Error Compensation for Single Pair-Pole Encoder Based on Ellipse Hypothesis

2012 ◽  
Vol 591-593 ◽  
pp. 1231-1235 ◽  
Author(s):  
Yi Fan Zeng ◽  
Fang Fang Jiang
Keyword(s):  
High Precision ◽  
Error Compensation ◽  
Compensation Effect ◽  
Low Cost ◽  
Compensation Method ◽  
Experimental Results ◽  
Single Pair ◽  
Quadrature Error ◽  
The Common ◽  
Interference Error

An error compensation method for the single pair-pole encoder has been discussed in this paper. This article analyzed offset, sensitivity error, quadrature error and ferromagnetic interference error of single-pole magnetic encoder to obtain the expression of each error. In order to facilitate error compensation, the common expression for describing the error has been summed up. The process for formatting the error can be assumed as the process of changing from circle to ellipse. Therefore the inverse of this process is the same as the process of error compensation. The experimental results show that the accuracy of magnetic encoder which used this method could reach ±1, thus the error compensation effect is obvious. The magnetic encoder which applied this method has the advantages of low-cost, high-precision and convenient to use.

A Low-Cost Head Supported Eye Tracker with High Precision

2013 ◽  
Vol 772 ◽  
pp. 455-460
Author(s):  
Jie Chun Chen ◽  
Shi Quan Ma ◽  
Li Ping Zhao
Keyword(s):  
High Precision ◽  
Relative Position ◽  
Low Cost ◽  
Experimental Results ◽  
Average Error ◽  
Eye Tracker ◽  
Experimental Apparatus ◽  
The Subject ◽  
Maximal Average

This paper discusses a low cost head-supported eye tracker. To measure the coordinates associated with a subjects gaze point fallen on a monitor, the subject places his head on a head support and keeps his head fixed. Meanwhile, a camera is used to capture images of the subjects left or right eye. The subjects gaze point fallen on a monitor can be determined according to the relative position of the pupil and glint in an eye image. This paper presents not only the principle of this eye tracker, but also the methods used to detect the pupil and glint in an eye image. At last, this paper presents some experimental results, and the experimental results show that the maximal average error of the experimental apparatus is 15 pixels or 0.4 in degrees.

Time Discriminating Design for High Precision Pulsed TOF Laser Rangefinder

2011 ◽  
Vol 105-107 ◽  
pp. 1951-1956
Author(s):  
Dong Qing Shen ◽  
Jian Yong Chen ◽  
Wan Cai Li ◽  
Hong Jiang ◽  
Zhen Yu Li
Keyword(s):  
Experimental Evidence ◽  
High Precision ◽  
Input Signal ◽  
High Performance ◽  
Low Cost ◽  
Threshold Value ◽  
Experimental Results ◽  
Measuring System ◽  
Laser Rangefinder ◽  
Constant Fraction Discriminator

The purpose of a time discriminator is to decide when the input is something you are interested in. It does this by putting out a logic pulse when the input signal meets an adjustable threshold value. A low cost high performance constant fraction discriminator (CFD) for laser rangefinder using pulsed TOF (time of flight) is proposed with the accuracy been improved. The theory of CFD is deduced and discussed and a distance measuring system has been established and experimental evidence is presented to show the feasibility of solving the time walking error problem to amend the precision and improving the environmental applicability, the distance error of +/-0.5mm was observed in the lab condition. The advantages of this instrument are highlighted and the experimental results are presented.

Thermal Error Compensation for a High Precision Lathe to Improve Machining Accuracy

2009 ◽  
Author(s):  
Byung-Sub Kim ◽  
Young-Chan Song ◽  
Chun-Hong Park ◽  
Jong-Kweon Park
Keyword(s):  
High Precision ◽  
Temperature Control ◽  
Error Compensation ◽  
Thermal Error ◽  
Experimental Results ◽  
Machining Accuracy ◽  
Thermal Drift ◽  
Temperature Changes ◽  
Precision Machines ◽  
Thermal Error Compensation

High precision machines require very stable operational environment: temperature control and vibration isolation. Tight temperature control for machines usually demand high cost to operate air conditioners. Some of high precision machines require the ambient temperature changes to maintain within ±0.1 degrees. In this paper, we present a thermal error compensation scheme and experimental results for improving machining accuracy of a high precision lathe. The testbed lathe has X- and Z-axes and they are driven by linear motors and hydrostatic oil bearing. Due to the temperature changes of the ambient air and supplied oil to the hydrostatic bearing, thermal deformation is generated and measured to be as much as 200–300 nanometers. To identify the dynamic relations between the temperature changes and the thermal drift, a state-space model is used in which state variables are constructed from the input measured temperatures and the output thermal drift data. The identified model is implemented in a servo control loop and the predicted thermal error is compensated by subtracting the predicted thermal drift from the servo command. In our simulation, a thermal error of 97 nanometers RMS over 3 hours is reduced to 55 nanometers RMS. Experimental results show an average of 24% reduction in thermal drift and support the validity of our approach.

