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Lego Figure holding a lego telescope. Photo

Arne Ardeberg

Professor emeritus

Lego Figure holding a lego telescope. Photo

Analytical Stiffness Optimization of High-Precision Hexapods for Large Optical Telescope Applications


  • Behrouz Afzali Far
  • Per Lidström
  • Kristina Nilsson
  • Arne Ardeberg


  • K. Persson
  • G. Sandberg
  • M. Wallin

Summary, in English

An analytical stiffness and eigenfrequency model of symmetric parallel 6-6 Stewart

platforms (hexapods) is developed based on geometrical design variables to optimize the

dynamical performance. The model is based upon Lagrangean dynamics in which the Bryant

angles are used for the kinematics formulation. With the analytical eigenfrequency model,

optimum stiffness characteristics can be obtained for any industrial application with limited

workspace such as optical collimation systems. The actuator length-flexibility dependency is

also considered in the analytical model. It is proposed that to increase the actuation bandwidth

in six degrees of freedom, an eigenfrequency cost function can be defined and optimized.

Publishing year





Proceedings of the 25th Nordic seminar on computational mechanics

Document type

Conference paper


  • Applied Mechanics


  • Gough Stewart platform
  • hexapod
  • analytical
  • stiffness
  • eigenfrequency
  • telescope

Conference name

25th Nordic Seminar on Computational Mechanics, 2012

Conference date

2012-10-25 - 2012-10-26

Conference place

Lund, Sweden