WO2022187097A1 - Heater/sensor assembly including a multi-strand wire with both heating and proximity sensing wires - Google Patents

Abstract

A heater/sensor assembly to perform heating of a surface and proximity sensing includes a heater carrier substrate including a first surface and a second surface. A multi-strand wire is arranged in a predetermined pattern adjacent to and in contact with the first surface of the heater carrier substrate, The multi-strand wire includes N heater wires that are insulated; and P proximity sensing wires that are insulated, where N and P are integers greater than zero and wherein the N heater wires and the P proximity sensing wires are wound together.

Description

HEATER/SENSOR ASSEMBLY INCLUDING A MULTI-STRAND WIRE WITH BOTH HEATING AND PROXIMITY SENSING WIRES

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of United States Provisional Application No. 63/156,059 filed on March 3, 2021. The entire disclosure of the application referenced above is incorporated herein by reference.

INTRODUCTION

[0002] The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

[0003] Vehicles such as partially or fully autonomous vehicles may include an autonomous vehicle control system that automatically controls driving of the vehicle under certain conditions. The autonomous vehicle control systems typically include a navigation system, an array of external sensors such as radar or lidar sensors and actuators that control steering, braking and acceleration of the vehicle.

[0004] For partially autonomous vehicles, certain driving situations may require a driver to intervene and/or take over driving of the vehicle. For example, driving on a highway may be handled by the autonomous vehicle control system. Driver intervention may be requested in the event of an accident or construction on the roadway or when the vehicle starts exiting the highway. As a result, the vehicles will likely need to sense whether or not the occupant’s hand or hands are on a steering wheel of the vehicle prior to disengagement of the vehicle control system.

[0005] Sensors located in seats of the vehicle may also be used to detect the presence or absence of an occupant of the vehicle. If an occupant is detected, safety restraints such as air bags and seat belt pretensioners may be selectively enabled or disabled. SUMMARY

[0006] A heater/sensor assembly to perform heating of a surface and proximity sensing includes a heater carrier substrate including a first surface and a second surface. A multi strand wire is arranged in a predetermined pattern adjacent to and in contact with the first surface of the heater carrier substrate, The multi-strand wire includes N heater wires that are insulated; and P proximity sensing wires that are insulated, where N and P are integers greater than zero and wherein the N heater wires and the P proximity sensing wires are wound together.

[0007] In other features, the heater/sensor includes a first non-conductive thread and a second non-conductive thread. The first non-conductive thread and the second non- conductive thread attach the multi-strand wire to the first surface of the heater carrier substrate. The first non-conductive thread and the second non-conductive thread loop around each other at stitch locations passing through the heater carrier substrate. The heater carrier substrate comprises a material selected from a group consisting of foam, felt, woven fabric and knitted fabric.

[0008] In other features, P is equal to one and N is greater than one. P insulation layers covering the P proximity sensing wires are marked differently than N insulation layers covering the N heater wires. Each of the N heater wires includes a single wire and an insulating layer surrounding the single wire. Each of the N heater wires includes multiple wires and an insulating layer surrounding the multiple wires. Each of the P proximity sensing wires includes a single wire and an insulating layer surrounding the single wire. Each of the P proximity sensing wires includes multiple wires and an insulating layer surrounding the multiple wires.

[0009] In other features, the sensor assembly is arranged in a vehicle seat assembly. The N heater wires and the P proximity sensing wires are wound around a core.

[0010] A capacitance measuring system for detecting an occupant of a vehicle includes the heater/sensor assembly. A measurement circuit is configured to output an excitation signal to the measurement circuit and the heater/sensor assembly; measure a resonant frequency of the measurement circuit and the heater/sensor assembly in response to the excitation signal; determine at least one capacitance value based on the resonant frequency; and determine whether a body part is in proximity to the P proximity sensing wires based on the at least one capacitance value. [0011] In other features, the measurement circuit includes an LC tank circuit. An excitation circuit is in communication with the LC tank circuit and is configured to generate the excitation signal that is output to the LC tank circuit. A frequency measurement circuit is in communication with the LC tank circuit and is configured to measure the resonant frequency in response to the excitation signal. A controller is configured to trigger the excitation signal; receive the resonant frequency; determine the capacitance value based on the resonant frequency; and determine whether the body part is in proximity to the P proximity sensing wires based on the capacitance value.

