230, for example, on a top face 252 of the second body 230.

The second sensing element 260B is entrenched in the first body 220, as shown in FIG. 3B. For example, the outer surface of the first body 220 can include a groove, and the second sensing element 260B can be installed into the groove to fill the groove. After installed within the groove, a portion of the second sensing element 260B is faces the groove and is positioned internal to the groove, another portion 264 of the second sensing element 260B is exposed outside of the groove and protrudes (e.g., in a direction along the z-axis) beyond the surface of the first body 220 to be exposed outside of the first body 220. For example, the second sensing element 260B can be a lead (such as a lead on a printed circuit board) formed integral with the first body 220 and into the groove, or can be formed separate from the first body 220 and later inserted into the groove of the first body 220.

The third sensing element 260C is embedded within the first body 220, As shown in FIG. 3C. That is, third sensing element 260C is formed integrally with the first body 220, and is positioned internal to the first body 220. An inner surface of the electric insulator 262 surrounds the third sensing element 260C. An outer surface of the electric insulator 262 is surrounded by and is positioned internal to the first body 220, to electrically isolate the third sensing element 260C from the first body 220.

FIG. 4A illustrates an example system 400 that includes an array 402 of NISMSs that detect a contact event with angular misalignment from parallel, according to this disclosure. FIG. 4B illustrates an enlarged view of an array of sensing elements on a contact face of a first body within the system shown in FIG. 4A, according to this disclosure. FIGS. 4A and 4B are described together as FIG. 4. The array 402 of multiple sensing elements 460_1 through 460_4 is a component of an NISMS that detects a contact event with angular misalignment from parallel, according to this disclosure. As shown in FIG. 4, a system 400 includes a first body 420 and a non-conductive second body 430. The first body 420 and the second body 430 can be the same as or similar to corresponding components 120 and 130 of FIG. 1. The second body 430 is composed of an electrically conductive material. The two contact faces 440 and 450 are subject to normal translation, for example, along the y-axis, as the arrows of movement 422 and 432 show.

The multiple NISMS sensing elements 460_1 through 460_4 (generally, 460) are applied (e.g., in the pattern of the array) as the array 402 to one contact face (440 or 450) among a pair of contact faces 440 and 450. Two sensing elements 460 can be used to indicate a closure angle θ (e.g., angle of angular misalignment) between the opposing two contact faces 440 and 450.

The NISMS detects a contact event upon contact made between the two faces contact faces 440 and 450 at a single sensing element 460 or at multiple sensing elements 460 of the array 402 concurrently. That is, the arrayed sensing element 460 will conduct electricity in a closed circuit, indicting local contact event detected. The ammeter 180 and/or voltmeter 190 can measure the electricity conducted in the closed circuit, enabling the NISMS to detect the contact event.

The spatial location of the sensing elements 460 within the array 402 together with a sequence of the conductivity change within the NISMS causes the NISMS to qualitatively indicate an angular deviation from parallel between the contact face pair 440 and 450. For example, the conductivity change can be measured by and output from the ammeter and voltmeter of FIG. 1.

For example, the NISMS can qualitatively indicate an angular misalignment from parallel in a particular direction of rotation. For example, when the third and fourth sensing elements 460_3 and 460_4 conduct electricity in a closed circuit, the NISMS can indicate a rotation of the second contact face 450 about a first hinge line H1, which is formed based on the spatial location of the third and fourth sensing elements 460_3 and 460_4. In this example, the contact events detected concurrently at the third and fourth sensing elements 460_3 and 460_4 (while the remaining sensing elements 460_1 and 460_2 remain open circuited without detection of a contact event) cause the NISMS to output an indicator that the second face 450 is rotated about H1 and offset in the direction of the x-z plane. The table below shows that the NISMS can indicate angular misalignment in the particular direction of rotation about other hinge lines H2, H3, and H4, as shown in Table 1.

TABLE 1

Plane of Angular
Axis of
Contact Event Currently Detected?

Misalignment
Rotation
460_1
460_2
460_3
460_4

y-z
H1
NO
NO
YES
YES

x-y
H2
YES
NO
YES
NO

y-z
H3
NO
YES
NO
YES

y-z
H4
YES
YES
NO
NO

The NISMS can include angular offset between the two contact faces 440 and 450 produces asynchronous continuity for sensing elements 460_1 through 460_4 as the faces make contact. By mapping continuous circuits for sensing elements, as shown in Table 1, a range of motion (ROM) relative angle of the pair of contact faces 440 and 450 can be determined based on which sequence of sensing elements 460_1 through 460_4 are conducting an electric signal.

