Capacitive sensing system and steering wheel

Abstract

The utility model provides a capacitive sensing system and a steering wheel, and relates to the technical field of vehicles. The capacitive sensing system comprises a lamination layer used for coating a framework, the lamination layer comprises a sensor layer, a first insulating layer, a shielding layer, a second insulating layer and a heating layer which are arranged in sequence, the first insulating layer and / or the second insulating layer are polyethylene insulating layers, and the capacitive sensing system can solve the problem of coating difficulty.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a capacitive sensing system and a steering wheel. Background Technology

[0002] Hands-off detection (HOD) is a technology that monitors whether the driver has their hands on the steering wheel. It is mainly used in driver assistance functions to ensure that the driver has control of the vehicle in an assisted driving state.

[0003] Currently, steering wheels that use hands-off detection technology generally have an insulating layer, which is mostly made of TPU material. However, due to the poor tensile properties of TPU material, it may cause difficulties in covering the steering wheel. Utility Model Content

[0004] The purpose of this application includes, for example, providing a capacitive sensing system that can solve the problem of difficult steering wheel wrapping.

[0005] The purpose of this application also includes, for example, providing a steering wheel that can solve the problem of difficult wrapping.

[0006] The embodiments of this application can be implemented as follows:

[0007] In a first aspect, embodiments of this application provide a capacitive sensing system comprising a stack for covering the frame, the stack comprising a sensor layer, a first insulating layer, a shielding layer, a second insulating layer and a heating layer arranged sequentially, wherein the first insulating layer and / or the second insulating layer are polyethylene insulating layers.

[0008] Optionally, the first insulating layer is a polyethylene insulating layer and the thickness of the first insulating layer is greater than the thickness of the second insulating layer, or the second insulating layer is a polyethylene insulating layer and the thickness of the first insulating layer is less than the thickness of the second insulating layer.

[0009] Optionally, the stacked layers satisfy: T1 / D1≤0.6;

[0010] Wherein, T1 is the thickness of the first insulating layer or the second insulating layer, and D1 is the distance between the surface of the sensor layer facing the first insulating layer and the surface of the heating layer facing the second insulating layer.

[0011] Optionally, the thickness of the first insulating layer is T1, and the sensor layer includes a plurality of sensors spaced apart from each other.

[0012] Optionally, an adhesive layer is provided between the sensor layer and the first insulating layer, between the first insulating layer and the shielding layer, and between the shielding layer and the second insulating layer, wherein the thickness of the adhesive layer is 0.07 to 0.1 mm.

[0013] Optionally, the distance between the surface of the sensor layer facing away from the first insulating layer and the surface of the heating layer facing away from the second insulating layer is less than or equal to 1.5 mm.

[0014] Optionally, the thickness of both the sensor layer and the shielding layer is less than or equal to 0.2 mm.

[0015] Optionally, the sensor layer and the shielding layer are both made of conductive fabric, and the heating layer is made of metal wire.

[0016] Secondly, embodiments of this application also provide a steering wheel, including a frame and the capacitive sensing system, the stack covering the frame.

[0017] Optionally, the steering wheel further includes a first foam layer, a second foam layer, and a leather layer, wherein the frame, the first foam layer, the stacked layers, the second foam layer, and the leather layer are arranged sequentially from the inside to the outside, and the sensor layer is closer to the second foam layer relative to the heating layer.

[0018] Optionally, the thickness of both the first foam layer and the second foam layer is less than or equal to 1.5 mm.

[0019] The beneficial effects of the capacitive sensing system and steering wheel provided in this application include, for example, solving the problem of difficult steering wheel wrapping, a capacitive sensing system is designed. This system includes a stack for wrapping on a frame, comprising a sensor layer, a first insulating layer, a shielding layer, a second insulating layer, and a heating layer arranged sequentially. The first insulating layer and / or the second insulating layer are polyethylene-based insulating layers. During the process of wrapping the steering wheel, since at least one of the first and second insulating layers is a polyethylene-based insulating layer, and polyethylene materials have good ductility, the stack can be easily wrapped onto the steering wheel frame, solving the problem of difficult steering wheel wrapping. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an end view of the steering wheel in an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the first type of stacking in the embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the second type of stacking in the embodiments of this application;

[0024] Figure 4 This is a schematic diagram of the third type of stacking in the embodiments of this application;

[0025] Figure 5 This is a schematic diagram of the fourth type of stacking in the embodiments of this application.

