近年來穿戴相關發展越來越蓬勃，特別是在虛擬-實境的綜合藝術表演中，例如: 電影「猩球崛起」。然而大部分虛擬實境的綜合內容是基於腳本預先錄製好的，而且演員需要大量的練習，使表演能夠完美演出。此外，如果我們想要在兩人的相對方向定位上有特殊效果，那麼預先錄製的的方法是不合適的。解決這個問題的一個方法是，使用高品質的相機偵測身體的姿勢或位置。但是精准度常會受限於光線或是障礙物。
本篇論文中，我們提出一個即時相對方向定位方法，這方法使用無線可穿戴式設備解決這個問題。我們結合BLE 所發送的Received SignalStrength Indicator (RSSI)與IMU 感測器資訊，來追蹤兩個表演者的相對方向定位的位置。但是RSSI 資料有波動與不穩定性、IMU 會引起累積的誤差。我們發明了「可靠程度」的RSSI 量測概念，並且把這概念運用在IMU 定期校正上。我們實驗的情況是，兩個人的舞蹈來驗證準確性，結果是令人滿意的。我們還使用Unity 來實踐人體骨架，以便與兩個舞者動作做比較。在未來，我們開發的方案可以用於藝術表演，使內容更豐富，更具互動性。

In recent years, wearable-related applications are flourishing, especially in virtual-real integrated art performance, such as “Rise of the Planet of the Apes”. However, most of the virtual-real integrated contents are pre-recorded based on the script, and the performer needs a lot of practice to make the integration perfect. Moreover, if we want to make special effect based on the relative directional positions of two performers, the pre-recorded approach is not suitable. One way to tackle this problem is to use the high-quality camera to detect the body posture or position.But the accuracy is usually limited in light intensity or obstacles.

In this thesis, we propose a real-time relative directional positioning approach using wireless wearable devices to solve this problem. We use Received Signal Strength Indicator (RSSI) of BLE, combined with IMU sensors to track two performers’ relative directional positions. The RSSI fluctuates and the IMU causes accumulated errors. We invent the concept of “reliable level” of RSSI measures to periodically correct the IMU errors. We experiment the scenario of two-person dance to validate the accuracy, and the result is satisfactory. We also use Unity to real-time render the human skeleton for comparison with the two dancers’ motion.In the future, our developed scheme can be used in the art performance to make the content richer and more interactive.

[1] Tech News. Available: http://finance.technews.tw/2015/11/22/taiwan-textile-industry-and-technology-smart-wearing/
[2] Money.udn.com. Available: http://money.udn.com/money/story/5612/1757509-VR%E5%95%86%E6%A9%9F%E5%A4%A7%E2%80%A6%E7%B4%A1%E7%B9%94%E6%A5%AD%E6%96%B0%E8%97%8D%E6%B5%B7
[3] Interactive Digital Performance art Available: https://www.youtube.com/watch?v=3JdT4fDi4iI
[4] Perfume. Available: https://www.youtube.com/watch?v=aiY_oRwmcpI
[5] Kknews. Available: https://kknews.cc/world/6or96l.html
[6] Daniel Roetenberg, Henk Luinge, and Per Slycke, “Xsens MVN: Full 6DOF Human Motion Tracking Using Miniature Inertial Sensors. XSENS Technologies,”version Apr 3, 2013.
[7] Oh, Jung H., Doojin Kim, and Beom H. Lee. "An indoor localization system for mobile robots using an active infrared positioning sensor." Journal of Industrial and Intelligent Information Vol 2.1 (2014).
[8] Henniges, Robin. "Current approaches of Wi-Fi positioning." IEEE Conference Publications. 2012.
[9] Introduction to BLE. Available: https://en.wikipedia.org/wiki/Bluetooth_low_energy
[10] Huang, Xu, Mark Barralet, and Dharmendra Sharma. "Accuracy of location identification with antenna polarization on RSSI." Proceedings of the International MultiConference of Engineers and Computer Scientists. Vol. 1. 2009.
[11] Bertuletti, S., et al. "Indoor distance estimated from Bluetooth Low Energy signal strength: comparison of regression models." 2016 IEEE Sensors Applications Symposium (SAS). IEEE, 2016.
[12] Wang, Yixin, et al. "RSSI-Based Bluetooth Indoor Localization." 2015 11th International Conference on Mobile Ad-hoc and Sensor Networks (MSN). IEEE,2015.
[13] Wikipedia contributors. 68-95-99.7 rule. Wikipedia.org. Downloaded: March 4,2015. Jimenez, Antonio R., et al. "A comparison of pedestrian dead-reckoning algorithms using a low-cost MEMS IMU." Intelligent Signal Processing, 2009. WISP 2009. IEEE International Symposium on. IEEE, 2009.
[15] Cheng, Chung Yu, et al. "Interactive Performance Using Wearable Devices: Technology and Innovative Applications" Volume 375 of the series Lecture Notes in Electrical Engineering pp 993-1006.
[16] Blumrosen, G., & Luttwak, A. (2013). Human body parts tracking and kinematic features assessment based on RSSI and inertial sensor measurements. Sensors, 13(9), 11289-11313.
[17] How to place the beacon. Available: https://getbrowniepoints.zendesk.com/hc/en-us/articles/211241288-Where-should-I-place-my-Beacon-
[18] Sandeep Mistry masters in Bluetooth services. Available: http://en.gravatar.com/mistrysandeep
(https://github.com/sandeepmistry/node-bleacon/blob/6a30f42353cfde1b08b1a0147cd5899c316e4422/lib/bleacon.js)
[19] Yun, Xiaoping, et al. "Self-contained position tracking of human movement using small inertial/magnetic sensor modules." Proceedings 2007 IEEE International Conference on Robotics and Automation. IEEE, 2007.
[20] Goyal, Pragun, et al. "Strap-down pedestrian dead-reckoning system." measurements 2 (2011): 3.
[21] Liu, Zexi, Chukwuemeka Aduba, and Chang-Hee Won. "In-plane dead reckoning with knee and waist attached gyroscopes." measurement 44.10 (2011): 1860-1868.
[22] Singhal, Toshak, Akshat Harit, and D. N. Vishwakarma. "Kalman Filter Implementation on an Accelerometer sensor data for three state estimation of a dynamic system." International Journal of Research in Engineering and Technology 1.6 (2012): 330-334.
[23] Brookner, Eli. Frontmatter and Index. John Wiley & Sons, Inc., 1998.
[24] Kose, Alper, Andrea Cereatti, and Ugo Della Croce. "Estimation of traversed distance in level walking using a single inertial measurement unit attached to the
waist." 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2011.