Theoretical Study of Multi-Theodolite Measurement System

In the field of aerospace, theodolite system is often used in the inspection of large object. A new measurement system that consists of four theodolites is presented in this paper, with which the "blind" problem raised in Original dual-theodolite system can be overcome. The principle of multi-theodolite system, together with the mathematicalmodel (both of calibration and of measurement) is given. And also the calibration process is discussed.

NEW MODEL OF THEODOLITE INDUSTRIAL MEASURING SYSTEM

Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision of the TIMS has been considered so low that the TIMS isnt applied to some precise measurements.The error in self locating TIMS is a main factor which affects the precision of the TIMS.A new model of the TIMS is given out in this paper,and it can eliminate the error in self locating the TIMS.The new model is not only investigated and analyzed theoretically but also verified by the real measured data.

THE THEORY AND APPLICATION OF THE STRUCTURE LIGHT ENGINEERING SURVEYING BASED ON A LASER THEODOLITE WITH THREE FREEDOMS OF ROTATION

The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed.According to the features of a huge object,,the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application.The observation of four sound concrete posts and forced centering plates.Subsequently,it is transformed into the huge object coordinate system.The scanning mode with plumb plane is selected as the main mode in the whole work.And other assistant methods,such as close range photogrammetry and the method of using reflection sheet,are applied to the work of “scanning dead angle”.At last,a surveying accuracy estimation of this method is done and a surveying accuracy test is finished.It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method,and has many superiority to some other surveying methods in the work of surveying “confining structure”.

Improvement Detecting Method of Optical Axes Parallelism of Shipboard Photoelectrical Theodolite Based on Image Processing

An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Pointolite replaced 0.2'' collimator to reduce the errors of crosshair images processing and improve the quality of image. What’s more, the high quality images could help to optimize the image processing method and the testing accuracy. The errors between the trial results interpreted by software and the results tested in dock were less than 10'', which indicated the improve method had some actual application values.

Bundle adjustment for data processing of theodolite industrial surveying system

The photogrammetric bundle adjustment was used in data processing of electronic theodolite industrial surveying system by converting angular observations into virtual photo coordinates. The developed algorithm has ability of precision estimation and data snooping, do not need initial values of exterior orientation elements and object point coordinates. The form of control condition for the system is quite flexible. Neither centering nor leveling is the theodolite needed and the lay out of theodolite position is flexible when the system is used for precise survey. Experiments carried out in test field verify the validity of the data processing method. [

Hermeneutical Theodolite of Requirements: Evaluating and Revealing the Quality Grades of Software Requirements and of Domain of Application

Throughout the development of software, during Requirements Engineering activities, software requirements dynamically and constantly evolve and mature from an “identified” stage to an “approved” stage. This evolution takes place individually for each requirement, in a very particular way, because it depends on the level of understanding that the requirements engineer reaches in relation to it. How, then, to monitor the evolution of each software requirement? How to know the quality of each software requirement? How to measure the level of understanding and difficulty that the requirements engineer has in relation to each software requirement? This paper aims to present a proposal to answer these questions through the use of an instrument developed specifically to assess and reveal the quality grades of each software requirement and also to assess and reveal that the levels of understanding and of difficulty of the requirements engineer is in relation to each software requirement. This instrument was called the Hermeneutical Theodolite of Requirements, which also can be applied to evaluate that the levels of understanding and of difficulty of the requirements engineer is in relation to the domain of application, essential input artifact and primordial to the specification of the requirements of software.

Measurement-driven Gauss-Hermite particle filter with soft spatiotemporal constraints for multi-optical theodolites target tracking

Multi-Optical Theodolite Tracking systems(MOTTs)can stealthily extract the target’s status information from bearings only through non-contact measurement.The constrained MOTTs are partially compatible,yet many existing research works and results are based on the known model,ignoring its discrimination with the target maneuvering behavior pattern.To compensate for these mismatches,this paper develops a Measurement-driven Gauss-Hermite Particle Filter(MGHPF),which elegantly fuses the spatiotemporal constraints and its soft form to perform MOTT missions.Specifically,the target dynamic model and tracking algorithm are based on the target behavior pattern with the adaptive turn rate,fully exploiting the spatial epipolar geometry characteristics for each intersection measurement by a minimax strategy.Then,the center of the feasible area is approximated via the analytic coordinate transformation,and the latent samples are updated via the deterministic Gauss-Hermite integral method with the target’s predictive turn rate.Simultaneously,the effects of truncation correction and compensation feedback from the current measurement and historical estimation data are adaptively incorporated into the PF’s importance distribution to cover the mixture likelihood.Besides,an effective causality-invariant updating rule is provided to estimate the parameters of these soft spatiotemporal constrained MOTTs with convergence guarantees.Simulated and measured results show good agreement;compared with the stateof-the-art Multi-Model Rao-Blackwell Particle Filter(MMRBPF),the proposed MGHPF improves the filtering accuracy by 7.4%-34.7%and significantly reduces the computational load.

