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Calibration performance investigation of an uncalibrated indigenous artefact probing for five-axis machine tool

100%

Rahman M. M. , Mayer R.

2016

tom Vol. 16, No. 1

33--42

On machine measurement of artefacts such as single ball, multiple balls or even prismatic shape artefact is gaining popularity for the calibration of five-axis machine tools. However, calibration results can be degraded due to errors from different process variables such as the measurement strategies, rotary axes indexations and artefact dismount and remount cycles. This research investigates the repeatability of uncalibrated indigenous artefact probing and machine tool error parameters calibration against a number of process variables. Uncertainties of the estimated parameters are estimated to quantify the calibration quality.

Pomiary kształtu ostrza narzędzi skrawających za pomocą współrzędnościowych maszyn pomiarowych

80%

Woźniak A. , Mayer R. , Bałaziński M. , Côté M.

2007

tom nr 9 supl.

215-220

W artykule przedstawiono analizę teoretyczną i badania doświadczalne dotyczące możliwości pomiaru geometrii ostrza narzędzi skrawających za pomocą współrzędnościowych maszyn pomiarowych (WMP). Na przykładzie pokazano, że mimo specyfikowanej wysokiej dokładności maszyn pomiarowych, informacja o kształcie ostrza o mikronowym promieniu może być istotnie zafałszowana przez wbudowane w oprogramowanie maszyny algorytmy korekcji promienia końcówki pomiarowej. Przedstawiono również podstawy działania nowego, opracowanego przez autorów, algorytmu korekcji promienia końcówki dla maszyn współrzędnościowych. W artykule zostanie wykazane, że nowy algorytm zapewnia znacznie dokładniejsze obliczenie punktów pomiarowych skorygowanych.

In this paper, the probe radius compensation problem during the measurement of tool cutting edges using a coordinate measuring machine (CMM) has been addressed. We first show that information about the real shape of the measured edges can be distorted using the CMM machine built-in data processing software for probe tip radius compensation. In order to accurately measure cutting tool edges which include discontinuous regions we propose to apply a new algorithm for the compensation of the probe radius in a CMM scanning process. The comparison of the measured cutting tool edge profile using the indigenous CMM software and the proposed method of probe radius compensation shows that our proposed method has better accuracy.

Feeding habits of invasive American mink (Neovision vison) in noethen Germany - potential implications for fishery and waterfowl

80%

Zschille J. , Stier N. , Roth M. , Mayer R.

tom 59

nr 1

In order to collect ecological data of invasive American mink (Neovison vison) at a fishpond area in northeastern Germany, we conducted a telemetry study in which 14 mink were radio-tracked. During this project, 2,502 scats from radio-tracked individuals were collected in the period from October 2003 to October 2005. Investigated mink principally prey on fish, small mammals and birds (eggs inclusive), whereas amphibians, reptiles and invertebrates were caught infrequently. Analysing mink scats of different seasons, we found significant seasonal variations of diet composition. In spring, fish, mammals and birds were hunted in similar amounts. During summer, birds made up the main part of the diet followed by mammals. In autumn, the proportion of birds in the mink diet decreased, whereas fish gained in importance. This trend continued during the winter period, when mink preyed almost exclusively on fish. Amphibians, crustaceans, insects, molluscs and reptiles were found only occasionally in scat samples. Among birds, the mink preyed mainly on the Eurasian Coot (Fulica atra) followed by the Mallard (Anas platyrhynchos). Mammalian prey was clearly dominated by the water vole (Arvicola terrestris) and among fish, mink hunted especially perch (Perca fluviatilis), roach (Rutilus rutilus) and carp (Cyprinus carpio). Results clearly demonstrate that mink is an opportunistic predator, which hunts its prey according to availability and vulnerability, respectively. Despite the high portions of fish in their autumn and winter diet, the economic damage caused by mink seems to be negligible. However, high predation rates on birds during the breeding season indicate a potential negative impact of mink on waterfowl.