Tip-tilt mechanism (3 d.o.f.)

Fine Precision Mechanism Based on Magnetic Bearing Technology (MABE)

Description

Micromega Dynamics has developped, under the GSTP II program of the European Space Agency (ESA), a multi-degrees-of-freedom fine precision mechanism based on the magnetic bearing technology. The main advantage of this technology is to allow a nanometric resolution over wide strokes without the need of multi-stage actuators. Hence, very high positioning accuracies with large bandwiths / small response times can be achieved. Rejection of external perturbations is also excellent.

Mabe high accuracy nanopositioning mechanism

A complete experiment is currently under design to be tested in-orbit on board the American Space Shuttle.

Operation

The payload is put into levitation. In-plane movements (T_x, T_y and q_z) are locked by 3 magnetic bearings while the payload position (T_z, q_x and q_y) is adjusted using three magnetic actuators. The 3 supporting springs are used for zero gravity simulation.

Benefits

The use of magnetic bearings as guiding elements and of one-stage magnetic actuators allows for long range, high precision and high bandwidth without wear.

Specifications

Reduced power dissipation

Simplified driving and control electronics
for space qualification

Precision in the nanometer range

Linear resolution (T_z) : 1 nm_rms

Linear stroke (T_z) :5 mm

Angular resolution (q_x and q_y) : 10 nrad

Angular stroke (q_x and q_y) : 2.5 mrad

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