Impact of attitude measurement errors on laser footprints positioning accuracy

2013 ◽  
Author(s):  
Teng Xu ◽  
Lijun Xu ◽  
Xiaolu Li ◽  
Xiangrui Tian
Keyword(s):  
Measurement Errors ◽  
Attitude Measurement ◽  
Positioning Accuracy

Improvement in a Surface Motor-Driven Planar Motion Stage

2006 ◽  
Vol 18 (6) ◽  
pp. 808-815 ◽  
Author(s):  
Wei Gao ◽  
◽  
Katsutoshi Horie ◽  
Songyi Dian ◽  
Kei Katakura ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Planar Motion ◽  
Two Dimensional ◽  
Positioning Accuracy ◽  
Accuracy Measurement ◽  
Linear Motors ◽  
Stator Windings ◽  
Motion Stage ◽  
Planar Motion Stage ◽  
Sinusoidal Surface

We report a surface motor-driven planar motion stage with an XYθZsurface encoder. The surface motor consists of two pairs of linear motors. Magnetic arrays are installed on the platen and stator windings of linear motors on the stage base. The platen is moved in the X and Y directions by X and Y linear motors. It is rotated around the Z axis by moment generated by the X or Y linear motors. The surface encoder consists of two two-dimensional (2D) angle sensors and an angle grid with 2D sinusoidal surface waves. The angle grid is installed on the platen. Sensors onside make the stage compact. The surface encoder is improved for higher positioning accuracy. Measurement errors of the surface encoder using two detectors – a quadrant PD and 2D PSD – are determined by simulation. The surface motor for increasing stage speed is modified. We conducted experiments comparing the previous prototype stage (Prototype I) and the improved stage (Prototype II).

Configuration of 3D Indoor Positioning System Based on Bluetooth Beacons

2021 ◽  
Vol 27 (1) ◽  
pp. 32-40
Author(s):  
V. M. Grinyak ◽  
Keyword(s):  
Measurement Errors ◽  
Theoretical Calculations ◽  
Tracking System ◽  
Linear Equations ◽  
Estimation Procedure ◽  
Accuracy Evaluation ◽  
Algebraic Equations ◽  
Positioning Accuracy ◽  
Model Interpretation ◽  
Linear Algebraic Equations

This paper devoted to research of indoors navigation problems under poor or insufficient quality of satellite navigational data environment. The problem of object positioning in 3D space by Bluetooth devices located indoors forming a multi-position tracking system is considered in this research. Emphasized that in order to succeed for such system it is required to pre-estimate distinctive accuracy. The proposed model interpretation of the positioning problem as the system of linear equations. The classic model interpretation for method of least squares is used for resolution. General problem of linearization around reference resolution is the locality of its features. There are three concepts of problems solvability, such as fundamental solvability (observability), solvability in conditions of instrumental measurement errors and solvability under conditions of finite accuracy of computation on a computer. The first aspect of solvability is interpreted by the completeness of the rank of the corresponding system of linear algebraic equations, the second and third ones represents by the conditionality of the problem and the convergence of the iterative estimation procedure. The conducted experiments show that for the positioning problem the attributes of the linearized model are accurate enough to represent the original nonlinear problem. Such interpretation allows to build theoretical accuracy estimation priors for object coordinates evaluations and to identify the areas with insufficient positioning accuracy. In this paper there are results of expected accuracy evaluation for various system patterns with full-scale experiments proving the theoretical calculations. Experiments for problems with using SKYLAB Beacon VG01 Bluetooth transmitters and smartphone HUAWEI WAS-LX1 are presented and confirmed that math model with linear approximation defined by authors is usable for solving indoors navigation problems using Bluetooth signal. So, for good enough quantity and appropriate location of the tracks the achievable positioning accuracy could be as good as 0.2—0.3 meters for all three coordinates. Such accuracy allows to navigate small hovering objects such as drones. In general, it looks promising to use Bluetooth trackers for solving positioning problems for indoors environments.

scholarly journals Ultrasonic localization method based on receiver array optimization schemes

2018 ◽  
Vol 14 (11) ◽  
pp. 155014771881201 ◽  
Author(s):  
Xiaonan Luo ◽  
Hucheng Wang ◽  
Suqing Yan ◽  
Jianming Liu ◽  
Yanru Zhong ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Sound Intensity ◽  
Small Scale ◽  
Positioning Accuracy ◽  
Localization Method ◽  
Redundant Data ◽  
Receiver Array ◽  
Array Optimization ◽  
Enclosed Space ◽  
Optimization Schemes

