Joint project: Development, prototypical implementation and evaluation of a new machine concept for the mechanization of felling and axing of the center block at 40 m tramline spacing.


The project aims to mechanize the felling and axing of trees from the mid-block at 40 m skid trail distance. The OUTREACH vehicle will complement the classic harvester, which has a limited reach.

  Sketch of the vehicle The OUTREACH basic idea: a new type of feller pre-feller vehicle in lightweight construction reaches the trees in the mid-block.

Near-natural forest management in Germany aims at a stable, mixed forest with trees of different ages, which provides sustainably valuable timber. This stability of the stands is achieved by regularly recurring, substance-preserving selective thinning. In Germany, regular thinning is carried out mechanized from tramlines (skid trails), which should have a spacing of 40 m in the interest of soil and resource conservation. According to the state of the art, full harvesters (harvesters) have a boom of 10 m reach. This leaves an intermediate block of 20 m width in which trees are felled by engine. The felled trees are later pulled to the skidding road by winches. From here, they are grabbed by the harvester and processed.
The feller-advance vehicle planned in OUTREACH is similar in design to a wheeled harvester (full harvester on wheels). The special OUTREACH boom in lightweight construction has a much greater reach and, with a boom length of 20 m, will cover half the tramline distance. This greater reach is only technically possible through the use of consistent lightweight construction on the boom and felling head.


The aim of the OUTREACH research project is to develop a functional prototype (boom and felling head) of the feller-advance vehicle, which will be verified, evaluated and validated both virtually in simulation and as a real prototype in various practical application scenarios. In addition to technical feasibility, the result should help to clarify central implementation issues and boundary conditions for actual product development from perspectives such as mechanical and lightweight engineering, electrical engineering and information technology, forestry and business management.


As part of the project, the Institute of Structural Mechanics and Lightweight Design is developing a digital twin with a focus on lightweight construction and weight optimization. In addition, a load and structural monitoring system for the boom of the feller-advance vehicle is being developed. Together with the project partners, the crane, winch and feller head are being developed and validated with the digital twin for all relevant application scenarios. In addition to the functionality of the mechanics, the focus is on checking the load assumptions and the safety concepts. The functionality of the developed concept for load and structure monitoring is also validated.


The project consortium includes the company HSM Hohenloher Spezial-Maschinenbau GmbH & Co. KG, the Kuratorium für Waldarbeit und Forsttechnik e.V. (KWF) and RWTH Aachen University with the Institute for Human-Machine Interaction (MMI) and the Institute for Structural Mechanics and Lightweight Design (SLA). The Institute for Human-Machine Interaction is in charge of the project.




The project is funded by the German Federal Ministry of Food and Agriculture (BMEL) under the funding code 2220NR309B and supervised by the Fachagentur Nachwachsende Rohstoffe e.V. (FNR) as project management agency.


Student theses

Der Experimentierbare Digitale Zwilling im Produktentwicklungsprozess des Leichtbaus



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