Motion simulation and calculation of the components of the lateral forces of the guiding wheels of a cotton-harvesting machine

BACKGROUND: One of the relevant issues to study is the motion of a cotton-harvesting machine (CHM) at the turning lanes of the cotton field along curvilinear path. At the same time, the CHM’s wheels rolling occurs with lateral slip of tires, so the machine may have unacceptable, according to the conditions for raw cotton harvesting, deviations in the lateral direction of the motion path when turning to enter the beds of the cotton field, and the traction performance of the CHM’s steered wheels declines significantly.

AIMS: Building mathematical models and carrying out kinematic simulations to determine the motion parameters and the values of lateral forces, the side slip resistance coefficients of tires of the CHM’s guide wheels necessary to achieve the required performance and to maintain the specified accuracy of the path motion along the headland of the cotton field with acceptable traction indicators.

METHODS: Dynamic processes are hugely complicated and difficult to analyze in full. The developed models are based on the balance equations and the wheels motion is not considered separately, taking into account tire deflections.

RESULTS: The kinematic scheme of turning of the MKh-1.8 CHM with front driving and rear steered wheels was considered. It was assumed that the MKh-1.8 CHM moves at a low constant velocity, so the centrifugal force can be neglected. In addition, lateral slip is the very parameter that reflects the impact of external force factors that go with the curvilinear motion on the machine.

CONCLUSIONS: Analyzing the obtained results, the following can be noted: during the curvilinear motion of the CHM, the main parameters that determine the turning of the machine are the CHM wheelbase, the average steering angle of the steered wheels and the slip angles of the rear axle. Moreover, it should be noted that the slip angles of the front and rear axles of the CHM, their values and change have a significant impact on the machine turning kinematics. The presence of lateral slip is the main reason of significant deviations from the given path of the CHM motion at a headland of a cotton field.