Surface Profiles Acquisition for Assessing Fatigues Life of Agricultural Machinery in Test Facilities

Publikations-Art

Kongressbeitrag

Autoren

D.S. Paraforos, H.W. Griepentrog

Erscheinungsjahr

2014

Tagungsname

The 18th International ISTVS Conference

Tagungsort

Seoul, Korea

Tagungsdatum

September 22-25, 2014

Assessing fatigue life of agricultural machinery can be a challenging task, especially when the machines assume dif-ferent configurations and move on varied terrain types. The main objective of this paper is to present the methodology of making an up-to-date comparison between real life use of agricultural machinery and use in test facilities regarding sur-face profiles and accumulated fatigue damage. Towards this aim, a number of strain gages were attached at critical points on a four-rotor swather. Measurements were acquired under all possible modes of the machine operation. Using the rainflow cycle counting algorithm in combination with Palmgren-Miner linear damage rule, the accumulated fatigue damage was evaluated at every use of the swather. In order to measure the absolute position surface profiles a sensor-frame was developed utilising an RTK-GPS, an Inertial Measurement Unit (IMU) and two laser pointers. An Extended Kalman Filter (EKF) algorithm was used to fuse GPS and IMU data. The surface profiles were modelled using the Pow-er Spectral Density (PSD) of a Gaussian model. Results indicated that this is a valid methodology to quantify vehicle’s accumulated damage on test tracks in respect to real life but Gaussian road models were insufficient to model surfaces with high irregularities.