Fault-tolerant inertial navigation system
First Claim
1. A fault-tolerant inertial navigation system, comprising:
- only two independent inertial navigation units, each of said inertial navigation units performing navigational functions, and each of said inertial navigation units comprising a plurality of single degree of freedom navigational instruments, none of which produce redundant measurements, including at least three linear force sensors and three angular change sensors, any two of said linear sensors and any two of said angular change sensors of either unit aligned other than co-linear; and
, all three of said linear sensors, and all three of said angular change sensors positioned in different planes;
each of said inertial navigation units producing a set of independently derived navigational solutions at each of their respective outputs, said independently derived navigational solutions providing estimates of error parameters indicative of the performance of each sensor in each of said navigation units;
means for comparing said independent navigational solutions of each of said navigation units and detecting any significantly degraded performance of either of said navigation units, by contrasting said estimates of error parameters of each instrument in one navigation unit with the estimates of error parameters in the other navigation unit;
whereby, one of said navigation units indicating such degraded performance, is isolated and identified as to being faulty.
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Accused Products
Abstract
Disclosed herein is a Fault-Tolerant Inertial Navigation System comprising, in a preferred embodiment, a Redundant Set of at least two Inertial Navigation Systems, from which one may identify and isolate at least one instrument within an Inertial Navigation Unit which shows substantial performance degradation. The two inertial navigation units are fully capable of performing navigational functions. Each of these inertial navigation units has a plurality of navigational instruments, including at least three linear sensors (such as accelerometers) and three angular change sensors (such as gyroscopes or ring laser gyroscopes). No two linear sensors nor any two angular change sensors of either unit are aligned colinearly. Each of the inertial navigation units produces a set of independent navigational solutions at each of their respective outputs. The independent navigational solutions of each of the navigation units are compared and any significantly degraded performance of any one linear sensor or any one angular change sensor is detected.
72 Citations
8 Claims
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1. A fault-tolerant inertial navigation system, comprising:
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only two independent inertial navigation units, each of said inertial navigation units performing navigational functions, and each of said inertial navigation units comprising a plurality of single degree of freedom navigational instruments, none of which produce redundant measurements, including at least three linear force sensors and three angular change sensors, any two of said linear sensors and any two of said angular change sensors of either unit aligned other than co-linear; and
, all three of said linear sensors, and all three of said angular change sensors positioned in different planes;each of said inertial navigation units producing a set of independently derived navigational solutions at each of their respective outputs, said independently derived navigational solutions providing estimates of error parameters indicative of the performance of each sensor in each of said navigation units; means for comparing said independent navigational solutions of each of said navigation units and detecting any significantly degraded performance of either of said navigation units, by contrasting said estimates of error parameters of each instrument in one navigation unit with the estimates of error parameters in the other navigation unit; whereby, one of said navigation units indicating such degraded performance, is isolated and identified as to being faulty. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A fault-tolerant inertial navigation system, comprising:
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only two independent inertial navigation units, each of said inertial navigation units measuring at least one of a plurality of navigational variables, such variables including position, velocity, and orientation, and each of said inertial navigation units comprising a plurality of single degree of freedom navigational instruments including at least three linear force sensors and three angular change sensors, any two of said linear sensors and any two of said angular change sensors of either unit aligned other than co-linear; and
, all three of said linear sensors, and all three of said angular change sensors positioned in different planes;each of said inertial navigation units producing a set of independently derived navigational solutions at each of their respective outputs, said independently derived navigational solutions providing estimates of error parameters indicative of the performance of each sensor in each of said navigation units; means for comparing said independent navigational solutions of each of said navigation units and detecting any significantly degraded performance of either of said navigation units, by contrasting said estimates of error parameters of each instrument in one navigation unit with the estimates of error parameters in the other navigation unit; whereby, one of said navigation units, indicating such degraded measurement performance, is isolated and identified as to being faulty.
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Specification