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US 6,477,465 B1Granted
Vehicle self-carried positioning method and system thereof
AssigneeAmerican GNC Corporation
InventorsHiram McCall, Ching-Fang Lin
Life of this patent
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Abstract
A vehicle self-carried positioning system, carried in a vehicle, includes an inertial measurement unit, a north finder, a velocity producer, a navigation processor, a wireless communication device, and a display device and map database. Output signals of the inertial measurement unit, the velocity producer, and the north finder are processed to obtain highly accurate position measurements of a vehicle on land and in water, and the vehicle position information can be exchanged with other users through the wireless communication device, and the location and surrounding information can be displayed on the display device by accessing a map database with the vehicle position information.
Claims48
A vehicle self-carried positioning system, comprising:
- an inertial measurement unit, carried in a vehicle, for sensing traveling displacement motions of said vehicle so as to produce digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;
- a north finder, carried in said vehicle, to produce a heading measurement of said vehicle;
- a velocity producer, carried in said vehicle, for producing a current axis velocity data of a body frame of said vehicle;
- and
- a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for
- comparing an IMU position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference;
- and
- feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value;
- wherein said navigation processor further comprises:
- an INS computation module, using said digital angular increments and velocity increments signals from said inertial measurement unit to produce inertial positioning measurements;
- a magnetic sensor processing module for producing a heading angle;
- a vehicle producer processing module for producing relative position error measurements for a Kalman filter;
- and
- an integration Kalman filter for estimating errors of said inertial positioning measurements to calibrate inertial positioning measurement errors;
- wherein said INS computation module further comprises:
- a sensor compensation module for calibrating errors of said digital angular increments and velocity increments signals;
- and
- an inertial navigation algorithm module for computing IMU position, velocity and attitude data;
- wherein said inertial navigation algorithm module further comprises:
- an attitude integration module for integrating said angular increments into said attitude data;
- a velocity integration module for transforming said measured velocity increments into a suitable navigation coordinate frame by using said attitude data, wherein said transformed velocity increments is integrated into said velocity data;
- and
- a position module for integrating said navigation frame velocity data into said position data;
- wherein said velocity producer processing module further comprises:
- a transformation module for transforming an input velocity data expressed in said body frame to a velocity expressed in a navigation frame;
- a scale factor and misalignment error compensation module for compensating scale factor and misalignment errors in said velocity;
- and
- a relative position computation for receiving said IMU velocity and attitude data and compensated velocity to form said relative position error measurements for said Kalman filter;
- wherein said Kalman filter module further comprises:
- a motion test module for determining whether said vehicle stops automatically;
- a measurement and time varying matrix formation module for formulating measurement and time varying matrix for a state estimation module according to motion status of said vehicle from said motion test module;
- and
- a state estimation module for filtering said measurement and obtaining optimal estimates of said IMU position errors.
30 more elements
A vehicle self-carried positioning system, comprising:
- an inertial measurement unit, carried in a vehicle, for sensing traveling displacement motions of said vehicle so as to produce digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;
- a north finder, carried in said vehicle, to produce a heading measurement of said vehicle;
- a velocity producer, carried in said vehicle, for producing a current axis velocity data of a body frame of said vehicle, wherein said velocity producer is an odometer which measures a relative velocity with respect to a ground on which said vehicle travels when said vehicle is a land vehicle;
- and
- a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for
- comparing an IMU position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference;
- and
- feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value.
5 more elements
A vehicle self-carried positioning system, comprising:
- an inertial measurement unit, carried in a vehicle, for sensing traveling displacement motions of said vehicle so as to produce digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;
- a north finder, carried in said vehicle, to produce a heading measurement of said vehicle;
- a velocity producer, carried in said vehicle, for producing a current axis velocity data of a body frame of said vehicle, wherein said velocity producer is a velocimeter which measures a relative velocity with respect to water where said vehicle travels when said vehicle is a water vehicle;
- and
- a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for
- comparing an IMU position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference;
- and
- feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value.
5 more elements
A vehicle self-carried positioning system, comprising:
- an inertial measurement unit, carried in a vehicle, for sensing traveling displacement motions of said vehicle so as to produce digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;
- a north finder, carried in said vehicle, to produce a heading measurement of said vehicle;
- a velocity producer, carried in said vehicle, for producing a current axis velocity data of a body frame of said vehicle;
- and
- a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for
- comparing an IMU position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference;
- and
- feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value;
- wherein said inertial measurement unit is a micro inertial measurement unit which comprises:
- an angular rate producer for producing X axis, Y axis and Z axis angular rate electrical signals;
- an acceleration producer for producing X axis, Y axis and Z axis acceleration electrical signals;
- an angular increment and velocity increment producer for converting said X axis, Y axis and Z axis angular rate electrical signals into digital angular increments and converting said input X axis, Y axis and Z axis acceleration electrical signals into digital velocity increments;
- and
- a thermal controlling means for maintaining a predetermined operating temperature of said angular rate producer, said acceleration producer and said angular increment and velocity increment producer.
