ICE THICKNESS MEASUREMENT SENSOR

• US 20150260501A1
• Filed: 02/19/2015
• Published: 09/17/2015
• Est. Priority Date: 03/13/2014
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: HA, Man Yeong, GO, Jeung Sang, SON, Changmin, MIN, June Kee
• Granted Patent: US 10,066,923 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64D 15/20 Means for detecting icing or initiating de-icing
• CPC Class Codes: G01B 7/08 using capacitive means
• CPC Class Codes: G01B 7/082 Height gauges

Abstract

An ice thickness measurement sensor 100 is provided to measure the thickness of ice extending from a circuit. The ice thickness measurement sensor comprises at least one capacitive sensor 150. The capacitance of the sensor 150 depends on the thickness of ice covering the sensor, because the presence of the ice changes the permittivity. The ice thickness measurement sensor may be used in a fluid pipe, for example to measure the thickness of ice extending from the inner surface of the pipe.

Claims

1. An ice thickness measurement sensor for measuring the thickness of ice on a surface comprising:

an insulating plate arranged to extend away from the surface from a proximal end to a distal end in use;

a first array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

a second array of electrodes formed on the insulating plate as parallel arms extending from a spine, wherein

the first array of electrodes and the second array of electrodes are interlaced such that an array of capacitors is formed by neighbouring pairs of electrodes from the respective first and second arrays, the array of capacitors forming a capacitive sensor.

2. An ice thickness measurement sensor according to claim 1, further comprising a base portion, wherein:

the insulating plate extends away from a first surface of the base portion; and

the ice thickness measurement sensor is arranged to measure the thickness of ice forming on the first surface of the base portion.

3. An ice thickness measurement sensor according to claim 1, wherein the insulating plate is arranged to extend perpendicularly away from the surface on which the ice thickness is to be measured in use.

4. An ice thickness measurement sensor according to claim 1, wherein the spine of the first array and the spine of the second array extend in a direction that points from the proximal end to the distal end of the insulating plate.

5. An ice thickness measurement sensor according to claim 1, further comprising:

a third array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

a fourth array of electrodes formed on the insulating plate as parallel arms extending from a spine, wherein;

the third array of electrodes and the fourth array of electrodes are interlaced such that a second array of capacitors is formed by neighbouring pairs of electrodes from the respective third and fourth arrays, the second array of capacitors forming a second capacitive sensor; and

a portion of the first array of capacitors is formed closer to the proximal end of the insulating plate than any portion of the second array of capacitors.

6. An ice thickness measurement sensor according to claim 5, further comprising:

a fifth array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

a sixth array of electrodes formed on the insulating plate as parallel arms extending from a spine, wherein;

the fifth array of electrodes and the sixth array of electrodes are interlaced such that a third array of capacitors is formed by neighbouring pairs of electrodes from the respective fifth and sixth arrays, the third array of capacitors forming a third capacitive sensor; and

the third capacitive sensor is formed closer to the proximal end of the insulating plate than the second capacitive sensor.

7. An ice thickness measurement sensor according to claim 1, wherein the electrodes are formed as conductive tracks on the insulating plate.

8. An ice thickness measurement sensor according to claim 1, wherein the electrodes are formed as plates extending perpendicularly from the insulating plate.

9. An ice thickness measurement sensor according to claim 6, wherein:

the insulating plate has two major surfaces separated by a thickness; and

both major surfaces of the insulating plate have the first and second arrays of electrodes, and optionally the third, fourth, fifth and/or sixth arrays of electrodes, formed thereon.

10. An ice thickness measurement sensor according to claim 1, further comprising a thermometer.

11. An ice thickness measurement sensor according to claim 1, further comprising a heater.

12. An ice thickness measurement system comprising:

an ice thickness measurement sensor according to claim 1; and

a measurement circuit for measuring the capacitance across the or each capacitive sensor.

13. An ice thickness measurement system according to claim 12, wherein the measurement circuit comprises a bridge circuit and an AC power supply.

14. A fluid pipe comprising an ice thickness measurement sensor according to claim 1, wherein:

the insulating plate extends away from an inner surface of the fluid pipe, such that the ice thickness measurement sensor is arranged to measure the thickness of ice formed on the inner surface in use.

15. A fluid pipe according to claim 14, wherein the insulating plate extends perpendicularly away from the inner surface of the fluid pipe.

16. A fluid pipe according to claim 14, wherein the fluid pipe is a fuel supply pipe, and the ice thickness measurement sensor is arranged to measure the thickness of any ice that forms out of the fuel in use.

17. A method of measuring the thickness of ice formed on a surface comprising:

providing an ice thickness measurement sensor comprising;

an insulating plate extending away from the surface;

a first array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

a second array of electrodes formed on the insulating plate as parallel arms extending from a spine, wherein

the first array of electrodes and the second array of electrodes are interlaced such that an array of capacitors is formed by neighbouring pairs of electrodes from the respective first and second arrays, the array of capacitors forming a capacitive sensor;

measuring the capacitance of the capacitive sensor; and

determining, from the measured capacitance, the thickness of any ice extending from the surface to cover at least a part of the sensor.

18. A method of measuring the thickness of ice formed on a surface according to claim 17, wherein:

the sensor is further provided with;

a third array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

a fourth array of electrodes formed on the insulating plate as parallel arms extending from a spine; and

the third array of electrodes and the fourth array of electrodes are interlaced such that a second array of capacitors is formed by neighbouring pairs of electrodes from the respective third and fourth arrays, the second array of capacitors forming a second capacitive sensor; and

a portion of the first array of capacitors is formed closer to the surface than any portion of the second array of capacitors; and

the method further comprises;

measuring the capacitance of the second capacitive sensor;

comparing the capacitance of the second sensor with the capacitance of the first sensor; and

determining, from the comparison, whether ice has formed on the sensor itself or from the surface from which the insulating plate extends.

19. A method of measuring the thickness of ice formed on a surface according to claim 17, wherein the step of measuring the capacitance of the sensor comprises:

providing the sensor as one branch of a bridge circuit; and

supplying AC current to the bridge circuit.