Modelling and experimental verification of a secondary controlled six-wheel pendulum arm forwarder
2015 (English)In: the 13th European Conference of ISTVS / [ed] Roberto Paoluzzi, 2015, 1-10 p.Conference paper (Refereed)
One of the major concerns in the forest industry is the impact on the soil caused by the forest machines duringharvesting, where damages can have a negative impact on e.g. further growth. One of the main reasons is wheel slip.Another concern is the working environment of the operator due to the harsh ground in the forest. Both these issueshave a negative impact on productivity. An attempt to overcome these challenges is made within a collaborative researchproject, which among others also includes Linköping University, where a new six-wheel pendulum arm forwarder isbeing developed. The new forwarder aims at reducing the soil damage by an even pressure distribution and smooth torquecontrol, as well as increased damping of the complete chassis, and thereby improving the working environment. This ispossible since each wheel, driven by its own hydraulic motor, is attached to a pendulum arm allowing to control the heightof each wheel independently of each other. The forwarder has a total maximum weight of 31 tonnes, including 14 tonnesmaximum load. It consists of two steerable joints and is driven by a 360 bhp diesel engine. The transmission consists oftwo hydraulic pumps and six hydraulic motors.This paper deals with the development of the driveline and presents the first experimental tests of the implementedcontrol strategies, where a secondary control approach is chosen for its ability to individually control the torque on eachwheel. The control strategies, presented in the paper, include pressure control, velocity control of the vehicle and ananti-slip controller. To support the development of the control strategies, models of the vehicle and hydraulic subsystemsare derived. The aim with this paper is to verify the concepts on the actual vehicle. The initial results are promising,indicating that the suggested concept is feasible.
Place, publisher, year, edition, pages
2015. 1-10 p.
Secondary control, forest machinery, forwarder, modelling
IdentifiersURN: urn:nbn:se:liu:diva-122390ISBN: 9781942112464OAI: oai:DiVA.org:liu-122390DiVA: diva2:866093
Proceedings of the 13th ISTVS European Conference, Rome, October 21-23, 2015