Method and Results of Evaluating the Operational Efficiency of Multi-Operational Forest Harvesting Machine Systems

Abstract

This article addresses the forecasting of the operational efficiency of multi-operational forest harvesting machine complexes. A methodology is proposed for this purpose, based on the use of a new evaluative criterion – the specific energy productivity potential of the machine complex. This potential is determined using the values of useful work performed by the machine with corresponding energy and time expenditures. The article outlines the procedure for assessing the structure of the joint technological cycle of harvesters and forwarders and the method for determining the values comprising the aforementioned criterion. Using the proposed methodology, an analysis of the efficiency of the roundwood loading operation by a forwarder's manipulator was conducted, depending on the harvester’s preliminary work technologies. Characteristic operating modes and execution variants for this operation were identified, which are up to 22,6% more efficient. It is noted that the efficiency of loading operations is significantly influenced by the synchronism and trajectory of the manipulator’s link movements and the performance of its hydraulic drive. It is proven that a forwarder manipulator’s hydraulic system with a separate drive for each consumer is 1,15–1,41 times more efficient in loading operations compared to a system with a common source of hydraulic energy and load sensing control. An analysis of the joint work efficiency of the most common harvesters and forwarders in the Republic of Belarus was performed for their various combinations within a single machine complex. Rational parameters for their technological processes were established. Technical specifications for prospective harvester and forwarder units within a multi-operational forest harvesting machine complex were substantiated. The complex is intended for logging in high-density stands with a normal distribution of stems (with volumes up to 1,4 m³ ) on soils with high bearing capacity.