Development and research of the test bench for the angle calibration of geodetic instruments ; Geodezinių kampų matavimo prietaisų kalibravimo įrangos kūrimas ir tyrimas
152 Pages
English

Development and research of the test bench for the angle calibration of geodetic instruments ; Geodezinių kampų matavimo prietaisų kalibravimo įrangos kūrimas ir tyrimas

-

Downloading requires you to have access to the YouScribe library
Learn all about the services we offer

Description

VILNIUS GEDIMINAS TECHNICAL UNIVERSITY Domantas BRUČAS DEVELOPMENT AND RESEARCH OF THE TEST BENCH FOR THE ANGLE CALIBRATION OF GEODETIC INSTRUMENTS Doctoral Dissertation Technological Sciences, Measurement Engineering (10T) Vilnius 2008 Doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2004–2008. Scientific Supervisor Prof Dr Habil Vytautas Giniotis (Vilnius Gediminas Technical University, Technological Sciences, Measurement Engineering – 10T). http://leidykla.vgtu.lt VGTU leidyklos TECHNIKA 1451 M mokslo literatūros knyga ISBN 978-9955-28-225-9 © Bručas, D., 2008 VILNIAUS GEDIMINO TECHNIKOS UNIVERSITETAS Domantas BRUČAS GEODEZINIŲ KAMPŲ MATAVIMO PRIETAISŲ KALIBRAVIMO ĮRANGOS KŪRIMAS IR TYRIMAS Daktaro disertacija Technologijos mokslai, matavimų inžinerija (10T) Vilnius 2008 Abstract The main idea of current PhD thesis is an accuracy analysis of testing and calibration of geodetic instruments. The object of investigation is an analysis of means and methods for testing and calibration of geodetic instruments for plane angle measurement, development of such calibration equipment, its accuracy investigation and the research of its accuracy increasing possibilities.

Subjects

Informations

Published by
Published 01 January 2008
Reads 28
Language English
Document size 8 MB

VILNIUS GEDIMINAS TECHNICAL UNIVERSITY
Domantas BRUČAS
DEVELOPMENT AND RESEARCH
OF THE TEST BENCH FOR THE
ANGLE CALIBRATION OF
GEODETIC INSTRUMENTS
Doctoral Dissertation
Technological Sciences, Measurement Engineering (10T)
Vilnius 2008 Doctoral dissertation was prepared at Vilnius Gediminas Technical University in
2004–2008.
Scientific Supervisor
Prof Dr Habil Vytautas Giniotis (Vilnius Gediminas Technical University,
Technological Sciences, Measurement Engineering – 10T).

















