Method for detecting capacitance between automotive interior components and the human body, sensing device with a capacitance induction layer, and hands-off detectable steering wheel

Abstract

A method for detecting capacitance between an automotive interior component and the human body is provided. The automotive interior component (1) is heated by a metal wire (22) during a heating cycle, the capacitance occupied by the human body is acquired by the metal wire (22) during a sampling cycle, and the occupation status of the automotive interior component (1) is obtained by comparing the capacitance occupied by the human body with a capacitance threshold. The above steps are repeated. A sensing device equipped with a capacitance induction layer (4) and a hands-off detectable steering wheel are further provided. The heating function and capacitance detection function can be realized by a time-division multiplexing method. Furthermore, by increasing the conductive capacitance induction layer (4) within the automotive interior component (1), the induction area can be increased and the sensitivity of capacitance detection can be improved.

Description

[Technical Field]

[0001] This application belongs to the field of automotive technology and specifically relates to a method for detecting capacitance between automotive interior components and the human body, a sensing device equipped with a capacitance induction layer, and a hands-off detectable steering wheel.

[0002] Cross-references of related applications This application claims priority based on a Chinese application filed with the China Patent Office on August 8, 2024, application number 2024110861496, titled "Method for detecting capacitance between automotive interior components and the human body," and a Chinese application filed with the China Patent Office on August 8, 2024, application number 2024110861477, titled "Sensing device with a capacitive induction layer and hands-off detectable steering wheel," the entire contents of which are incorporated by reference into this application. [Background technology]

[0003] In current automotive design, there is a growing demand for intelligent and user-friendly features in automotive interior components. Accurately detecting the occupancy status of interior components (e.g., steering wheel, seat, etc.) by occupants is crucial. Conventional methods for detecting occupancy of automotive interior components often rely on simple mechanical switches or pressure sensors, but these have many limitations. Mechanical switches are prone to wear and tear over time, reducing the reliability of detection. Pressure sensors have poor detection accuracy and response speed, failing to meet the ever-increasing needs of users.

[0004] The occupancy sensor includes a flake substrate and a metal wire placed on the flake substrate. With technological advancements, detection methods based on the capacitance principle have emerged, namely, methods that use the capacitance formed between the sensor metal wire embedded in an automobile interior component and the human body to determine the occupancy status. As shown in Figure 2, C1 in Figure 2 is the induced capacitance generated between the metal wire and the human body.

[0005] However, conventional capacitive detection methods still have room for improvement in terms of sensitivity, and in some complex use cases, misjudgments or response delays can occur, impairing the user experience and the intelligent functions of the vehicle. [Overview of the Initiative]

[0006] In view of the above-mentioned defects or shortcomings in the prior art, the embodiments of this application provide a method for detecting capacitance between an automobile interior component and the human body.

[0007] The capacitance detection method includes steps S100 of setting an occupied capacitance threshold, a sampling period and a heating period; step S200 of heating the automobile interior part with a metal wire during the heating period, installing a human body occupancy sensor inside the automobile interior part, and installing a flake substrate and the metal wire arranged on the flake substrate inside the human body occupancy sensor; step S300 of obtaining the total occupied capacitance of the human body using the human body occupancy sensor during the sampling period, further providing a conductive capacitance induction layer inside the automobile interior part, and obtaining the total occupied capacitance of the human body by the induced capacitance generated between the human body and the metal wire, between the human body and the capacitance induction layer and between the metal wire and the capacitance induction layer; and the human body occupancy Step S400 includes: comparing the total capacitance with the occupied capacitance threshold to obtain a comparison result, the comparison result including a first comparison result and a second comparison result, and if the total occupied capacitance of the human body is greater than or equal to the occupied capacitance threshold, the first comparison result is obtained, and if the total occupied capacitance of the human body is less than the occupied capacitance threshold, the second comparison result is obtained, the first comparison result indicates that the automobile interior part is occupied, and the second comparison result indicates that the automobile interior part is not occupied; step S500 to execute step S200; step S600 to update the total occupied capacitance of the human body and execute steps S300 to S400; and step S700 to repeat steps S500 to S600.

[0008] Optionally, the step of the human body occupancy sensor acquiring the total human body occupancy capacitance at the sampling period includes step S310, which is the step of obtaining the total sampling capacitance based on a first induced capacitance, a second induced capacitance, and a third induced capacitance, wherein the first induced capacitance is the induced capacitance between the human body and the metal wire, the second induced capacitance is the induced capacitance between the human body and the capacitance induction layer, and the third induced capacitance is the induced capacitance between the metal wire and the capacitance induction layer; and step S320, which is the step of obtaining the total human body occupancy capacitance by a capacitance averaging method.

[0009] Optionally, the capacitance induction layer is provided on the side of the metal wire that is spaced apart from the flake substrate.

[0010] Optionally, the capacitance induction layer is provided on either side of the metal wire, and the capacitance induction layer is configured to be weakly conductive and to accept the mapped charge of the metal wire to expand the induction area.

[0011] Optionally, a flake substrate is provided on any side of the metal wire, the flake substrate being made of a non-conductive material, and the capacitance induction layer is provided on the side of the metal wire spaced apart from the flake substrate.

[0012] Optionally, an adhesive layer is provided on the side of the metal wire that is separated from the flake-shaped substrate, and the adhesive layer is made of a weakly conductive conductive adhesive and is the capacitance induction layer.

[0013] Optionally, a first adhesive layer is provided on the side of the metal wire that is spaced apart from the flake-shaped substrate, and a coating layer is provided on the side of the first adhesive layer that is spaced apart from the metal wire, wherein the coating layer is a flexible flake-shaped structure made of a weakly conductive material and is the capacitance induction layer.

[0014] Optionally, the metal wire is bonded to the flake substrate by a second adhesive layer, the second adhesive layer being a weakly conductive conductive adhesive and the capacitance induction layer.

[0015] Optionally, the flake-shaped substrate is weakly conductive and is used as the capacitance induction layer.

[0016] Optionally, a skin is provided on the side of the metal wire that is spaced apart from the flake-shaped substrate, and the skin is made of a weakly conductive material and is the capacitance induction layer.

