Anomaly Detection and Diagnostics of a Wheel Loader Using Dynamic Mathematical Model and Joint Probability Distributions
Krogerus, Tomi; Hyvönen, Mika; Backas, Joni; Huhtala, Kalevi (2015)
Krogerus, Tomi
Hyvönen, Mika
Backas, Joni
Huhtala, Kalevi
Tampere University of Technology. Department of Intelligent Hydraulics and Automation
2015
Proceedings of the Fourteenth Scandinavian International Conference on Fluid Power, SICFP15. May 20-22, 2015. Tampere, Finland
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201603143631
https://urn.fi/URN:NBN:fi:tty-201603143631
Kuvaus
Peer reviewed
Tiivistelmä
In this paper, we present anomaly detection and diagnostics for articulated frame steered hydraulic wheel loader. The presented methodology is based on the analysis and comparison of the responses of a dynamic mathematical model and a real wheel loader using a joint probability distribution of correlation coefficients of multiple variables. The behaviour of an undamaged machine is modelled by probability density functions of the correlation coefficients using histograms and test how well the future behaviour fits the model. First, the time series data of multiple variables are segmented into segments of the same length. Correlation coefficients are then calculated for each segment and the distributions of the correlation coefficients are estimated by computing probability density functions using histograms. Finally, the joint probabilities that the correlations in the data segments of the time series data are observed are calculated using the already computed histograms. The diagnostics is based on the combination of static threshold and threshold based on mean value of joint probabilities. The dynamic mathematical model of the wheel loader is presented with verification results. A jammed flushing valve of the hydrostatic transmission was used as an anomaly to study the changes in the joint probability values. Finally, the efficiency of the presented method is presented with good results regarding detection of anomalies and diagnostics of the wheel loader.
Kokoelmat
- TUNICRIS-julkaisut [17116]