Embedded-System Development of a Presenter Position-Sensing Detector for Follow Spot Lighting Control

Abstract

Light is normally dimmed in a presentation room for a clearer image projection. However, it also can affect the visibility of the audiences to the presenter, thus, may cause inefficient communication. This problem can be solved using a spotlight following the presenter. This study aimed to develop an embedded system of a presenter position-sensing detector for follow spot lighting control with broader detection coverage using a Kinect sensor. The system consists of 3 major components including 1) a Kinect sensor with a turntable, 2) a PAR lamp and a follow spot lighting system, and 3) a DMX protocol controller. When the presenter’s joint locations and postures from the Kinect are digitally processed, the position and command is received and run to control the servo motor turntable, the follow spot light and the PAR lamp accordingly. The data were analyzed by means and standard deviation. It was found that in every 0.5 meters away from the presenter, the sensor at a fixed position can detect and identify the presenter in a total of 24 positions, while the sensor on the servo motor turntable rotating at the center, left and right positions by 20 degree each frame can detect up to 36 positions, which is increased by 50%. The average detection error is 0.10 meter with the S.D. of 0.08 meters. At a 3 meter distance from the Kinect, the system covers the detection area of 5 meters. Regarding the lighting control, the average error is 0.46 meter with the S.D. of 0.22 meters. The system is suitable for a medium room size and it can increase the efficiency of the presentation without any spotlight controlling staff.