[0017] Optionally, the weakly conductive material may be obtained by carburizing, printing, immersion in a conductive liquid, electroplating, or by adding conductive fibers to woven fibers.

[0018] Optionally, the sheet resistance of the capacitance induction layer is 10 3 ~10 6 It is Omega.

[0019] Optionally, the capacitance averaging method includes: step S321 setting the number of samples; step S322 obtaining a total capacitance sequence, wherein the total capacitance sequence includes a plurality of the total sampling capacitances, and the number of total sampling capacitances in the total capacitance sequence is the same as the number of samples; and step S323 obtaining the total capacitance occupied by the human body by arithmetic mean of the total capacitance sequence.

[0020] Optionally, the step of updating the total capacitance occupied by the human body includes the steps of: S610, which involves deleting the first sampled total capacitance in the total capacitance sequence and adding the sampled total capacitance obtained in the next sampling period to the end of the total capacitance sequence to obtain the updated total capacitance sequence; S620, which involves obtaining the next total capacitance occupied by the human body by arithmetic mean of the updated total capacitance sequence to be the first total capacitance occupied; and S630, which involves updating the total capacitance occupied by the human body in step S323 to the first total capacitance occupied.

[0021] Optionally, the product of the sum of the sampling period and the heating period and the number of samplings is smaller than a predetermined detection time, whereby the comparison result is obtained at least once within the predetermined detection time.

[0022] Optionally, the duration of the heating period is 2.5 times or more the duration of the sampling period.

[0023] Optionally, the capacitance inducing layer has weak conductivity.

[0024] Optionally, the capacitance inducing layer has strong conductivity, and has a ferroelectric layer between itself and the metal wire.

[0025] The embodiments of the present application further provide a sensing device comprising a capacitance inducing layer. The sensing device comprising the capacitance inducing layer includes a cushion structure, the cushion structure includes a functional layer and an extension layer, the functional layer at least includes a metal wire and an insulating layer, the metal wire is configured for heating and induction, the extension layer is disposed on any side of the metal wire, has weak conductivity, and is configured to receive the mapped electric charge of the metal wire to expand the induction area.

[0026] Optionally, a base material is provided on the first surface on any side of the functional layer, the base material is made of a weakly conductive material and is the extension layer.

[0027] Optionally, a base material is provided on any side of the metal wire, the base material is made of a non-conductive material, and the extension layer is provided on the side of the metal wire facing away from the base material.

[0028] Optionally, an adhesive layer is provided on the side of the metal wire facing away from the base material, the adhesive layer is made of a weakly conductive conductive adhesive and is the extension layer.

[0029] Optionally, a first adhesive layer is provided on the side of the metal wire that is spaced apart from the substrate, and a coating layer is provided on the side of the first adhesive layer that is spaced apart from the metal wire, wherein the coating layer is a flexible flake structure made of a weakly conductive material and is the expansion layer.

[0030] Optionally, the metal wire is bonded to the substrate by a second adhesive layer, the second adhesive layer being the expansion layer and using a weakly conductive adhesive.

[0031] Optionally, the sheet resistance of the extended layer is 10 3 ~10 6 It is Omega.

[0032] Optionally, the sensing device further includes a skin, which is installed on the side of the metal wire spaced apart from the substrate, is made of a weakly conductive material, and is the extended layer.

[0033] Optionally, the weakly conductive material may be obtained by carburizing, printing, immersion in a conductive liquid, electroplating, or by adding conductive fibers to woven fibers.

[0034] Embodiments of this application further provide a hands-off detectable steering wheel. The hands-off detectable steering wheel includes a steering wheel body, and a sensing device having the above-mentioned capacitance induction layer is installed on the surface of the steering wheel body.

[0035] As described above, the embodiment of this application provides a method for detecting capacitance between an automobile interior component and the human body. The automobile interior component is heated with a metal wire during the heating cycle, the total capacitance occupied by the human body is acquired by a human body occupancy sensor having a metal wire during the sampling cycle, and the occupancy status of the automobile interior component is obtained by comparing the total capacitance occupied by the human body with the occupied capacitance threshold. The above steps are repeated and the heating function and capacitance detection function can be realized using a time-division multiplexing method. Furthermore, this application can increase the induction area, i.e., the total capacitance occupied by the human body, by increasing the conductive capacitance induction layer within the automobile interior component, thereby improving the sensitivity of capacitance detection.

[0036] Embodiments of this application provide a sensing device and a hands-off detectable steering wheel equipped with a capacitive induction layer, comprising a functional layer and an expansion layer, wherein the functional layer comprises at least a metal wire and an insulating layer, the metal wire being for heating and induction, and the expansion layer provided on either side of the metal wire, having weak conductivity, and configured to accept the mapped charge of the metal wire and expand the induction area.

[0037] Compared to the prior art, this application has the following beneficial effects. The sensing device equipped with a capacitance induction layer according to this application is installed on a vehicle interior component such as a vehicle seat or steering wheel, and is configured to sense information such as a person sitting or gripping the steering wheel by their hands based on changes in capacitance. By providing a weakly conductive expansion layer above or below the metal wire, capacitance is generated between the metal wire and the human body, between the metal wire and the expansion layer, and between the expansion layer and the human body, increasing the induced capacitance for multi-frequency capacitance detection, improving the sensitivity of the multi-frequency capacitance detection occupation technology, and improving the accuracy of judgment.

