Multivariable experiment for testing the productivity of the system of wood harvesting machines
The article examines systems of machines for wood harvesting under the conditions of Amurskaya oblast. Factors influencing the productivity of these systems of machines have been investigated. The wood density for larch has been studied in various districts of Amurskaya oblast. It has been found out that machine capacity depends on wood breed, density and humidity. To determine the influence of the wood density on the machine capacity when sawing, the samples of larch have been used. The samples used have been of suitable age for operating harvesting. It has been determined in the laboratory that the expended machine capacity, when sawing the larch growing in different districts of Amurskaya oblast, is 2,870-4,000 Wt. According to the analysis of the factors influencing the productivity of the system of wood harvesting machines, variable experimental factors have been chosen, as well as their limits. All the factors, forming the process of experimental research, have changed simultaneously on certain dependences, and the mathematical model of the shifting productivity of the system of machines has become the final result of the multivariable experiment. Regression equation has been built in the encoded kind. Thus, the generalized formula has been received for productivity dependence on larch wood sawing capacity, density and humidity. The section of productivity response surface, depending on wood sawing capacity and density (under humidity fixed at zero level W = 46 %), has showed evidently that the maximum productivity value can be reached under the following factor values: wood density is from 600 to 800 kg/m<sup>3</sup>, capacity is from 3,160 to 3,600 Wt.