[0026] Icons: 100 - Skeleton; 200 - Stacked layers; 210 - Sensor layer; 220 - First insulating layer; 230 - Shielding layer; 240 - Second insulating layer; 250 - Heating layer; 260 - Adhesive layer; 300 - First foaming layer; 400 - Second foaming layer; 500 - Leather layer. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0032] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0033] As disclosed in the background section, steering wheels currently employing hands-off detection technology generally have an insulating layer, which is mostly made of TPU material. However, due to the poor tensile properties of TPU material, it may cause difficulties in covering the steering wheel. Embodiments of this application provide a steering wheel that at least addresses this technical problem.

[0034] Please refer to Figure 1 , Figure 2 The steering wheel provided in the embodiments of this application includes a frame 100 and a capacitive sensing system. The capacitive sensing system includes a stack 200 covering the frame 100. The stack 200 includes a sensor layer 210, a first insulating layer 220, a shielding layer 230, a second insulating layer 240 and a heating layer 250 arranged in sequence. The first insulating layer 220 and / or the second insulating layer 240 are polyethylene insulating layers.

[0035] The first insulating layer 220 and / or the second insulating layer 240 being polyethylene insulating layers includes: only the first insulating layer 220 being a polyethylene insulating layer, or only the second insulating layer 240 being a polyethylene insulating layer, or both the first insulating layer 220 and the second insulating layer 240 being polyethylene insulating layers.

[0036] The heating layer 250 is closer to the frame 100 than the sensor layer 210. The sensor layer 210 is a capacitive sensor used to sense the capacitance change between the sensor layer 210 and the ground. The first insulating layer 220 and the second insulating layer 240 both serve to provide insulation and prevent short circuits. The shielding layer 230 can shield the influence of the frame 100 and the heating layer 250 on the sensing function of the sensor layer 210 to a certain extent.

[0037] Since at least one of the first insulating layer 220 and the second insulating layer 240 is a polyethylene insulating layer, and polyethylene materials have better ductility, compared with insulating layers made of TPU materials, the laminate 200 in this embodiment can more easily cover the frame 100 during the process of covering the steering wheel, thus solving the problem of difficult steering wheel covering.

[0038] It should be noted that polyethylene (PE) is a widely used thermoplastic polymer with excellent electrical insulation properties.

[0039] Based on different polymerization methods and molecular structures, polyethylene materials can be divided into the following main types: Low-density polyethylene (LDPE): produced by high-pressure polymerization, with more branches on the molecular chain and a lower density (approximately 0.91-0.93 g / cm³). 3 It possesses good flexibility, transparency, and heat-sealing properties; Linear low-density polyethylene (LLDPE): produced through low-pressure polymerization, its molecular chains are relatively linear, but still contain a small number of short branches, with a density of 0.91-0.94 g / cm³. 3 It combines the flexibility of LDPE with the strength of HDPE; High-density polyethylene (HDPE): produced through low-pressure polymerization, it has highly linear molecular chains, fewer branches, and a higher density (approximately 0.94-0.97 g / cm³). 3 It has high strength, rigidity and chemical resistance; Ultra-high molecular weight polyethylene (UHMWPE): with extremely high molecular weight (over 1 million), it has excellent wear resistance, impact resistance and low coefficient of friction, but it is more difficult to process.

[0040] The density range of polyethylene is 0.91-0.97 g / cm³. 3 Low-density polyethylene and linear low-density polyethylene have good flexibility and ductility, while high-density polyethylene is harder and more brittle. In the embodiments of this application, the polyethylene used in the first insulating layer 220 and the second insulating layer 240 is preferably low-density polyethylene and linear low-density polyethylene.

[0041] TPU is a thermoplastic polyurethane elastomer whose molecular structure contains hard and soft segments. The hard segments provide the material's strength and modulus, while the soft segments impart elasticity. However, a high hard segment content in TPU significantly increases its rigidity and hardness, thus limiting its ductility. In contrast, PE is a linear or branched polyolefin material with more flexible molecular chains, exhibiting good ductility and flexibility.