http://leidykla.vgtu.lt
VGTU leidyklos TECHNIKA 1451 M mokslo literatūros knyga







ISBN 978-9955-28-225-9

© Bručas, D., 2008
VILNIAUS GEDIMINO TECHNIKOS UNIVERSITETAS
Domantas BRUČAS
GEODEZINIŲ KAMPŲ
MATAVIMO PRIETAISŲ
KALIBRAVIMO ĮRANGOS
KŪRIMAS IR TYRIMAS
Daktaro disertacija
Technologijos mokslai, matavimų inžinerija (10T)
Vilnius 2008
Abstract
The main idea of current PhD thesis is an accuracy analysis of testing and
calibration of geodetic instruments. The object of investigation is an analysis of
means and methods for testing and calibration of geodetic instruments for plane
angle measurement, development of such calibration equipment, its accuracy
investigation and the research of its accuracy increasing possibilities. These
objects are important for successful testing or calibration of geodetic instruments
for angle measuring which is essential in ensuring the precision of measurements
taken in surveying, construction, mechanical engineering, etc.
There are several main goals of the presented work. First one is an analysis
of the angle measuring methods and devices suitable for the testing and
calibration of geodetic instruments, according to the results of the mentioned
analysis the second task can be formulated – creation of a multi-reference plane
angle testing and calibration equipment at Institute of Geodesy, Vilnius
Gediminas Technical University and investigate the parameters of its accuracy.
The third task is to investigate the accuracy increasing possibilities of the
equipment, and implementation some of them into the practice.
The thesis consists of four chapters, introduction, conclusions, list of
references and appendixes.
Introduction is dedicated for an introduction to the problem and its
topicality. There are also formulated purposes and tasks of the work; the used
methods and novelty of solutions are described; author‘s publications and
structure of the thesis are presented.
First chapter covers an analysis of most used means and methods of
precise plane angle measurement which can be implemented in the testing and
calibration of geodetic instruments with the most attention paid to the precision,
automation and calibration possibilities. The analysis involves both classical
means such as circular scale/microscope(s) or polygon/autocollimator measu-
rements and the modern means as “ring laser” or precise angular encoders.
In the second chapter the multi-reference test rig created and based on the
research described in the first chapter is described, with most of the attention
being paid to the technical decisions implemented in the device.
In the third chapter the statistical and spectral analysis of accuracy of the
test rig based on the results of the measurements is presented. According to the
analysis performed, there are methods for accuracy increasing (namely moder-
nized scale calibration method) proposed in the fourth chapter, with method
practical implementation test results statistically analysed.
The results of the researche were published in 7 reviewed scientific
periodical and 2 other publications. There were 3 presentations made at the
conferences in Lithuania.
Reziumė
Disertacijoje nagrinėjamos geodezinių kampus matuojančių prietaisų
patikros bei kalibravimo metodai bei priemonės. Pagrindinis tyrimo objektas yra
geodezinių prietaisų tikslumo parametrų matavimo būdų ir priemonių analizė,
kalibravimo įrenginio kūrimas, jo tikslumo charakteristikų tyrimas bei įrenginio
tobulinimas. Šie objektai yra svarbūs vykdant geodezinių prietaisų kalibravimą,
kas savo ruožtu yra labai svarbu užtikrinant reikiamą šių prietaisų matavimų
tikslumą geodezijoje, statybose, mašinų gamyboje ir t. t.
Pagrindinis disertacijos tikslas – geodezinių kampų matavimo prietaisų
kalibravimo galimybių analizė ir sukurto kalibravimo įrenginio tikslumo para-
metrų tyrimas.
Darbe sprendžiami keli pagrindiniai uždaviniai: plokščiųjų kampų mata-
vimo metodų bei įrenginių, tinkamų geodeziniams prietaisams kalibruoti,
analizė; daugiaetalonio kampų kalibravimo stendo kūrimas Vilniaus Gedimino
technikos universiteto Geodezijos institute bei jo tikslumo charakteristikų tyri-
mas; stendo tikslumo didinimo galimybių bei priemonių tyrimas, ir apskritiminių
skalių kalibravimo būdų tobulinimas.
Disertaciją sudaro šeši skyriai, įvadas, išvados, literatūros sąrašas bei
priedai.
Įvade nagrinėjamas problemos aktualumas, formuluojamas darbo tikslas
bei uždaviniai, aprašomas mokslinis darbo naujumas, pristatomi autoriaus
pranešimai ir publikacijos, disertacijos struktūra.
Pirmasis skyrius skirtas labiausiai paplitusių plokščiųjų kampų matavimo
būdų bei priemonių tinkamų geodeziniams prietaisams kalibruoti apžvalgai,
daugiausiai dėmesio skiriant priemonių tikslumui, automatizavimo bei kalibra-
vimo galimybėms. Apžvalga apima tiek klasikines priemones, tokias kaip apskri-
timinės skalė/mikroskopas(ai) ar daugiakampė prizmė/autokolimatorius, tiek
modernias, kaip „žiedinis lazeris“ ar preciziniai kampo keitikliai.
Antrajame skyriuje pateiktas daugiaetalonio kampų patikros bei kalib-
ravimo stendo, sukurto remiantis analize, aprašyta antrajame skyriuje, konst-
rukcija bei veikimo principas, daugiausiai dėmesio skiriant inžineriniams bei
techniniams sprendimams pritaikytiems stende.
Trečiajame skyriuje pateikta statistinė bei spektrinė sukurtojo stendo eks-
perimentinių matavimų tikslumo analizė. Remiantis šia analize ketvirtajame sky-
riuje pasiūlyti stendo tikslumo didinimo būdai bei priemonės, – patobulintas
apskritiminių skalių kalibravimo metodas, – su praktiniu metodo pritaikymu bei
matavimo rezultatų statistine bei spektrine analize.
Disertacijos tema paskelbtos 7 publikacijos recenzuojamuose periodi-
niuose mokslo leidiniuose bei 2 kituose leidiniuose. Skaityti 3 pranešimai Lietu-
vos ir tarptautinėse konferencijose.

