Hiroto Aida

Design and implementation of an energy-efficient lighting system driven by wireless sensor networks

A wireless sensor network is a technology that aims to collect real world information by wireless communication which connects many computer to network, and it is expected its practical realization. On the other hand, research on the office environment also has attracted a great deal of attention in recent years. It has been reported that light environment affects the productivity of user. In this paper, we propose wireless sensor network-driven intelligent lighting system (WSN-ILS below). WSN-ILS provides a light environment to each user by innetwork processing in wireless sensor network. WSN-ILS achieves energy-efficient light environment by performing an individual control to each lighting from sensor node. WSN-ILS has two schemes to control lighting from the sensor node. We will examine effectiveness of the WSN-ILS on an existing equipment.

Indoor Relative Positioning Scheme Using Illuminance and Color Temperature

As schemes for indoor positioning of persons and objects using near field communication and/or visible light communication come closer to reality, expectations are centering on the spread of indoor location-based services. A problem with these schemes is that they are costly because special equipment is often required for transmission and reception. As relative positioning schemes by controlling illuminance and color temperature of existing indoor lighting, this study proposes those using luminance and color temperature. Relative positioning schemes using luminance and color temperature rapidly estimate a relative position by switching multiple lighting patterns of a ceiling lighting system. By gradually adjusting luminance and color temperature for different locations, positioning is possible on the basis of the degree of change in sensed values. We implemented this relative positioning scheme using luminance and color temperature and evaluated the relation between the Euclidean distance and the real distance between sensors in a real space simulating an office. As a result, it was clarified that there was a correlation between the Euclidean distance and the real distances between sensors in 5 stages.

E-Book Browsing Method by Augmented Reality Considering Paper Shape

E-books have an advantage over printed books in that they allow users to read multiple books on a device such as a tablet or a smartphone. However, e-books also have drawbacks, such as the lack of book weight and of paper-like texture. This study proposes a method in which a user can read while experiencing the tactile sensations of book weight and paper feel through the superimposed display of an e-book page on paper space using augmented reality. Book pages deform to various shapes depending on the way a book is held. If an e-book is superimposed and displayed without adapting to changes in the paper space, differences in visual and tactile information are created and cause discomfort to the user. Therefore, in this study, a proposed method was applied that estimates the curvature of a book and applies a correction to the projection, and the accuracy of the corrections was measured. The effectiveness of the method was verified with respect to the usability of the proposed system through an experiment with test subjects.

Comparison of Power Consumption Reduce Effect of Intelligent Lighting System and Lighting Control System Using Motion Sensors

Designed in accordance with conventional uniform lighting systems, lighting control systems that use motion sensors allow lighting control per area because they only switch on the lights linked to the motion sensors. However, further power consumption reductions can be possible using a dimmer control for individual lights to supply the level of brightness desired by each worker (hereafter referred to as target illuminance) instead of the per-area method. In the present study, we therefore conducted a comparative experiment with regard to the power consumption of a lighting control system that uses motion sensors and a system that controls the lighting for each worker (hereafter referred to as intelligent lighting system). The validity of the power consumption reduction in offices where intelligent lighting system was introduced was determined using a comparative simulation. A simulation was performed for various worker patterns in a mock-up of an actual office environment to verify the validity of the proposed system. The simulation results showed the effectiveness of the proposed method under all work patterns and thus indicated that the intelligent lighting system saves more energy than the lighting control system that uses motion sensors.