Correction method for non-landing measuring of vehicle-mounted theodolite based on static datum conversion

During the non-landing measuring of vehicle mounted theodolite, especially under high-speed tracking measurement, the misalignment of theodolite's center of mass and spindle etc. will cause high-frequency vibration of theodolite platform, increase the observation error of targets and even unbelievable results. In this paper, a correction method of non-landing measuring of theodolite based on static datum conversion is presented, which can effectively improve the observation accuracy of theodolite. The CCD camera is fixed to the theodolite platform to calculate the gesture shaking quantity of theodolite platform in geodetic coordinate system through the real time imaging of static datum. The observation results of theodolite are corrected by using such shaking quantity. The experiment shows that the correction accuracy exceeds 10 s of arc. The intrinsic parameter calibration technology of camera based on stellar angular distance and absolute conic put forward in this paper can prevent the estimated error of extrinsic parameters influencing the intrinsic parameter calibration and improve the intrinsic parameter calibration accuracy; the static datum conversion technology can reduce the influence of installation error of camera and theodolite platform on gesture measuring of the platform. The simulation experiment shows that when the shaking range of the platform is less than 30 min of arc, the influence of the three-axis installation error of camera within 3deg on the accuracy of correction results is less than 8 s of arc. The method in this paper can be extended to and used in the field of gesture shaking measuring and micro-structure deformation of various unstable platforms, therefore it is of important theoretical research significance and has wide engineering application prospect.

Adjustable contrast optical target device for test of acquisition of photoelectric theodolite

A new device used to detect the low contrast target acquisition of photoelectric theodolite is designed and its reliability is experimentally demonstrated.The adjustable contrast optical target device,which can simulate the sky background luminance and a low contrast target,is established.It utilizes a big integrating sphere and a small one to simulate the luminance of the background and target respectively.Importantly,by controlling the luminous flux of the two integrating spheres,the targets and background radiance can be continuously adjustable under the condition of constant color temperature.Thus,the contrast can be controlled continuously in the range of 0%-90% and its stability is better than 1%.The biggest background luminance exceeds 60 W m-2str-1 in the spectral range of 400-800 nm.

Visible and Infrared Band Tracking and Measuring Control System

This paper describes a new tracking and measuring control system for optical and electronic theodolite.This control system can provide automatic flying object tracking and measuring in visible and infrared band.It also can provide real-time output of the measured results.By using the multi-mode measuring methods and the on-axis tracking control technique, the stability of automatic tracking,tracking accuracy and the comprehensive tracking performance of the theodolite can be improved.At the same time the smooth switch-over among several tracking modes can be carried out.New tracking techniques have been developed to deal with angular tracking rate that exceed 60 deg/s in velocity and 90 deg/s 2 in acceleration.At the present the tracking and measuring control system has been successfully applied in the optical and electronic theodolite.

Axis intersection measurement of three-axis turntable with two crosshair targets

In order to measure three-axis intersection error, two crosshair targets were fixed in the inner axis frame of a three-axis turntable. Also a theodolite was used to point its telescope to the targets and to measure the horizontal angles when three axes were on equi-spaced angle positions. The calculation equations of the axis intersection were deduced from the mounting position of the theodolite, positions of two targets, angular positions of three axes, and the measured horizontal angles with the theodolite. Finally, a practical measurement is carried out on a horizontal three-axis turntable and error analysis is conducted.

STRUCTURAL PARAMETERS CALIBRATION BY POSTURE MEASUREMENT ON PARALLEL 6-DOF PLATFORM

Some approaches to measure parallel 6-degree of freedom platform's posturestatically and to calibrate the platform's actual structural parameters by measuring a series of theplatform's varying postures are studied. In the case where high posture accuracy is requiredrelatively, to obtain the platform's actual structural parameters is very important. Threedimensions measurement with 2 theodolites are used to obtain the platform's postures statically andNewton iterative method is adopted to calibrate structural parameters. Some measures taken in themeasurement and the calibration are discussed in detail. And the experiment results of theplatform's posture control before and after the calibration are given. The results show that theplatform's posture control accuracy after the calibration is improved notably.

A Method of Precision Testing Relative Relation of Space Points and Its Application

In response to the high requirements of industrial precision test, presenting a method of testing relative relation of space points was studied. The spatial-coordinate testing system was established by using high precision theodolites and horizontal staff. The related test was conducted with the use of the space intersection and the precision was evaluated based on the error of baseline. In the practical application of radar-development base, the relative relation of space points was implemented by using electronic theodolite and horizontal staff, which can be easily operated. Furthermore, it can be conveniently used to test small areas where the instruments are difficult to be installed and for high industrial requirements of precision test. The test results can fully meet the strict industrial requirements.