초록 ▼

A navigation system 12 for an evasive maneuvering reentry vehicle (EMRV) 10 includes a three-axes strapdown inertial navigator 14 which includes RLGs or other types of gyroscopes and also accelerometers. An altimeter, such as a radar altimeter 16, which is normally provided on the EMRV 10, provides

A navigation system 12 for an evasive maneuvering reentry vehicle (EMRV) 10 includes a three-axes strapdown inertial navigator 14 which includes RLGs or other types of gyroscopes and also accelerometers. An altimeter, such as a radar altimeter 16, which is normally provided on the EMRV 10, provides an output (h) to the navigation system 12, the output being expressive of the altitude of the EMRV 10 from the earth\s surface. The altitude measurement output (h) is processed by a statistical filter, such as a Kalman filter 18, in conjunction with the inertial solution () from the navigator 14. The output of the filter 18 is an estimated inertial correction which is combined with the inertial position and velocity output of the navigator 14 at a block 20 to yield a corrected position and velocity output. It is shown that a single altitude measurement is sufficient to derive three position and three velocity compensations for the EMRV 10.

대표청구항 ▼

In an evasive maneuvering atmospheric reentry vehicle, navigation apparatus comprising: three-axis strap-down inertial navigation means having an output expressive of a position and a velocity of the vehicle; radar altimeter means having an output expressive of an altitude of the vehicle above the s

In an evasive maneuvering atmospheric reentry vehicle, navigation apparatus comprising: three-axis strap-down inertial navigation means having an output expressive of a position and a velocity of the vehicle; radar altimeter means having an output expressive of an altitude of the vehicle above the surface of the earth; Kalman filter means, having a first input coupled to the output of the inertial navigation means and a second input coupled to the output of the altimeter means, for generating an output expressive of an estimated correction to the vehicle position and to the vehicle velocity in accordance with the expression; [Figure] where [KX KX]T are six scalars related to gains of the Kalman filter, (h) is the altimeter means output, is the position output of the inertial navigation means, X is the velocity output of the inertial navigation means, ALT is the inertial navigation means altitude solution, (h-ALT) is a scalar difference between the altimeter means output (h) and the inertial navigation means altitude solution, X is the corrected vehicle position, and X is the corrected vehicle velocity; the navigation apparatus further comprising summation means, having a first input coupled to the output of the navigation means and a second input coupled to the output of the Kalman filter means, for summing the output of the navigation means and the output of the generating means to produce a corrected vehicle position X, a corrected vehicle velocity X and a guidance position error △X, in accordance with △X=(X-).