[0012] In other features, a driver circuit is arranged between the LC tank circuit and the N heater wires and is configured to drive the N heater wires in response to the excitation signal. A shield layer is arranged on the second surface of the heater carrier substrate. The shield layer comprises a conductive layer attached to the second surface of the heater carrier substrate. The shield layer comprises a predetermined pattern of conductive thread attached to the second surface of the heater carrier substrate. The shield layer is connected by a capacitor to the N heater wires and the driver circuit.

[0013] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0015] FIG. 1A is a plan view of an example of a steering wheel including a capacitive sensing and heating system with a heater/sensor assembly according to the present disclosure;

[0016] FIG. 1 B is a side view of an example of a seat including a capacitive sensing and heating system with a heater/sensor assembly according to the present disclosure;

[0017] FIG. 2A is a plan view of an example of a heater/sensor assembly according to the present disclosure;

[0018] FIGs. 2B and 2C are perspective view of examples of the heater/sensor assembly including a multi-strand wire with one or more proximity sensing wires and one or more heater wires according to the present disclosure; [0019] FIG. 2D is an enlarged plan view of an example of the heater/sensor assembly according to the present disclosure;

[0020] FIG. 2E is a side cross-sectional view of an example the heater/sensor assembly according to the present disclosure; [0021] FIGs. 3A and 3B illustrate examples of patterns of the multi-strand wire arranged on the heater carrier substrate according to the present disclosure;

[0022] FIG. 4A is a simplified electrical schematic of an example of a capacitive sensing and heating system according to the present disclosure;

[0023] FIG. 4B is a simplified electrical schematic of another example of a capacitive sensing and heating system according to the present disclosure;

[0024] FIG. 5A is a more detailed electrical schematic of an example of a capacitive sensing and heating system according to the present disclosure;

[0025] FIG. 5B is a more detailed electrical schematic of another example of a capacitive sensing and heating system according to the present disclosure; [0026] FIG. 6 is a timing diagram illustrating an example of time multiplexing of heating and capacitive sensing; and

[0027] FIG. 7 is a flowchart illustrating an example of a method for operating a capacitive sensing and heating system according to the present disclosure.

[0028] In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

[0029] The foregoing disclosure relates to proximity sensing involving measurement of capacitance to determine the presence or absence of a hand or other body part of a person adjacent to a surface including a proximity sensor. For example, the proximity sensing may be used in a vehicle to sense a driver’s hand(s) on a steering wheel of a vehicle or an occupant seated in a seat. As can be appreciated, while specific examples are disclosed for illustration, the disclosure relates more generally to the detection of the presence or absence of a person in another location of a vehicle and/or in other non vehicle environments. [0030] In automotive applications, a heating system (such as seat heater, steering wheel heater and/or a heater for another surface) typically includes a multi-strand wire that is attached to a heater carrier substrate. The heater carrier substrate is attached to a surface such as a steering wheel, seating surface or other location.

[0031] When heating is enabled, power is supplied to N heater wires of the multi-strand wire to cause heating of those wires and the surface of the steering wheel or the seat. As will be described further below, the multi-strand wire further includes P proximity sensing wires, where P and N are integers greater than zero. The N heater wires and the P proximity sensor wires can have the same gauge or different gauges. For example, the N heater wires can be larger than the P proximity sensor wires or vice-versa.

[0032] Each wire in the multi-strand wire may include a single wire with an insulating outer cover or a braided wire including an insulating outer cover. The wires of the multi strand wire are wound together. In some examples, the multi-strand wire is attached to a surface-facing side of the heater carrier substrate using one or more non-conductive threads.

[0033] In some examples, the heating system performs time multiplexing between heating and proximity sensing functions. The N heater wires of the multi-strand wire may be used for active shielding during proximity sensing using the P proximity sensing wires to reduce system parasitic capacitance and/or a separate shield may be arranged on a second surface of the heater carrier substrate. The multi-strand wire can be arranged in a desired pattern. Additional multi-strand wires can be used to accommodate different heating zones and/or proximity sensing zones on the surface to be heated.

[0034] In some examples, ends of the P proximity sensing wires are separated from the N heater wires during the assembly process and are connected to a proximity sensing circuit as will be described further below. The N heater wires in the multi-strand wire are used for heating either continuously or time-multiplexed to provide active capacitive shielding.