Error Compensation Method of Harmonic Analysis for Time Grating Sensor

2011 ◽  
Vol 121-126 ◽  
pp. 3850-3854
Author(s):  
Zi Ran Chen ◽  
Dong Lin Peng ◽  
Yong Zheng ◽  
Fang Yan Zheng ◽  
Tian Heng Zhang
Keyword(s):  
Harmonic Analysis ◽  
High Precision ◽  
Measurement System ◽  
Error Compensation ◽  
Production Cost ◽  
Measurement Accuracy ◽  
Compensation Method ◽  
Precision Time ◽  
Error Tracing ◽  
Mechanical Machining

Due to the complexity of measurement system, it is hard correct errors by using traditional error separation and error tracing technology. To reduce the production cost and improve the measurement accuracy, a novel error compensation method based on harmonic analysis is presented in this paper. In this way, high precision time grating sensors can be manufactured with low precision mechanical machining method. The experiment results prove that errors can be reduce within ±2″.

The Beidou Satellite High-Precision Timing Applied Research

2014 ◽  
Vol 981 ◽  
pp. 381-385
Author(s):  
Zhao Peng Hu ◽  
Yu Hua ◽  
Shi Feng Li
Keyword(s):  
High Precision ◽  
Applied Research ◽  
Satellite Navigation ◽  
Information Infrastructure ◽  
Experimental Results ◽  
National Information Infrastructure ◽  
Common View ◽  
Orientation System ◽  
The Common ◽  
National Information

The Beidou (BD) satellite navigation & orientation system is so important of national information infrastructure for our country. After research the BD system in the timing area, whlie analysed the advantage of the Beidou satellite timing technology compared with other conventional timing method, combined with high precision timing experiment and depending on the Common-view experimental results proved that the beidou statllite navigation & orientation system has high research value.

Online harmonic error compensation of Atan2 function for a low-cost automotive sensor application

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jie Zhou ◽  
Markus Dietrich ◽  
Paul Walden ◽  
Johannes Kolb ◽  
Martin Doppelbauer
Keyword(s):  
Error Compensation ◽  
Low Cost ◽  
Compensation Method ◽  
Position Sensor ◽  
Calibration Function ◽  
Automotive Applications ◽  
Online Calibration ◽  
Sensor Application ◽  
Computational Capacity ◽  
Harmonic Distortions

Abstract A new compensation method of harmonic distortions by using Atan2 function is introduced in this paper. It provides a simple online calibration function to determine the parameters of harmonic distortions. Thus, it can be implemented in a microcontroller with less computational capacity and can increase the accuracy of a low-cost angle position sensor for automotive applications.

Research on GNSS/SINS Tightly Coupled Integrated Navigation System

2014 ◽  
Vol 1049-1050 ◽  
pp. 1832-1835 ◽  
Author(s):  
Yao Wei Chang ◽  
Shuai Chen
Keyword(s):  
High Precision ◽  
Navigation System ◽  
Error Compensation ◽  
Coupled System ◽  
Compensation Method ◽  
Integrated Navigation ◽  
Selection Algorithm ◽  
Integrated Navigation System ◽  
Tightly Coupled ◽  
Multiple Step

When a missile runs under the complex situation such as high dynamic flying, receiver signal being blocked and so on, the GNSS receiver sometimes gets less than four satellites. For the loosely coupled system, the navigation accuracy will decrease over time. In this paper ,tightly coupled integrated navigation system which is based on pseudo range and pseudo range rate dynamically adjusts the dimension of the system according to the number of visible satellites, in order to achieve seamlessly navigation; a multiple step optimum precision factor satellite selection algorithm is proposed, an error compensation method which is based on the state transition is designed and implemented. Experiments show that when the number of visible satellites changes, tightly coupled system can seamlessly switch, when more than four satellites are received, the multiple step optimum precision factor selection algorithm can provide a combination of high precision satellites, by applying the error compensation method to calibrating the system, high-precision navigation can be achieved.

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