Ultrasonic Radar System for Minimally Privacy-Violative Activity Observation
Figure 1:Ultrasonic Radar System
In the ultrasonic radar system developed by the authors, it is assumed that
the human head is an object moving at a relatively high vertical position
in a living area, and emitting ultrasonic sounds and receiving them back as
they are reflected from the head can detect the position of the head. This
section explains the principle used to measure and calculate, that is, to
locate, the position of a human head with unconstraint.
If the positions of the i-th transmitter, j-th receiver and head are )BC )BC , respectively, and the propagation distance is , as shown in Figure 3, then the following equation of a spheroid can be obtained.
If )BCand are known, then the head position can be calculated from the three equations of a spheroid.
Figure 3: Principle of measurement
Figure 4: Probability distributions for human head detection
Figure 5: Tracking position of a human head
Figure 6: Result of experimememt for discrimination
- S. Murakami, T. Hori, Y. Nishida, H. Mizoguchi, )BgUsing an Ultrasonic Tagging System to Assist with Protective Care in Nursing Homes: Evidence-Based Nursing Using a Patientfs Life Log (in Japanese),h in Proceedings of the 23rd Annual Conference of the Robotics Society of Japan, pp. 3D33(1)-(4), September 2005 (Keio University).
- S. Murakami, Y. Nishida, T. Hori, H. Mizoguchi, )BgA Minimally Privacy-Violative Activity Observation System: Tracking People and Objects Using a Combined Tag-Radar Ultrasonic System (in Japanese),h in Proceedings of JSME Robotics and Mechatronics Conference 2005 (ROBOMEC2005), 1A1-N-095(1)-(4), June 2005.
- T. Hori, Y. Nishida, "Ultrasonic Sensors for the Elderly and Caregivers in a Nursing Home," Proceedings of the 7th International Conference on Enterprise Information Systems ICEIS 2005, Vo. 5, pp. 110-115, May 2005
- Y. Nishida, S. Murakami, H. Toshio, H. Mizoguchi, "Minimally Privacy-Violative System for Locating Human by Ultrasonic Radar Embedded on Ceiling," in Proceedings of 2004 IEEE International Conference on Systems, Man and Cybernetics (SMC '04), pp. 1549-1554, October 2004
- T. Hori, Y. Nishida, S. Murakami, H. Aizawa, H. Mizoguchi, "Distributed Sensor Network for a Home for the Aged," in Proceedings of 2004 IEEE International Conference on Systems, Man and Cybernetics (SMC '04), pp. 1577-1582, October 2004
- S. Murakami, Y. Nishida, T. Hori, H. Mizoguchi, )BgDetecting Human Head Location Using a Simply Installed Ultrasonic Radar System,h in Proceedings of the 22nd Annual Conference of the Robotics Society of Japan, 1A23(1)-(2), September 2004.
- Y. Nishida, S. Murakami, T. Hori, H. Mizoguchi, )BgA Minimally Privacy-Violative Human Locating System: Calculating Head Position Using Ultrasonic Radar Installed in a Ceiling (in Japanese),h in Proceedings of JSME Robotics and Mechatronics Conference 2004 (ROBOMEC2004), 1A1-H-47(1)-(4), June 2004.