Modelling of the objects' positioning process on the conveyor with the positioning rectilinear barrier and the system of driven oblique rollers

The paper deals with the positioning process modelling of the cuboidal objects along the conveyor edge by means of an oblique friction force field with a rectilinear barrier. The friction field is created by a system of driven oblique rollers. A modified nonlinear Kelvin model was used to describe the normal reaction forces at the contact points of the object with the conveyor and barrier. There were taken into account two 2D vector friction models: the LuGre and the Bengisu-Akay, representing the dynamic and static groups of friction models, respectively. The LuGre model has been modified to overcome the limitations of the classic model in terms of the invariability of the normal contact forces. The use of scaling of the stiffness coefficient (due to the normal contact force) allows the friction simulation while bodies collision, i.e. when the normal contact force shows rapid changes in value and the initial sliding velocity is non-zero. A method for determining the dynamic parameters of the LuGre model is proposed. The results of numerical and experimental research on the positioning process show acceptable compliance and validity of the adopted assumptions.