scholarly journals Research on Target Localization Method of CRTS-III Slab Ballastless Track Plate Based on Machine Vision

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3033
Author(s):  
Xinjun Liu ◽  
Wenjiang Wu ◽  
Liaomo Zheng ◽  
Shiyu Wang ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Coordinate System ◽  
Industrial Robots ◽  
Target Localization ◽  
Visual Localization ◽  
Production Environment ◽  
Positioning Accuracy ◽  
Position Information ◽  
Localization Method ◽  
Localization System ◽  
Ballastless Track

In the construction of high-speed railway infrastructure, a CRTS-III slab ballastless track plate has been widely used. Anchor sealing is an essential step in the production of track plates. We design a novel automated platform based on industrial robots with vision guidance to improve the automation of a predominantly human-powered anchor sealing station. This paper proposes a precise and efficient target localization method for large and high-resolution images to obtain accurate target position information. To accurately update the robot’s work path and reduce idle waiting time, this paper proposes a low-cost and easily configurable visual localization system based on dual monocular cameras, which realizes the acquisition of track plate position information and the correction of position deviation in the robot coordinate system. We evaluate the repeatable positioning accuracy and the temporal performance of the visual localization system in a real production environment. The results show that the repeatable positioning accuracy of this localization system in the robot coordinate system can reach ±0.150 mm in the x- and y-directions and ±0.120° in the rotation angle. Moreover, this system completes two 18-megapixel image acquisitions, and the whole process takes around 570 ms to meet real production needs.

scholarly journals Combined GNSS/SLAM-Based High Accuracy Indoor Dynamic Target Localization Method

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaona Zhang ◽  
Shufang Zhang ◽  
Qiaosong Li ◽  
Xin Wang ◽  
Shujing Sun
Keyword(s):  
High Frequency ◽  
Frequency Component ◽  
High Accuracy ◽  
Target Localization ◽  
High Frequency Component ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Position Information ◽  
Localization Method ◽  
Dynamic Target

As the indoor dynamic target localization does not detect and repair the circumferential jump value in time, which leads to large position and attitude errors and low-velocity stability, a combined Global Navigation Satellite System/Simultaneous Localization and Mapping- (GNSS/SLAM-) based high-precision indoor dynamic target localization method is proposed. The method uses Empirical Mode Decomposition (EMD) to decompose the noisy signal, obtains the noise energy as the dominant mode from the decomposed components, extracts the useful signal energy as the main dividing point, removes the high-frequency signal, constructs the low-frequency component to realize low-pass filtering and denoising, selects a suitable threshold processing function to make the high-frequency signal component retain the detailed signal effectively to realize high-frequency component denoising, detects and fixes the circumferential jump of the observed data, and detects and fixes the circumferential jump of each frequency. The indoor dynamic target positioning method is established by combining GNSS/SLAM to achieve high accuracy target positioning. The experimental results show that the position and attitude errors are small, and the velocity is stable, which indicates that the position information is closer to the dynamic target, i.e., the target positioning is more accurate. To address the problems of scale drift and frequent initialization due to environmental factors in monocular vision SLAM, an Ultra Wideband (UWB)/vision fusion localization model that takes into account the scale factor is proposed, which can give full play to the complementary characteristics between UWB and vision; solve the problems of visual initialization, scale ambiguity, and absolute spatial reference; and improve UWB localization accuracy and localization frequency as well as reducing the number of base stations. The model can reliably achieve 0.2 m accuracy in indoor environments with sparse texture or frequent light changes.

Target Localization Based on Two Broadband Guide Sources

2017 ◽  
Vol 25 (02) ◽  
pp. 1750020
Author(s):  
Meijuan Yao ◽  
Licheng Lu ◽  
Li Ma ◽  
Shengming Guo
Keyword(s):  
Field Model ◽  
Water Environment ◽  
Target Localization ◽  
Information Need ◽  
Position Information ◽  
Matched Field Processing ◽  
Localization Method ◽  
Accurate Localization ◽  
Shallow Water Environment ◽  
Environment Parameters

A new method of target localization based on two broadband guide sources is presented, using which only few environment information need to be known in range-independent shallow water environment. This method, based on warping trasnsform, calculates the replica field by calculating the position information and phase information of the field, respectively. Also, compared with the traditional Matched Field Processing localization method, it can avoid the dependence on environment parameters and the field model. Accurate localization results are obtained when the Signal-Noise ratio is higher than 15[Formula: see text]dB and the range of the target is less than 20[Formula: see text]km.

DEVELOPMENT OF AUTOMATED EVALUATION OF POSITIONING ACCURACY FOR SPECIALIZED NETWORKS’ POINTS IN TRILATERATION NETWORKS

2020 ◽  
Author(s):  
Мурат Газизович Мустафин ◽  
Глеб Андреевич Фролов
Keyword(s):  
Coordinate System ◽  
Visual Basic ◽  
Microsoft Excel ◽  
Positioning Accuracy ◽  
Automated Evaluation ◽  
Visual Basic For Applications ◽  
Multiple Configurations

В данной работе рассмотрен принцип работы созданного алгоритма, позволяющего автоматически определять среднюю квадратическую погрешность планового положения пунктов сетей трилатерации и представлены результаты автоматизации данного процесса при различных конфигурациях сети, с использованием пакетов Microsoft Excel, Visual Basic for Applications. This paper presents automatic solution for evaluating accuracy of positioning for specialized networks’ points in a plane coordinate system. The paper presents results of automation of this process through analysis of multiple configurations of trilateral networks using Microsoft Excel, Visual Basic for Applications.

scholarly journals Research of Calibration Method for Industrial Robot Based on Error Model of Position

