Methods and apparatus for monitoring microrolling processes using embedded sensing

1. An apparatus configured to rotate, comprising:

a geometric shape disposed about a first longitudinal axis, the geometric shape having a first end, a second end, and an outer surface at a radius r from the longitudinal axis, the geometric shape defining at least one void therein, the at least one void disposed along a second longitudinal axis that is (i) substantially parallel to the first longitudinal axis and (ii) situated between the first longitudinal axis and the outer surface, the at least one void not intersecting the outer surface; and

a transducer assembly disposed within the at least one void, the transducer assembly including at least one transducer element constructed and arranged to produce an indication corresponding to pressure distribution applied along the outer surface of the geometric shape.

2. The apparatus of claim 1 , wherein the geometric shape is substantially cylindrical.

3. The apparatus of claim 1 , wherein the at least one transducer element includes a capacitive transducer having a first conductor and a second conductor.

4. The apparatus of claim 3 , further including a dielectric material disposed between the first conductor and the second conductor.

5. The apparatus of claim 3 , wherein a distance between the first conductor and the second conductor changes in response to pressure applied to the outer surface.

6. The apparatus of claim 1 , wherein the outer surface includes a plurality of sections from the first end to the second end, each section including a corresponding transducer element, the plurality of sections being used to produce a spatial and temporal pressure distribution profile.

7. The apparatus of claim 1 , wherein the transducer assembly further includes a transmitter configured to convey the indication from the apparatus.

8. The apparatus of claim 7 , wherein the transmitter is a wireless transmitter.

9. A system for measuring pressure experienced by a rotating apparatus, comprising:

a roller disposed about a first longitudinal axis, the roller having a first end and a second end, and an outer surface at a radius r from the longitudinal axis, the roller defining at least one void therein, the at least one void disposed at a distance d from the outer surface and along a second longitudinal axis that is (i) substantially parallel to the first longitudinal axis and (ii) situated between the first longitudinal axis and the outer surface;

a transducer assembly disposed within the at least one void, the transducer assembly including at least one transducer element constructed and arranged to produce an indication corresponding to pressure distribution applied along the outer surface of the roller; and

a data acquisition module constructed and arranged to receive the indication from the at least one transducer element and to transform the indication into a value corresponding to pressure applied to the outer surface.

10. The apparatus of claim 9 , wherein the at least one transducer element includes a capacitive sensor having a first conductor and a second conductor.

11. The system of claim 9 , wherein the indication is a capacitance, the data acquisition module converts the capacitance to a voltage, and the data acquisition module samples the voltage to produce the indication.

12. The apparatus of claim 9 , wherein the transducer assembly further includes a wireless transmitter configured to transmit the indication from the apparatus.

13. The system of claim 9 , wherein the data acquisition module provides an excitation signal to the one or more transducer elements to determine a characteristic of the one or more transducer elements.

14. The system of claim 13 , wherein the characteristic is a capacitance value.

15. The system of claim 9 , wherein the outer surface consists of a plurality of sections from the first end to the second end, each section having a corresponding sensor element.

16. The system of claim 9 , wherein the data acquisition module uses back-projection to transform the indication into a spatial and temporal pressure distribution profile corresponding to pressure applied to the outer surface from the first end to the second end.

17. A method of determining a spatial and temporal pressure distribution profile on an outer surface of a rotating apparatus disposed about a first axis, comprising:

producing, by a transducer assembly embedded within the rotating apparatus at a distance d from the outer surface of the rotating apparatus, two or more pressure indications along the outer surface parallel to the first axis in response to pressure distribution applied along the outer surface of the rotating apparatus;

sampling, by an acquisition assembly, the two or more pressure indications from the transducer assembly and storing the sampled two or more pressure indications; and

processing the two or more pressure indications to produce the pressure distribution profile describing the pressure applied to the outer surface.

18. The method of claim 17 , the processing further includes back-projecting the one or more pressure indications to calculate the pressure distribution profile.

19. The method of claim 17 , further including converting the one or more pressure indications into an alternative physical parameter.

20. The method of claim 17 , wherein the acquisition assembly is collocated with the rotating apparatus.