[0038] To more clearly describe the technical modes of the embodiments of this disclosure, the drawings used in the embodiments are briefly described below. The drawings described are merely illustrative of some embodiments of this disclosure and do not limit the scope. Those skilled in the art can obtain other relevant drawings based on these drawings without inventive ability. [Brief explanation of the drawing]

[0039] [Figure 1] This is a flowchart of a method for detecting capacitance between an automobile interior component and the human body according to an embodiment of this application. [Figure 2] This is a schematic diagram of a conventional automotive interior component, specifically an automotive seat, that does not have a capacitance induction layer for capacitance detection. [Figure 3] This is a schematic diagram of capacitance detection when a capacitance induction layer is arranged on a metal wire, in the case where the automotive interior component is an automotive seat, according to an embodiment of this application. [Figure 4] This is a schematic diagram of the configuration of the occupied sensor and the capacitance induction layer according to the embodiment of this application. [Figure 5] This is a schematic diagram of capacitance detection according to an embodiment of this application, where the automotive interior component is an automotive seat and the flake substrate is a capacitance induction layer. [Figure 6] This is a schematic diagram of the novel sensor according to the embodiment of this application. [Figure 7] This is a schematic diagram of the metal wire layout according to an embodiment of this application. [Figure 8] This is a schematic diagram of the layout of the metal wire and capacitance induction layer according to an embodiment of this application. [Figure 9] This is a schematic circuit diagram showing the addition of a capacitance induction layer according to the embodiment of this application. [Figure 10] Figure 9 is the equivalent circuit diagram. [Figure 11] This is a schematic exploded view of an automotive interior component, specifically a steering wheel, where a flake substrate is used as a capacitance induction layer. [Figure 12]This is a schematic exploded view of an automotive interior component, specifically a steering wheel, when a capacitive induction layer is added (the flake substrate is made of a non-conductive material). [Figure 13] This is a schematic diagram of a sensing device (where the extended layer is the substrate) equipped with a capacitance induction layer according to an embodiment of this application. [Figure 14] This is a schematic diagram of a sensing device equipped with a capacitance induction layer (where the extended layer is an adhesive layer) according to an embodiment of this application. [Figure 15] This is a schematic diagram of a sensing device equipped with a capacitance induction layer (where the extended layer is the second adhesive layer) according to an embodiment of this application. [Figure 16] This is a schematic diagram showing the configuration when a metal wire according to an embodiment of this application is sewn onto a base material. [Figure 17] This is a schematic diagram showing the configuration when a metal wire is bonded to a substrate according to an embodiment of this application. [Figure 18] This is a schematic diagram of a sensing device equipped with a capacitance induction layer according to an embodiment of this application, when applied to a sheet (the substrate is made of a non-conductive material). [Figure 19] This is a schematic diagram of a sensing device equipped with a capacitive induction layer according to an embodiment of this application, when applied to a sheet (the substrate is an extended layer). [Figure 20] This is a schematic cross-sectional view of a hands-off detectable steering wheel (with an extended layer as the base material) according to an embodiment of this application. [Figure 21] This is a schematic cross-sectional view of a hands-off detectable steering wheel (with an extended layer as the surface) according to an embodiment of this application. [Figure 22] This is a schematic cross-sectional view of a hands-off detectable steering wheel according to an embodiment of this application (where the extended layer is the substrate and has a third adhesive layer and a fourth adhesive layer). [Figure 23] This is a schematic cross-sectional view of a hands-off detectable steering wheel (where the extended layer is an adhesive layer) according to an embodiment of this application. [Modes for carrying out the invention]

[0040] The present application will be described in more detail below with reference to the drawings and embodiments. The specific embodiments described herein are for the purpose of interpreting the relevant application and are not intended to limit it. Also, for the sake of clarity, the drawings show only those relevant to the application.

[0041] As long as there is no contradiction, the embodiments and features described herein can be combined with each other. The present application will be described below using embodiments with reference to the drawings.

[0042] In view of the technical problems mentioned in the background art, embodiments of this application provide a method for detecting capacitance between an automotive interior component and the human body. As shown in Figure 1, the capacitance detection method includes the following steps.

[0043] S100: Sets the occupied capacitance threshold, sampling period, and heating period.

[0044] Optionally, the duration of the heating cycle is 2.5 times or more the duration of the sampling cycle, for example, the heating cycle is 200 milliseconds and the sampling cycle is 20 milliseconds, totaling 0.22 seconds. Occupied capacitance is the capacitance generated between the human body and the interior component of the automobile when the human body touches (occupies) the interior component.

[0045] S200: The automotive interior part 1 is heated by the metal wire 22 in the heating cycle. A human body occupancy sensor 2 is installed inside the automotive interior part 1, and a flake substrate 21 and the metal wire 22 placed on the flake substrate 21 are installed inside the human body occupancy sensor 2.

[0046] The automotive interior component 1 may be an automotive seat, a steering wheel, or another interior component having a heating function and an occupancy detection function. A temperature sensor configured to detect the temperature of the automotive interior component 1 is installed inside the automotive interior component 1.

[0047] S300: The total capacitance occupied by the human body is acquired by the human body occupancy sensor 2 at the sampling period. A conductive capacitance induction layer 4 is further provided within the automobile interior component 1, and the total capacitance occupied by the human body is obtained by the induced capacitance generated between the person and the metal wire 22, between the person and the capacitance induction layer 4, and between the metal wire 22 and the capacitance induction layer 4. Specifically, the following steps are included.

[0048] S310: The total sample capacitance is obtained based on the first induced capacitance, the second induced capacitance, and the third induced capacitance. The first induced capacitance is the induced capacitance between the human body and the metal wire 22, the second induced capacitance is the induced capacitance between the human body and the capacitance induction layer 4, and the third induced capacitance is the induced capacitance between the metal wire 22 and the capacitance induction layer 4. Specifically, the following steps are included.

[0049] S311: Obtain the first induced capacitance between the human body and the metal wire 22.

[0050] The outer layer of the metal wire 22 is coated with enamel insulation, and an insulating protective layer is further provided on the outermost layer of the metal wire 22. The metal wire 22 is sewn onto the flake-shaped base material 21, and due to the limitations of the embroidery process, a certain amount of spacing must be provided between the metal wires 22, resulting in a relatively sparse wiring configuration. As shown in Figure 7, the presence of wiring spacing results in a relatively small effective induction area.

[0051] If the induction area between the occupancy sensor 2 and the human body is S, the thickness of the surface cover 3 of the automobile interior part 1 is d, and the dielectric constant is ε, then the induced capacitance can be calculated using the following formula.

[0052] C=εS / 4πkd∝S / d Equation (2).

[0053] Clearly, capacitance C is directly proportional to induction area S. Because the surface area of ​​the metal wire 22 is relatively small and the wiring is relatively sparse due to process limitations, the effective induction area (S) is very small, and the induced capacitance is only on the order of picofarads (pF), generally around 50pF.

