Superconducting sixaxis accelerometer
Abstract
A new superconducting accelerometer, capable of measuring both linear and angular accelerations, is under development at the University of Maryland. A single superconducting proof mass is magnetically levitated against gravity or any other proof force. Its relative positions and orientations with respect to the platform are monitored by six superconducting inductance bridges sharing a single amplifier, called the Superconducting Quantum Interference Device (SQUID). The six degrees of freedom, the three linear acceleration components and the three angular acceleration components, of the platform are measured simultaneously. In order to improve the linearity and the dynamic range of the instrument, the demodulated outputs of the SQUID are fed back to appropriate levitation coils so that the proof mass remains at the null position for all six inductance bridges. The expected intrinsic noise of the instrument is 4 x 10(exp 12)m s(exp 2) Hz(exp 1/2) for linear acceleration and 3 x 10(exp 11) rad s(exp 2) Hz(exp 1/2) for angular acceleration in 1g environment. In 0g, the linear acceleration sensitivity of the superconducting accelerometer could be improved by two orders of magnitude. The design and the operating principle of a laboratory prototype of the new instrument is discussed.
 Publication:

In NASA
 Pub Date:
 August 1990
 Bibcode:
 1990mcae.reptQ....P
 Keywords:

 Accelerometers;
 Angular Acceleration;
 Gravity Gradiometers;
 Levitation;
 Superconductivity;
 Weightlessness;
 Degrees Of Freedom;
 Demodulation;
 Design Analysis;
 Drag;
 Gravitation;
 Inductance;
 Linearity;
 Prototypes;
 Proving;
 Sensitivity;
 Spacecraft Instrumentation