Наукові конференції України, XVII ПРОГРЕСИВНА ТЕХНІКА, ТЕХНОЛОГІЯ та інженерна освіта

Розмір шрифту: 
Yu. M. Kuznetsov, D. O. Dmytriev, P. V. Keba, S. M. Piven

Остання редакція: 2016-06-16

Тези доповіді

Extensive research of mechanisms of parallel structure ( MPS ) began in the 1960s from studies purely kinematic properties of structures with multiple closed circuits operating simultaneously, the basis of this was laid by I.I. Artobolevskiy, V. O. Astatin, V.A. Glazunov, A.Sh. Koliskor, A.I. Korendyaev, F. M. Dimentberg, Е.І Vorobyov, K. Cappel, J. Denavit, V. Gough, C. Gosselin, J. Gwinnett, K.H. Hant, D. Stewart, K. Sugimoto, M. Nakagawa and the others[4]. In these studies, primarily resolved the theoretical questions such as the synthesis of wide class of spatial mechanisms, defining function that related of incoming and outgoing links positions and their special “dead” positions; definition of the kinematic relations surplus; analytical solutions for direct and inverse problems of kinematics; the definition of working space. Improved manipulation properties of MPS determined the next stage of their development - application in robotic systems. In this particular area the researches have been conducted by famous scientists as K.I. Zablonskiy, І.Т. Monashko, B.М. Schekin, R. Clavel, L. Tsai, J.-P. Merlet, R. Stamper. MPS become using for operations control, welding, coordinate measuring, loading-unloading work.

Starting from the 1980s using of machine-tools with MPS greatly expanded. They began to be part of metal-working equipment to process complex geometry working-pieces. The first MPS machine-tools hexapods, were built on the basis of the classic Stewart platform. The study of MPS as a machine-tools dedicated by V.L. Afonin, D.A, V.V.Bushuev, Dmitriev, А.F. Kraynev, V.А. Krizhanovskiy, Yu.М. Kuznetsov, І.І. Pavlenko, P.V. Podzorov, Yu.V Poduraev, V.І. Sidorko, V.B. Strutinskiy, І.G. Holshev, I. Bonev, J S.Chen, U.Heisel, M.Honegger, R. Katz, L. Kubler, M.Valasek and the others[1,4].

Existing methods of MPS kinematic schemes synthesis do not unambiguously choose its kinematic scheme because the same output unit displacements can be performed by using different kinematic schemes. As MPS kinematic chains, that connect a base with output links, work in parallel, so each kinematic chain has own operational limit that depends on initial links location. In addition, there are many different types of connections .That is why synthesis of manufacturing equipment, built on the basis of mechatronic systems with MPS should be concorded with specific production tasks.

For developing usage of parallel structures in machine-tools, expanding to deepening areas of MPS employing in metal-working there are some requirements, namely [1, 2]:

  1. Ensure high accuracy of processing and positioning the tool and the workpiece.
  2. Provide increased rigidity of the moving links.
  3. Multitasking of machine-tools new generation.
  4. Ensure the necessary degree of freedom (DOF) of the end-effector (EE) to perform multifunctional tasks.
  5. Increase the size of the machine-tools EE working space (WS).
  6. Provide high-performance processing.
  7. Make free access for loading (unloading) of details, for maintenance and for tool and equipment installation.

MPS machine-tools configurations expansion and their improvement possible through the use of shell and frame structures constructed as for specific technological requirements and as for standardized units and components. This is achieved by the fact that the axis of the main frame to which the sliders translation movement mechanisms are attached such as that their point of intersection in the machine-tool layout are arranged in such a way to form a spatial polyhedral frame. Also the number of rods and guides mounted on the edges of the frame can be increased to the necessary number of drives, which allows to increase the functionality of the EE with the relative decline the layout mass-dimensional characteristics, increasing its stiffness and expansion of machine-tool technological capabilitie.

At National Technical University of Ukraine "Kyiv Polytechnic Institute" produced a line of machine-tools to perform processing of complex geometry work-pieces. Machine-tools guide sliders at l‑coordinates that form pyramidal frame and the work-piece in the XY plane, depending on the basic movements of EE in the workspace.

Machine-tools control system builds on the concept of P-CNC (Personal Computer-Numerical Control), which has one-software architecture in which all control tasks (geometry, logic, terminal) resolved solely through software without using additional hardware devices. For interacting between computer and machine-tools control electrical parts uses special controller<t2 />, which the convert computer signal to the step motor analog signals [4]. The computer receives signals of machine-tools EE zero position sensors. The controller has three independent axes in three coordinates and works by STEP/DIR (step/direction) protocol with LPT computer port in real time. The controller receives information on the steps number and direction of rotation that has to execute by step motors.