FIG. 5A illustrates an example system 500 that includes an asymmetrical pattern 502 of NISMSs 510a-510g that detect a contact event with orthogonal translation-induced offset misalignment from parallel, according to this disclosure. FIG. 5B illustrates the asymmetrical pattern of NISMSs on the two contact faces aligned within the system shown in FIG. 5A, viewed according to a point of view plane B-B. FIGS. 5A and 5B are described together as FIG. 5. The system 500 includes at least one continuity NISMS 510A that includes a continuity sensing element 560a positioned on the first contact face 540 at a spatial location that is an origin point 512. The continuity NISMS 510A includes a continuity return element 570a positioned on the second contact face 550 at a spatial location that corresponds to (e.g., is centered about, and that overlaps) the origin point 512. When the two contact faces 540 and 550 physically contact in parallel alignment (without angular misalignment and without offset misalignment), the spatial locations of the continuity sensing element 560a and continuity return element 570a overlap at the origin 512 and electrically connect with each other as an aligned pair of elements. In a scenario where one or both contact faces (e.g., 540 and 550) are non-conducting, one or more aligned pair of elements can be applied to enable such continuity NISMS 510a to generate an electric signal as an indicator of a contact event at the origin 512.

To detect orthogonal translation-induced offset misalignment from parallel, the system 500 includes a plurality of NISMSs 510A-510G arranged such that fewer than all pairs of elements are able to create a conducting circuit upon face contact. For example, the NISMSs 510A-510G within the system 500 include a set of multiple sensing elements 560a-560g of an NISMS arranged in a first pattern 504 on the first contact face 540 of the first body 520, and a set of multiple corresponding return elements 570a-570g arranged on the second contact face 550 of the second body 530 in a second pattern 506 different from the first pattern 504, according to this disclosure. If the two parallel faces 540 and 550 shift orthogonally (e.g., in a direction shown by 2D axes 514) relative to the body translation vector 522 and 532, the sequence (e.g., set) of sensing elements that are conducting an electric signal will change, indicating a translation in the face plane. If the parallel faces 540 and 550 are aligned, as shown in FIG. 5, then the sensing elements 560b-560g and corresponding return elements 570b-570g that form the non-aligned pairs, respectively, will not overlap and will form an open switch that is not conducting an electric signal.

For example, if second contact face 550 shifts orthogonally (e.g., a positive z direction) such that the non-aligned pair of elements 560b and 570b overlaps at the spatial location of the second sensing element 560b, then the second NISMS 510b outputs an electrical signal that is an indicator of orthogonal translation-induced offset misalignment from parallel in the positive z direction. That is, the non-aligned pair of elements 560b and 570b electrically contact each other to conduct an electric signal between the first and second terminals of a power source. The orthogonal shift in the face plane does not disconnect the continuity NISMS 510a, which continues conducting an electrical signal that indicates parallel alignment.

Asymmetrical arrangements of sensing elements cause electric signal generation based on relative translation of faces 540 and 550. Resolution of the angle of misalignment and extent of face translation can be changed based on number and relative location of sensing element pairs.

FIG. 6A illustrates an example system 600 that includes a symmetrical pattern of an NISMS that detects a contact event and determines an orthogonal translation vector as a measurement of offset misalignment from parallel, according to this disclosure. FIG. 6B illustrates the two contact faces aligned within the system shown in FIG. 6A, sharing the same geometric pattern of sensing elements with different element spacing dimensions, viewed according to a point of view plane C-C. FIGS. 6A and 6B are described together as FIG. 6. For example, the plurality of NISMSs 610a-610e includes a geometric pattern 602 of multiple sensing elements 660a-660e that mate with multiple corresponding return elements 670a-670e arranged in the same geometric pattern with a different element spacing dimension. For example, the spacing dimension of the sensing elements 660a-660e can be a first distance d1 between the sensing elements, and the spacing dimension of the return elements 670a-670e can be a second distance d2 between the return elements that is greater than the first distance d1.

For example, the geometric pattern 602 includes an array, which includes a first row, a second row, a first column, a second column, which can be similar to the array pattern in the system 400 of FIG. 4, and can be rotated (e.g., 45°). The geometric pattern 602 additionally includes a center point where an origin 612 of a continuity NISMS 610a (including an aligned pair of elements 660a and 670b) is located, for example, the geometric pattern 602 can resemble 5-points on a rolling-die, or can be referred to as a quincunx pattern. The diameters of the continuity pair of elements 660a and 670b can be different from each other, for example, the diameter of the first return element 670a can be greater than the diameter of the first sensing element 660a. The diameters of the arrayed sensing elements 660b-660e (other than the continuity pair at the origin 613), which form the rows and columns of the array of sensing elements, can be equivalent to each other. The diameters of the arrayed return elements 670b-670e, which form the rows and columns of the array of return elements, can be equivalent to each other, and can be the same as or different from the diameter of the arrayed sensing elements.

To determine an orthogonal translation vector, a specified partial overlap area of a cross sectional area of the arrayed sensing element 660b-660e partially overlaps and is in physical and electrical contact with a corresponding arrayed return element 670b-670e when the two contact faces 640 and 650 are parallel aligned and in physical contact. A reference resistance measurement or reference conductivity measurement can be defined based on the electrical signals generated by the set of arrayed NISMSs 610b-610e partially overlapping, in addition to the electrical signal from the overlap within the continuity NISMS 610a at the origin 613. A translation vector can be determined based on the measured resistance at each NISMS element. The change in resistance measurement (R) is resultant from the changing cross-sectional area of the NISMS elements. For example, the change in resistance measurement (R) is relative to the reference resistance measurement and can be estimated based on Equation 1 below, where R denotes resistance, L denotes length of the material measured, and A denotes a cross-sectional area of the material overlapped.

