A Skyline Deflection Analysis Methodology for Timber Volume Estimation in Yarding Operations

This paper describes the approach followed to perform an automatic load monitoring during yarding activities. The goal of this methodology is the weight assessment of the loaded biomass during the inhaul phase in cable logging operations. The approach is based on the development of dedicated mathematical models that assessing the skyline deflection, tension, and slope permit to estimate the hauled load through an indirect approach. To carry out this experience an in-scale standing skyline system with single-span was set-up. The experiment was conducted at 0%, 10% and 20% of slope, respectively, and the skyline deflection was measured during travels with 0, 5, 10, 20, 30 and 40 kg of fully suspend loads. Besides these, the assessment was performed at mounting tensions of 10 and 100 kg. According to the different estimative models and the operative context, the collected results showed a difference between the estimated load and the reference one lower than 20% in terms of mass. In conclusion is possible to affirm that the proposed approach can be a suitable compromise for the indirect estimation of timber during fully suspended yarding operation