Multiplexed fiberoptic gyro control
First Claim
1. A method of controlling a plurality of fiberoptic gyros comprising:
- connecting an undemodulated, non-integrated, preamplified electrical output of each of said gyros to a multiplexing means, said multiplexing means having an output at which an electrical signal from only one of said gyros appears;
connecting said output of said multiplexing means to an input of a gyros controller;
alternately switching, with said multiplexing means, from one gyro output to another in a predetermined sequence;
operating on said electrical signal, after converting said electrical signal to a digital signal, from said one of said gyros with a digital processor to produce a modulation and rate feedback signal, and, optionally, an angular rate signal, an angle signal or both; and
applying said modulation and rate feedback signal to an input of each of said gyros to drive a phase modulator included in each of said gyros.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus and methods are disclosed for the time division multiplexing of fiberoptic gyros to reduce the amount of control electronics required. Each of a plurality of gyros is sampled at a rate of nτ, where τ is the gyro optical transit time and n is an integer. The sampled signal is fed to a digital signal processor (DSP) for processing and used to form a rate feedback signal. The rate feedback signal is converted to analog form to drive the phase modulator drive of each gyro. In preferred embodiments the multiplexed sample rate is at least ten times the bandwidth of the gyros. The rate data can be filtered and output by the DSP and the DSP can integrate the rate data to give angle data. The use of precision analog circuits is avoided.
-
Citations
13 Claims
-
1. A method of controlling a plurality of fiberoptic gyros comprising:
-
connecting an undemodulated, non-integrated, preamplified electrical output of each of said gyros to a multiplexing means, said multiplexing means having an output at which an electrical signal from only one of said gyros appears; connecting said output of said multiplexing means to an input of a gyros controller; alternately switching, with said multiplexing means, from one gyro output to another in a predetermined sequence; operating on said electrical signal, after converting said electrical signal to a digital signal, from said one of said gyros with a digital processor to produce a modulation and rate feedback signal, and, optionally, an angular rate signal, an angle signal or both; and applying said modulation and rate feedback signal to an input of each of said gyros to drive a phase modulator included in each of said gyros.
-
-
2. A method of controlling a plurality of fiberoptic gyros with a single set of multiplexing control electronics, each said gyro providing an undemodulated, non-integrated electrical signal at an output which is fed to an associated preamplifier, comprising:
-
connecting a preamplified signal output of each of said preamplifiers to a multiplexing means, said multiplexing means having an output at which a preamplified signal from only one of said gyros appears; selecting one of said gyros so that said preamplified signal corresponds to its output; gating said preamplifier associated with said one gyro with a gating signal to select portions of said preamplified signals to be passed; connecting said output of said multiplexing means to an input of an analog-to-digital converter; sampling said preamplified signal with said analog-to-digital converter to produce a corresponding digital signal; operating one said digital signal with a digital signal processor to produce a digital modulation and rate feedback signal, said gating signal, and, optionally, an angular rate signal, an angle signal, or both; converting said digital modulation and rate feedback signal to a corresponding analog signal; applying said corresponding analog signal to an input of a phase modulator included in said one of said gyros; repeating the sequence of above steps for each of the remaining gyros in said plurality of gyros; and repeating the sequence of above steps as long as operation of the gyros is desired.
-
-
3. An apparatus for controlling a plurality of fiberoptic gyros, comprising:
-
multiplexing means having a plurality of amplified electrical inputs from said fiberoptic gyros and having an undemodulated, non-integrated, preamplified output at which an electrical signal from only one of said gyros appears; gyro controller means having an input connected to said output of said multiplexing means, for operating on said electrical signal of said one of said gyros with a digital signal processing means to produce a modulation and rate feedback signal, and, optionally, an angular rate signal, an angle signal, or both; and means for applying said modulation and rate feedback signal to an input of each of said gyros to drive a phase modulator included in each of said gyros. - View Dependent Claims (4, 5, 6, 7)
-
-
8. An apparatus for controlling a plurality of fiberoptic gyros, comprising:
-
multiplexing means having a plurality of gated preamplified undemodulated, non-integrated inputs from said fiberoptic gyros and having an output at which an electrical signal from only one of said gyros appears; sampling means having an input connected to said output of said multiplexing means, for converting said electrical signal to a corresponding digital signal at an output; digital signal processing means connected to said output of said sampling means for operating on said digital signal to produce a digital modulation and rate feedback signal at a first output, an angular rate signal as desired at a second output, an angle signal as desired at a third output, and a gating signal at a fourth output for gating said preamplified inputs to said multiplexing means; digital-to-analog conversion means connected to said first output of said digital signal processing means, for converting said digital modulation and rate feedback signal to a corresponding analog signal at an output; and phase modulation drive selection means having an input responsive to said corresponding analog signal for applying said corresponding analog signal to an input of said phase modulator included in said gyro. - View Dependent Claims (9, 10, 11, 12, 13)
-
Specification