Contents

Introduction ......................................................................................................... 1
1. Review and Analysis of Angle Measuring Instruments and Equipment
Calibration ...................................................................................................... 5
1.1. Analysis of Accuracy Parameters of Angle Measuring Instruments........... 5
1.2. Polygon/Autocollimator .............................................................................. 7
1.2.1. Principle of Operation ........................................................................... 7
1.2.2. Multiangular Prism Calibration Method ............................................. 11
1.2.3. Main Technical Features of the Polygon/Autocollimator Means of
Measure................................................................................................ 13
1.3. Precision Index Table................................................................................ 14
1.3.1. Principle of Action .............................................................................. 14
1.3.2. Main Technical Features of the Precision Index Means of Measure .. 16
1.4. Angle Measurements Taken by the Visual Scale/Microscope(s).............. 16
1.4.1. Principle of Action and Main Features................................................ 16
1.4.2. Circular Scales Calibration Methods................................................... 18
1.4.3. Main Technical Features of the Circular Scale/Microscope(s)
Means of Measure................................................................................ 24
1.5. Angular Encoders...................................................................................... 25
1.5.1. Principle of Action and Main Features................................................ 25
1.5.2. Some Examples of Photoelectric Encoders Applications ................... 29
1.5.3. Main Technical Features of the Photoelectric Angular Encoder
Means of Measure................................................................................ 32
1.6. Ring Laser ................................................................................................. 33
1.6.1. Principle of Action .............................................................................. 33
1.6.2. Main Technical Features of the „Ring Laser“ Means of Measure ...... 34
1.7. Main Technical Features of All the Mentioned Means of Measure.......... 35
st1.8. Conclusions of the 1 Chapter................................................................... 35
2. Design and Technical Parameters of the Bench for Testing Angle
Measuring Devices........................................................................................ 37
2.1. Basic Mechanical Design, It’s Accuracy Specifications........................... 37
2.1.1. Basic Test Rig Design......................................................................... 37
2.1.2. Mechanical Disc (Scale) Properties (Causing Errors)......................... 42
2.1.3. Test Rig Specifications........................................................................ 44
2.2. Main Electric and Electronic Parts of the Test Rig ................................... 44
2.3. Additional Measuring Devices – Autocollimator Mounting and
Modifications ............................................................................................ 47
2.3.1. General Measuring Arrangement ........................................................ 47
2.3.2. Modification of the Autocollimator .................................................... 48
2.3.3. General Measurements Accuracy of Polygon/Autocollimator............ 52
2.4. Scale Measuring Instruments – Microscope Mounting and
Modifications ............................................................................................ 53
2.4.1. General Arrangement .......................................................................... 53
2.4.2. Modification and Mounting of the Microscope(s) .............................. 54
2.5. The Mounting of Tested Geodetic Device Onto the Test Rig................... 58
2.5.1. General Mounting ............................................................................... 58
2.5.2. Collimation of Tested Device.............................................................. 59
nd2.6. Conclusions of the 2 Chapter.................................................................. 62
3. The Research of the Test Bench Accuracy.................................................. 63
3.1. The Precision Analysis of Angular Positioning Performed by
Photoelectric Angle Encoder..................................................................... 63
3.2. Angular Position Determination Performed by Circular
Scale/Microscope Accuracy Analysis....................................................... 74
3.3. Photoelectric Angle Encoder Eccentricity Analysis.................................. 81
3.4. The Accuracy Evaluation of the Wild Turning Table................................ 84
rd3.5. Conclusions of the 3 Chapter .................................................................. 88
4. Development of the Circular Scale Calibration Method ........................... 91
4.1. Use of Two Microscopes or the Circular Scale Calibration...................... 91
4.1.1. Selection of the Most Appropriate Method for Scale Calibration....... 91
4.1.2. Analysis of the “Constant Angle Setting in Full Circle” Method ....... 92
4.1.3. The Influence of Eccentricity on Described Method .......................... 95
4.2. Modified Circular Scale Calibration Method............................................ 97
4.2.1. General Approach to the Modification of “Constant Angle Setting
in Full Circle” Method......................................................................... 97
4.2.2. Expansion of Microscopes Positioning Possibilities of the
Modified Method ............................................................................... 102
4.3. Example of Circular Scale Calibration Using the Modified Method ...... 105
4.4. Analysis of the Suggested Method Test Results ..................................... 108
4.5. The Circular Scale Eccentricity Analysis................................................ 114
th4.6. Conclusions of the 4 Chapter ................................................................ 118
General Conclusions........................................................................................ 119
References ........................................................................................................ 121
List of D. Bručas Published Works on the Topic of the Dissertation ......... 131
Appendix A. Scale Calibration Measurement Results................................. 133
Appendix B. Main Results of “Hilger & Watts” Multiangular Prism
Calibration Performed at PTB.................................................................. 141