Ultrasonic localization system using trilateration has been adopted in various types of full-enclosed and semi-enclosed space. For small-scale or enclosed scenarios, there is an important phenomenon, that is, the ultrasonic wave may rapidly reflect back and forth between the walls to form different normal waves during the process of propagation, which may break the inverse square law of sound intensity (the sound intensity in free space is inversely proportional to the square of the distance). The other problem is that the sound intensity of some local corner points are obviously stronger than those points near the acoustic source, which may confuse the ultrasonic receivers and bring significant differences in measurement errors. To avoid excessive errors influence for the positioning accuracy, in this article, a novel ultrasonic localization method based on receiver array optimization schemes is reported. The main purpose is to activate the ultrasonic receiver in the area as well as shield the ultrasonic receiver outside the area. The system error will be reduced based on this method, and most of the redundant data will be eliminated. The simulation results are visualized and compared with the existing methods. The positioning accuracy measured by our method is increased significantly.

Impacts of Random Attitude Measurement Errors on Airborne Laser Scanning Image

2011 ◽  
Vol 38 (3) ◽  
pp. 0314001
Author(s):  
王建军 Wang Jianjun ◽  
徐立军 Xu Lijun ◽  
李小路 Li Xiaolu
Keyword(s):  
Measurement Errors ◽  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Attitude Measurement ◽  
Airborne Laser

scholarly journals A Closed-Form Localization Algorithm and GDOP Analysis for Multiple TDOAs and Single TOA Based Hybrid Positioning

2019 ◽  
Vol 9 (22) ◽  
pp. 4935 ◽  
Author(s):  
Deng ◽  
Wang ◽  
Zheng ◽  
Fu ◽  
Yin ◽  
...  
Keyword(s):  
Closed Form ◽  
Measurement Errors ◽  
Communication Systems ◽  
Distribution Systems ◽  
Weighted Least Squares ◽  
Cellular Communication ◽  
Multiple Time ◽  
Localization Algorithm ◽  
Positioning Accuracy ◽  
Hybrid Positioning

Cellular communication systems support mobile phones positioning function for Enhanced-911 (E-911) location requirements, but the positioning accuracy is poor. The fifth-generation (5G) cellular communication system can use indoor distribution systems to provide accurate multiple time-difference-of-arrival (TDOA) and single time-of-arrival (TOA) measurements, which could significantly improve the indoor positioning ability. Unlike iterative localization algorithms for TDOA or TOA, the existing closed-form algorithms, such as the Chan-Ho algorithm, do not have convergence problems, but can only estimate position based on one kind of measurement. This paper proposes a closed-form localization algorithm for multiple TDOAs and single TOA measurements. The proposed algorithm estimates the final position result using three-step weighted least squares (WLSs). The first WLS provides an initial position for the last two steps. Then the algorithm uses two WLSs to estimate position based on heteroscedastic TDOA and TOA measurements. In addition, the geometric dilution of precision (GDOP) of the proposed hybrid TDOA and TOA positioning has been derived. The analysis of GDOP shows that the proposed hybrid positioning has lower GDOP than TDOA-only positioning, which means the proposed hybrid positioning has a higher accuracy limitation than TDOA-only positioning. The simulation shows that the proposed localization algorithm could have better performance than closed-form TDOA-only positioning methods, and the positioning accuracy could approximate Cramer-Rao lower bound (CRLB) when the TDOA measurement errors are small.

Research on Vessel Positioning System Based on Kalman Filtering

2011 ◽  
Vol 58-60 ◽  
pp. 2428-2433
Author(s):  
Guang Qian Chu ◽  
Yan Cao ◽  
Chao Liang Si
Keyword(s):  
Kalman Filtering ◽  
Measurement Errors ◽  
Multipath Propagation ◽  
Line Of Sight ◽  
Positioning System ◽  
Positioning Accuracy ◽  
Environmental Models ◽  
Signal Characteristics ◽  
Channel Environment ◽  
Non Line Of Sight

In recent years, the typhoon happens frequently. When typhoon suddenly arrives, the only way to rescue the ship which calls for help in time is to locate the position of the ship in the sea quickly and exactly. But in the ocean, due to the non-ideal channel environment, multipath propagation between accident vessels and monitor stations. All these factors will make the detection of error in measurement of signal characteristics, thus affecting the positioning accuracy. In order to improve the location accuracy of accident vessel in the ocean, two kinds of methods are used. One is to search for realistic channel environmental models for the line-of-sight and the non-line-of-sight propagations to study the characteristics of signal measurements error with good robustness of high-precision positioning algorithms.The other is to analyze the main cause of the different kinds of the measurement errors to find their solutions to decrease the errors.

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