
An Acoustical Machine Learning Approach to
Determine Abrasive Belt Wear of Wide Belt Sanders
Maximilian Bundscherer ∗†, Thomas H. Schmitt †, Sebastian Bayerl †, Thomas Auerbach‡and Tobias Bocklet†,
†Department of Computer Science -Technische Hochschule N¨
urnberg Georg Simon Ohm N¨
urnberg, Germany
‡Production Technology -Hans Weber Maschinenfabrik GmbH Kronach, Germany
∗Email: maximilian.bundscherer@th-nuernberg.de
Abstract—This paper describes a machine learning approach
to determine the abrasive belt wear of wide belt sanders used
in industrial processes based on acoustic data, regardless of the
sanding process-related parameters, Feed speed, Grit Size, and
Type of material. Our approach utilizes Decision Tree, Random
Forest, k-nearest Neighbors, and Neural network Classifiers to
detect the belt wear from Spectrograms, Mel Spectrograms,
MFCC, IMFCC, and LFCC, yielding an accuracy of up to 86.1%
on five levels of belt wear. A 96% accuracy could be achieved with
different Decision Tree Classifiers specialized in different sanding
parameter configurations. The classifiers could also determine
with an accuracy of 97% if the machine is currently sanding
or is idle and with an accuracy of 98.4% and 98.8% detect the
sanding parameters Feed speed and Grit Size. We can show that
low-dimensional mappings of high-dimensional features can be
used to visualize belt wear and sanding parameters meaningfully.
Index Terms—acoustic sensors, abrasive belt wear, tool wear,
machine learning, industrial process, wide belt sanding machines
I. INTRODUCTION
Wide belt sanding machines are commonly used in indus-
trial processes to remove material from a workpiece by an
abrasive belt [1]. This paper uses acoustic data and machine
learning methods to determine the abrasive belt wear of a
WEBER KSF 1350 wide belt sander. Our models aim to
optimize tool change intervals, a critical optimization criterion
in industrial processes [2]. We used lightweight approaches
that potentially allow our models to be deployed on low-
cost endpoints such as a Raspberry Pi or ESP32. The use of
acoustic sensors, like microphones as additional sensors and
low-cost edge devices for classification in industrial processes,
is convenient and inexpensive since no machines or production
chains need to be strongly modified or rebuilt. Fig. 1 gives a
schematic overview of our approach.
A. Our contributions
•Recording and labeling of wide belt sanding machine
operations with 18 sanding process-related parameter
configurations.
•Describing and evaluating a machine learning based
method for classifying five levels of belt wear, machine
state (is actual sanding or is idle), and sanding parameters.
•Meaningful low-dimensional mapping of high-
dimensional features.
This study is partially supported by the European Social Funds (ESF)
No. R.6-V0332.2.43/1/5.
Fig. 1: Schematic overview of our approach.
•Models that use acoustic data only and can operate on
lightweight edge devices.
B. Related work
In the literature, a distinction is made between the terms
grinding, sanding, and polishing to describe abrasive pro-
cesses. [1] presents an approach to detect abrasive grinding
belt wear over three levels on a grinding machine using sound
and current as features under varying grinding parameters.
Convolutional Neural Networks are used to predict belt grind-
ing tool wear in a polishing process using 3-axes force and
vibration data as models input by [3]. Other publications
have focused on details of the grinding process [4] and tool
condition monitoring [5]. This study’s novelty is applying
acoustic machine learning detection to wide belt sanding
machines and focuses on the varying wood sanding parameters
Feed speed, Grit Size, and Type of material.
II. DATA
Wide belt sanding machines have sanding process-related
parameters that influence the acoustics characteristics of the
process more than the abrasive belt wear itself. This phe-
nomenon has also been observed in grinding machines [6].
The sander was allowed to cool down between recordings to
mitigate the influence of different engine temperatures.
arXiv:2210.13273v1 [eess.AS] 24 Oct 2022