Mass unbalance modulation pickoff attenuation and speed control in electrostatic gyroscope system

A suspension system for an electrostatic gyroscope of a type which incorporates a plurality of electrodes arranged in a symmetrical array around a mass unbalanced conductive ball, which ball is adapted to be spun around a spin axis, said system comprising:

• first means responsive to electrode pickoff signals for generating a plurality of first signals, each of the first signals containing MUM and servo components;
• second means responsive to the plurality of first signals for generating a plurality of reconstructed MUM signals and a second signal having a frequency indicative of the speed of the ball as it spins around the spin axis;
• third means responsive to the plurality of reconstructed MUM signals and to the second signal for developing a plurality of speed control signals;
• fourth means responsive to the first signals and reconstructed MUM signals for internally developing a plurality of servo signals containing substantially no MUM signals, said fourth means including fifth means responsive to the plurality of speed control signals and the plurality of servo signals for developing a plurality of force signals;
• and
• fifth means responsive to the plurality of force signals for selectively applying potentials to the electrodes of each pair to control the positioning and speed of the conductive ball and for developing the electrode pickoff signals.

A system comprising:

• a spherical conductive ball having a center of mass displaced from the geometric center thereof, said ball being adapted to be spun about a spin axis;
• a plurality of electrodes arranged in a symmetrical array around said ball;
• a plurality of circuits being responsive to a plurality of force signals containing substantially no mass unbalanced modulation components for respectively supplying a plurality of voltages to said plurality of electrodes to control the positioning and speed of said ball and for generating the plurality of pickoff signals;
• a first circuit responsive to a plurality of pickoff signals for generating a plurality of first signals;
• a second circuit responsive to the plurality of first signals for developing a second signal indicative of the speed of said spinning ball and for developing a plurality of mass unbalanced modulation third signals therefrom;
• a third circuit responsive to the second and third signals from said second circuit for developing a plurality of fourth signals for subsequently controlling the speed of said spinning ball;
• and
• a fourth circuit responsive to the first, third and fourth signals for developing the plurality of force signals to enable and plurality of circuits to control the speed and position of said spinning ball.

A suspension system for an electrostatic gyroscope of a type which incorporates four pairs of electrodes arranged in a symmetrical array around a conductive ball, which ball is adapted to be spun around a spin axis, said system comprising:

• four amplifier means being respectively responsive to four associated force signals for selectively applying potentials to the four pairs of electrodes to control the positioning and speed of the conductive ball and for developing four pickoff signals, each pickoff signal being indicative of the position of the ball in relation to an axis of suspension associated with a corresponding pair of electrodes;
• a pickoff circuit for developing four first signals in response to the pickoff signals;
• a reconstruction circuit responsive to the four first signals for developing reconstructed MUM signals in three mutually orthogonal axes, respectively, and for developing a second signal having a frequency indicative of the actual speed of the spinning ball;
• a speed control circuit being responsive to the reconstructed MUM signals and to the second signal for developing an associated speed control signal in each of the three mutually orthogonal axes in order to precisely control the actual speed of the spinning ball;
• and
• a servo suspension circuit responsive to the four first signals, the three reconstructed MUM signals and the three speed control signals for developing the four associated force signals to cause said four amplifier means to precisely position and speed-control the spinning ball.

A system comprising:

• a mass unbalanced conductive ball adapted to be spun around a spin axis;
• a plurality of electrodes around said ball;
• means responsive to a plurality of forcing signals for selectively applying signals to said electrodes to control the positioning and rotational speed of said ball;
• first means coupled to said applying means for developing a plurality of composite signals, a plurality of reconstructed MUM signals and a ball speed signal indicative of the rotational speed of said ball, each of the composite signals containing MUM and servo components;
• second means responsive to the ball speed signal and the plurality of reconstructed MUM signals for generating speed control signals;
• and
• third means for respectively subtracting the plurality of reconstructed MUM signals from the plurality of composite signals to eliminate the MUM signals and for respectively adding the speed control signals to the differences therebetween to generate the plurality of forcing signals to enable said applying means to control the positioning and rotational speed of said ball.