Dual range, torque rebalancing of inertial sensor

Claim 2

Apparatus for use with a torque rebalanced inertial sensor having a torque rebalance winding which restores the position of the sensor against inertial forces acting thereon in response to currents thereto, and providing an output signal indicative of inertial changes being sensed thereby, comprising: mode control means settable into either one of two stable states and presenting either a high rate mode signal or a low rate mode signal, alternatively, for respectively designating a high rate sensing mode or a low rate sensing mode; converter means responsive to the output signal of the inertial sensor for providing signal manifestations of the direction and the magnitude of the inertial changes being sensed thereby; means responsive to said converter means and to said mode control means to provide output signals as a function of said signal manifestations of said converter means in respective dependence on said mode signals; feedback current means responsive to said mode control means and said converter means operable to alternatively provide negative feedback current of either a first magnitude or a second magnitude depending on said mode signals, said first magnitude being an integral multiple of said second magnitude, in either of two polarities in dependence on said signal manifestations of said converter means, to the torque rebalance winding of the inertial sensor; and means responsive to the magnitudes represented by said signal manifestations of said converter means for correspondingly setting said mode control means into one or the other of said states, alternatively.

Claim 3

Apparatus according to claim 1 wherein said converter means is also responsive to said mode control means to provide said signal manifestation as a function of the output signal of the inertial sensor in respective dependence on said mode signals.

Claim 4

Apparatus according to claim 1 wherein said feedback current means comprises a plurality of current switches arranged as a polarity switching bridge, a first group of said switches being operable in response to said signal manifestation representing a first direction and a second group of said switches being alternatively operable in response to said signal manifestation representing a second direction.

Claim 5

Apparatus according to claim 1 wherein said feedback current means comprises a normally operative low voltage source feeding a current control transistor in series with the torque rebalance winding, together with a normally connected current sensing resistor connected in series with the torque rebalance winding, the voltage developed across said current sensing resistor being fed back to control said current regulating transistor; a high voltage source, said high voltage source having a voltage which is substantially said integral multiple of the voltage of said low voltage source, said high voltage source being connectable to said current regulator transistor in response to said high rate mode signal; and a second current sensing resistor selectively connected in parallel with said first current sensing resistor in response to said high rate mode signal, the resistance of said normally connected current sensing resistor being substantially said integral multiple of the resistance of said second current sensing resistor.

Claim 6

Apparatus for use with a torque rebalanced inertial sensor having a torque rebalance winding which restores the position of the sensor against inertial forces acting thereon in response to currents applied thereto, and providing an output signal indicative of inertial changes being sensed thereby, comprising: timing means providing a plurality of related, cyclic timing signals, including first and second timing signals, said first timing signals having a frequency which is an integral multiple of said second timing signals; mode control means settable into either one of two stable states and presenting either a high rate mode signal or a low rate mode signal, alternatively, for respectively designating a high rate sensing mode or a low rate sensing mode; converter means responsive to the output signal of the inertial sensor for providing a signal manifestation of the direction and the magnitude of the inertial changes being sensed thereby; an up/down counter; means responsive to said timing means, said converter means, and said mode control means to apply to said up/down counter either said first timing signals in response to said high rate mode signal or said second timing signals in response to said low rate mode signal, to count said counter up or down in respective dependence on said signal manifestation of said converter means; feedback current means responsive to said mode control means and said converter means operable to alternatively provide negative feedback current of either a first magnitude or a second magnitude depending on said mode signals, said first magnitude being said integral multiple of said second magnitude, in either of two polarities in dependence on said signal manifestation of said converter means, to the torque rebalance winding of the inertial sensor; and means responsive to said converter means for setting said mode control means into one of said states.

Claim 7

Apparatus for use with a torque rebalanced inertial sensor having a torque rebalance winding which restores the position of the sensor against inertial forces acting thereon in response to currents applied thereto, and providing an output signal indicative of inertial changes being sensed thereby, comprising: timing means providing a plurality of related, cyclic timing signals, including first and second timing signals, said first timing signals having a frequency which is an integral multiple of said second timing signals; mode control means settable into either one of two stable states and presenting either a high rate mode signal or a low rate mode signal, alternatively, for respectively designating a high rate sensing mode or a low rate sensing mode; converter means responsive to the output signal of the inertial sensor for providing a signal manifestation of the direction and the magnitude of the inertial changes being sensed thereby; an up/down counter; means responsive to said timing means, said converter means, and said mode control means to apply to said up/down counter either said first timing signals in response to said high rate mode signal or said second timing signals in response to said low rate mode signal, to count said counter up or down in respective dependence on said signal manifestation of said converter means; feedback current means responsive to said mode control means and said converter means operable to alternatively provide negative feedback current of either a first magnitude or a second magnitude depending on said mode signals, said first magnitude being said integral multiple of said second magnitude, in either of two polarities in dependence on said signal manifestation of said converter means, to the torque rebalance winding of the inertial sensor; and means responsive to said converter means for setting said mode control means into one of said states.

Claim 8

Apparatus according to claim 5 wherein said timing means provides a cyclic series of cycle control signals at a frequency which is a sub-multiple of said second timing signals, said cycle control signals defining the first half and the second half of each cycle, and wherein said converter means comprises: means providing a linear ramp voltage, said ramp voltage representing negative directions of the inertial sensor during the first half of each cycle and representing positive directions of the inertial sensor in the second half of each cycle; means for converting the output of the inertial sensor to a DC voltage the magnitude of which is a function of the direction and the magnitude of the inertial changes being sensed thereby; and comparison means for comparing said DC voltage with said linear ramp voltage and providing said signal manifestation in response to said DC voltage exceeding the magnitude of said ramp voltage.

Claim 9

Apparatus according to claim 6 wherein said converter means is further responsive to said mode control means to provide said linear ramp voltage with either a first peak magnitude or a second peak magnitude which is said integral multiple of said first peak magnitude, in dependence on said mode signals.