[0035] In some examples, the multi-strand wire is twisted to assure that one or more proximity sensor wires are facing a surface where proximity sensing is performed. In other examples, the P proximity sensing wires are marked differently than the N heater wires to allow easy identification during the assembly process. For example, different colors, numbers, logos and/or patterns can be used. [0036] As can be appreciated, the heater/sensor assembly according to the present disclosure enables assembly of both the heater wire and the proximity sensing wires in one step, which saves material and machine time.

[0037] Referring now to FIG. 1A, a capacitive sensing and heating system 20 for a steering wheel 22 is shown. The capacitive sensing and heating system 20 includes a capacitive sensing and heating controller 24. In some examples, a switch 28 may be used by a passenger to actuate heating of the steering wheel 22. After sensing the capacitance (or resonant frequency), the capacitance sensing and heating controller 24 may report the results to one or more other vehicle controllers 26 via a vehicle communication bus. In some examples, the sensed capacitance may be used to determine whether or not the driver’s hands are on the steering wheel.

[0038] The steering wheel 22 includes a heater/sensor assembly 42 that is located adjacent to or wrapped around a steering wheel support portion 40. The heater/sensor assembly 42 may define a single heating zone or a plurality of heating zones. Capacitance sensing may also be performed in a single sensing zone or a plurality of sensing zones. The capacitive sensing and heating controller 24 controls timing and the supply of power during heating. The capacitive sensing and heating controller 24 also controls timing and measurement of capacitance during sensing.

[0039] Referring now to FIG. 1 B, a capacitive sensing and heating system 50 for a seat 51 is shown. The seat 51 includes a seat portion 52 and a backrest portion 54. The capacitive sensing and heating system 50 includes a capacitive sensing and heating controller 58. In some examples, a switch 62 may be used by a passenger to actuate heating of the seat 51 .

[0040] In some examples, the switch 28 (FIG. 1A) and the switch 62 (FIG. 1 B) include a physical switch or button. In other examples, the switches 28 and 62 may be accessed via a touchscreen associated with an infotainment system or other input device. In still other examples, the switches 28 and 62 are actuated automatically in conjunction with a heating, ventilation and air conditioning system (FIVAC) (not shown).

[0041] The seat 51 includes a heater/sensor assembly 64 that is located in the seat portion 52. The heater/sensor assembly 64 may include a single zone or a plurality of heating and/or sensing zones. The capacitive sensing and heating controller 58 controls timing and the supply of power during heating. The capacitive sensing and heating controller 58 also controls measurement of capacitance. In some examples, the sensed capacitance may be used to determine whether or not an occupant is located in the seat.

[0042] Referring now to FIGs. 2A-2E, various examples of the heater/sensor assembly 100 are shown. In FIG. 2A, the heater/sensor assembly 100 includes a heater carrier substrate 110 having a first surface and a second surface. A multi-strand wire 114 is arranged on and in contact with the heater carrier substrate 110 in a predetermined pattern.

[0043] The heater/sensor assembly 100 may include a single multi-strand wire or two or more multi-strand wires arranged in zones. In some examples, two or more multi strand wires 114 from two or more zones overlap as shown in FIG. 2A. In other words, two or more multi-strand wires 114 overlap if one multi-strand wire 114 is arranged between any two portions of another multi-strand wire 114. In other examples, the multi strand wires 114 form two or more zones and do not overlap.

[0044] In FIG. 2B, the multi-strand wire 114 is shown to include a core or carrier 117, P proximity sensing wires 116 and N heater wires 118. In some examples, the core or carrier 117 is made of an insulating material. While a single proximity sensor wire is shown for example purposes, additional proximity sensing wires can be used. While N=4 heater wires 118-1 , 118-2, 118-3, and 118-4 are shown for example purposes, additional or fewer heater wires can be used.

[0045] In FIG. 2C, the multi-strand wire 114 is shown to include a center wire 119 (rather than the core or carrier 117), P proximity sensing wires 116 and N heater wires 118. The center wire 119 can be a proximity sensing wire, a heater wire or a wire that is connected to another reference potential. Rather than winding around the center wire 119, all of the wires in the multi-strand wire can be wound together.

[0046] In FIGs. 2D and 2E, the multi-strand wire 114 is attached to the heater carrier substrate 110 by the non-conductive threads 120 and 130 on the first and second surfaces, respectively. In some examples, the non-conductive threads 120 and 130 are sewn in a zig-zag pattern at an obtuse angle with respect to a line perpendicular to a longitudinal length of the multi-strand wire 114. The non-conductive threads 120, 130 loop around each other at stitch locations 134.

