Electronic compass

• US 6,853,918 B2
• Filed: 05/03/2001
• Issued: 02/08/2005
• Est. Priority Date: 05/03/2000
• Status: Expired due to Fees

• Current Assignee: Sulas Sergio
• Original Assignee: Sulas Sergio
• Inventors: Kozlowski, Janusz, Palangio, Paolo
• Primary Examiner(s): Nguyen, Thu V.
• Application Number:
  US10/275,393
• Publication Number:
  US 20030167122A1
• Time in Patent Office: 1,377 Days
• Field of Search: 701/34, 701/200, 701216-217, 701220-221, 701/224, 702/90, 702 92- 95, 73/17.6, 333/16, 333/19
• US Class Current: 701/224
• CPC Class Codes: G01C 17/30 Earth-inductor compasses
• CPC Class Codes: G01R 33/04 using the flux-gate principle

Abstract

An electronic compass comprises a saturable core sensor (2) with a core (3) made of ferromagnetic material surrounded by an electric winding (3′), a first couple of electric windings (4, 5) around the sensor (2) having reciprocally orthogonal turns, a second couple of electric windings (8, 9) around said first couple (4, 5) having reciprocally orthogonal turns. The gap between the winding (3′) and the first couple of windings (4, 5) and between the first couple of windings (4, 5) and the second couple of windings (8, 9) is filled with a material having a low thermal expansion coefficient, preferably epoxy fiberglass reinforced plastic, supporting the windings of said first (4, 5) and second (8, 9) couple of windings. It is also provided an electronic control circuit (20, 21, 22).

Claims

1. Electronic compass comprising:

electronic control means;

at least a saturable core sensor having a core made of an aluminum ring supporting a coil of amorphous ferromagnetic material, the core being surrounded by an exciting electric winding;

the core sensor comprising;

a first gap, provided between the exciting electric winding and a first couple of windings filled by first rigid means;

wherein

said first couple of windings surrounding and being supported by said first rigid means, have reciprocally orthogonal turns;

a second gap, provided between said first couple of windings and a second couple of windings filled by second rigid means;

wherein

said second couple of windings surrounding and being supported by said second rigid means, have reciprocally orthogonal turns.

2. Electronic compass according to claim 1, wherein said filling means are made of a low thermal expansion coefficient material, preferably epoxy fiberglass reinforced plastic.

3. Electronic compass according to claim 2, wherein there are provided two sensors.

4. Electronic compass according to claim 1, wherein said electronic control means comprise means for determining the real course angle of the vehicle, thus counterbalancing the errors produced by magnetic deviation.

5. Electronic compass according to claim 4, wherein said electronic control means provide means configured to display the data detected by the compass.

6. Electronic compass according to claim 5, wherein said electronic control means comprise at least an analogical/digital converter and a logical unit.

7. Electronic compass according to claim 6, wherein said electronic control means also comprise a memory communicating with the logical unit and a satellite auto-locating unit and in that the logical unit acquires further data from said memory and from said satellite auto-locating unit.

8. Electronic compass according to claim 7, wherein the logical unit is adapted for carrying out at least the following steps:

a) acquire the signals emitted by the aforesaid at least a sensor,

b) settle a course angle and

c) acquire again the signals emitted by said at least a sensor, repeating the aforesaid cycle.

9. Electronic compass according to claim 6, wherein, by determining the course angle, the logical unit is adapted for carrying out at least the further following steps:

a) address the memory through said course angle and acquire from the memory the correction parameters stored in the memory cell addressed through said course angle;

b) obtain the real course angle;

c) acquire again the signals emitted by said at least a sensor, repeating the aforesaid cycle.

10. Electronic compass according to claim 1, wherein through each winding of the second couple of windings a signal having proportional amplitude and opposite direction in relation to the signal emitted by the corresponding winding of the first couple of windings runs.

11. Electronic compass according to claim 1, wherein through said winding a pulse current periodically saturating the core with a frequency of 9.6 kHz, a duration of 5 microseconds and an intensity of 100 A/m runs.

12. Electronic compass according to claim 1, wherein the core sensor is connected to a vehicle by suspension means comprising a couple of suspension oscillating axes placed on overlapping planes to form a composite pendulum having two different oscillating frequencies.

13. Compass according to claim 12, wherein the axes of the core sensor are turned 45°

in relation to said suspension oscillating axes.

14. Electronic compass according to claim 12, wherein the suspension means are configured to counterbalance inclination angles till ±

75°

.

15. Electronic compass according to claim 12, wherein said suspension means comprise the couple of suspension axes made of a non-magnetic material, four ball bearings made of a non-magnetic alloy, a central supporting element of the axes and two supporting elements made of non-magnetic material sustaining said ball bearings.

16. Electronic compass according to claim 15, wherein the suspension axes are made of a copper-tin alloy and the ball bearings are made of a copper-beryllium alloy.