Characteristics of external influences on the operation of machine-tractor units

The most significant feature of the operation of agricultural machine-tractor aggregates is the random nature of external influences, which determines its output indices. The main task of the theory of complex systems should be considered the development of methods that allow on the basis of their functioning to obtain the characteristics of individual elements and analyze the interaction between these elements and the external environment, to determine the characteristics of the system as a whole. The purpose of the study is to analyze the characteristics of external influences as a reaction to the operation of machine-tractor units. When solving many problems of agricultural mechanics (researching technological and production processes, building models and synthesizing the parameters of working organs and aggregates), it is necessary to take into account the external factors that determine the main regularities of various processes. The process of operation of the unit can be represented in the form of a set of states - vectors of output quantities: agrotechnical, technological, kinematic, energy-power and so on. The role of input quantities is played by external conditions and control actions, which also have a certain set of states. External influences on the unit are technological, operational and constructive factors, the number of which include soil resistance, the surface profile of the field, the physical and mechanical properties of the material being processed (soil density, soil moisture, etc.), the technical condition of the machine working bodies, and the depth of processing. As the speed of motion increases, the correlation between the sections of the random function decreases. As the speed of motion increases, the spectral density decreases, and its maximum value shifts towards higher frequencies; spread of the values of random function with respect to the mathematical expectation increases with increasing aggregate speed; by correlation functions and spectral densities, it is possible to establish the main parameters of random processes, variances, the mean square deviations prevailing in the frequency process and the corresponding periods, the dispersion distributions over frequencies that are necessary to establish the parameters of the output indicators characterizing the level of functioning of agricultural machine-tractor aggregates.

external influence, machine-tractor unit, correlation function, spectral density, traction resistance