[0054] S312: Obtain the second induced capacitance between the human body and the capacitance induction layer 4.

[0055] Optionally, the capacitance induction layer 4 is provided on the side of the metal wire 22 that is spaced apart from the flake substrate 21.

[0056] Optionally, the capacitance induction layer 4 is provided on any side of the metal wire 22, has weak conductivity, and is configured to induce capacitance and expand the induction area.

[0057] The principle for providing the capacitance induction layer 4 can be understood from the capacitance formula C = εS / 4πkd.

[0058] In the capacitance equation, the meaning of each parameter is as follows: C represents the capacitance of the capacitor, ε represents the dielectric constant of the dielectric material, and the dielectric constant differs depending on the dielectric material (e.g., air, plastic, ceramic, etc.). The dielectric constant of air is close to 1, and certain ceramic materials have relatively high dielectric constants. S represents the opposing area of ​​the two plates of the capacitor, d represents the distance between the two plates of the capacitor, and the smaller the distance between the two plates, the larger the capacitance, and k is the Coulomb constant, which is approximately 9.0 × 10⁻⁶. 9 N·m 2 / C 2 That is the case.

[0059] As can be seen from the capacitance formula above, because the distance between the metal wire 22 and the capacitance induction layer 4 is very small, after the capacitance induction layer 4 is provided, the induction area S increases from the original surface area of ​​the metal wire 22 to the sum of the surface area of ​​the metal wire 22 and the surface area of ​​the capacitance induction layer 4, thereby effectively increasing the induced capacitance.

[0060] Optionally, an insulating layer is further provided on the surface of the metal wire 22, which insulates the metal wire 22 from other structures and prevents leakage current. The insulating layer in this embodiment covers the surface of the metal wire 22. Optionally, the insulating layer is an insulating varnish applied to the surface of the metal wire 22.

[0061] However, although the insulating layer is provided on the metal wire 22, unexpected damage to the insulating layer may occur during processing and use. Since the metal wire 22 may conduct electricity with the capacitance induction layer 4, if electricity conducts between the damaged metal wire 22, it will cause a short circuit. Because the capacitance induction layer 4 has weak conductivity and a very high sheet resistance, even if the insulating layer is damaged, the current between the metal wire 22 at the damaged location is very small, and the amount of heat generated is also very small. This makes it possible to prevent burnout of the sensing device caused by a short circuit when the insulating layer is damaged.

[0062] Optionally, a flake-shaped substrate 21 is provided on any side of the metal wire 22, the flake-shaped substrate 21 is made of a non-conductive material, and the capacitance induction layer 4 is provided on the side of the metal wire 22 that is spaced apart from the flake-shaped substrate 21.

[0063] Optionally, an adhesive layer 8 is provided on the side of the metal wire 22 that is separated from the flake-shaped base material 21, and the adhesive layer 8 is made of a weakly conductive adhesive and is the capacitance induction layer 4. Optionally, if the adhesive layer 8 is a weakly conductive adhesive, during the installation process, release paper coated with the weakly conductive adhesive is used, the release paper is peeled off, and the weakly conductive adhesive is bonded to the side of the metal wire 22 that is separated from the base material 21.

[0064] Optionally, on the side of the metal wire 22 away from the sheet-shaped base material 21, a first adhesive layer 32 is provided, and on the side of the first adhesive layer 32 away from the metal wire 22, a covering layer 31 is provided. The covering layer 31 is a flexible sheet-like structure made of a weakly conductive material, and is the capacitance induction layer 4. Optionally, the flexible sheet-like structure of the covering layer 31 is a foam or a woven fabric made of a weakly conductive material.

[0065] Optionally, the metal wire 22 is adhered to the sheet-shaped base material 21 by a second adhesive layer, and the second adhesive layer uses a weakly conductive conductive adhesive, and is the capacitance induction layer 4.

[0066] With reference to Figure 3, Figure 4, Figure 8 and Figure 12, the capacitance induction layer 4 is any material with high durability and flexibility, including metal cloth, weakly conductive fiber cloth, or containing a weakly conductive component. The capacitance induction layer 4 and the occupancy sensor 2 are two independent layers, but are in close contact with each other, and the gap therebetween is substantially zero. Figure 12 is an exploded view, and in practice, the capacitance induction layer 4 and the metal wire 22 are in close contact with each other. The metal wire 22 is connected to a control module via a wire harness, and the control module stores a program for executing the method for detecting capacitance between an automobile interior component and a human body according to the embodiments of the present application.

[0067] Optionally, the sheet-shaped base material 21 has weak conductivity, and is used as the capacitance induction layer 4.

[0068] Optionally, a skin 7 is disposed on the side of the metal wire 22 away from the sheet-shaped base material 21, the skin 7 is made of a weakly conductive material, and is the capacitance induction layer 4.

[0069] Optionally, the weakly conductive material is obtained by carburization, printing, immersion in a conductive liquid, electroplating, or a method of adding conductive fibers to woven fibers.

[0070] Optionally, the sheet resistance of the capacitance induction layer 4 is 10 3 ~10 6 Ω.

[0071] Referring to Figures 5, 6, 8, and 11, the capacitance induction layer 4 is used as the flap-shaped substrate 21 of the occupancy sensor 2, and the metal wires 22 are directly sewn to the capacitance induction layer 4. This integrates the capacitance induction layer 4 and the occupancy sensor 2, and the resulting integrated component is referred to as a new type of sensor 5 with receiving and expanding functions. The flap-shaped substrate 21 of the new type of sensor 5 is a weakly conductive fiber cloth or any material containing a weakly conductive component that has high durability and flexibility. The capacitance induction layer 4, used as the flap-shaped substrate 21, lies on the same layer as the occupancy sensor 2, and the interlayer distance is zero. Analyzing from the perspective of induction area, filling the entire plane with induced charge by the capacitance induction layer 4 is equivalent to eliminating the gaps between the metal wires 22, thus significantly increasing the induction area.

[0072] S313: The third induced capacitance between the metal wire 22 and the capacitance induction layer 4 is obtained.

