Electrostatic pickoff system for ball gyros of the electrostatic levitation type

Claim 2

A gyroscope comprising: a case; a ball adapted to be spun about a spin axis, said ball being provided with a radial unbalance so that said ball orbits as it spins about the spin axis; a set of electrostatic electrodes disposed within said case and in a three dimensional array about said ball; circuit means for establishing electrical field signals between said electrodes and said ball; pickoff means associated with said electrodes and responsive to the approach and recession of said ball for modulating the electrical field signals between said ball and said electrodes in a phase and amplitude pattern unique to the particular orientation of the spin axis of said ball relative to said electrodes; signal circuits coupled to said pickoff means for demodulating the modulated electrical field signals to develop demodulated signals; means responsive to the demodulated signals for developing phase information signals indicative of the attitude of the spin axis of said ball relative to said set of electrodes; and computing means responsive to the phase information signals for computing the attitude of the spin axis of said ball relative to said set of electrodes.

Claim 3

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; servo means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; and first means for measuring the phase relationships of the modulated electrical signals to develop a plurality of phase signals indicative of the attitude of said ball relative to said plurality of electrodes.

Claim 4

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; servo means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; and first means for measuring the phase relationships of the modulated electrical signals to develop a plurality of phase signals indicative of the attitude of said ball relative to said plurality of electrodes.

Claim 5

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop sinasoidal demodulated signals; and means responsive to the sinasoidal demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes.

Claim 6

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop sinasoidal demodulated signals; and means responsive to the sinasoidal demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes.

Claim 7

The electrostatic gyroscope of claim 3 wherein said developing means includes: means responsive to the sinasoidal demodulated signals for generating a plurality of logic time signals; a source of clock pulses; and means for selectively counting a plurality of sequences of clock pulses as a function of the plurality of logic time signals to develop the output signals.

Claim 8

The electrostatic gyroscope of claim 4 further including: computing means responsive to the output signals for computing the attitude of said ball relative to said plurality of electrodes.

Claim 9

The electrostatic gyroscope of claim 4 wherein said generating means includes: a plurality of detectors for generating the plurality of logic time signals as functions of the phases of the sinasoidal demodulated signals.

Claim 10

The electrostatic gyroscope of claim 6 wherein said counting means includes: a plurality of gating means responsive to the clock pulses and to the plurality of logic time signals for developing a plurality of sequences of clock pulses; and a plurality of counters for respectively counting the plurality of sequences of clock pulses to develop the output signals.

Claim 11

The electrostatic gyroscope of claim 7 further including: computing means responsive to the output signals for computing the attitude of said ball relative to said plurality of electrodes.

Claim 12

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop demodulated signals; and means responsive to the demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes, said developing means including: means responsive to the demodulated signals for generating a plurality of logic time signals, said generating means including a plurality of phase lock loops for generating the plurality of logic time signals, each of the logic time signals being a square wave signal locked in phase with the associated demodulated signal; a source of clock pulses; and means for selectively counting a plurality of sequences of clock pulses as a function of the plurality of logic time signals to develop the output signals.

Claim 13

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapted to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop demodulated signals; and means responsive to the demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes, said developing means including: means responsive to the demodulated signals for generating a plurality of logic time signals, said generating means including a plurality of phase lock loops for generating the plurality of logic time signals, each of the logic time signals being a square wave signal locked in phase with the associated demodulated signal; a source of clock pulses; and means for selectively counting a plurality of sequences of clock pulses as a function of the plurality of logic time signals to develop the output signals.

Claim 14

The electrostatic gyroscope of claim 9 wherein said counting means includes: a gate circuit; a counter; and means for selectively allowing the plurality of logic time signals to sequentially enable said gate circuit to pass a plurality of sequences of clock pulses to said counter to be counted, said counter selectively counting the plurality of sequences of clock pulses to develop the output signals.

Claim 15

The electrostatic gyroscope of claim 10 further including: computing means responsive to the output signals for computing the attitude of said ball relative to said plurality of electrodes.

Claim 16

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapated to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop demodulated signals; and means responsive to the demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes, said developing means developing first and second output signals, each output signal containing a composite of both phase and amplitude components, said first and second output signals being indicative of the attitude of the spin axis of said ball relative to preselected ones of said electrodes, said developing means including: means responsive to a first one of said demodulated signals for producing first and second reference signals in phase quadrature with each other, said producing means including: a phase lock loop for locking the first one of said demodulated signals in phase with the rate at which said ball is spun around its spin axis in order to develop the first reference signal; and a phase shifter for shifting the phase of the first reference signal by substantially 90° to develop the second reference signal; and demodulation means responsive to the first and second reference signals and to a second one of said demodulated signals for developing the first and second output signals.

Claim 17

An electrostatic gyroscope comprising: a mass unbalanced conductive ball adapated to be spun around a spin axis; a plurality of electrodes positioned around said ball; means for selectively providing electrical signals to said plurality of electrodes to freely suspend said ball among said electrodes, the electrical signal at each electrode being modulated at the spin frequency of said ball as said ball moves away from or toward the electrode; means for demodulating the modulated electrical signals to develop demodulated signals; and means responsive to the demodulated signals for developing output signals containing phase information indicative of the attitude of said ball relative to said set of electrodes, said developing means developing first and second output signals, each output signal containing a composite of both phase and amplitude components, said first and second output signals being indicative of the attitude of the spin axis of said ball relative to preselected ones of said electrodes, said developing means including: means responsive to a first one of said demodulated signals for producing first and second reference signals in phase quadrature with each other, said producing means including: a phase lock loop for locking the first one of said demodulated signals in phase with the rate at which said ball is spun around its spin axis in order to develop the first reference signal; and a phase shifter for shifting the phase of the first reference signal by substantially 90° to develop the second reference signal; and demodulation means responsive to the first and second reference signals and to a second one of said demodulated signals for developing the first and second output signals.

Claim 18

The electrostatic gyroscope of claim 12 wherein said second means further includes: an inverter for inverting the first one of said demodulated signals before it is applied to said phase lock loop.

Claim 19

The electrostatic gyroscope of claim 12 wherein said demodulation means includes: first and second demodulators respectively responsive to the first and second reference signals for demodulating the second one of said demodulated signals to develop the first and second output signals.