Portable Navigation System

• US 20100198511A1
• Filed: 01/27/2010
• Published: 08/05/2010
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• Current Assignee: Trusted Positioning Inc. (TDK Corporation)
• Original Assignee: Trusted Positioning Inc. (TDK Corporation)
• Inventors: Hunter, Andrew, Syed, Zainab, El-Sheimy, Naser, Wright, David Bruce, Goodall, Chris
• Granted Patent: US 9,651,387 B2
• Time in Patent Office: Days
• US Class Current: 701/216
• CPC Class Codes: G01C 21/265 constructional aspects of navigation devices, e.g. housings, mountings, displays G01C21/3688 takes precedence
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01C 21/3626 Details of the output of route guidance instructions traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/52 Determining velocity
• CPC Class Codes: G01S 19/53 Determining attitude

Abstract

A portable navigation module and its method of operation are disclosed for seamlessly providing navigation and positioning information to a user. The module comprises: means, such as a GPS receiver, for receiving a first set of navigational information from an external source, such as satellites; and an inertial sensor unit for generating a second set of navigational information at the module. The navigational information is used by a processor programmed with a core algorithm, to identify the mode of conveyance algorithm and an orientation or misalignment algorithm. The algorithm utilizes the navigational information, aided by the mode of conveyance information and the orientation information, to produce a filtered navigation solution (which comprises position, velocity and attitude). The solution is suitably displayed, preferably on a detachable display unit.

The system has the following attributes: the solution is produced seamlessly, even if one source of navigational information is temporarily out of service; the accuracy of the solution is assisted by use of the mode of conveyance and orientation information; and there is no requirement for the module to be permanently aligned with the direction of movement of the conveyance platform.

Claims

1. A portable navigation system module comprising:

a) a receiver for receiving navigational information from an external source and producing an output of absolute navigational information pertaining to the module, in the form of signals indicative thereof;

b) an assembly of sensors for generating navigational information at the module and producing an output in the form of signals indicative thereof; and

c) a processor coupled to receive the outputs from the receiver and sensor assembly and operative to use the navigational information provided thereby to establish the mode of conveyance of the module and the orientation of the sensors in the form of information indicative thereof, said processor further being operative to use the navigational information derived from the receiver and sensors, the mode of conveyance information and the orientation information to determine and produce a navigation solution.

2. The module as set forth in claim 1 wherein the processor is programmed to use a conveyance algorithm operative to determine the mode of conveyance, an orientation algorithm operative to determine orientation of the sensors and a core algorithm operative to determine a filtered navigation solution.

3. The module as set forth in claim 1 wherein:

the processor uses a core algorithm to process the navigational information and aids the core algorithm using the mode of conveyance and orientation information.

4. The module as set forth in claim 1 wherein:

the processor uses a core algorithm to process the navigational information and aids the core algorithm with platform specific aiding and constraints using the mode of conveyance and orientation information.

5. The module as set forth in claim 1, wherein the processor is operative to produce the navigation solution automatically and seamlessly in the event that the receiver is temporarily inoperative.

6. The module as set forth in claim 1, wherein the receiver is a GPS receiver and the processor is operative to produce the navigation solution automatically and seamlessly.

7. The module as set forth in claim 1 wherein the sensor assembly comprises accelerometer means for measuring module accelerations and gyroscope means for measuring module turning rates.

8. The module as set forth in claim 1 wherein:

the receiver is a GPS receiver;

the sensor assembly comprises means for measuring module accelerations, means for measuring module turning rates, means for measuring magnetic field strength for use in determining module heading and means for measuring pressure at the module for use in determining altitude changes of the module; and

the processor is operative to produce the navigation solution automatically and seamlessly.

9. The module as set forth in claim 1 wherein:

the receiver is a GPS receiver;

the sensor assembly comprises three orthogonal accelerometers for measuring module accelerations, three orthogonal gyroscopes for measuring module turning rates, three orthogonal magnetometers for measuring magnetic field strength for use in determining module heading and a barometer for measuring pressure at the module for use in determining altitude changes of the module; and

the processor is operative to produce the navigation solution seamlessly.

10. The module as set forth in claim 2 wherein:

the core algorithm is an Extended Kalman filter operative to determine and produce seamlessly a filtered navigation solution.

11. A method for producing a navigation solution using a portable navigation system module, comprising:

receiving navigational information at the module from an external source and producing signals indicative thereof;

generating navigational information at the module using sensors and producing signals indicative thereof;

determining the mode of conveyance of the module using navigational information derived from the receiver and sensor signals and producing information indicative thereof;

determining the orientation of the sensors using navigational information derived from the receiver and sensor signals and producing information indicative thereof; and

processing the navigational information, the mode of conveyance information and the orientation information as a composite whole to determine and seamlessly produce a filtered navigation solution pertaining to the module.

12. A method for producing a navigation solution using a portable navigation system module, comprising:

providing and using a composite of navigational information, derived from an external source and measured at the module with sensors, to determine the mode of conveyance of the module and the orientation of the sensors; and

using the composite navigational information, the mode of conveyance information and the orientation information to seamlessly produce a navigation solution pertaining to the module.