Research of dynamics of movement of grain and forage harvesters by methods of mathematical and imitating modeling

The mathematical model of movement of the grain and forage harvester is considered, the possibility of its algorithmization in the software complex is shown, as well as the data confirming its adequacy. The mathematical model includes dynamic and kinematic equations of relation of angular and linear velocities with angular and spatial coordinates. The peculiarity of the model is in the use of a set of coordinate systems, which allowed to take into account not only the weight and size and layout features of the type of machines under study, but also the nature of interaction of the elastic wheel with the damped base. In the given model the speed of movement of the combine is set not by the forced change of the coordinate of the center of mass of the skeleton, but is formed by the modeling of the process of interaction of driving wheels with the support base. This approach provides a more adequate description of the process of curvilinear movement of the combine, allows you to simulate the movement of the machine, acceleration, braking, overcoming obstacles, slipping and slipping processes, taking into account the characteristics of the tire and traction properties of the soil. The approach adopted ensures sufficient accuracy of the model with a minimum set of factors and requirements for calculation. Experimental and computational data obtained as a result of simulation are presented. Comparison of active forces and acceleration spectral densities in the main parts of the combine showed sufficient convergence of results. The revealed inaccuracy is caused by the discrepancy between the numerical description of the supporting surface and the test road, the presentation of the combine's frame as an absolutely rigid body, and differences in the elastic-viscous properties of tires. Conclusions are made and directions of the further researches providing improvement of operational properties of self-propelled combines at the expense of systems of suspension of wheels and working elements are defined.