Magnetic wheel sensor for vehicle navigation system

• US 6,446,005 B1
• Filed: 08/13/1999
• Issued: 09/03/2002
• Est. Priority Date: 08/13/1999
• Status: Expired due to Fees

• Current Assignee: GPS Industries LLC (Ingersoll Rand, Inc.)
• Original Assignee: Prolink Inc.
• Inventors: Tekniepe, William, Velasquez, Richard, Bingeman, Kirk
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): To, Tuan C
• Application Number:
  US09/373,556
• Time in Patent Office: 1,117 Days
• Field of Search: 701/215, 701/216, 701/217, 701/213, 701/214, 180/168, 180/167, 377/24.1, 342/357, 342/357.14, 342/107, 342/106, 342/108, 342/457, 342/451, 342/463, 473/407, 473/409, 473/137, 473/169
• US Class Current: 701/215
• CPC Class Codes: A63B 2024/0025 Tracking the path or location of one or more users, e.g. players of a game
• CPC Class Codes: A63B 2071/0691 Maps, e.g. yardage maps or electronic maps
• CPC Class Codes: A63B 2102/32 Golf
• CPC Class Codes: A63B 2220/12 Absolute positions, e.g. by using GPS
• CPC Class Codes: A63B 2220/13 Relative positions
• CPC Class Codes: A63B 2220/14 Geo-tagging, e.g. for correlating route or track location data with specific information related to that specific location
• CPC Class Codes: A63B 2220/16 Angular positions
• CPC Class Codes: A63B 2220/20 Distances or displacements
• CPC Class Codes: A63B 2220/30 Speed
• CPC Class Codes: A63B 2220/36 Speed measurement by electric or magnetic parameters
• CPC Class Codes: A63B 2220/80 Special sensors, transducers or devices therefor
• CPC Class Codes: A63B 2225/30 Maintenance
• CPC Class Codes: A63B 24/0021 Tracking a path or terminating locations
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01P 3/487 delivered by rotating magnets
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS

Abstract

A system is disclosed for determining precise locations of the golf carts on a golf course in real time as the carts are in use during play of the course. Each cart is outfitted with a dead reckoning navigation (DRN) system for determining speed and direction, and a compass for determining heading of the cart during play. With these parameters and a known origin of the cart to which the DRN system has been calibrated, such as location of a tee box, the location of the cart relative to a known feature of the course such as a cup or hazard may be calculated. The DRN system uses a magnetic wheel sensor assembly having a magnetic strip with spaced alternating opposite magnetic poles affixed to the rim of an inside wheel well or mounting fixture therefor of the cart, mounted to confront a Hall effect sensor. During rotation of the wheel and the strip when the cart is moving, the sensor detects passage of the alternating poles, to measure speed and forward or backward direction of the cart. A compass determines heading of the cart. The DRN system allows operation on courses where GPS-based systems cannot maintain LOS, and is periodically calibrated by a known signal, such as a DGPS signal.

Claims

1. A system for determining the precise locations of a plurality of golf carts on a golf course in real time as the golf carts are in use during play of the golf course, comprising:

a base station including apparatus for wireless communication with each of said carts;

each of said carts having a DC electric motor propulsion system, and each of said carts being outfitted with a dead reckoning navigation (DRN) system and a heading detector to fix the location of the respective cart relative to at least one known feature of the golf course to which the respective DRN system has been calibrated;

each said DRN system including a magnetic wheel sensor assembly constructed and adapted for detecting speed and forward-backward direction of the cart and for inhibiting electrical and magnetic fields arising from said motor propulsion system and from other sources external to said magnetic wheel sensor assembly from interference with operation of said magnetic wheel sensor assembly;

each of said carts further including apparatus for wireless communication with said base station including communication of data derived from said DPN system and said heading detector indicative of location of the respective cart relative to said at least one known feature; and

each of said carts having a receiver for receiving differential global positioning system DGPS) signals from earth satellites for re-calibration of the DRN system thereof to said at least one known feature from time to time during each round of play of the golf course, whereby to restore the accuracy of the DRN system upon each re-calibration for relatively accurate determination of real-time location of the respective cart on said golf course.

2. The location determining system of claim 1, wherein said heading detector comprises a floated compass positioned substantially directly above said magnetic wheel sensor assembly on the respective golf cart.

