Transportation and assembly of miniature and micro bodies are rapidly developing and ground-breaking technologies motivated by the trend toward miniaturization of mass-produced products. Currently, the research on these topics is of the utmost importance in most fields of sciences and industries, especially related to new and high technologies. Transportation of micro bodies is an especially difficult task as adhesive forces between the micro bodies become more dominant than inertial and gravity forces and a large number of components sometimes should be positioned at the same time. For the implementation of this process, the method of vibratory transportation can be effectively used.
A new method is proposed for transportation of miniature and micro bodies on an oscillating platform under in a wide range controlled dry friction, when the friction force, in respect of the nominal friction force, is being changed in the both directions i.e. increased and decreased, thus expanding the range of the vibrational transportation parameters and the transportation accuracy. The project objective is to develop a vibrational transportation system for miniature and micro bodies on an oscillating platform under in a wide range controlled dry friction and determine its functional and operational characteristics. In order to implement the project objective, it is planned to investigate dry friction control systems and develop methods and means for expanding the range of dry friction control and determine the dependence of the dry friction force on the control parameters, on the basis of theoretical research and computer simulation to determine the dynamical characteristics of the transportation process, develop an experimental stand for miniature and micro body transportation and carry out experimental research and functionality tests.
Project funding:
Projects funded by the Research Council of Lithuania (RCL), Projects carried out by researchers’ teams
Project results:
The engineering concept is proposed for vibrational transportation of bodies on the horizontal harmonically vibrating platform with dry friction control over a wide range,. The functional capabilities and advantages of practical application of the proposed conveying method are revealed.
It was determined that in order to control the dry friction between the horizontal vibrating platform and the conveyed body in a wide range, pneumatic suction or magnetic attraction forces, as well as high-frequency vibrations in the contact zone, can be effectively used, and accordingly, the velocity and direction of the conveyed body depend on the dynamic parameters of these measures. During the implementation of the project, dry friction control systems were developed, dynamic and mathematical models of these systems were created, and the dependences of the dry friction force on the dynamic parameters of the investigated systems were determined.
The dynamic and mathematical models of the vibratory transportation of miniature and microminiature bodies on a longitudinally oscillating platform, and on a platform subjected to circular motion, with dry friction control over a wide range, have been developed. The modelling software was developed and the influence of the control parameters on the transportation was defined, as well as the functional and dynamic characteristics of the transportation process were determined. It was demonstrated that the directional motion of the body is determined by the frictional asymmetry of the transportation system. The direction and velocity of the body motion on the platform can be controlled over a wide range by varying the phase shift between the horizontal harmonic oscillations of the platform and the function of dynamic dry friction control, as well as by varying the width of the function of the modification of the effective coefficient of friction with respect to the harmonic oscillation period.
Experimental equipment for the dynamic control of dry friction and vibratory transportation of miniature and microminiature bodies on a longitudinally oscillating horizontal platform and on a horizontal platform subjected to circular motion, with dry friction control over a wide range, has been developed, and experimental investigations have been carried out on the processes of dynamic dry friction control and vibrational transportation. The dynamic characteristics of these processes have been determined and the functional capabilities were tested.
A comparative analysis of the results of theoretical research, numerical modelling, and experimental research was carried out. It showed a good agreement between the obtained results in qualitative and quantitative terms and validated the functional capabilities of the vibrational transportation of bodies on a horizontal harmonically vibrating platform with dry friction control over a wide range.
The results have shown that the proposed vibratory transportation method, which is based on periodic dry friction control over a wide range, offers new functional capabilities, such as a capability to move individual objects on the same platform in opposite directions and at different velocities at the same time by imposing different friction control parameters on different regions of the platform or on different objects. In addition, objects can be subjected to translation and rotation at the same time by imposing different friction control parameters on different regions of the platform. The presented research extends the classical theory of vibrational transportation and has a practical value for modern industries that operate manufacturing systems performing tasks with miniature and microminiature bodies such as handling and transportation, manipulation, positioning, feeding, sorting, aligning, or assembling.
Period of project implementation: 2019-06-17 - 2022-06-30
Project coordinator: Kaunas University of Technology