[0042] TPU materials typically have high tensile strength and elastic modulus, but relatively low elongation at break. This is because during the stretching process, the hard segments of TPU materials restrict the deformation ability of the soft segments. In contrast, PE materials have higher elongation at break, especially in low-density polyethylene, where the flexibility of the molecular chains allows them to withstand greater deformation.

[0043] TPU material has a homogeneous polymer structure, and the interaction between hard and soft segments limits the overall deformability of the material. In contrast, PE material has a more uniform microstructure and stronger slippage ability between molecular chains, thus it can better disperse stress during stretching.

[0044] In general, PE material has better ductility than TPU material. When an insulating layer made of PE material is applied to the steering wheel, it can effectively reduce the difficulty of the steering wheel wrapping process.

[0045] In an optional embodiment, the first insulating layer 220 is a polyethylene insulating layer and the thickness of the first insulating layer 220 is greater than the thickness of the second insulating layer 240, wherein the thickness of the second insulating layer 240 is the thickness of the insulating layer in a conventional steering wheel, and the thickness of the first insulating layer 220 is thicker than the thickness of the second insulating layer 240.

[0046] In another optional embodiment, the second insulating layer 240 is a polyethylene insulating layer and the thickness of the first insulating layer 220 is less than the thickness of the second insulating layer 240, wherein the thickness of the first insulating layer 220 is the thickness of the insulating layer in a conventional steering wheel, and the thickness of the second insulating layer 240 is thicker than the thickness of the first insulating layer 220.

[0047] In this embodiment, the steering wheel also includes a first foam layer 300, a second foam layer 400, and a leather layer 500. The frame 100, the first foam layer 300, the stack 200, the second foam layer 400, and the leather layer 500 are arranged sequentially from the inside to the outside. The sensor layer 210 is closer to the second foam layer 400 than the heating layer 250.

[0048] It should be noted that the frame 100 is located in the innermost layer of the steering wheel, the first foam layer 300 covers the frame 100, the laminate 200 covers the first foam layer 300, the second foam layer 400 covers the laminate 200, and the leather layer 500 covers the second foam layer 400.

[0049] Since at least one of the first insulating layer 220 and the second insulating layer 240 in the laminate 200 is made of polyethylene material, the laminate 200 has good extensibility. During the process of covering the laminate 200 with the first foam layer 300, the laminate 200 is easier to stretch, the covering process is easier, and wrinkles are less likely to occur. The shape of the steering wheel is also easier to control.

[0050] The shape of the skeleton 100 can be circular or elliptical, or part of the skeleton 100 can be arc-shaped while the other part is straight. It is understood that the shape of the skeleton 100 can be determined according to actual needs and is not limited thereto.

[0051] In some embodiments, the stack 200 satisfies: T1 / D1≤0.6; where T1 is the thickness of the first insulating layer 220 or the second insulating layer 240, and D1 is the distance between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240.

[0052] It should be noted that T1 can be the thickness of the first insulating layer 220 or the thickness of the second insulating layer 240; for example... Figure 3 As shown, when T1 is the thickness of the first insulating layer 220, the ratio of the thickness of the first insulating layer 220 to the distance between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is less than or equal to 0.6; Figure 4 As shown, when T1 is the thickness of the second insulating layer 240, the ratio of the thickness of the second insulating layer 240 to the distance between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is less than or equal to 0.6; Figure 5 As shown, when the thickness of the first insulating layer 220 and the second insulating layer 240 is T1, the ratio of the thickness of the first insulating layer 220 to the distance between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is less than or equal to 0.6, and the ratio of the thickness of the second insulating layer 240 to the distance between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is less than or equal to 0.6.

[0053] Due to the limitations on the wheel rim diameter after the wrapping is completed and the reliability of the wrapping process, the compression ratio k is defined as T1 / D1, that is, the compression ratio k needs to be less than or equal to 0.6.

[0054] In an optional embodiment, the distance D1 between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is 0.8 mm. According to the compression ratio k = T1 / D1≤0.6, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 is ≤0.48 mm. In this case, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 can be selected as 0.4 mm.

