US 12,442,936 B2
Inertial coasting position and velocity solution separation
Kenneth Steven Morgan, St. Petersburg, FL (US); Ruth Dagmar Kreichauf, River Falls, WI (US); and Benjamin Meier, Shakopee, MN (US)
Assigned to Honeywell International Inc., Charlotte, NC (US)
Filed by Honeywell International Inc., Charlotte, NC (US)
Filed on Jan. 13, 2022, as Appl. No. 17/575,250.
Claims priority of provisional application 63/210,442, filed on Jun. 14, 2021.
Prior Publication US 2024/0337762 A1, Oct. 10, 2024
Int. Cl. G01S 19/49 (2010.01); G01S 19/21 (2010.01)
CPC G01S 19/49 (2013.01) [G01S 19/215 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A system comprising:
a plurality of aiding sensors onboard a vehicle, the aiding sensors including a Global Navigation Satellite System (GNSS) receiver, and at least one aiding sensor that comprises an altitude sensor;
an onboard inertial measurement unit (IMU) operative to produce inertial measurements for the vehicle;
a navigation system onboard the vehicle, the navigation system operatively coupled to the aiding sensors and the IMU, the navigation system comprising a main navigation filter and an inertial navigation system (INS) operatively coupled to the main navigation filter, wherein the main navigation filter is operative to receive aiding data from the aiding sensors including GNSS aided data, and the INS is operative to receive inertial data from the IMU and generate an inertial navigation solution for the vehicle; and
an onboard inertial coasting monitor in operative communication with the navigation system, the inertial coasting monitor operative to receive inertial data from the IMU and aiding data from the altitude sensor, the inertial coasting monitor comprising a set of inertial coast sub-filters, the inertial coasting monitor in operative communication with the main navigation filter, wherein each inertial coast sub-filter is aided by the inertial data from the IMU and the aiding data from the altitude sensor, wherein each inertial coast sub-filter provides a navigation solution that has not processed the GNSS aided data for a given number of seconds, wherein the given number of seconds varies for each sub-filter;
wherein the inertial coasting monitor is operative to perform a position detection process or a velocity detection process, or both the position detection process and the velocity detection process;
wherein the position detection process comprises:
compute a position discriminator for each respective inertial coast sub-filter, with the position discriminator defined as a position error separation between the main navigation filter and each respective inertial coast sub-filter;
compute a position threshold for each of the inertial coast sub-filters, with the position threshold defined as a position uncertainty separation between the main navigation filter and each inertial coast sub-filter; and
compare the position discriminator to the position threshold, for each inertial coast sub-filter, to detect if there is a fault in the aiding data;
wherein the velocity detection process comprises:
compute a velocity discriminator for each respective inertial coast sub-filter, with the velocity discriminator defined as a velocity error separation between the main navigation filter and each respective inertial coast sub-filter;
compute a velocity threshold for each of the inertial coast sub-filters, with the velocity threshold defined as a velocity uncertainty separation between the main navigation filter and each inertial coast sub-filter; and
compare the velocity discriminator to the velocity threshold, for each inertial coast sub-filter, to detect if there is a fault in the aiding data.