Effect of Changing Differential Perspective on Estimation of Time-to-contact (original) (raw)
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Calibration System of Internal Delay Difference for Two-way Satellite Time Transfer
IEEJ Transactions on Electronics, Information and Systems, 2005
Non-member, Lam quoc Tung * , Non-member Two Way Satellite Time and Frequency Transfer (TWSTFT) enables us to perform time transfer precisely, for atmospheric and geometric delays between the earth station and the satellite are almost canceled because of the path reciprocity. However, the delays in the uplink path and the downlink path of the earth station cannot cancel due to the different signal paths. The delay difference makes the absolute value of the time difference unknown, while the fluctuation in the delay difference degrades the stability of the time transfer. We have developed a delay-difference calibration system using a multi-channel TWSTFT modem. Because the signals for the calibration are processed with the received time-transfer signals from other stations, not only a short-term variation but also a secular change in the delay difference can be measured. It is found that the diurnal variation of the delay difference becomes a few hundred pico-second even if the low noise amplifier works in the temperature-controlled box. As for the time transfer result between two hydrogen masers, its stability was improved by the correction of the delay difference. We confirmed the calibration system was important to improve the precision of TWSTFT.
IEEJ Transactions on Electronics, Information and Systems
This paper reports on the automation technique of live line re-connection included in the electricity distribution work using robot manipulator. There are two major technical issues ;visual measurement of the position of the object in an unstructured outdoor environment and insertion of the wire terminals to a metal sleeve for connection. As a distinctive structure of the work, the distance to the object from CCD camera is quite shorter than the distance to the background. Therefore, we can obtain a clear image of the object while the background is out of focus. We have developed a method of object detection by template matching combined with differential filtering technique of image. The direction of the electric wire and the direction of the sleeve were aligned and the tip of the wire is positioned to the tip of a sleeve using this method. Once the position is reached, the insertion process starts using the compliance control with estimation of the contact force In addition, we have developed procedures for error recovery based on the state transition analysis.
Shisutemu Seigyo Jōhō Gakkai ronbunshi, 2018
Modern society is called a stressful society due to long working hours with electronic equipment and/or human relationships in workplaces, and hence periodic stress checking is required. It is known that there is a relationship between heart rate variability and mental stress. Detection of R-R Interval (RRI) from facial video images is expected to enable noncontact and unconsciously monitoring of mental stress. This study proposes a high-accuracy and short-time RRI estimation method in facial video images, which is called multiple-measurement-points-voting-method, MMVM in short. MMVM can detect RRI of individual facial pixels with time-course color signal change, and estimate RRI from the detected RRIs of multiple points. MMVM was applied to 252 trials of 32 subjects, and was compared with ground truth RRI measured using plethysmographic sensor. The mean absolute error of MMVM was 17.7 ms. And, the minimum measurement duration to reach target accuracy of MMVM was 2.8 sec, and that of ICA method was 5.3 sec. MMVM shortens the measurement time by about 47%.
Effects of gaze target mismatch in human–robot joint visual attention on subjective evaluation
2013
In joint visual attention, the robot should not only follow a human’s gaze but also understand the gaze target of the human. To achieve this goal, we believe the key is mutual adjustment based on the subjectivity of the robot rather than the unilateral imitation of the human’s target. In humans, mismatches in the gaze target identification are naturally accepted as subjectivity; the same cannot be said for robots, in which obedience is expected. We examined the case of mismatches in the gaze target that could entail a change in the subjective evaluation of the robot (Experiment 1). We found that when the mismatch became apparent, although the concordance rate of the gaze target was high, human’s evaluation of understanding of the gaze target by the robot tended to be worse. Also impressions of “friendly,” “kind,” “cute,” and “funny” were reduced, but those of “humanity” and “complexity” tended to increase. In addition, we added a procedure to show a few symbolic facial expressions t...