Dynamics of Multielement Agricultural Aggregates, Taking Into Account Nonholonomic Constraints and Spatial Motion

Abstract

The paper studies a discrete system of multielement agricultural aggregate composed of a tractor, hopper and seeder. Mechanical model includes these elements, which are considered as rigid bodies and perform spatial motion subject to of the wheels considering elasticity. As the geometric constrains taking into account the flat surface of the earth and the hinges connecting the units. The aggregate is controlled by angle of the steering wheel or the angle between the tractor half-frames. A feature o f the model is the account of non-holonomic constraints caused by the rolling o f the wheels. This significantly reduces the number o f degrees o f freedom and also complicates the process of forming the equations o f motion. Differential equations are automatically generated by a special system of computer algebra KiDyM based on a general dynamics equation. The gravity force, the driving force and the resistance force applied to the elements o f the aggregate defined as force interactions. The studied linear motion, maneuvers with constant and harmonic law change o f control angle.