Wyniki wyszukiwania - BazTech

1

Uncertainty evaluation of multilateration-based geometric error measurement considering the repeatibility of positioning of the machine tool

Liu Xingbao, Xia Yangqiu, Rui Xiaoting

Metrology and Measurement Systems

|

2023

|

Vol. 30, nr 1

49--63

EN

The sequential multilateration principle is often adopted in geometric error measurement of CNC machine tools. To identify the geometric errors, a single laser tracker is placed at different positions to measure the length between the target point and the laser tracker. However, the measurement of each laser tracker position is not simultaneous and measurement accuracy is mainly subject to positioning repeatability of the machine tool. This paper attempts to evaluate the measurement uncertainty of geometric errors caused by the positioning repeatability of the machine tool and the laser tracker spatial length measurement error based on the Monte Carlo method. Firstly, a direct identification method for geometric errors of CNC machine tools based on geometric error evaluation constraints is introduced, combined with the geometric error model of a three-axis machine tool. Moreover, uncertainty contributors caused by the repeatability of positioning of numerically controlled axes of the machine tool and the laser length measurement error are analyzed. The measurement uncertainty of the geometric error and the volumetric positioning error is evaluated with the Monte Carlo method. Finally, geometric error measurement and verification experiments are conducted. The results show that the maximum volumetric positioning error of the machine tool is 84.1 μm and the expanded uncertainty is 5.8 μm (𝑘 = 2). The correctness of the geometric error measurement and uncertainty evaluation method proposed in this paper is verified compared with the direct geometric error measurement methods.

2

Application of the FARO laser tracker to the study of selected functional characteristics of a Kawasaki ZD130 industrial robot

Ćwiąkała P., Cisińska A., Szotek S.

Measurement Automation Monitoring

|

2015

|

Vol. 61, No. 10

475--479

EN

The paper presents the test results of the following functional characteristics of a Kawasaki ZD130 industrial robot: the accuracy and repeatability of unidirectional positioning, the variance of multidirectional positioning and the accuracy and repeatability of distance. The influence of the speed of movement and load on the values of aforementioned functional characteristics was also examined. Measurements were made with the FARO Laser Tracker Vantage coordinate measuring machine. The research was conducted in accordance with the PN-EN ISO 9283:2003 standard.

3

Rotation error modeling and identification for Robot kinematic calibration by circle point method

Santolaria J., Conte J., Pueo M., Javierre C.

Metrology and Measurement Systems

|

2014

|

Vol. 21, nr 1

85--98

EN

Screw axis measurement methods obtain a precise identification of the physical reality of the industrial robots’ geometry. However, these methods are in a clear disadvantage compared to mathematical optimisation processes for kinematical parameters. That’s because mathematical processes obtain kinematical parameters which best reduce the robot errors, despite not necessarily representing the real geometry of the robot. This paper takes the next step at the identification of a robot’s movement from the identification of its real kinematical parameters for the later study of every articulation’s rotation. We then obtain a combination of real kinematic and dynamic parameters which describe the robot’s movement, improving its precision with a physical understanding of the errors.

4

Udział geodezji w eksperymentach fizyki wysokich energii

Wójcik G. J.

Technical Sciences. Supplement / University of Warmia and Mazury in Olsztyn

|

2005

|

suppl. 2

27--45

PL

Eksperymenty fizyki wysokich energii wymagają stałej obsługi geodezyjnej o dużej dokładności. Celem tych pomiarów jest dokładne ustawienie gigantycznych maszyn w żądanym przez fizyków miejscu w przestrzeni. Urządzenia te pozwalają na nadanie cząsteczkom prędkości przyświetlnych, dlatego dokładne wyznaczenie położenia ich elementów jest warunkiem sprawnego przebiegu eksperymentów. Bardzo nietypowe warunki (wąskie tunele, sąsiedztwo innych obiektów o bardzo "złej geometrii") dyktują konieczność zastosowania różnorodnych metod pomiarów geodezyjnych. W artykule podano przykłady pomiarów geodezyjnych wykonywanych w Fermi National Accelerator Laboratory w USA. Grupa geodezyjna laboratorium jest odpowiedzialna zarówno za pomiary naziemnych i podziemnych sieci punktów kontrolnych, jak i za ustawianie i justowanie tych gigantycznych maszyn. Użyto prawie wszystkich metod geodezyjnych, jak pomiary klasyczne, GPS, pomiary z użyciem instrumentów laserowych i fotogrametria cyfrowa.

EN

The demands of high-energy physics experiments require frequent use of geodetic services of the highest accuracy. Precision surveys allow elements of these massive machines to be aligned to the spatial locations designed by the beam physicists. Because the machines can accelerate a particle to nearly the speed of light, correct positioning of machine elements is very critical to the success of the experiment. Very difficult environmental conditions, narrow tunnels, and "bad geometry" dictate the use of a variety of geodetic surveying methods. This paper discusses several examples of geodetic surveys performed by the Alignment and Metrology Group (AMG) of the Fermi National Accelerator Laboratory in USA. AMG is responsible for alignment of the machines, as well as survey control of surface and underground networks. AMG uses many modern metrology applications: classical geodetic survey, GPS, Laser Tracker technology and digital photogrammetry.