11 more elements
A vehicle self-carried positioning system, comprising:
- an inertial measurement unit, carried in a vehicle, for sensing traveling displacement motions of said vehicle so as to produce digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;
- a north finder, carried in said vehicle, to produce a heading measurement of said vehicle;
- a velocity producer, carried in said vehicle, for producing a current axis velocity data of a body frame of said vehicle, wherein said velocity producer is a velocimeter which measures a relative velocity with respect to water where said vehicle travels when said vehicle is a water vehicle;
- and
- a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for
- comparing an IMU position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference;
- and
- feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value;
- wherein said micro IMU comprises a first circuit board, a second circuit board, a third circuit board, and a control circuit board arranged inside a case, said first circuit board being connected with said third circuit board for producing X axis angular sensing signal and Y axis acceleration sensing signal to said control circuit board, said second circuit board being connected with said third circuit board for producing Y axis angular sensing signal and X axis acceleration sensing signal to said control circuit board, said third circuit board being connected with said control circuit board for producing Z axis angular sensing signal and Z axis acceleration sensing signals to said control circuit board, wherein said control circuit board is connected with said first circuit board and then said second circuit board through said third circuit board for processing said X axis, Y axis and Z axis angular sensing signals and said X axis, Y axis and Z axis acceleration sensing signals from said first, second and control circuit board to produce digital angular increments and velocity increments, position, velocity, and attitude solution.
6 more elements
A vehicle self-carried positioning method, comprising the steps of:
- (a) sensing traveling displacement motions of a vehicle and producing digital angular increments and velocity increments signals in response to said traveling displacement motions by an inertial measurement unit;
- (b) sensing magnetic field of the earth to measure a heading angle of said vehicle by a north finder;
- (c) measuring a relative velocity of said vehicle relative to a transportation surface where said vehicle moving thereon by a velocity producer, and
- (d) deducing position data in an integration processor, using said digital angular increments and velocity increments signals, said heading angle, said relative velocity of said vehicle relative to said transportation surface, wherein the deducing step (d) further comprises the steps of:
- (d.1) computing inertial positioning measurements using said digital angular increments and velocity increments signals;
- (d.2) computing said heading angle using said earth's magnetic field measurements;
- (d.3) creating a relative position error measurement in a velocity producer processing module of said navigation processor using said relative velocity of said vehicle relative to said transportation surface for a Kalman filter;
- (d.4) creating a relative position error measurement in said velocity producer processing module using said relative velocity of said user relative to said water for a Kalman filter;
- and
- (d.5) estimating errors of said inertial positioning measurements to calibrate inertial positioning measurement errors;
- wherein the estimating step (d.5) further comprises the steps of:
- (d.5.1) performing motion tests to determine whether said vehicle stops to initiate a zero-velocity update,
- (d.5.2) formulating measurement equations and time varying matrix for said Kalman filter, and
- (d.5.3) computing estimates of error states using said Kalman filter.
11 more elements
A vehicle self-carried positioning method, comprising the steps of:
- (a) sensing traveling displacement motions of a vehicle and producing digital angular increments and velocity increments signals in response to said traveling displacement motions by an inertial measurement unit;
- (b) sensing magnetic field of the earth to measure a heading angle of said vehicle by a north finder;
- (c) measuring a relative velocity of said vehicle relative to a transportation surface where said vehicle moving thereon by a velocity producer, and
- (d) deducing position data in an integration processor, using said digital angular increments and velocity increments signals, said heading angle, said relative velocity of said vehicle relative to said transportation surface, wherein the deducing step (d) further comprises the steps of:
- (d.1) computing inertial positioning measurements using said digital angular increments and velocity increments signals;
- (d.2) computing said heading angle using said earth's magnetic field measurements;
- (d.3) creating a relative position error measurement in a velocity producer processing module of said navigation processor using said relative velocity of said vehicle relative to said transportation surface for a Kalman filter;
- (d.4) creating a relative position error measurement in said velocity producer processing module using said relative velocity of said user relative to said water for a Kalman filter;
- and
- (d.5) estimating errors of said inertial positioning measurements to calibrate inertial positioning measurement errors;
- wherein the computing step (d.1) further comprises said steps of:
- (d.1.1) integrating said angular increments into attitude data;
- (d.1.2) transforming measured velocity increments into a suitable navigation coordinate frame by use of said attitude data, wherein said transferred velocity increments are integrated into velocity data, denoted as velocity integration processing;
- and
- (d.1.3) integrating said navigation frame velocity data into position data, denoted as position integration processing;
- wherein the estimating step (d.5) further comprises the steps of:
- (d.5.1) performing motion tests to determine whether said vehicle stops to initiate a zero-velocity update,
- (d.5.2) formulating measurement equations and time varying matrix for said Kalman filter, and
- (d.5.3) computing estimates of error states using said Kalman filter.
16 more elements
Dependencies are inferred from the claim text.