[0047] Referring now to FIG. 3A and 3B, examples of different arrangements of the multi-strand wire 114 on the heater carrier substrate 110 are shown. As described above, a single multi-strand wire can be secured by one or more non-conductive threads to the heater carrier substrate 110. Multiple multi-strand wires 114 (such as pairs of multi strand wires 114-1 and 114-2 in FIG. 3A or pairs of multi-strand wires 114-1 , 114-2, ..., and 114-M, where M is an integer greater than 2 in FIG. 3B) can be secured by one or more non-conductive threads to the heater carrier substrate 110. In some examples, multiple zones can be provided on the heater carrier substrate in one direction (e.g. vertically in FIG. 3A) or two or more orthogonal directions (e.g. vertically and horizontally in FIG. 3B).

[0048] In some examples, the N heater wires of the multi-strand wire 114 can be used as a shield layer since they are located immediately below the P proximity sensing wires acting as the proximity sensor. In other examples, a shield (see e.g. FIG. 4B) is arranged below the second or lower surface of the heater carrier substrate 110 to reduce capacitive coupling. In some examples, the shield may include a conductive surface or a pattern of conductive thread or wire attached to the second surface of the heater carrier substrate.

[0049] Referring now to FIG. 4A and 4B, simplified electrical schematics of examples of capacitive sensing and heating systems according to the present disclosure are shown. In FIG. 4A, a capacitive sensing and heating system 150 includes a heater/sensor assembly 151. The heater/sensor assembly 151 includes a P proximity sensing wires 152 and N heater wires 154 as described above. While a single zone circuit will be described below for purposes of illustration and clarity, additional zones can be readily added.

[0050] A heater driver circuit 158 selectively supplies power from a voltage source 160 to the N heater wires 154 to increase a temperature of the steering wheel or seat. When capacitive sensing is desired, the heater driver circuit 158 does not supply power to the N heater wires 154.

[0051] An excitation circuit 170 selectively outputs an excitation signal (such as a square wave or other waveform shape) to a LC tank circuit 172 that is also connected to the P proximity sensing wires 152. In some examples, the excitation signal is also output to the N heater wires 154 via a driver circuit 180. When a passenger’s hands are in the vicinity of the P proximity sensing wires 152, the capacitance of the combined circuit varies. The variation in capacitance, in turn, affects a resonant frequency of the LC tank circuit 172. In some examples, the driver circuit 180 supplies a similar excitation signal to the N heater wires 154 to eliminate the effect of stray capacitance between the P proximity sensing wires 152 and the N heater wires 154 or other grounded structures nearby (since they are at the same voltage potential).

[0052] A frequency measurement circuit 178 measures the resonant frequency of the LC tank circuit 172. A controller 190 controls the timing and operation of heating and capacitance sensing performed by the heater driver 158, the excitation circuit 170 and the frequency measurement circuit 178.

[0053] In FIG. 4B, a shield layer 156 (such as a conductive surface or a pattern of conductive thread or wire) is arranged beneath the heater carrier substrate to reduce the effect of stray capacitance between the P proximity sensing wires 152 and the N heater wires 154 or other grounded structures nearby.

[0054] Referring now to FIGs. 5A and 5B, more detailed electrical schematics for examples of capacitive sensing and heating systems according to the present disclosure are shown. In FIG. 5A, a capacitive sensing and heating system 200 includes a heater/sensor assembly 221. The heater/sensor assembly 221 include P proximity sensing wires 220 and N heater wires 222. A heater controller 208 enables and controls the switch driver 210, which selectively supplies control signals to a high side (FIS) switch 214 and a low side (LS) switch 216. The FIS switch 214 includes a first terminal that is connected to a vehicle battery or other power source. The FIS switch 214 further includes a second terminal that is connected to one end of the N heater wires 222.

[0055] The LS switch 216 includes a first terminal that is connected to an opposite end of the N heater wires 222. The LS switch 216 further includes a second terminal that is connected to the reference potential. Control terminals of the FIS switch 214 and the LS switch 216 are connected to the switch driver 210. In some examples, the switch driver 210 supplies a pulse width modulated (PWM) signal to the FIS switch 214 and the LS switch 216 based upon demand for heating, although other types of modulation can be used.