[0055] In an optional embodiment, the distance D1 between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is 1 mm. According to the compression ratio k = T1 / D1≤0.6, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 is ≤0.6 mm. In this case, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 can be selected as 0.55 mm.

[0056] In an optional embodiment, the distance D1 between the surface of the sensor layer 210 facing the first insulating layer 220 and the surface of the heating layer 250 facing the second insulating layer 240 is 1.2 mm. According to the compression ratio k = T1 / D1≤0.6, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 is ≤0.72 mm. In this case, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 can be selected as 0.7 mm.

[0057] The thickness of the insulating layer in existing steering wheels is generally less than 0.1 mm. In the three optional embodiments mentioned above, the thickness T1 of the first insulating layer 220 or the second insulating layer 240 is increased compared to the thickness of the insulating layer in existing steering wheels.

[0058] It should be noted that at the instant the heating layer 250 begins heating, it switches to a grounded state, causing a sudden increase in the parasitic capacitance of the shielding layer 230. This, in turn, causes a signal abrupt change in the sensor layer 210 through the parasitic capacitance Cp1 between the shielding layer 230 and the sensor layer 210. The smaller the distance between the heating layer 250 and the shielding layer 230, the larger the parasitic capacitance between them, and the easier it is for the influence of the shielding layer 230 to be transmitted to the sensor layer 210. Conversely, if the distances between the sensor layer 210 and the shielding layer 230, and between the shielding layer 230 and the heating layer 250, are small, the parasitic capacitances between them will be large, resulting in a smaller signal increment when the steering wheel is gripped.

[0059] When the thickness of the first insulating layer 220 is increased compared to the thickness of the insulating layer in the existing steering wheel, the distance between the shielding layer 230 and the sensor layer 210 is increased, thereby reducing the parasitic capacitance Cp1 between the shielding layer 230 and the sensor layer 210. This weakens the impact of the heating layer 250 on the sensor layer 210 when it is heated, as well as the impact of the shielding layer 230 on the sensor layer 210, thus improving the signal quantity and optimizing the signal-to-noise ratio.

[0060] When the thickness of the second insulating layer 240 is increased compared to the thickness of the insulating layer in the existing steering wheel, the distance between the shielding layer 230 and the heating layer 250 is increased, thereby reducing the parasitic capacitance Cp2 between the shielding layer 230 and the heating layer 250, and thus weakening the impact of the heating layer 250 on the shielding layer 230 when it is heated.

[0061] When the thickness of the first insulating layer 220 is increased compared to the thickness of the insulating layer in the existing steering wheel, and the thickness of the second insulating layer 240 is increased compared to the thickness of the insulating layer in the existing steering wheel, the distance between the shielding layer 230 and the sensor layer 210 and the distance between the shielding layer 230 and the heating layer 250 are increased simultaneously. This reduces the parasitic capacitance Cp1 between the shielding layer 230 and the sensor layer 210 and the parasitic capacitance Cp2 between the shielding layer 230 and the heating layer 250, thereby weakening the impact of the heating layer 250 on the sensor layer 210 and the shielding layer 230 when heating, as well as the impact of the shielding layer 230 on the sensor layer 210.

[0062] On the other hand, when the thickness of the first insulating layer 220 is increased compared to the thickness of the insulating layer in the existing steering wheel, and the thickness of the second insulating layer 240 is increased compared to the thickness of the insulating layer in the existing steering wheel, the parasitic capacitance between the sensor layer 210 and the shielding layer 230 will be reduced, and the parasitic capacitance Cp2 between the shielding layer 230 and the heating layer 250 will be reduced, thereby helping to increase the signal increment when the hand is holding the steering wheel.

[0063] In an optional embodiment, the thickness of the first insulating layer 220 is T1, and the sensor layer 210 includes a plurality of sensors spaced apart from each other.

[0064] Multiple sensors can be arranged at intervals along the circumference of the frame 100, meaning multiple sensors are located in different areas around the steering wheel, and all sensors are bonded to the first insulating layer 220 via an adhesive layer 260. When a person touches the steering wheel, one of the sensors will detect a contact signal. In other embodiments, the sensors can also be arranged at intervals in the fore-and-aft direction of the steering wheel.

