Development of a Sensorized Timber Processor Head Prototype – Part 1: Sensors Description and Hardware Integration

Forest operations are in constant development to provide increasingly higher standards of
economic and environmental sustainability. The latest innovation trends are concentrated in
the generation, storage and management of data related to the harvesting process, timber
products and logistics operations. Current technologies provide productivity and position, but
only physical parameters are made available for timber products. The possibility of providing
a comprehensive quality evaluation of roundwood early in the supply chain and linking the
information to each log provides a new tool for optimization of the whole forest-timber supply
chain. Current in-field methods for grading logs are based on visual rating scales, which are
subjective, operator-dependent and time-consuming. As an alternative, a sensorized processor
head was developed, featuring the following sensors: near infrared (NIR) spectrometer and
hyperspectral cameras to identify surface defects, stress wave and time of flight sensors to
estimate timber density, hydraulic flow sensor to estimate cross-cutting resistance and delimbing
sensors to estimate branches number and approximate position. The prototype also deployed
an RFID UHF system, which allowed the identification of the incoming tree and individually
marked each log, relating the quality parameters recorded to the physical item and
tracing it along the supply chain. The tested sensors were installed and designed to be independent,
nevertheless, their integrated use provides a comprehensive evaluation of timber
quality. This paper presents the technical solutions adopted, the main hindrances found and
some preliminary results of the operative prototype as tested in laboratory and in forest operational
conditions.