R≈L/A (1)

In some embodiments, the continuity NISMS 610a maintains a constant (e.g., invariant to translation) contact area, which invariance can be used as a basis upon which to calibration or correct temperature induced resistance change.

FIG. 7 illustrates a front view of a system 700 that includes a sensing element 760 and an abrasion sensing element 780 (also referred to as an abradable resistive element) of an NISMS that detects a contact event and face wear from a conductive second body, according to this disclosure. The abrasion sensing element 780 is composed of an abradable resistive material that reduces cross-sectional length (L) in response to abrasion from physical contact with the second body 730. The abradable resistive material can be carbon-ceramic composite, amorphous carbon, or other material. The second body 730 is composed of conductive material and can be the same as or similar to the second body 130 of FIG. 1. In some embodiments, the second body 730 can be composed of non-conductive material, in which case, a conducting return path can be provided for the second body similar to the return paths associated with the return elements 270a-270c of FIG. 2A.

When the second contact face 750 physically contacts the abrasion sensing element 780 at the first contact face 740, both contact and face wear (e.g., abrasion) can be determined. A length (L) of the abrasion sensing element 780 shortens due to abrasion from a previous length L1 to a current length L2. The change of length (ΔL) of the abrasion sensing element 780 represents a change of length of the first body 720 before face wear to a current length of the shortened first body 720′. The face wear is determined based on a change in resistance of the sensing element 760 that includes the abrasion sensing element 780. The change in resistance (ΔR) of the abrasion sensing element 780 also represents a change in resistance at the spatial location of the sensing element 760. The resistance measurement corresponding to the spatial location of the sensing element 760 can be estimated according to Equation 2, where the change of length (ΔL) of the abrasion sensing element 780 is determined based on L2 subtracted from L2, and where the cross sectional area of the abrasion sensing element 780 is denoted as A. In various embodiments of this disclosure, the cross sectional area of the abrasion sensing element 780 can be equivalent to or greater than the cross sectional area of a lead (composed of lead material) that forms part of the sensing element 760.

ΔR≈ΔL/A (2)

FIG. 8 illustrates a front view of a sensing element 860 and an abradable resistive element 780 of an NISMS that detects a contact event and face wear from a second body 830, according to this disclosure. That is, two contact faces 840 and 850 of the first body 830 and the second body 830 physically contact when the bodies exhibit movement in a direction normal to a face plane. The second body 830 is composed of conductive material and can be the same as or similar to the second body 130 of FIG. 1. For example, the second body 830 is composed of a conductive material, but is unable to support installation of return element onto the second contact face 850. In some embodiments, the second body 830 is unable to support a surface mounted return path installed onto another face of the second body 830, other than the second contact face 850. Installation of the NISMS 810 includes installing (via surface mounting, entrenching, embedding) a return element 870 (onto the first body 820 that also includes the sensing element 780 of FIG. 7 installed. The cross sectional area of the abrasion sensing element 780 can be greater than the cross sectional area of the sensing element 860 that is a lead, and can be greater than the cross sectional area of a second lead 870 that forms a return path 870. In some embodiments, the abradable resistive element 780, which is electrically coupled to both the return path 870 and to the path of the sensing element 860 lead, performs a similar function to both functions of a pair of aligned elements (e.g., 560a and 570a of FIG. 5). The shortened first body 820′ can be shortened similar to the shortened first body 720′ of FIG. 7.

FIG. 9 illustrates an example method 900 for using a normal interface surface mating sensor according to this disclosure. The method 900 can be performed by a computer processor of automated manufacturing system that is configured to install an NISMS onto or embed an NISMS into a first body and/or the second body of FIGS. 1-8. The processor can use or control other components of the automated manufacturing system to perform the method 900, however, for simplicity, the method 900 is described as performed by the processor.

At block 902, the processor provides a power source including a first terminal and a second terminal. At block 904, the processor provides an ammeter connected to the first terminal of the power source to measure electrical current at the first terminal. At block 904, the processor provides a voltmeter connected in parallel with the first terminal and the second terminal of the power source to measure voltage across the power source.

At block 906, the processor provides a plurality of electrically conductive sensing elements coupled to the first terminal of the power source and positioned on a first contact face of a surface of an external first body, flush with the first contact face. The plurality of electrically conductive sensing elements is arranged in a pattern such that a spatial location of each sensing element among the plurality of electrically conductive sensing elements forms a normal interface surface mating sensor (NISMS) that generates an electrical signal when a conductive area on an opposing contact face of an external second body physically contacts the first contact face of the first body at the spatial location of the NISMS.

As part of providing the plurality of sensing elements, at block 908, the processor arranges the plurality of sensing elements in a pattern such that a spatial location of each sensing element among the plurality of electrically conductive sensing elements forms a normal interface surface mating sensor (NISMS). Each NISMS generates an electrical signal when a conductive area on an opposing contact face of an external second body physically contacts the first contact face of the first body at the spatial location of the NISMS.