Pen Tip Position Estimation Using Least Square Sphere Fitting for Customized Attachments of Haptic Device

Author(s):  
Masanao Koeda ◽  
Masahiko Kato
2021 ◽  
Vol 13 (15) ◽  
pp. 2997
Author(s):  
Zheng Zhao ◽  
Weiming Tian ◽  
Yunkai Deng ◽  
Cheng Hu ◽  
Tao Zeng

Wideband multiple-input-multiple-output (MIMO) imaging radar can achieve high-resolution imaging with a specific multi-antenna structure. However, its imaging performance is severely affected by the array errors, including the inter-channel errors and the position errors of all the transmitting and receiving elements (TEs/REs). Conventional calibration methods are suitable for the narrow-band signal model, and cannot separate the element position errors from the array errors. This paper proposes a method for estimating and compensating the array errors of wideband MIMO imaging radar based on multiple prominent targets. Firstly, a high-precision target position estimation method is proposed to acquire the prominent targets’ positions without other equipment. Secondly, the inter-channel amplitude and delay errors are estimated by solving an equation-constrained least square problem. After this, the element position errors are estimated with the genetic algorithm to eliminate the spatial-variant error phase. Finally, the feasibility and correctness of this method are validated with both simulated and experimental datasets.


2018 ◽  
Vol 14 (11) ◽  
pp. 155014771878689 ◽  
Author(s):  
Shenghong Li ◽  
Lingyun Lu ◽  
Mark Hedley ◽  
David Humphrey ◽  
Iain B Collings

A widely used scheme for target localization is to measure the time of arrival of a wireless signal emitted by a tag, which requires the clocks of the anchors (receivers at known locations) to be accurately synchronized. Conventional systems rely on transmissions from a timing reference node at a known location for clock synchronization and therefore are susceptible to reference node failure. In this article, we propose a novel localization scheme which jointly estimates anchor clock offsets and target positions. The system does not require timing reference nodes and is completely passive (non-intrusive). The positioning algorithm is formulated as a maximum likelihood estimation problem, which is solved efficiently using an iterative linear least square method. The Cramér–Rao lower bound of positioning error is also analyzed. It is shown that the performance of the proposed scheme improves with the number of targets in the system and approaches that of a system with perfectly synchronized anchors.


2013 ◽  
Vol 13 (4) ◽  
pp. 194-199 ◽  
Author(s):  
Shugui Liu ◽  
Hongling Zhang ◽  
Yinghua Dong ◽  
Shaliang Tang ◽  
Zhenzhu Jiang

For different tasks, probe tip should be changed in the 3D vision coordinate measuring system and the accurate determination of probe tip center position is critical. A novel and simple approach for calibrating the probe tip center position of the light pen is presented in this paper. Hundreds of images of the light pen with different postures are collected while the probe tip is kept in firm contact with a reference conical hole. The probe tip position is determined by computing the rotation matrix and translation vector from the obtained images by using the least square fitting method. The experimental results demonstrate the effectiveness of the proposed approach. Its repeatability reaches 0.033 mm, 0.030 mm, and 0.043 mm in x, y, and z axes, respectively, and its convergence speed is satisfactory.


Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1055 ◽  
Author(s):  
Romeo Giuliano ◽  
Gian Carlo Cardarilli ◽  
Carlo Cesarini ◽  
Luca Di Nunzio ◽  
Francesca Fallucchi ◽  
...  

In the last few years, indoor localization has attracted researchers and commercial developers. Indeed, the availability of systems, techniques and algorithms for localization allows the improvement of existing communication applications and services by adding position information. Some examples can be found in the managing of people and/or robots for internal logistics in very large warehouses (e.g., Amazon warehouses, etc.). In this paper, we study and develop a system allowing the accurate indoor localization of people visiting a museum or any other cultural institution. We assume visitors are equipped with a Bluetooth Low Energy (BLE) device (commonly found in modern smartphones or in a small chipset), periodically transmitting packets, which are received by geolocalized BLE receivers inside the museum area. Collected packets are provided to the locator server to estimate the positions of the visitors inside the museum. The position estimation is based on a feed-forward neural network trained by a measurement campaign in the considered environment and on a non-linear least square algorithm. We also provide a strategy for deploying the BLE receivers in a given area. The performance results obtained from measurements show an achievable position estimate accuracy below 1 m.


2015 ◽  
Vol 2015 (0) ◽  
pp. _1A1-E01_1-_1A1-E01_4 ◽  
Author(s):  
Mayuko DOI ◽  
Masanao KOEDA ◽  
Akio TSUKUSHI ◽  
Hiroshi NOBORIO ◽  
Katsuhiko ONISHI ◽  
...  

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