[0056] An excitation circuit 240 outputs an excitation signal to a LC tank circuit 242 including an inductor Lo and a capacitor Co that are connected in parallel to the excitation circuit 240. First terminals of the inductor Lo and the capacitor Co are connected to a first node 245 that is also connected to the P proximity sensing wires 220. In some examples, a capacitance Ci is connected between second terminals of the inductor Lo and capacitor Co and a reference potential such as ground. The capacitance C1 ensures equal load capacitance for both nodes of the LC tank circuit 242. In some cases this C1 capacitor is not needed and can be omitted

[0057] A driver circuit 246 includes first and second resistors Ri and R2, respectively that are connected in series between the first node 245 and the reference potential. A non-inverting input of an amplifier 234 is connected between the first resistor Ri and the second resistor R2. An inverting input of the amplifier 234 is connected by a third resistor R3 to the reference potential. A fourth resistor R4 is connected from an output of the amplifier 234 to the inverting input of the amplifier 234.

[0058] The output of the amplifier 234 is coupled by a second capacitor C2 to the opposite end of the N heater wires 222 and to a fifth resistor Rs that is also connected to the reference potential. The capacitance C2 connects the driving signal to the N heater wires 222. The resistance Rs ensures the ground DC potential during capacitance sensing.

[0059] During heating of the steering wheel, capacitive sensing is inactive. During capacitive sensing, the HS and LS switches disconnect the N heater wires 222 from power. During capacitive sensing, the capacitance of sensor 220 as well as the capacitance Co and Ci and the inductance Lo forms a parallel LC resonant circuit. The excitation circuit 240 generates the excitation signal causing the parallel LC resonant circuit to oscillate at a resonant frequency determined in part by the capacitance of the P proximity sensing wires 220, Co, Ci and Lo. The resonant frequency is measured by the frequency measurement circuit 244.

[0060] To lower the sensor capacitance between the P proximity sensing wires 220 and the N heater wires 222, the measurement signal is also applied to the N heater wires 222 using the driver circuit 246. The controller 254 controls the switch driver 210, the excitation circuit 240 and the frequency measurement circuit 244.

[0061] In FIG. 5B, a shield layer 224 is arranged on the second surface of the heater carrier substrate and adjacent to the N heater wires 222 to provide additional shielding if needed. The driver circuit 246 is further connected to the shield layer 224 by a third capacitance C3. The driver circuit 246 outputs a signal onto the P proximity sensing wires, the N heater wires 222 and/or the shield layer 224 during excitation and/or frequency measurement to neutralize stray capacitance.

[0062] Referring now to FIG. 6, the controller 254 performs time multiplexing of heater enable and capacitive sensing enable signals. The controller performs heating and capacitive sensing during a period t. The period t includes a first sub-period ti during which heating is performed and a second sub-period t2 during which capacitive sensing is performed. In some examples, the first sub-period ti > the second sub-period t2. In some examples, the first sub-period ti > 85% t and the second sub-period t2 < 15% t, although other values can be used.

[0063] Referring now to FIG. 7, a method 300 for operating a capacitive sensing and heating system according to the present disclosure is shown. At 310, the method determines whether the vehicle is ON. In some examples, the vehicle is ON when an ignition switch or other switch is ON, however other criteria may be used. At 314, the method determines whether heating is enabled. If 314 is true, HS and LS switches are controlled based on heat demand at 318 and the method continues at 320.

[0064] At 320, the method determines whether capacitive sensing is enabled. If 320 is false, the method returns to 310. If 320 is true, the method continues at 324 and opens the HS and LS switches (and close the driver switch shown in FIG. 8). At 328, an excitation signal is output to the LC tank circuit and to the heater (or the heater and the shield layer if used). At 330, the resonant frequency is measured. At 332, the HS and the driver switch are opened (and LS switches is closed or opened). At 334, the resonant frequency is determined.

[0065] At 336, the total capacitance of the circuit is determined. At 340, either the controller or another vehicle controller determines whether the hands of the passengers are on the wheel (or the passenger is located in the seat) based on the calculated capacitance or delta capacitance values. In some examples, the resonant frequency or delta frequency can be used to identify whether or not the passengers hands are on the steering wheel. For example, the resonant frequency can be compared to one or more frequency thresholds or used to index a lookup table.

[0066] Examples of suitable materials for heating or sensing function can be any conductive material having a resistance value that is suitable for the particular application. Examples of materials that can be used for the heater wires and/or proximity sensing wires include copper (Cu), an alloy of copper and nickel (Ni) such as CuNi (2- 10%), other Cu alloys, conductive carbon fiber (for example, Carbotex), conductive fiber, fiber coated with metal such as silver (Ag), Ni and/or Cu, or other suitable materials.