3. The location determining system of claim 2, wherein said floated compass is installed in the roof of the respective golf cart.

4. The location determining system of claim 1, wherein said magnetic sensor assembly comprises a Hall effect sensor and a magnet, wherein said Hall effect sensor is fixed relative to a wheel of the respective golf cart and said magnet is coupled to said wheel for rotation about said Hall effect sensor as said wheel rotates during driving of said golf cart.

5. The location determining system of claim 4, wherein said magnetic sensor assembly further comprises an electrically conductive housing for said Hall effect sensor and connected to said sensor to share the same electrical ground therewith.

6. The location determining system of claim 5, wherein said housing is electrically insulated from the chassis of said golf cart.

7. The location determining system of claim 5, wherein said Hall effect sensor comprises dual Hall effect sensor elements to enable generation of directional signals therefrom indicative of distinguishing movement of said golf cart in forward and backward directions.

8. The location determining system of claim 4, wherein said magnet comprises a magnetic strip with multiple alternating magnetic poles thereon, and said magnetic strip is affixed to a wheel well of said wheel or mounting fixture thereof for passage of said alternating magnetic poles adjacent to said Hall effect sensor as said wheel and said magnetic strip thereon rotates during driving of the respective golf cart about said golf course.

9. The location determining system of claim 8, wherein said Hall effect sensor is positioned to confront said magnetic strip in spaced-apart relation thereto to detect the number of alternating magnetic poles passing by said Hall effect sensor and the direction thereof as said magnetic strip rotates on said wheel during driving of said golf cart.

10. The location determining system of claim 9, wherein said Hall effect sensor is mounted on an axle of said golf cart on which said wheel rotates.

11. The location determining system of claim 10, wherein said Hall effect sensor is mounted above said axle.

12. The location determining system of claim 1, wherein said base station includes display means for observing the locations of said plurality of golf carts from information communicated to said base station by the respective golf carts.

13. Apparatus for installation on a golf cart to calculate the distance from the cart to a golf cup, a hazard, or other feature of a hole of a golf course which has been surveyed so that the location of said golf cup, hazard, or other feature on said hole is known, to enable close approximation of the distance thereto from the lie of a golf ball proximate said cart, said golf cart having access to GPS transmissions solely for calibration of a dead reckoning (DR) navigation system installed on the cart, said apparatus comprising:

a DR wheel sensor assembly for determining speed and direction of said cart relative to a known point of origin of said hole, said assembly including a magnetic strip having a plurality of alternating magnetic poles impressed longitudinally thereon for attachment to a cylindrical wall of a wheel or mounting fixture therefor of said golf cart, and a Hall effect sensor for detecting said alternating magnetic poles during rotation of said wheel when attached in a fixed location on said golf cart in confronting relation to said magnetic strip, to measure speed and forward-backward direction of the golf cart, and further including an electrically conductive housing for said sensor adapted for electrical insulation from the chassis of the golf cart, said housing connected to the sensor to share the same electrical ground therewith, so as to inhibit electrical and magnetic interference with operation of the sensor from the propulsion system of the golf cart or from other sources of electrical or magnetic field.

14. Apparatus according to claim 13, wherein said Hall effect sensor comprises dual Hall effect sensor elements to enable generation of directional signals therefrom indicative of distinguishing movement of said golf cart in forward and backward directions.

15. Apparatus according to claim 13, wherein said access of the cart to GPS transmissions is provided by a GPS receiver for recalibrating the DR navigation system at least once during play of said hole to restore a predetermined level of accuracy to said DR navigation system by substantially removing error buildup arising since the immediately preceding calibration thereof.

16. A golf cart equipped to provide a user of the cart a close approximation of the actual distance from the cart to a golf cup, a hazard, or other feature of known location on a hole of a golf course being played by the cart user, by means of a distance measuring system, a dead reckoning (DR) navigation system, and a OPS receiver for GPS calibration and sporadic re-calibration of said DR system, said distance measuring system, said DR system and said GPS receiver installed on the cart, the DR system comprising a sensor assembly constructed and adapted to determine speed and forward-backward direction of the cart and including portions of said assembly adapted to inhibit electrical and magnetic interference with operation of the sensor of said assembly from the propulsion system of the cart and from other sources of electrical and magnetic fields external to the sensor assembly.