Systems, methods and apparatuses for continuous in-vehicle and pedestrian navigation
Accelerometers are used to provide acceleration data in 3 dimensions, from which vehicle distance traveled may be calculated during GPS outage using a one step integration of a 3-D pseudo acceleration vector. Magnetometers may also be used in combination with the accelerometers to calculate direction of travel. The system may be utilized for combined in-vehicle navigation and pedestrian navigation applications, and the same hardware is utilized for both system applications.
1 . A method of providing continuous navigation, comprising:
identifying the last known location of an object using, at least in part, a GPS signal; and
estimating a distance travelled by the object from the last known location using only information received from an accelerometer located on a device positioned on the object, wherein estimating the distance is based on a single integration of a three dimensional acceleration vector derived from the accelerometer,
wherein the device is positioned on the object, but receives no other electrical or mechanical inputs from the object.
2 . The method of claim 1 , wherein the object is a vehicle or a pedestrian.
3 . The method of claim 1 , further comprising determining a next location of the object based on information received from the accelerometer and a magnetometer of the device.
4 . The method of claim 1 , further comprising estimating a heading of the object based on a magnetometer located on the device positioned on the object.
5 . The method of claim 1 , further comprising conducting tilt measurements on the accelerometer when the object is not moving.
6 . The method of claim 1 , further comprising normalizing three dimensional data received from the accelerometer, prior to estimating the distance travelled by the object, to generate normalized three dimensional data.
7 . The method of claim 6 , wherein normalizing the three dimensional data received from the accelerometer comprises using quaternion rotation calculations to generate the normalized three dimensional data.
8 . The method of claim 6 , wherein normalizing the three dimensional data received from the accelerometer comprises using tilt measurements of the accelerometer to generate the normalized three dimensional data.
9 . The method of claim 6 , wherein the three dimensional acceleration vector derived from the accelerometer is generated from the normalized three dimensional data.
10 . The method of claim 1 , further comprising filtering the three dimensional acceleration vector derived from the accelerometer prior to the single integration of a three dimensional acceleration vector.
11 . The method of claim 1 , further comprising determining if the object is moving by filtering the three dimensional acceleration vector.
12 . The method of claim 1 , further comprising determining whether global positioning system (GPS) signals are available subsequent to estimating a distance travelled by the object.
13 . The method of claim 12 , further comprising calculating regression, when GPS signals are available, between the estimated distance travelled by the object and an estimated GPS distance travelled determined from the GPS signals.
14 . A computer-readable medium having stored thereon computer-executable instructions for performing the method of claim 1 .
15 . A device positioned on an object, for providing continuous navigation, comprising:
an accelerometer; and
at least one computer program operable to:
identify the last known location of the object using, at least in part, a GPS signal; and
estimate a distance travelled by the object from the last known location using only information received from the accelerometer, wherein estimating the distance is based on a single integration of a three dimensional acceleration vector derived from the accelerometer,
wherein the device is positioned on the object, but receives no other electrical or mechanical inputs from the object.
16 . The device of claim 15 , wherein the object is a vehicle or a pedestrian.
17 . The device of claim 15 , further comprising a magnetometer, and wherein the at least one computer program is further operable to determine a next location of the object based on information received from the accelerometer and a magnetometer of the device.
18 . The device of claim 15 , further comprising a magnetometer, and wherein the at least one computer program is further operable to estimate a heading of the object.
19 . The device of claim 15 , wherein the at least one computer program is further operable to conduct tilt measurements on the accelerometer when the object is not moving.
20 . The device of claim 15 , wherein the at least one computer program is further operable to normalize three dimensional data received from the accelerometer, prior to estimating the distance travelled by the object, to generate normalized three dimensional data.
21 . The device of claim 20 , wherein the at least one computer program is further operable to normalize the three dimensional data using quaternion rotation calculations.
22 . The device of claim 20 , wherein the at least one computer program is further operable to normalize the three dimensional data using tilt measurements of the accelerometer.
23 . The device of claim 20 , wherein the at least one computer program is further operable to generate the three dimensional acceleration vector, derived from the accelerometer, from the normalized three dimensional data.
24 . The device of claim 15 , wherein the at least one computer program is further operable to filter the three dimensional acceleration vector derived from the accelerometer prior to the single integration of a three dimensional acceleration vector.
25 . The device of claim 15 , wherein the at least one computer program is further operable to determine if the object is moving by filtering the three dimensional acceleration vector.
26 . The device of claim 15 , wherein the at least one computer program is further operable to determine whether global positioning system (GPS) signals are available subsequent to estimating a distance travelled by the object.
27 . The device of claim 26 , wherein the at least one computer program is further operable to calculate regression, when GPS signals are available, between the estimated distance travelled by the object and an estimated GPS distance travelled determined from the GPS signals.