[0065] When the thickness of the first insulating layer 220 is T1, the thickness of the first insulating layer 220 can be increased compared to the thickness of the insulating layer in the existing steering wheel. When the sensor layer 210 includes multiple sensors, if the thickness of the first insulating layer 220 is increased compared to the thickness of the insulating layer in the existing steering wheel, the distance between the shielding layer 230 and each sensor is increased, thereby reducing the parasitic capacitance between the shielding layer 230 and each sensor. When one sensor detects a contact signal, other sensors are less likely to detect the contact signal, thus effectively solving the crosstalk problem between sensors.

[0066] For example, the sensor layer 210 includes four sensors arranged circumferentially along the steering wheel, with the four sensors located in four areas: the upper left, lower left, upper right, and lower right of the steering wheel, respectively.

[0067] When a person touches one of the areas on the upper left, lower left, upper right, or lower right of the steering wheel, the sensor in that area can detect the contact signal, while the sensors in the other three areas are less likely to detect the contact signal.

[0068] For example, when a person touches the upper right area of ​​the steering wheel, the sensor located in the upper right area of ​​the steering wheel can detect the contact signal, while the sensors located in the upper left, lower left, and lower right areas of the steering wheel are less likely to detect the contact signal; or, when a person touches the upper left area of ​​the steering wheel, the sensor located in the upper left area of ​​the steering wheel can detect the contact signal, while the sensors located in the upper right, lower left, and lower right areas of the steering wheel are less likely to detect the contact signal.

[0069] When a person's hand simultaneously touches two of the areas on the upper left, lower left, upper right, and lower right of the steering wheel, the sensors in those two areas can detect the contact signal, while the sensors in the other two areas are less likely to detect the contact signal.

[0070] For example, when a person's hand simultaneously touches the upper left and lower right areas of the steering wheel, the sensors located in the upper left and lower right areas of the steering wheel can detect the contact signal, while the sensors located in the lower left and upper right areas of the steering wheel are less likely to detect the contact signal; or, when a person's hand simultaneously touches the upper left and upper right areas of the steering wheel, the sensors located in the upper left and upper right areas of the steering wheel can detect the contact signal, while the sensors located in the lower left and lower right areas of the steering wheel are less likely to detect the contact signal.

[0071] It is understandable that the number of sensors included in sensor layer 210 and the arrangement of the sensors can be determined according to actual needs, and there are no restrictions on this.

[0072] In some embodiments, an adhesive layer 260 is provided between the sensor layer 210 and the first insulating layer 220, between the first insulating layer 220 and the shielding layer 230, and between the shielding layer 230 and the second insulating layer 240, wherein the thickness T2 of the adhesive layer 260 is 0.07 to 0.1 mm.

[0073] The adhesive layer can be double-sided adhesive. One side of the adhesive layer 260 between the sensor layer 210 and the first insulating layer 220 is bonded to the sensor layer 210, and the other side of the adhesive layer 260 between the sensor layer 210 and the first insulating layer 220 is bonded to the first insulating layer 220. One side of the adhesive layer 260 between the first insulating layer 220 and the shielding layer 230 is bonded to the first insulating layer 220, and the other side of the adhesive layer 260 between the first insulating layer 220 and the shielding layer 230 is bonded to the shielding layer 230. One side of the adhesive layer 260 between the shielding layer 230 and the second insulating layer 240 is bonded to the shielding layer 230, and the other side of the adhesive layer 260 between the shielding layer 230 and the second insulating layer 240 is bonded to the second insulating layer 240.

[0074] For example, the thickness T2 of the adhesive layer 260 is 0.07 mm, 0.08 mm, 0.09 mm or 0.1 mm. It is understood that the thickness T2 of the adhesive layer 260 can be determined according to actual needs and is not limited thereto.

[0075] In some embodiments, the distance D0 between the surface of the sensor layer 210 facing away from the first insulating layer 220 and the surface of the heating layer 250 facing away from the second insulating layer 240 is less than or equal to 1.5 mm.