2021 ◽  
Vol 11 (3) ◽  
pp. 1287
Author(s):  
Tianyan Chen ◽  
Jinsong Lin ◽  
Deyu Wu ◽  
Haibin Wu
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Calibration Method ◽  
Error Model ◽  
Position Error ◽  
Industrial Robots ◽  
Positioning Error ◽  
Robot Position ◽  
General Measurement ◽  
Parameter Error

Based on the current situation of high precision and comparatively low APA (absolute positioning accuracy) in industrial robots, a calibration method to enhance the APA of industrial robots is proposed. In view of the "hidden" characteristics of the RBCS (robot base coordinate system) and the FCS (flange coordinate system) in the measurement process, a comparatively general measurement and calibration method of the RBCS and the FCS is proposed, and the source of the robot terminal position error is classified into three aspects: positioning error of industrial RBCS, kinematics parameter error of manipulator, and positioning error of industrial robot end FCS. The robot position error model is established, and the relation equation of the robot end position error and the industrial robot model parameter error is deduced. By solving the equation, the parameter error identification and the supplementary results are obtained, and the method of compensating the error by using the robot joint angle is realized. The Leica laser tracker is used to verify the calibration method on ABB IRB120 industrial robot. The experimental results show that the calibration method can effectively enhance the APA of the robot.

Method of Optimization for Target Localization Model Parameters Based on LSSVR

2011 ◽  
Vol 268-270 ◽  
pp. 934-939
Author(s):  
Xue Wen He ◽  
Gui Xiong Liu ◽  
Hai Bing Zhu ◽  
Xiao Ping Zhang
Keyword(s):  
Particle Swarm Optimization ◽  
Fitness Function ◽  
Particle Swarm ◽  
Parameters Optimization ◽  
Target Localization ◽  
Likelihood Method ◽  
Support Vector ◽  
Swarm Optimization ◽  
Localization Accuracy ◽  
Localization Method

Aiming at improving localization accuracy in Wireless Sensor Networks (WSN) based on Least Square Support Vector Regression (LSSVR), making LSSVR localization method more practicable, the mechanism of effects of the kernel function for target localization based on LSSVR is discussed based on the mathematical solution process of LSSVR localization method. A novel method of modeling parameters optimization for LSSVR model using particle swarm optimization is proposed. Construction method of fitness function for modeling parameters optimization is researched. In addition, the characteristics of particle swarm parameters optimization are analyzed. The computational complexity of parameters optimization is taken into consideration comprehensively. Experiments of target localization based on CC2430 show that localization accuracy using LSSVR method with modeling parameters optimization increased by 23%~36% in compare with the maximum likelihood method(MLE) and the localization error is close to the minimum with different LSSVR modeling parameters. Experimental results show that adapting a reasonable fitness function for modeling parameters optimization using particle swarm optimization could enhance the anti-noise ability significantly and improve the LSSVR localization performance.

A New Method of 6-DOF Serial Robot’s Trajectory Planning under Multi-Constraints

2014 ◽  
Vol 602-605 ◽  
pp. 1352-1357 ◽  
Author(s):  
Yong Ting Zhao ◽  
Bin Zheng ◽  
Hong Lin Ma
Keyword(s):  
Coordinate System ◽  
Trajectory Planning ◽  
Angular Displacement ◽  
Joint Space ◽  
New Method ◽  
Position Information ◽  
Physical Constraints ◽  
Dynamic Constraints ◽  
Quaternion Interpolation ◽  
And Performance

This paper proposes a new method of 6-DOF serial robot’s trajectory planning. Ensuring to satisfy the physical constraints of space conditions, the robot’s trajectory is interpolated in the Cartesian coordinate system, and using quaternion interpolation to solve the multiple solution problem in RPY interpolation. Meanwhile, the interpolated position information is transformed into the angular displacement information of the joint coordinate system, and the joint space trajectory planning is achieved using the genetic algorithms integrated velocity, acceleration, jerk and torque and other important kinematic and dynamic constraints. In robot safety and stability, the method is better than the general approach, and it has both the ideal trajectory parameters of the global search ability and performance planning.

A simple and rapid calibration methodology for industrial robot based on geometric constraint and two-step error

2018 ◽  
Vol 45 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Jiabo Zhang ◽  
Xibin Wang ◽  
Ke Wen ◽  
Yinghao Zhou ◽  
Yi Yue ◽  
...  
Keyword(s):  
Coordinate System ◽  
Large Scale ◽  
Industrial Robot ◽  
Geometric Constraint ◽  
Machining Process ◽  
Kinematic Parameters ◽  
Robot Calibration ◽  
Positioning Accuracy ◽  
Content Type ◽  
Rapid Calibration

Purpose The purpose of this study is the presentation and research of a simple and rapid calibration methodology for industrial robot. Extensive research efforts were devoted to meet the requirements of online compensation, closed-loop feedback control and high-precision machining during the flexible machining process of robot for large-scale cabin. Design/methodology/approach A simple and rapid method to design and construct the transformation relation between the base coordinate system of robot and the measurement coordinate system was proposed based on geometric constraint. By establishing the Denavit–Hartenberg model for robot calibration, a method of two-step error for kinematic parameters calibration was put forward, which aided in achievement of step-by-step calibration of angle and distance errors. Furthermore, KUKA robot was considered as the research object, and related experiments were performed based on laser tracker. Findings The experimental results demonstrated that the accuracy of the coordinate transformation could reach 0.128 mm, which meets the transformation requirements. Compared to other methods used in this study, the calibration method of two-step error could significantly improve the positioning accuracy of robot up to 0.271 mm. Originality/value The methodology based on geometric constraint and two-step error is simple and can rapidly calibrate the kinematic parameters of robot. It also leads to the improvement in the positioning accuracy of robot.

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