Calibration Experiments on a Visual Measurement System for Pinion Gears

Author(s):  
Jie Tang ◽  
Xiaobing Liu ◽  
Lingyu Chai ◽  
Zhaoyao Shi ◽  
Rui Li

Abstract Visual measurement is one of the important measurement methods for pinion gears. The measurement principle and the systematic structure of a pinion gear visual measuring system were given. Pixel equivalent is the key parameter in the visual measurement system, which needs to be calibrated before dimensions evaluation. A glass dot calibration plate was applied in the system calibration. Pixel equivalent calibration experiment, LED brightness experiment, edge compensation experiment and multiposition edge compensation experiment was carried out. The parameter pixel equivalent is determined by the comparison between the physical size of center distance of adjacent mark circle in the glass dot calibration plate and its pixels number obtained by the visual system. The center distance of adjacent mark circle was chosen to avoid the affection of the brightness of light source and the sub-pixel technology was used. The proper brightness condition of LED light was selected in the LED brightness experiment. Under this condition, the compensation of edge deviation was obtained by analyzing the edge position deviation in the diameter measurement of the mark circle of the calibration plate. The experimental results show that the pixel equivalent is 5.59522μm/Pixel, and the compensation of edge deviation is 0.54μm. 49 diameters of the circular marker were measured in edge compensation experiment, the largest difference between the measured diameter in central vision after compensation and its physical dimensions is 0.3μm, which is 0.2μm in muti-position edge compensation experiment. The calibration methods and the experimental research are important for the designed visual measurement system for pinion gears.

ROBOT ◽  
2011 ◽  
Vol 33 (3) ◽  
pp. 299-302 ◽  
Author(s):  
Yi WANG ◽  
Changjie LIU ◽  
Xueyou YANG ◽  
Shenghua YE

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4852
Author(s):  
Grzegorz Bomba ◽  
Artur Ornat ◽  
Piotr Gierlak

The article discusses the quality testing of a measuring system consisting of a CNC machine with measuring probes. The research was conducted in a broader context regarding the implementation of the closed door technology, i.e., production without human intervention, in an aviation plant manufacturing aircraft gearbox systems. This technology may involve automated measuring operations performed in machining centers, and not in measuring laboratories, provided that the quality of the measurements is appropriate. The aim of the study was to investigate whether the CNC machining device can be used to measure the geometric features of aircraft gearbox housing. For this purpose, measurement experiments were carried out with the use of three different probes. Measurements were carried out using four sequences of increasing complexity, so that, after error analysis, it was possible to find the causes of possible irregularities. A reference ring with known dimensions and position in the working space of the machine was used for the measurements performed as part of the assessment of the measurement system. The quality of the measurements was evaluated with the use of repeatability and reproducibility testing and statistical process control. The analysis results showed that the tested measurement system ensures adequate accuracy and repeatability, and the measurement process is characterized with adequate efficiency in relation to the manufacturing tolerance of the components produced using the machine. Thus, it was proven that the measurement process can be carried out on a machining device, which enables its integration into the closed door technology.


2012 ◽  
Vol 184-185 ◽  
pp. 1613-1617
Author(s):  
Jin Fang Zhu

This article studies the embedded SPC and its application in roundness measuring system by analyzing the current roundness measurement principle and technology. With analyzing the process of data collection, date treatment and various kinds of tool graphic construction, we study the feasibility of integrating SPC into roundness measurement and finally apply the embedded SPC as pure software into roundness measuring system. We design the roundness measuring system based on embedded SPC and develop the roundness measuring system of low power consumption, high accuracy and easy application, which is suitable for industry field usage.


