ABB Robotic Laser Doppler Anemometry Measurements With RobotStudio® With An Open Wind Channel And An Ellipsoid
M. Berger (1), T. Hausberger (2), J. Sieberer (2), T. Senfter (1), T. Kofler (1), C. Mayerl (1), M. Kraxner (1), B. Massow (2), M. Pillei (1)
(1) Dept. of Environmental, Process & Energy Engineering, MCI - The Entrepreneurial School, Austria
(2) Dept. of Mechatronics, MCI - The Entrepreneurial School, Austria
Laser Doppler anemometry is a state-of-the-art non-invasive experimental flow measurement technique. Traditionally used linear traversing units can only change the position of the measurement probe, but cannot change the orientation of the probe. A six degrees of freedom robot can simplify and fasten up the pose planning and measurement process real-offline. A developed LDA software plug-in for RobotStudio is used to real-offline plan and perform flow measurements in an open wind channel (flow rate = 300 m³/h) with an ellipsoid (diameter y=z = 140 mm and x = 40 mm). In 25 mm, 20 mm, 15 mm, 10 mm, 5 mm and 2 mm orthogonal distance of the ellipsoid surface the tangential velocity component is determined. Accuracy and repeatability of the robot-LDA system is found and compared to the traditional linear traversing system. Results show a positive velocity gradient towards the axis of the wind channel with a velocity range of 4.4 – 20.3 m/s. At 25 mm distance the tangential velocity is in the range of 4.4 – 12.5 m/s, at 20 mm 7.6 – 17.5 m/s, at 15 mm 12.1 – 19.7 m/s, at 10 mm 16.5 – 20.1 m/s, at 5 mm 19.0 – 20.2 m/s and at 2 mm 18.3 – 20.3 m/s. In positive y and negative z-direction, a reduction of the tangential velocity component is found in all measurements. At a distance of 25 mm, the measurement surface is slightly outside to the wind channel inlet (diameter = 80 mm). The closer the measurement surface is at the wind channel axis, the higher is the wind channel axial component. Robot-LDA average accuracy of 13 µm and repeatability of 10 µm is in the range of the linear traversing unit where the accuracy is 20 µm and the repeatability is 6 µm. The robot-LDA measurement system is an alternative to the existing linear-LDA with the advantages of real-offline robot path planning for arbitrary surfaces requiring six degrees of freedom probe placement.