[0067] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

[0068] Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0069] In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

[0070] In this application, including the definitions below, the term “module” or the term “controller” may be replaced with the term “circuit.” The term “module” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0071] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may allow load balancing. In a further example, a server (also known as remote, or cloud) module may accomplish some functionality on behalf of a client module.

[0072] The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules.

[0073] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0074] The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

[0075] The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0076] The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

[0077] None of the elements recited in the claims are intended to be a means-plus- function element within the meaning of 35 U.S.C. §112(f) unless an element is expressly recited using the phrase “means for,” or in the case of a method claim using the phrases “operation for” or “step for.”

Claims

CLAIMS What is claimed is:

1 . A heater/sensor assembly to perform heating of a surface and proximity sensing, comprising: a heater carrier substrate including a first surface and a second surface; a multi-strand wire arranged in a predetermined pattern adjacent to and in contact with the first surface of the heater carrier substrate, wherein the multi-strand wire includes:

N heater wires that are insulated; and P proximity sensing wires that are insulated, where N and P are integers greater than zero and wherein the N heater wires and the P proximity sensing wires are wound together.

2. The heater/sensor assembly of claim 1 , further comprising: a first non-conductive thread; and a second non-conductive thread, wherein the first non-conductive thread and the second non-conductive thread attach the multi-strand wire to the first surface of the heater carrier substrate.

3. The heater/sensor assembly of claim 2, wherein the first non-conductive thread and the second non-conductive thread loop around each other at stitch locations passing through the heater carrier substrate.

4. The heater/sensor assembly of claim 1 , wherein the heater carrier substrate comprises a material selected from a group consisting of foam, felt, woven fabric and knitted fabric.

5. The heater/sensor assembly of claim 1 , wherein P is equal to one and N is greater than one.

6. The heater/sensor assembly of claim 1 , wherein P insulation layers covering the P proximity sensing wires are marked differently than N insulation layers covering the N heater wires.

7. The heater/sensor assembly of claim 1, wherein each of the N heater wires includes a single wire and an insulating layer surrounding the single wire.

8. The heater/sensor assembly of claim 1, wherein each of the N heater wires includes multiple wires and an insulating layer surrounding the multiple wires.

9. The heater/sensor assembly of claim 1, wherein each of the P proximity sensing wires includes a single wire and an insulating layer surrounding the single wire.

10. The heater/sensor assembly of claim 1, wherein each of the P proximity sensing wires includes multiple wires and an insulating layer surrounding the multiple wires.

11. The heater/sensor assembly of claim 1, wherein heater/sensor assembly is arranged in a vehicle seat assembly.

12. The heater/sensor assembly of claim 1, wherein the N heater wires and the P proximity sensing wires are wound around a core.

13. A capacitance measuring system for detecting an occupant of a vehicle, comprising: the heater/sensor assembly of claim 1 ; a measurement circuit configured to: output an excitation signal to the measurement circuit and the heater/sensor assembly; measure a resonant frequency of the measurement circuit and the heater/sensor assembly in response to the excitation signal; determine at least one capacitance value based on the resonant frequency; and determine whether a body part is in proximity to the P proximity sensing wires based on the at least one capacitance value.

14. The capacitive measuring system of claim 13, wherein the measurement circuit includes: an LC tank circuit; an excitation circuit in communication with the LC tank circuit and configured to generate the excitation signal that is output to the LC tank circuit; a frequency measurement circuit in communication with the LC tank circuit and configured to measure the resonant frequency in response to the excitation signal; and a controller configured to: trigger the excitation signal; receive the resonant frequency; determine the capacitance value based on the resonant frequency; and determine whether the body part is in proximity to the P proximity sensing wires based on the capacitance value.

15. The capacitance measuring system of claim 14, further comprising: a driver circuit arranged between the LC tank circuit and the N heater wires and configured to drive the N heater wires in response to the excitation signal.

16. The capacitance measuring system of claim 15, further comprising a shield layer arranged on the second surface of the heater carrier substrate.

17. The capacitance measuring system of claim 16, wherein the shield layer comprises a conductive layer attached to the second surface of the heater carrier substrate.

18. The capacitance measuring system of claim 16, wherein the shield layer comprises a predetermined pattern of conductive thread attached to the second surface of the heater carrier substrate.

19. The capacitance measuring system of claim 16, wherein the shield layer is connected by a capacitor to the N heater wires and the driver circuit.