[0073] As shown in Figures 9 and 10, C2 represents the second induced capacitance, C3 represents the third induced capacitance, and C1 represents the first induced capacitance. Because the distance between the capacitance induction layer 4 and the metal wire 22 is negligibly small, the loss of charge mapping between them is very small. As can be seen from equation (2), the induced capacitance is inversely proportional to the distance between the capacitance induction layer 4 and the metal wire 22, thereby guaranteeing the induction performance of the capacitance induction layer 4.

[0074] S314: The first induced capacitance, the second induced capacitance, and the third induced capacitance are input into the total capacitance calculation function to obtain the total capacitance.

[0075] The equivalent circuit of the embodiment of this application is shown in Figure 9, and the capacitance calculation function is given by the following formula.

[0076] C=C1+C2×C3 / (C2+C3) Formula (1) Here, C represents the total capacitance, C1 represents the first induced capacitance, C2 represents the second induced capacitance, and C3 represents the third induced capacitance.

[0077] Optionally, the total sampling capacitance may be directly obtained without performing steps S311 to S314, or the first inductive capacitance, the second inductive capacitance, and the third inductive capacitance may be obtained by steps S311 to S314, and the total sampling capacitance may be obtained by calculation.

[0078] The metal wire 22 functions not only as an induction electrode but also as a heater, enabling both capacitance detection and the heating function of the conventional automotive interior component 1.

[0079] S320: The total capacitance occupied by the human body is obtained by the Capacitance Mean Strategy. Specifically, this includes the following steps.

[0080] S321: Set the number of samples.

[0081] S322: Obtain the total capacitance sequence. The total capacitance sequence includes a plurality of the total capacitances of the samples, and the number of total capacitances in the total capacitance sequence is the same as the number of samples.

[0082] Optionally, if the number of samples is four, the capacitance sequence is [C1, C2, C3, C4]. Here, C1 represents the total sampling capacitance obtained in the first sampling, C2 represents the total sampling capacitance obtained in the second sampling, C3 represents the total sampling capacitance obtained in the third sampling, and C4 represents the total sampling capacitance obtained in the fourth sampling.

[0083] S344: The total capacitance occupied by the human body is obtained by arithmetic mean taking the total capacitance sequence.

[0084] In the embodiment of this application, the second and third induced capacitances are added to the prior art, and the total capacitance value obtained by formula (1) is greater than the first induced capacitance. Preferably, the capacitance induction layer 4 is a very dense flexible material similar to a metal plate, and the induction area is much larger than that of the metal wires 22 compared to the sparse wiring method of the metal wires 22, so the second induced capacitance is much larger than the first induced capacitance. Also, the distance between the capacitance induction layer 4 and the metal wires 22 is almost zero, and the third induced capacitance is much larger than the first induced capacitance.

[0085] S400: The total capacitance occupied by the human body is compared with the occupied capacitance threshold to obtain a comparison result. The comparison result includes a first comparison result and a second comparison result. If the total capacitance occupied by the human body is greater than or equal to the occupied capacitance threshold, the first comparison result is obtained. If the total capacitance occupied by the human body is less than the occupied capacitance threshold, the second comparison result is obtained. The first comparison result indicates that the automobile interior part 1 is occupied, and the second comparison result indicates that the automobile interior part 1 is not occupied.

[0086] S500: Step S200 is executed. That is, after capacitance detection, the automotive interior part 1 is heated again.

[0087] S600: Update the total capacitance occupied by the human body and perform steps S300 to S400. Specifically, this includes the following steps.

[0088] S610: The first sampled total capacitance in the total capacitance sequence is deleted, and the sampled total capacitance obtained in the next sampling period is added to the end of the total capacitance sequence to obtain the updated total capacitance sequence. Taking the case where the number of samples is four as an example, the updated total capacitance sequence is [C2, C3, C4, C5]. Here, C5 represents the sampled total capacitance obtained in the fifth sampling.

[0089] S620: The following total capacitance occupied by the human body is obtained by arithmetic mean taking the updated total capacitance sequence, and this is defined as the first total capacitance occupied.

[0090] S630: The total capacitance occupied by the human body in step S344 is updated to the first total capacitance occupied.

[0091] S700: Steps S500 to S600 are repeated. In addition to the initial capacitance detection, the total capacitance occupied by the human body is updated each time capacitance detection is performed thereafter, and then capacitance detection is performed again. This application uses a time-division multiplexing method to alternately execute the capacitance detection function and the heating function, and by adding the capacitance induction layer 4, the induced capacitance can be increased and the detection sensitivity can be improved.

[0092] The test was conducted using an example in which the metal wire 22 is 5.8 meters long, the wiring spacing of the metal wire 22 is 10 mm, the capacitance induction layer 4 is a weakly conductive cloth measuring 0.7 m x 0.4 m, the material of the surface cover 3 is leather, and the thickness of the surface cover 3 is 4 mm. Test data without the capacitance induction layer 4 is shown in Table 1, and test data with the capacitance induction layer 4 added is shown in Table 2.

[0093] Table 1 JPEG2026533926000002.jpg25170

[0094] Table 2 As can be seen by comparing Table 1 and Table 2, the total capacitance increased by 65% ​​when the capacitance induction layer 4 was provided on the metal wire 22 compared to the conventional design, and the total capacitance increased by 73% when the flake substrate 21 was used as the capacitance induction layer 4 compared to the conventional design.

[0095] Optionally, the product of the sum of the sampling period and the heating period and the number of samples is less than a predetermined detection time. This ensures that the comparison result can be obtained at least once within the predetermined detection time.

[0096] Optionally, if the predetermined detection time is 1 or 2 seconds, the heating cycle is 200 milliseconds, and the sampling cycle is 20 milliseconds, totaling 0.22 seconds, then four cycles of heating and capacitance detection can be performed within 1 or 2 seconds, and the occupancy status of the interior components by a human body can be confirmed within 1 or 2 seconds.

[0097] Optionally, the capacitance induction layer 4 is weakly conductive.

