A comparison of novel chassis suspended machines for sustainable forestry

• We model different suspension systems by using multi-body dynamics simulations.
• Performance analysis of the different configurations traveling on the test track.
• We examine capability of surpassing obstacles of bogies and pendulum-arm.
• The dynamic behavior of a mid-sized forwarder with different suspended systems.
• Dynamic behavior of three forwarder concepts is compared quantitatively.

Cut-to-length logging (CTL) is a mechanized harvesting process where trees are delimbed and cut to length directly at the stump. The main challenges for the manufacturers of forestry machines for CTL logging are to address new customer demands and tougher health and environmental legislations by finding means that: (1) further increase the harvesting and log transportation productivity, e.g. by enabling operation on eco-soils, (2) reduce the damage to the soil, e.g. by controlling the ruts depth and preserving the root layer, (3) reduce exhaust emissions, e.g. by reducing the rolling resistance, and (4) reducing the daily vibration dosage for the machine operators, e.g. by active chassis and cabin damping.This paper presents of a number of passive forwarder chassis suspension concepts and compares their performance from three perspectives: their gentleness to terrain and operator, as well as their potential for improved fuel efficiency. Based on multi-body dynamics simulations, it is shown that a passive pendulum arm suspension can reduce the lateral accelerations in a passively suspended cabin with 50% compared to traditional bogie machines when travelling in rough hard terrain.