US 6,480,152 B2Granted

Integrated GPS/IMU method and microsystem thereof

AssigneeAmerican GNC Corporation

InventorsChing-Fang Lin, Dong An

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Abstract

An integrated Global Positioning System (GPS)/Inertial Measurement Unit (IMU) method and MicroSystem is disclosed, wherein data from an IMU, a MEMS IMU preferred, a GPS chipset, and an earth magnetic field detector are mixed in a mixed GPS/IMU/Magnetic Data microprocessor to achieve a low cost, micro size, and low power consumption mixed GPS/IMU/magnetic position, velocity, and attitude solution. Furthermore, to deal with sensitivity of the MEMS inertial sensors to environment temperature, a temperature based scheduler, error estimator, and a current acting error estimator are co-operated to minimize the mismatching between the filter system modules and the actual ones due to change of environment temperature, so that the system of the present invention can provide high performance and stable navigation solution over a wide range of environment temperature.

Claims14

Dependent claims

An integrated Global Positioning System (GPS)/Inertial Measurement Unit (IMU) microsystem for a carrier, comprising:

an IMU, for producing orthogonal three-axis (X axis, Y axis and Z axis) angular rate signals and orthogonal three-axis (X-axis, Y axis and Z axis) acceleration signals to a mixed GPS/IMU/Magnetic Data Microprocessor through an IMU processing interface;
an Earth's magnetic field detector, for producing said Earth's magnetic field vector measurement signals, including X, Y, Z axes signals of said Earth's magnetic field vector measurement in said body frame of said carrier, to said mixed GPS/IMU/Magnetic Data Microprocessor through a magnetic processing interface;
a GPS chipset, for receiving GPS RF (Radio Frequency) signals and providing GPS measurements, including GPS position and velocity data or GPS raw pseudorange, range rate, and carrier phase measurements and ephemeris and navigation message from is GPS satellites to said mixed GPS/IMU/Magnetic Data Microprocessor through an GPS interface;
wherein said mixed GPS/IMU/Magnetic Data Microprocessor, for computing a mixed GPS/IMU/magnetic position, velocity, attitude and heading solution, by means of combining said three-axis angular rate and three-axis acceleration, said GPS measurements, and said Earth magnetic field vector measurement, in order to provide a rich and accurate motion measurement of said carrier to meet diverse needs;
an user Interface, for exchanging said mixed GPS/IMU/magnetic position, velocity, attitude and heading data with an external user;
and
a power supply and clock module, for providing all voltage and timing signals for other devices of said system of said present invention.

4 more elements

An integrated GPS/IMU method, comprising the steps of:

(a) producing orthogonal three-axis (X axis, Y. axis and Z axis) angular rate signals and orthogonal three-axis (X-axis, Y axis and Z axis) acceleration signals to a mixed GPS/IMU/Magnetic Data Microprocessor through an IMU processing interface by an IMU;
(b) producing said Earth's magnetic field vector measurement signals, including X, Y, Z axes signals of said Earth's magnetic field vector measurement in said body frame of said carrier, to said mixed GPS/IMU/Magnetic Data Microprocessor through a magnetic processing interface, by an Earth's magnetic field detector;
(c) receiving GPS RF (Radio Frequency) signals and providing GPS measurements, including GPS position and velocity data or GPS raw pseudorange, range rate, and carrier phase measurements and ephemeris and navigation message from GPS satellites to said mixed GPS/IMU/Magnetic Data Microprocessor through an GPS interface by a GPS chipset;
(d) computing a mixed GPS/IMU/magnetic position, velocity, attitude and heading solution, by means of combining said three-axis angular rate and three-axis acceleration, said GPS measurements, and said Earth magnetic field vector measurement, in order to provide a rich and accurate motion measurement of said carrier to meet diverse needs, by said mixed GPS/IMU/Magnetic Data Microprocessor;
(e) exchanging said mixed GPS/IMU/magnetic position, velocity, attitude and heading data with an external user, by an user Interface;
and
(f) providing all voltage and timing signals for other devices of said system of said present invention, by a power supply and clock module.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/912,158Filed 20 Jul 2001 · us provisional application
Priority: 20 Jul 2000
Published: US 2002/0021245 A121 Feb 2002
Granted: 12 Nov 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01S 19/47
By combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement: the supplementary…
G01C 21/1654
Combined with non-inertial navigation instruments: with electromagnetic compass
G01S 19/35
Receivers: constructional details or hardware or software details of the signal processing chain
G01S 19/53
The satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting…:…