[0098] To prevent electrical leakage, the metal wire 22 is covered with an insulating layer, but during the embroidery process, the insulating layer may be damaged by the embroidery equipment or other factors. In this case, if a highly conductive capacitive induction layer 4 is used, there is a risk of short circuits, which may lead to the burning of interior components due to overheating. In contrast, if a weakly conductive material is used, the resistance of the weakly conductive material is 10 3 Ω~10 6 When the resistance is very high (Ω), the current is very small, and the amount of heat generated is also very small. This reduces the risk of product damage.

[0099] Optionally, the capacitance induction layer 4 is ferroconductive, and a ferroelectric layer is provided between the capacitance induction layer 4 and the metal wire 22.

[0100] If the capacitance induction layer 4 has strong conductivity, the sensitivity of the occupancy sensor 2 is higher. However, the metal wire 22 is relatively unsafe because it is prone to short-circuiting by coming into contact with the capacitance induction layer 4 if the insulating layer is damaged, and the conductivity of the capacitance induction layer 4 must be selected according to the actual needs.

[0101] The foregoing describes preferred embodiments and the technical principles used in this application. As those skilled in the art will see, the scope of this application is not limited to technical forms made by specific combinations of the above technical features, but also includes other technical forms made by any combination of the above technical features or equivalent features, without departing from the spirit of the invention. For example, technical forms made by substituting the above features with other technical features having similar functions disclosed in this application.

[0102] Embodiments of this application further provide a sensing device equipped with a capacitive induction layer. The sensing device equipped with a capacitive induction layer includes a functional layer and an extended layer 4, wherein the functional layer includes at least a metal wire 22 and an insulating layer, and the metal wire 22 is for heating and induction. The metal wire 22 here corresponds to the metal wire 22 described above.

[0103] Optionally, the insulating layer insulates the metal wire 22 from other structures, preventing leakage current. The insulating layer in this embodiment covers the surface of the metal wire 22. Optionally, the insulating layer is an insulating varnish applied to the surface of the metal wire 22.

[0104] Optionally, as shown in Figures 13, 18, and 19, the functional layer is a cushioning layer for the sensing device to perform its function. In the capacitance detection occupation technology, which heats a metal wire with a high voltage at certain times and a low voltage at other times by adjusting the voltage duty cycle of the voltage applied to the metal wire, the metal wire 22 performs both a heating function as a heating element and a sensing function as an inductive element. When the metal wire 22 performs its sensing function, the sensing sensitivity in this technology is low because the surface area of ​​the metal wire 22 is small. In view of this, the technology has been improved.

[0105] The functional layer is formed by winding a metal wire 22. The insulating layer is located on the outer layer of the metal wire 22, and the functional layer is a long, layered structure obtained by winding the metal wire 22.

[0106] Optionally, a wire harness 6 is connected to the metal wire 22, and the wire harness 6 is configured to be inserted into the control module of the sensing device.

[0107] The expansion layer 4 is provided on either side of the metal wire 22, has weak conductivity, and is configured to accept the mapped charge of the metal wire 22 and expand the induction area. Here, the expansion layer 4 corresponds to the capacitance induction layer 4 described above.

[0108] The principle for providing the extended layer 4 can be understood from the capacitance equation C = εS / 4πkd.

[0109] In the capacitance equation, the meaning of each parameter is as follows: C represents the capacitance of the capacitor, ε represents the dielectric constant of the dielectric material, and the dielectric constant differs depending on the dielectric material (e.g., air, plastic, ceramic, etc.). The dielectric constant of air is close to 1, and certain ceramic materials have a relatively large dielectric constant. S represents the opposing area of ​​the two plates of the capacitor, d represents the distance between the two plates of the capacitor, the smaller the distance, the larger the capacitance, and k is the Coulomb constant, which is approximately 9.0 × 10⁻⁶. 9 N·m 2 / C 2 That is the case.

[0110] As can be seen from the capacitance formula above, the distance between the metal wire 22 and the expansion layer 4 is very small, so there is almost no loss of charge projected from the metal wire 22 to the expansion layer 4. After the expansion layer 4 is provided, the induction area S increases from the original surface area of ​​the metal wire 22 to the sum of the surface area of ​​the metal wire 22 and the surface area of ​​the expansion layer 4, thereby effectively increasing the induced capacitance.

[0111] However, although the insulating layer is provided on the metal wire 4, unexpected damage to the insulating layer may occur during processing and use. Since the metal wire 22 may conduct electricity with the expansion layer 4, if electricity conducts between the damaged metal wire 22, it will cause a short circuit. Because the expansion layer 4 is weakly conductive and has a very high sheet resistance, even if the insulating layer is damaged, the current between the metal wire 22 at the damaged location is very small, and the amount of heat generated is also very small. This makes it possible to prevent the sensing device from burning out due to a short circuit when the insulating layer is damaged.

[0112] As shown in Figures 13 and 19, a base material 21 is optionally provided on either side of the metal wire 22, and the base material 21 is made of a weakly conductive material and is the expanded layer 4. The base material 21 here corresponds to the flake-shaped base material 21 described above.

[0113] Optionally, a base material 21 is provided on any side of the metal wire 22, the base material being made of a non-conductive material, and the expansion layer 4 is provided on the side of the metal wire 22 that is spaced apart from the base material 21.

[0114] Optionally, as shown in Figure 16, the metal wire 22 is sewn to the base material 21. As shown in Figure 14, when the metal wire 22 is sewn to the base material 21, an adhesive layer 8 is provided on the side of the metal wire 22 that is separated from the base material 21. The adhesive layer 8 adheres the cushion structure, which consists of the functional layer and the expansion layer 4, to the other layers. The adhesive layer 8 is made of a weakly conductive adhesive, and in this case, it is the expansion layer 4.

[0115] Optionally, the adhesive layer 8 is a weakly conductive adhesive, and during the installation process, release paper coated with the weakly conductive adhesive is used, the release paper is peeled off, and the weakly conductive adhesive is bonded to the side of the metal wire 22 that is separated from the base material 21.

[0116] Optionally, if the metal wire 22 is sewn to the base material 21, a flexible flake structure can be added above the metal wire 22 to solve the problem of uneven appearance after the steering wheel is covered, which is caused by the sewing of the metal wire 22. A soft foam or fabric can be used as the flexible flake structure, and this soft foam or fabric, nonwoven fabric, etc., is made of a weakly conductive material.

