Modeling and Multivariable Control Design Methodologies for Hexapod-Based Satellite Vibration Isolation Academic Article uri icon


  • A mathematical model of a six-degree-of-freedom (6-DOF) hexapod system for vibration isolation was derived in the discrete-time domain on the basis of the experimental data obtained from a satellite. Using a Box-Jenkins model structure, the transfer functions between six piezoelectric actuator input voltages and six geophone sensor output voltages were identified empirically. The 6×6 transfer function matrix is symmetric, and its off-diagonal terms indicate the coupling among different input/output channels. Various multi-input multi-output (MIMO) control techniques such as Linear Quadratic Gaussian and H∝ were proposed for active vibration isolation in the broadband up to 100 Hz. The simulation results using these controllers obtain 13 and 8 dB vibration attenuation at 25 and 35 Hz, respectively. Copyright © 2005 by ASME.

author list (cited authors)

  • Joshi, A., & Kim, W.

citation count

  • 7

publication date

  • November 2004