Author(s):  
Bryan W. Schlake ◽  
Brian S. Daniel ◽  
Ron Voorheis

In pursuit of improved safety, Norfolk Southern Corp. (NS) has partnered with Amberg Technologies to explore the potential benefits of a laser-based measurement system for measuring over dimensional freight rail shipments. Shipments that do not fall within a standard geometric envelope, denoted as Plate B in the Association of American Railroads (AAR) Open Top Loading Rules [1], are considered to be over dimensional, or High-Wide Loads (HWLs). Extending beyond the limits of the Plate B diagram, these loads are not permitted in unrestricted interchange service. Instead, they must be measured both at points of origin and at interchange points. For US Class I Railroads, the de facto method for measuring HWLs requires mechanical personnel to either climb on the equipment or use a ladder and physically measure the overall height and width of the load. Using a tape measure, plumb line, and 6-foot level, car inspectors, or carmen, must often make multiple measurements to determine the height or width of a critical point on the load. The summation of these measurements can be subject to mathematical human error. In addition to the inherent limitations with regards to accuracy and efficiency, this method of measurement presents considerable safety challenges. The objective of the project was to develop a portable, cost-effective and accurate measurement system to improve the day-to-day operational process of measuring HWLs and reduce human exposure to railyard hazards. Norfolk Southern worked closely with Amberg Technologies to provide a clear overview of the current measuring methods, requirements, challenges and risks associated with HWLs. Amberg then developed a prototype system (with patent pending) and successful tests have been completed at both a point of origin for NS shipments and at a location where HWLs are received at interchange. The measuring system consists of a tripod mounted laser, a specially designed track reference target (TRT) and software designed specifically for HWL measurements. The system allows car inspectors to take measurements from a safe, strategic location away from the car. As a result, this system eliminates the need to climb on the equipment or a ladder and greatly reduces the amount of time spent on and around live tracks. In addition, initial tests indicate that this technology reduces the labor time required to measure HWLs by as much as one half while improving measurement accuracy. These tests have demonstrated that a laser-based system has the potential to greatly improve the safety, efficiency and accuracy associated with measuring HWLs.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1297
Author(s):  
Viktor Skrickij ◽  
Eldar Šabanovič ◽  
Dachuan Shi ◽  
Stefano Ricci ◽  
Luca Rizzetto ◽  
...  

Railway infrastructure must meet safety requirements concerning its construction and operation. Track geometry monitoring is one of the most important activities in maintaining the steady technical conditions of rail infrastructure. Commonly, it is performed using complex measurement equipment installed on track-recording coaches. Existing low-cost inertial sensor-based measurement systems provide reliable measurements of track geometry in vertical directions. However, solutions are needed for track geometry parameter measurement in the lateral direction. In this research, the authors developed a visual measurement system for track gauge evaluation. It involves the detection of measurement points and the visual measurement of the distance between them. The accuracy of the visual measurement system was evaluated in the laboratory and showed promising results. The initial field test was performed in the Vilnius railway station yard, driving at low velocity on the straight track section. The results show that the image point selection method developed for selecting the wheel and rail points to measure distance is stable enough for TG measurement. Recommendations for the further improvement of the developed system are presented.


1999 ◽  
Author(s):  
Chunhe Gong ◽  
Jingxia Yuan ◽  
Jun Ni

Abstract Robot calibration plays an increasingly important role in manufacturing. For robot calibration on the manufacturing floor, it is desirable that the calibration technique be easy and convenient to implement. This paper presents a new self-calibration method to calibrate and compensate for robot system kinematic errors. Compared with the traditional calibration methods, this calibration method has several unique features. First, it is not necessary to apply an external measurement system to measure the robot end-effector position for the purpose of kinematic identification since the robot measurement system has a sensor as its integral part. Second, this self-calibration is based on distance measurement rather than absolute position measurement for kinematic identification; therefore the calibration of the transformation from the world coordinate system to the robot base coordinate system, known as base calibration, is not necessary. These features not only greatly facilitate the robot system calibration but also shorten the error propagation chain, therefore, increase the accuracy of parameter estimation. An integrated calibration system is designed to validate the effectiveness of this calibration method. Experimental results show that after calibration there is a significant improvement of robot accuracy over a typical robot workspace.