[0076] It should be noted that, considering the diameter and structural arrangement of the steering wheel rim, the distance D0 between the surface of the sensor layer 210 facing away from the first insulating layer 220 and the surface of the heating layer 250 facing away from the second insulating layer 240 generally does not exceed 1.5mm.

[0077] For example, the distance D0 between the surface of the sensor layer 210 facing away from the first insulating layer 220 and the surface of the heating layer 250 facing away from the second insulating layer 240 is 1.3mm, 1.4mm or 1.5mm. It is understood that the distance D0 between the surface of the sensor layer 210 facing away from the first insulating layer 220 and the surface of the heating layer 250 facing away from the second insulating layer 240 can be determined according to actual needs and is not limited thereto.

[0078] In some embodiments, the sensor layer 210 and the shielding layer 230 are both made of conductive fabric, and the heating layer 250 is made of metal wire.

[0079] Both the sensor layer 210 and the shielding layer 230 can be made of pure nickel conductive fabric (PET). In other embodiments, the heating layer 250 can also be made of other materials with heating functions, and there is no limitation on this.

[0080] In some embodiments, the thickness T3 of the sensor layer 210 and the thickness T4 of the shielding layer 230 are both less than or equal to 0.2 mm.

[0081] Since both the sensor layer 210 and the shielding layer 230 are made of conductive fabric, the thickness selection of the sensor layer 210 and the shielding layer 230 can be consistent.

[0082] For example, the thickness T3 of the sensor layer 210 and the thickness T4 of the shielding layer 230 are both 0.1 mm, 0.15 mm or 0.2 mm. It is understood that the thickness T3 of the sensor layer 210 and the thickness T4 of the shielding layer 230 can be determined according to actual needs, and there is no limitation on them.

[0083] In some embodiments, the thickness of the first foam layer 300 and the thickness of the second foam layer 400 are both less than or equal to 1.5 mm.

[0084] The thickness of the first foam layer 300 and the thickness of the second foam layer 400 can be consistent. For example, the thickness of the first foam layer 300 and the thickness of the second foam layer 400 are both 1.3mm, 1.4mm or 1.5mm. It is understood that the thickness of the first foam layer 300 and the thickness of the second foam layer 400 can be determined according to actual needs, and there is no limitation on this.

[0085] In addition, the control system matched with the steering wheel is equipped with a controller and a wiring harness. The controller is used to collect and process the signals from the sensor layer 210, and the controller communicates and interacts with the controller on the vehicle. The wiring harness is used to realize the electrical connection for power supply and communication between the controller and the vehicle, as well as the electrical connection between the controller and the sensor layer 210.

[0086] The technical effects of the capacitive sensing system and steering wheel provided in this application embodiment include at least the following: Since at least one of the first insulating layer 220 and the second insulating layer 240 in the stack 200 is made of polyethylene material, the stack 200 has good ductility. During the process of covering the stack 200 with the first foam layer 300, the stack 200 is easier to stretch, the covering process is easier, and wrinkles are less likely to occur, making it easier to control the shape of the steering wheel; when the thickness of the first insulating layer 220 is increased compared to the thickness of the insulating layer in existing steering wheels, the distance between the shielding layer 230 and the sensor layer 210 increases, thereby weakening the impact of the heating layer 250 on the sensor layer 210 during heating and the impact of the shielding layer 230 on the sensor layer 210; when the thickness of the second insulating layer 240 is increased compared to the thickness of the insulating layer in existing steering wheels, the distance between the shielding layer 230 and the heating layer 250... The increased distance between layers 250 reduces the impact of heating layer 250 on shielding layer 230 during heating. When the thickness of the first insulating layer 220 is increased compared to the existing insulating layer in the steering wheel, and the thickness of the second insulating layer 240 is also increased compared to the existing insulating layer in the steering wheel, the distances between shielding layer 230 and sensor layer 210, as well as between shielding layer 230 and heating layer 250, are simultaneously increased. This reduces the impact of heating layer 250 on sensor layer 210 and shielding layer 230 during heating, as well as the impact of shielding layer 230 on sensor layer 210. With the increased thickness of the first insulating layer 220 compared to the existing insulating layer in the steering wheel, and with multiple sensors spaced apart, when some sensors detect a contact signal, other sensors are less likely to detect the contact signal, effectively solving the crosstalk problem between sensors.

