Precision Control of the 6-DOF Parallel Kinematic Mechanism of Space Application Based on Compensation of Kinematic and

  • PDF / 270,676 Bytes
  • 10 Pages / 612 x 792 pts (letter) Page_size
  • 98 Downloads / 176 Views

DOWNLOAD

REPORT


CTURAL MECHANICS AND STRENGTH OF FLIGHT VEHICLES

Precision Control of the 6-DOF Parallel Kinematic Mechanism of Space Application Based on Compensation of Kinematic and Temperature Errors S. A. Matveeva, E. B. Korotkova, N. S. Slobodzyana, Yu. A. Zhukova, and A. A. Kiseleva, * a

Ustinov Baltic State Technical University “Voenmekh”, ul. 1ya Krasnoarmeiskaya 1, St. Petersburg, 190005, Russia *e-mail: [email protected] Received March 18, 2020; revised April 29, 2020; accepted April 30, 2020

Abstract—The paper introduces the ways to improve the control accuracy of the parallel kinematic mechanisms of space application. The sources of errors in positioning and orientation of the mechanism developed are given. The ways are suggested for compensating the kinematic and temperature errors of linear drives and mechanism members. DOI: 10.3103/S1068799820020026 Keywords: Gough–Stewart platform, hexapod, parallel kinematic mechanism, extended kinematics problem, linear drive, compensation, ball screw, linear thermal expansion, calibration.

INTRODUCTION To achieve the limit qualitative characteristics of the spacecraft information systems, it is necessary to orient their on-board equipment (antennas, telescopes, reflectors, etc.) towards the spacecraft with the highest precision. Modern requirements for the accuracy of positioning the on-board equipment and orientation of the spacecraft are measured in micrometers and micro radians. In order to solve problems of precision positioning and orientation, parallel kinematic mechanisms (PKM) [1, 2] are most commonly used, the advantages of which include high stiffness, accuracy, and load carrying capacity [3]. There is a promising point to use the PKM in space equipment for guidance, stabilizing, and vibration damping of the precision instrument of a spacecraft [4, 5]. However, PKMs of general purpose do not have the opportunity to function in space because of using the general-purpose component base that does not have radiation hardness. In addition, space-applied PKMs should have high reliability, durability, and work flawlessly in a wide range of temperatures and under the conditions of ionizing radiation. Thus, the current task is to develop a precision parallel kinematics mechanism for space application that can achieve required levels of accuracy, reliability, durability, and operation safety. The Ustinov Baltic State Technical University “Voenmekh” (St. Petersburg) and the Reshetnev AO Information Satellite Systems (Zhelenogorsk) develop the joint project of the range of multi-degree of freedom parallel kinematic mechanisms meant for work as parts of modern and promising satellite platforms. As a result of this cooperation, the PKM-hexapod was developed similar to the Gough–Stewart platform [6] in its concept of action that is shown in Fig.1. The hexapod allows moving of the object located on its movable platform towards the base along six degrees of freedom (6-DOF) by changing the linear dimensions of its “legs” with the help of linear drives with micrometrical accuracy. I