[0117] As shown in Figure 15, optionally, a non-conductive first adhesive layer 32 is provided on the side of the metal wire 22 that is spaced away from the base material 21, and a coating layer 31 is provided on the side of the first adhesive layer 32 that is spaced away from the metal wire 22. The coating layer 31 is a flexible flake structure made of a weakly conductive material, and in this case, it is the expansion layer 4.

[0118] Optionally, the flexible flake structure of the coating layer 31 is a foam or fabric made of a weakly conductive material.

[0119] Optionally, as shown in Figure 17, the metal wire 22 is bonded to the substrate 21. Optionally, the metal wire 22 is bonded to the substrate 21 by a second adhesive layer, the second adhesive layer being a weakly conductive adhesive, in this case the expansion layer 4.

[0120] Optionally, the weakly conductive material may be obtained by carburizing, printing, immersion in a conductive liquid, electroplating, or by adding conductive fibers to woven fibers.

[0121] Optionally, the sheet resistance of the extended layer 4 is 10 3 ~10 6 It is Omega.

[0122] Optionally, the sensing device further includes a skin 7. The skin 7 is installed on the side of the metal wire 22 that is spaced apart from the base material 21, is made of a weakly conductive material, and is the extended layer 4.

[0123] Optionally, each layer of the sensing device according to this application can be used as an extension layer. The configuration of each layer structure other than the extension layer can be combined with each other and is not limited to the above-described embodiments.

[0124] This embodiment further provides a hands-off detectable steering wheel, the hands-off detectable steering wheel including a steering wheel body, and a sensing device having the above-mentioned capacitance induction layer installed on the surface of the steering wheel body.

[0125] Optionally, the steering wheel body includes a steering wheel armature 9 positioned on the innermost side (furthest from the side gripped by the human body) and a first foam layer 10 covering the steering wheel armature 9. A sensing device equipped with the above-mentioned capacitance induction layer is installed on the side of the first foam layer 10 that is spaced apart from the steering wheel armature 9.

[0126] Optionally, refer to the hands-off detectable steering wheel shown in Figure 20, where the extended layer 4 of the hands-off detectable steering wheel is the base material 21. The base material 21, made of a weakly conductive material, is provided on the side of the metal wire 22 that is spaced apart from the main body, and a second foamed layer 11 is provided on the side of the base material 21 that is spaced apart from the main body, and the second foamed layer 11 is produced by a secondary foaming process.

[0127] Referring to an embodiment of a hands-off detectable steering wheel shown in Figure 21, the extended layer 4 of the hands-off detectable steering wheel is the surface 7 made of a weakly conductive material. In this case, the base material 21 is made of a non-conductive material, and the functional layer is formed by winding the metal wire 22 around the base material 21. A second foam layer 11 is provided on the side of the functional layer spaced apart from the first foam layer 10, and the second foam layer 11 is manufactured by a secondary foaming process.

[0128] Referring to the hands-off detectable steering wheel shown in Figure 22, the expanded layer 4 of the hands-off detectable steering wheel is the base material 21, in which case a third adhesive layer 33 made of a non-conductive material is provided on the side of the first foam layer 10 that is spaced away from the steering wheel armature 9, and the third adhesive layer 33 is for bonding the expanded layer 4 to the main body. The base material 21 is provided on the side of the third adhesive layer 33 that is spaced away from the main body, and the metal wire 22 is wound around the base material 21. The base material 21 further has a fourth adhesive layer 34 on the side that is spaced away from the main body, and the fourth adhesive layer 34 is for bonding the skin 7 to the base material 21.

[0129] Referring to the hands-off detectable steering wheel shown in Figure 23, the extension layer 4 of the hands-off detectable steering wheel is the adhesive layer 8, in which case the base material 21 is made of a non-conductive material and is configured to adhere to and cover the steering wheel body by the third adhesive layer 33. The metal wire 22 is wound around the base material 21, and the adhesive layer 8 is provided on the side of the base material 21 that is spaced apart from the third adhesive layer 33, and the adhesive layer 8 is for adhering the skin 7 to the base material 21, and the skin 7 is made of a non-conductive material.

[0130] In this application, the principles and embodiments of this application will be explained using specific examples. The above description of the examples is merely to facilitate understanding of the methods and core ideas of this application. The above are merely preferred embodiments of this application, and there are limitations to expressing them in words, and objectively, an infinite number of specific structures exist. Those skilled in the art may make some improvements, enhancements or modifications, or combine the above technical features appropriately, provided that they do not deviate from the principles of this application. Any such improvements, enhancements, modifications or combinations, or direct application of the ideas and technical forms of this application to other contexts without improvement, are all within the scope of protection of this application.

[0131] As described above, the embodiments of this application provide a method for detecting capacitance between an automotive interior component and the human body, a sensing device equipped with a capacitance induction layer, and a hands-off detectable steering wheel, which can improve the sensitivity of capacitance detection and thus improve the accuracy of judgment. [Explanation of Symbols]

[0132] 1. Automotive interior parts 2 Occupancy Sensors 21 Piece-shaped base material (base material) 22 Metal wire 3. Surface cover 4. Capacitive induction layer (extended layer) 5 New Sensors 6 Wire Harness 31 Covering layer 32 1st adhesive layer 7 Epidermis 33 Third adhesive layer 34 4th adhesive layer 8 Adhesive layer 9 Skeleton 10. First foam layer 11. Second foam layer

Claims

1. Step S100 involves setting the occupied capacitance threshold, sampling period, and heating period, Step S200 is the process of heating the automobile interior part (1) with a metal wire (22) in the aforementioned heating cycle, installing a human body occupancy sensor (2) inside the automobile interior part (1), and installing a flake substrate (21) and the metal wire (22) placed on the flake substrate (21) inside the human body occupancy sensor (2), Step S300 is obtained by acquiring the total capacitance occupied by the human body using the human body occupancy sensor (2) at the sampling period, and further providing a conductive capacitance induction layer (4) within the automobile interior part (1), and the total capacitance occupied by the human body is obtained by the induced capacitance generated between the human body and the metal wire (22), between the human body and the capacitance induction layer (4), and between the metal wire (22) and the capacitance induction layer (4), Step S400 involves comparing the total capacitance occupied by the human body with the occupied capacitance threshold to obtain a comparison result, and if the comparison result includes a first comparison result and a second comparison result, and the total capacitance occupied by the human body is greater than or equal to the occupied capacitance threshold, then the first comparison result is obtained, and if the total capacitance occupied by the human body is less than the occupied capacitance threshold, then the second comparison result is obtained, and the first comparison result indicates that the automobile interior part (1) is occupied, and the second comparison result indicates that the automobile interior part (1) is not occupied. Step S500 is performed by executing step S200, Step S600 involves updating the total capacitance occupied by the human body and executing steps S300 to S400, Step S700 includes repeating steps S500 to S600. A method for detecting capacitance between an automobile interior component and the human body, characterized by the features described herein.