Introduction
Topicality of the Research

There are instruments allowing precise planar angle measurements widely
used in geodesy, surveying, machine engineering and other branches of industry.
Such instruments are theodolites, digital theodolites, tacheometers, total stations,
etc. Since such instruments often are used for very precise and important
measurements, like all the other these instruments must be tested and calibrated.
Testing of these instruments is regulated according to ISO 17123-3 (Optics
and optical instruments – Field procedures for testing geodetic and surveying
instruments – Part 3: Theodolites) and ISO 17123-5 (Optics and optical
instruments – Field procedures for testing geodetic and surveying instruments –
Part 5: Electronic tacheometers). According to the standards accuracy of the
angle measurement performed by an instrument (i.e. the difference of two
measured directions in case of horizontal angle and the difference of the
measured direction and the one determined with inclination sensors or the tubular
level in case of a vertical angle measurement) must be tested in field conditions
using the known length reference measure for the angle measurement
(triangulation principle). Using such method it is possible to get only a very
restricted number of angular measurements, and it does not allow collecting a
large number of different (desired) tested angular values. On the other hand
tested geodetic instrument display a vast number of discrete values on their
display unit during measurement, and these values must also be checked.
1 2 Introduction
Additionally, the standards mentioned above describe only the procedures for
testing geodetic instruments concerned with determining only the uncertainties of
measurement, without taking into account any biases (systematic errors)
produced by the measuring unit.
For the determination of both biases and random errors produced by the
geodetic measuring instrument a special device must be used, also the calibration
of the geodetic measuring instruments requires a large number of angular values
to be compared with the reference values. Such procedure due to its technical
complexity and expensiveness of the testing device is not regulated by any
standard at all. Devices capable of performing such procedures are usually
operated by companies – manufacturers of measurement equipment and are not
available for the wide public and the users of these instruments [36].
It is obvious that the test bench must be developed capable of performing
the geodetic instruments plane angle testing (the evaluation of measuring
instrument suitability for work by means of experimental evaluation of its
metrological characteristics and revising its correspondence to the assigned
requirements) and calibration (the operations which at certain conditions
determine the relations between the calibrated instrument measurants and the
corresponding values of the reference means) [64]. It was decided to create such
a test bench at Institute of Geodesy Vilnius Gediminas Technical University. The
test bench was supposed to comply with the need of geodetic angle measuring
instruments (such as theodolites and tacheometers) testing or calibration (in some
cases) and additionally be suitable for testing of the angle measuring devices
used in the other branches of industry (i.e. be used as a comparator).
Since the construction of such test bench is technically complicated and
expensive it was decided to construct the device for testing/calibration of
geodetic instruments horizontal plane angle (i.e. the angular difference of two
measured directions) measurements as a prime goal. The main subject of the
study presented here will be the construction and the accuracy research of such
bench designed for testing/calibration of the geodetic instruments for horizontal
plane angle measurements.

Aim and Tasks of the Work

The aim of this work is the analysis of testing/calibration possibilities for
geodetic angle measuring instruments, creation of testing and calibration
equipment suitable for this task and the research of accuracy of such equipment.
The tasks of this research can be formulated as follows:
1. To perform the analysis of the angle measuring methods and devices
suitable for testing and calibration of geodetic instruments.