2018 ◽  
Vol 41 (4) ◽  
pp. 1149-1159
Author(s):  
Yonghua Lu ◽  
Jing Li ◽  
Xiang Zhang ◽  
Yang Li

For measuring the thrust of combined nozzles in satellite thruster with a small space, the test method that the nozzle directly sprays on the load baffle is employed in this paper. The key problem is how to design the positions of 10 load baffles and how to construct the measurement system. A set of complete and automatic nozzle thrust measurement system is designed and built, and the influence of the load baffle applied on the flow field of nozzles is analyzed using the software FLUENT. Furthermore, the load surface locations of the sensors for the different types of nozzles are analyzed. We draw the conclusion that the load baffle position should range from 4–8 mm for the I-type nozzle and range in 6–12 mm for II-type and III-type nozzle. The correction coefficients of the thrust forces for all channels of the measurement system are determined in the calibration experiment. The uncertainty of measurement system is estimated and the error source of the measurement system is traced. We found that the systematic uncertainty is mainly contributed by the A-type uncertainty which is related with the nozzle dimension and its inner structure. The B-type uncertainty of system is contributed by the force sensor.


Author(s):  
Алексей Николаевич Самойлов ◽  
Юрий Михайлович Бородянский ◽  
Александр Валерьевич Волошин

В процессе автоматизации решения прикладных измерительных задач, в том числе на базе фотограмметрических методов, возникает проблема соответствия измерительной системы объекту и условиям измерения. Для того чтобы измерительная система позволяла заранее оценить возможность получения достоверных результатов, а также наилучшим образом подстраивалась под условия измерения, необходимо наличие специализированных алгоритмов и моделей. В общем случае такие модели ориентированы на квалифицированных технических специалистов, обладающих необходимыми знаниями в области информационных технологий. Особенностью применения фотограмметрических измерительных систем в лесной и металлургической промышленности является низкая квалификация пользователей в сфере информационных технологий, что обуславливается характером выполняемых работ и условиями привлечения. Данный фактор не позволяет решить задачу подстройки системы традиционными методами, в которых процессом настройки управляет пользователь. В этой связи в статье предлагается модель и алгоритм формирования измерительной системы по первичным входным данным, в котором процессом настройки управляет сама система. In the process of automating the solution of applied measurement tasks, including on the basis of photogrammetric methods, there is a problem of compliance of the measurement system with the object and measurement conditions. In order for the measuring system to assess in advance the possibility of obtaining reliable results, as well as to best adapt to the conditions of measurement, it is necessary to have specialized algorithms and models. In general, such models are aimed at qualified technicians with the necessary knowledge in the field of information technology. A feature of the application of photogrammetric measurement systems in the forestry and metallurgical industry is the low qualification of users in the field of information technology, which is determined by the nature of the work performed and the conditions of attraction. This factor does not solve the problem of adjusting the system by traditional methods in which the user controls the configuration process. In this regard, the article proposes a model and algorithm for forming a measuring system from primary input data, in which the system itself controls the adjustment process.


2018 ◽  
Vol 11 (2) ◽  
pp. 166-180 ◽  
Author(s):  
Long Xin ◽  
Delin Luo ◽  
Han Li

PurposeThe purpose of this paper is to develop a monocular visual measurement system for autonomous aerial refueling (AAR) for unmanned aerial vehicle, which can process images from an infrared camera to estimate the pose of the drogue in the tanker with high accuracy and real-time performance.Design/methodology/approachMethods and techniques for marker detection, feature matching and pose estimation have been designed and implemented in the visual measurement system.FindingsThe simple blob detection (SBD) method is adopted, which outperforms the Laplacian of Gaussian method. And a novel noise-elimination algorithm is proposed for excluding the noise points. Besides, a novel feature matching algorithm based on perspective transformation is proposed. Comparative experimental results indicated the rapidity and effectiveness of the proposed methods.Practical implicationsThe visual measurement system developed in this paper can be applied to estimate the pose of the drogue with a fast speed and high accuracy and it is a feasible measurement strategy which will considerably increase the autonomy and reliability for AAR.Originality/valueThe SBD method is used to detect the features and a novel noise-elimination algorithm is proposed. Besides, a novel feature matching algorithm based on perspective transformation is proposed which is robust and accurate.


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