Dead reckoning based initialization of position and heading using discrete position indicators
A method and system for operating a hand-held computer system for navigation. Embodiments of the present invention includes novel improvements to a navigation method and implementation through a device, which can include inertial and/or magnetic field sensors integrated within a hand held device. The method can include using a single-fix method or a dual-fix method. The single fix method includes monitoring travel distance or time for a pre-specified condition and updating the heading from a dead reckoning process based on a first position fix by using a map. The dual-fix method includes obtaining a second position fix and updating the heading based on the difference in displacement vectors from the dead reckoning process based on the first position fix.
1. A computer implemented method for navigation performed by a hand-held computer system programmed to perform the method comprising:
receiving a first position fix;
storing a starting position;
compute a navigation path using a dead reckoning process, the navigation path having a navigation heading and a dead reckoning displacement vector;
receiving a second position fix;
computing a heading correction using the difference between the dead reckoning displacement vector and a displacement vector based on the second position fix, wherein computing a heading correction using the difference between the dead reckoning displacement vector and a displacement vector based on the second position fix is executed under a dual fix condition; and
updating the navigation heading using the heading correction.
2. The method of claim 1 wherein the first position fix is obtained from a Near Field Communication (NFC) tag, an Indoor Messaging System (IMES) beacon, a Bluetooth Wireless device, or a Wi-Fi access point.
3. The method of claim 1 wherein the hand-held computer system comprises a memory; and wherein storing a starting position comprises storing a starting position in the memory.
4. The method of claim 1 wherein the hand-held computer system includes a physical sensor selected from an accelerometer, a gyroscope, a magnetometer, or a pressure sensor; wherein the dead reckoning process includes computing the navigation path using the physical sensor.
5. The method of claim 1 wherein the second position fix is obtained from a Near Field Communication (NFC) tag, an Indoor Messaging System (IMES) beacon, a Bluetooth wireless device, or a Wi-Fi access point.
6. The method of claim 1 wherein the hand-held computer system includes a display; and wherein updating the navigation heading includes displaying the navigation heading on the display.
7. A computer implemented method for navigation performed by a hand-held computer system programmed to perform the method comprising:
receiving a first position fix;
storing a starting position;
compute a navigation path using a dead reckoning process, the navigation path having a navigation heading and a dead reckoning displacement vector;
monitoring for a pre-specified condition;
receiving a second position fix;
computing a heading correction based on a map upon detection of the pre-specified condition;
computing a heading correction using the difference between the dead reckoning displacement vector and a displacement vector based on the second position fix, wherein computing a heading correction using the difference between the dead reckoning displacement vector and a displacement vector based on the second position fix is executed under a dual fix condition; and
updating the navigation heading using the heading correction.
8. The method of claim 7 wherein the first and second position fixes are obtained from a Near Field Communication (NFC) tag, an Indoor Messaging System (IMES) beacon, a Bluetooth wireless device, or a Wi-Fi access point.
9. The method of claim 7 wherein the hand-held computer system includes a physical sensor selected from an accelerometer, a gyroscope, a magnetometer, or a pressure sensor; wherein the dead reckoning process includes computing the navigation path using the physical sensor.
10. The method of claim 7 wherein the pre-specified condition includes an acceleration condition, an angular rotation condition, a magnetic field condition, or a pressure condition.
11. The method of claim 7 wherein the hand-held computer system comprises a memory; and wherein storing a starting position comprises storing a starting position in the memory.
12. The method of claim 7 wherein the hand-held computer system includes a display; and wherein updating the navigation heading includes displaying the navigation heading on the display.
13. The method of claim 7 wherein computing a heading correction based on a map upon detection of the pre-specified condition is executed in under a single fix condition.