[0087] In summary, this application provides a capacitive sensing system and a steering wheel. The capacitive sensing system includes a stack 200 for covering a frame 100. The stack 200 includes a sensor layer 210, a first insulating layer 220, a shielding layer 230, a second insulating layer 240, and a heating layer 250 arranged sequentially. Since at least one of the first insulating layer 220 and the second insulating layer 240 is made of polyethylene material, the stack 200 can easily cover the frame 100 during the steering wheel covering process, solving the problem of difficult steering wheel covering. Furthermore, in low-temperature environments, especially extreme environments such as extremely low temperatures, where the heating layer needs to be activated, the insulating layer made of polyethylene material is thickened. Compared with TPU material insulating layers, polyethylene material insulating layers have superior ductility and tensile strength, which can significantly improve the texture of the steering wheel covering. Specifically, after being wrapped around the steering wheel, the polyethylene insulation layer system has a smoother shape compared to the TPU insulation layer system. At the same time, it effectively mitigates the impact of parasitic capacitance on detection and improves the detection accuracy of the capacitive sensing system on the hand in extreme environments.

[0088] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A capacitive sensing system, characterized in that, Includes a stack (200) for covering the frame (100) of the steering wheel, the stack (200) including a sensor layer (210), a first insulating layer (220), a shielding layer (230), a second insulating layer (240) and a heating layer (250) arranged in sequence, wherein the first insulating layer (220) and / or the second insulating layer (240) are polyethylene insulating layers.

2. The capacitive sensing system according to claim 1, characterized in that, The stack (200) satisfies: T1 / D1≤0.6; Wherein, T1 is the thickness of the first insulating layer (220) or the second insulating layer (240), and D1 is the distance between the surface of the sensor layer (210) facing the first insulating layer (220) and the surface of the heating layer (250) facing the second insulating layer (240).

3. The capacitive sensing system according to claim 2, characterized in that, The sensor layer (210) includes a plurality of phase-spaced sensors, and the thickness of the first insulating layer (220) is T1.

4. The capacitive sensing system according to claim 1, characterized in that, The first insulating layer (220) is a polyethylene insulating layer and the thickness of the first insulating layer (220) is greater than the thickness of the second insulating layer (240), or the second insulating layer (240) is a polyethylene insulating layer and the thickness of the first insulating layer (220) is less than the thickness of the second insulating layer (240).

5. The capacitive sensing system according to any one of claims 1-4, characterized in that, An adhesive layer (260) is provided between the sensor layer (210) and the first insulating layer (220), between the first insulating layer (220) and the shielding layer (230), and between the shielding layer (230) and the second insulating layer (240). The thickness of the adhesive layer (260) is 0.07 to 0.1 mm.

6. The capacitive sensing system according to any one of claims 1-4, characterized in that, The distance between the surface of the sensor layer (210) facing away from the first insulating layer (220) and the surface of the heating layer (250) facing away from the second insulating layer (240) is less than or equal to 1.5 mm.

7. The capacitive sensing system according to any one of claims 1-4, characterized in that, The thickness of the sensor layer (210) and the thickness of the shielding layer (230) are both less than or equal to 0.2 mm.

8. The capacitive sensing system according to any one of claims 1-4, characterized in that, The sensor layer (210) and the shielding layer (230) are both made of conductive fabric, and the heating layer (250) is made of metal wire.

9. A steering wheel, characterized in that, The system includes a frame (100) and a capacitive sensing system according to any one of claims 1-8, wherein the stack (200) covers the frame (100).

10. The steering wheel according to claim 9, characterized in that, The steering wheel also includes a first foam layer (300), a second foam layer (400), and a leather layer (500). The frame (100), the first foam layer (300), the stack (200), the second foam layer (400), and the leather layer (500) are arranged sequentially from the inside to the outside. The sensor layer (210) is closer to the second foam layer (400) than the heating layer (250).

11. The steering wheel according to claim 10, characterized in that, The thickness of the first foam layer (300) and the thickness of the second foam layer (400) are both less than or equal to 1.5 mm.

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