions by Rust Fungus Based on Temperature and Wetness Duration

The style of agriculture practiced in Japan and other countries in Asia is small scale compared to that in North America. While systematic production and management systems have been maintained in Europe and America, Japanese agricultural style tends to depend on past experiences, and application of agricultural chemicals is guided by the calendar and past experiences. Japan is also advanced in the field of plant disease prediction. This paper focuses on a prediction model of disease infection for a foliar parasite on Welsh onions. Rust fungus disease is the most typical disease on Welsh onions, and the Weibull probability density function is appropriate for approximating the infection rate of the disease. The model utilizes temperature and wetness duration to predict the infection of Welsh onions by rust fungus. Producers, then, can use the model to determine the day on which the infection rate will rapidly increase, then carry out appropriate countermeasures to the disease. The proposed prediction method is applicable to several infections found throughout Asia.

About Ideal Paddling Form of Flat-water Kayak using a Paddling Machine

INTRODUCTION In recent years motion capture has been introduced to the field of sports science.This technology is used to assist athletes in becoming more capable and proficient in their sport. For example, motion capture has been used to correct and optimize athletic form in baseball, track and field, swimming, in addition to a host of other sports. However, an item which has not been very extensively researched is competitive form and training methodology. Therefore, this paper focuses on flat-water kayaking in which we compared and examined both the paddling of athletes having a high level of skill and that of junior athletes with less experience, using motion capture during participation in an inter-high school competition in Akita Prefecture. Here, motion analysis was used to examine and elucidate ideal form for flat-water kayaking.

Development of a tendon driven system using a pneumatic balloon

This paper is a study on a new type of a tendon system driven by a pneumatic balloon. It consists of a tendon and a silicon tube. Both ends of the silicon tube are closed and the tube expands like a balloon with the supply of air, which distends the silicon tube and pulls the tendon. Two types of actuation systems are considered. One is a high power system while the other a long stroke type. These two actuation systems have a difference in the mechanism of driving the tendon. In the high power system, the tendon is wound around the balloon. On the other hand, for the long stroke type, one end of the tendon is clamped near the balloon. The states of expansion are examined for both the high power type and the long stroke type. A cover is introduced to prevent the excessive expansion of the inflated balloon. The basic characteristics of the two tendon systems are discussed. A comparison with a human muscle is also presented.

Control performance of pneumatic artificial muscle

The robot in the future will be lightened and, in addition, the complex tasks will be done by the consumption of less energy. To achieve this, the development of an artificial muscle actuator which is as soft as a human-being becomes indispensable. At present, the artificial muscle actuator used is the McKibben type, but the heat and mechanical loss of this actuator are large because of the friction caused by the expansion and contraction of the sleeve. Therefore, we developed the artificial muscle tube where the Carbon fiber of the high intensity had been built into the silicon tube. In this report, the results of the examined the mechanical property of silicone rubber is reported, and the shrinking characteristics, response characteristics, and control performance as a pneumatic actuator are reported.