Multi-objective performance optimization of pendulum-arm suspensions for forestry machines

The development of forestry machines is currently heading towards new solutions that reduce their impact on the environment and in particular on the soft forest soil. In addition, new machine solutions must be physically and mentally less damaging to the operators. Chassis-suspended solutions in the market of forestry machines are practically non-existent. The implementation of chassis suspensions in forestry machines is therefore a very interesting research area in forestry technology. In this context, the XT28, a six-wheeled medium size forwarder prototype with active pendulum arm suspension, is currently being realized by Extractor AB in collaboration with the Forestry Research Institute of Sweden. The present project focuses on analyzing and comparing the performance that active, semi-active and passive suspension systems with a pendulum arm architecture would provide to forestry machines, by studying their implementation in the XT28 prototype A methodology to optimize and analyse forestry vehicle suspension performance using multi-objective optimization algorithms, multi-body dynamics and standardized vibration measures is proposed and applied to the XT28 case. The proposed methodology provides a fair and standardized way to compare the performance of the different suspensions. Simulation and optimization results show that well designed pendulum arm suspension systems have the potential to significantly improve forestry vehicle performance in terms of terrain friendliness and whole body vibration levels, compared to unsuspended systems.