US 5,176,030 A · Low frequency angular velocity sensor

Abstract

A magnetohydrodynmic angular rate sensor is described. A housing supports first and second coaxial proof masses in respective annular channels, permitting relative motion between the axis of the proof masses and the housings. First and second magnets associated with each annular channel result in an electric potential being generated across each channel proportional to the relative circumferential velocity between the proof masses and the housing. The annular channels are connected together to form a continuous pumped fluid circuit which introduces a radial flow velocity in each channel. At low rotational frequencies, a circumferential velocity component is induced in the proof masses due to Coriolis acceleration which results in a measurable electrical voltage across the annular channels. The low frequency response of the sensor is therefor extended to lower frequencies.

Claims9

Dependent claims

An angular rate sensor comprising:

a housing having first and second spaced apart annular channels, having a common axis lying along an axis of measurement, each channel having an electrically conductive fluid proof mass, said housing rotating with respect to said proof mass about said axis;
a first magnet located adjacent said first annular channel, and a second magnet adjacent said second annular channel;
an inner sense electrode in contact with an inner surface of said first and second annular channels;
first and second outer sense electrodes in contact with exterior portions of respective of said first and second annular channels;
and,
pumping means for pumping said fluid proof mass between said first and second annular channels, whereby a radial flow is introduced into said annular channels, which results in an electrical signal being induced between said inner sense electrode and said first and second outer sense electrodes as a result of Coriolis acceleration induced circumferential velocity components to said proof mass.

3 more elements

A wideband angular rate .omega. measuring device comprising:

a housing supporting first and second annular channels having a common axis, each of said channels including an electrically conductive liquid which functions as an inertial proof mass;
first and second magnets opposite a respective of said first and second annular channels;
first and second electrode means associated with respective of said first and second annular channels, said electrode means providing a signal in response to relative motion between said inertial proof mass in each of said channels and said housing;
a pumping means connecting each of said annular channels, providing a flow of said liquid in an orthogonal direction to the plane of said first and second channels, providing radial flow into said channels;
and,
a summing circuit for combining signals produced from said electrode means, whereby a signal is produced proportional to the circumferential velocity of said housing with respect to said liquid.

3 more elements

Dependencies are inferred from the claim text.

Low frequency angular velocity sensor

Life of this patent

Low frequency angular velocity sensor

Life of this patent

Abstract

Claims9