2. The step of acquiring the total capacitance occupied by the human body using the human body occupancy sensor (2) at the sampling period is as follows: Step S310, where the total sample capacitance is obtained based on the first induced capacitance, the second induced capacitance, and the third induced capacitance, the first induced capacitance being the induced capacitance between the human body and the metal wire (22), the second induced capacitance being the induced capacitance between the human body and the capacitance induction layer (4), and the third induced capacitance being the induced capacitance between the metal wire (22) and the capacitance induction layer (4), The step S320 includes obtaining the total capacitance occupied by the human body by a capacitance averaging method. A method for detecting capacitance between an automobile interior component and a human body, as described in feature 1.

3. The capacitance induction layer (4) is provided on the side of the metal wire (22) that is spaced apart from the flake substrate (21). A method for detecting capacitance between an automobile interior component and a human body, as described in claim 1 or 2.

4. The capacitance averaging method described above is: Step S321 to set the number of samples, Step S322 is to obtain a total capacitance sequence, wherein the total capacitance sequence includes a plurality of the total sample capacitances, and the number of total sample capacitances in the total capacitance sequence is the same as the number of samples, Step S323 includes obtaining the total capacitance occupied by the human body by arithmetic mean averaging the total capacitance sequence. A method for detecting capacitance between an automobile interior component and a human body, as described in claim 2 or 3.

5. The step of updating the total capacitance occupied by the human body is, Step S610 involves deleting the first sampled total capacitance in the total capacitance sequence, adding the sampled total capacitance obtained in the next sampling period to the end of the total capacitance sequence, and obtaining the updated total capacitance sequence. Step S620 involves obtaining the next total capacitance occupied by the human body by arithmetic mean of the updated total capacitance sequence, and setting this as the first total capacitance occupied. Step S630 includes updating the total capacitance occupied by the human body in step S323 to the first total capacitance occupied. The method for detecting capacitance between an automobile interior component and a human body, as described in feature 4.

6. The product of the sum of the sampling period and the heating period and the number of samples is smaller than the predetermined detection time, thereby obtaining the comparison result at least once within the predetermined detection time. A method for detecting capacitance between an automobile interior component and a human body, as described in 4 or 5.

7. The duration of the heating cycle is 2.5 times or more the duration of the sampling cycle. A method for detecting capacitance between an automobile interior component and a human body, as described in any one of claims 1 to 6.

8. The capacitance induction layer (4) has weak conductivity. A method for detecting capacitance between an automobile interior component and a human body, as described in any one of claims 1 to 3.

9. The capacitance induction layer (4) is ferroconductive, and a ferroelectric layer is provided between the capacitance induction layer (4) and the metal wire (22). A method for detecting capacitance between an automobile interior component and a human body, as described in any one of claims 1 to 3.

10. It includes a functional layer and an extension layer (4), The functional layer includes at least a metal wire (22) and an insulating layer, and the metal wire (22) is for heating and induction. The extended layer (4) is provided on either side of the metal wire (22), has weak conductivity, and is configured to accept the mapped charge of the metal wire (1) and expand the induction area. A sensing device equipped with a capacitive induction layer, characterized by the features described above.

11. A base material (21) is provided on either side of the metal wire (22), and the base material (21) is made of a weakly conductive material and is the expanded layer (4). A sensing device comprising a capacitance induction layer as described in feature 10.

12. A base material (21) is provided on any side of the metal wire (22), the base material (21) is made of a non-conductive material, and the expansion layer (4) is provided on the side of the metal wire (22) that is spaced apart from the base material (21). A sensing device comprising a capacitance induction layer as described in feature 10.

13. An adhesive layer (8) is provided on the side of the metal wire (22) that is separated from the base material (21), and the adhesive layer (8) is made of a weakly conductive conductive adhesive, and is the expansion layer (4). A sensing device comprising a capacitance induction layer as described in feature 12.

14. A first adhesive layer (32) is provided on the side of the metal wire (22) that is spaced apart from the base material (21), and a coating layer (31) is provided on the side of the first adhesive layer (32) that is spaced apart from the metal wire (22). The coating layer (31) is a flexible flake structure made of a weakly conductive material and is the expansion layer (4). A sensing device comprising a capacitance induction layer as described in feature 12.

15. The metal wire (22) is bonded to the substrate (21) by a second adhesive layer, and the second adhesive layer is made of a weakly conductive adhesive and is the expansion layer (4). A sensing device comprising a capacitance induction layer as described in feature 12.

16. The sheet resistance of the extended layer (4) is 10 ３ ~10 ６ It is Omega A sensing device comprising a capacitance induction layer according to any one of claims 10 to 15.

17. The sensing device further includes a skin (7), which is installed on the side of the metal wire (22) that is separated from the base material (21), is made of a weakly conductive material, and is the expanded layer (4). A sensing device comprising a capacitance induction layer as described in feature 10.

18. The weakly conductive material is obtained by carburizing, printing, immersion in a conductive liquid, electroplating, or by adding conductive fibers to woven fibers. A sensing device comprising a capacitance induction layer according to feature 11, 14, or 17.

19. A steering wheel capable of detecting hands-off behavior, The hands-off detectable steering wheel includes a steering wheel body, and a sensing device having a capacitance induction layer according to any one of claims 10 to 18 is installed on the surface of the steering wheel body.

Images