ON THE SEMIACTIVE CONTROL OF A STEWART PLATFORM WITH FLEXIBLE JOINTS

  • Luciana MAJERCSIK Transilvania University of Brasov

Abstract

The mathematical model of a Stewart platform is presented in order to apply the piezoelectic semiactive control to ensure the stability of its movements. In the case of the Stewart platform, there is a difference between a single-input and single-output system (SISO) and a multi-input and multi-output system (MIMO). To eliminate multiple input and output couplings and to convert a MIMO system into a SISO system, the system is decoupled into six single-axis systems. The nodal model of a single bar with included PZT actuator is defined. The first vibration mode of this nodal model is a rigid mode, and the corresponding natural frequency is zero. A structure with a rigid vibration mode is unstable and therefore needs control to remove it from this vibration mode. The piezoelectric semiactive control of a Stewart platform with 6 piezoelectric vibration isolation elements, in the (5-250) Hz range is discussed. The control is achieved by eliminating the rigid vibration mode that leads to instability.

Published
Jun 28, 2019
How to Cite
MAJERCSIK, Luciana. ON THE SEMIACTIVE CONTROL OF A STEWART PLATFORM WITH FLEXIBLE JOINTS. Romanian Journal of Mechanics, [S.l.], v. 4, n. 1, p. 27-38, june 2019. ISSN 2537-5229. Available at: <http://journals.srmta.ro/index.php/rjm/article/view/90>. Date accessed: 23 may 2024.