Steering wheel hands-free detection sensor

Abstract

A hands-free detection (FD) sensor of a steering wheel of a vehicle comprises: an electrically insulating substrate having a first surface and a second surface opposite to the first surface; a first metal layer disposed on the first surface of the electrically insulating substrate; and a first electrical conductor having a first end directly electrically connected to the first metal layer, wherein the first metal layer is attached to the first surface of the electrically insulating substrate without an adhesive.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present disclosure is a PCT international application claiming the benefit of U.S. Provisional Patent Application No. 63 / 428,265, filed November 28, 2022. The entire disclosure of the above-referenced application is incorporated herein by reference. AREA

[0002] The present disclosure relates to steering wheels and, more particularly, to hands-free detection sensors of vehicle steering wheels. BACKGROUND

[0003] The background description provided herein is intended to provide a general context for the disclosure. The work of the presently named inventors, to the extent described in this Background section, as well as aspects of the description not otherwise considered prior art at the time of filing, are not expressly or by implication admitted as prior art to the present disclosure.

[0004] In some vehicles, steering wheels include heaters to heat the steering wheels. Additionally, the steering wheels may include hands-free detection sensors (e.g., capacitive sensors) to detect whether or not a passenger's hand or hands are on the vehicle's steering wheel. For example, in partially autonomous vehicles, while an autonomous control system automatically controls the vehicle's driving under some conditions, some situations may require a driver to intervene and / or assume control of the vehicle. For example, while driving on a highway may be handled by the autonomous control system, driver intervention may be requested in the event of an accident or construction on the roadway, or if the autonomous system is unable to operate.Using hands-free detection sensors in the steering wheels, the vehicles can detect whether or not an occupant's hand or hands are on the steering wheel before disabling the autonomous control system. SUMMARY

[0005] According to one feature, a hands-free detection (FD) sensor of a steering wheel of a vehicle is described and comprises: an electrically insulating substrate having a first surface and a second surface opposite the first surface; a first metal layer disposed on the first surface of the electrically insulating substrate; and a first electrical conductor having a first end directly electrically connected to the first metal layer, wherein the first metal layer is attached to the first surface of the electrically insulating substrate without an adhesive.

[0006] According to further features, the first metal layer is a first metal film layer.

[0007] According to further features, a second metal film layer is disposed on the second surface of the electrically insulating substrate; and a second electrical conductor has a first end directly electrically connected to the second metal film layer.

[0008] According to further features, the first and second metal film layers are layers of aluminum film.

[0009] According to further features, the first and second metal film layers are layers of copper film.

[0010] According to further features, the electrically insulating substrate comprises one of polyester, polyurethane and a polymer film.

[0011] According to further features, a plurality of openings extend through the electrically insulating substrate, the first metal film layer and the second metal film layer.

[0012] According to further features, the openings are all the same size.

[0013] According to further features, the openings comprise at least two different sizes.

[0014] According to further features, the openings all have the same shape.

[0015] According to further features, the openings comprise at least two different shapes.

[0016] According to further features, the distance between adjacent openings is the same.

[0017] According to further features, the distance between adjacent openings comprises at least two different distances.

[0018] According to further features, the first end of the first electrical conductor is adhered to the first metal film layer and the first end of the second electrical conductor is adhered to the second metal film layer.

[0019] According to further features, one of electrically conductive adhesive and electrically conductive glue is included that adheres the first end of the first electrical conductor to the first metal film layer, and the first end of the second electrical conductor is adhered to the second metal film layer.

[0020] According to further features, a first thickness of the first metal film layer and a second thickness of the second metal film layer are less than a third thickness of the electrically insulating substrate.

[0021] According to further features, the first and second thicknesses are less than 2 micrometers.

[0022] According to further features, the first and second thicknesses are less than 1 micrometer.

[0023] According to further features, the first and second thicknesses are less than 0.5 micrometers.

[0024] According to further features, the first metal film layer and the second metal film layer are deposited on the electrically insulating substrate using chemical vapor deposition.

[0025] According to further characteristics, vapor deposition is a physical vapor deposition.

[0026] According to one feature, a steering wheel comprises: the FD sensor and an electric heater, wherein the second metal film layer is radially disposed between the first metal film layer and the electric heater.

[0027] According to further features, an electrical insulator is arranged between the second metal film layer and the electrical heater.

[0028] In other features, the electrical insulator is a foam.

[0029] According to further features, a system comprises: the FD sensor and a hands-free module configured to: electrically connect to second ends of the first and second electrical conductors; and detect when a driver's hands are released from the steering wheel based on a capacitance between the first and second metal film layers.

[0030] According to further features, the first and second electrical conductors are insulated electrical conductors.

[0031] According to one feature, a hands-free detection (FD) sensor of a steering wheel of a vehicle comprises: an electrically insulating substrate having a first surface and a second surface opposite to the first surface; a first metal layer disposed on the first surface of the electrically insulating substrate; and a second metal layer disposed on the second surface of the electrically insulating substrate, wherein each of the first metal layer and the second metal layer comprises: a second electrically insulating substrate having a third surface and a fourth surface opposite to the third surface; a first metal film layer disposed on the third surface; and a second metal film layer disposed on the fourth surface.

[0032] According to further features, a first thickness of the second electrically insulating substrate is greater than a second thickness of the first metal film layer and greater than a third thickness of the second metal film layer.

[0033] According to further features, the first metal film layer and the second metal film layer are deposited on the second electrically insulating substrate using chemical vapor deposition.

[0034] According to further characteristics, vapor deposition is a physical vapor deposition.

[0035] According to further features, linear slots extend through the first electrically insulating substrate, the first metal layer and the second metal layer.

[0036] According to further features, the linear slots are arranged in a V-shape.

[0037] According to further features, the linear slots comprise first rows of linear slots that are parallel and second rows of linear slots that form orthogonal angles with the linear slots of the first rows.

[0038] According to further features, a first thickness of the second electrically insulating substrate is greater than a second thickness of the first metal film layer and a third thickness of the second metal film layer.

[0039] According to further features, the second electrically insulating substrate is made of polyester and the first and second metal film layers comprise aluminum.

[0040] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, in which: Fig. 1 is a perspective view of an example of a steering wheel of a vehicle; Fig. Figure 2 is an exploded perspective view of a heater and a hands-free detection (FD) sensor prior to attachment to a steering wheel; Fig. 3 includes an exploded perspective view of the FD sensor; Fig. 4 includes a cross-sectional view of the FD sensor; Fig. 5 is a perspective view of an exemplary implementation of the FD sensor 208 from a viewpoint toward a sensor metal film layer; Fig. Figure 6 is a close-up perspective view of openings through the FD sensor; Fig. 7 is another perspective view of an exemplary implementation of the FD sensor from a viewpoint toward a sensor metal film layer; Fig. 8 includes a cross-sectional view of an exemplary portion of the steering wheel; Fig. 9 is a functional block diagram of an exemplary vehicle control system; Fig. 10 to 12 include cross-sectional views of an exemplary portion of the steering wheel; Fig. 13 to 14 are perspective views of an exemplary implementation of the FD sensor from a viewpoint toward a sensor metal film layer; Fig. 15 includes an exploded perspective view of the FD sensor; Fig. 16 includes a cross-sectional view of the FD sensor; Fig. 17 is an exploded perspective view of a sensor metal layer or a shielding metal layer; Fig. 18 comprises a cross-sectional view of the sensor metal layer or the shielding metal layer; and Fig. 19 includes a cross-sectional view of an exemplary portion of the steering wheel.

[0042] Reference numerals may be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0043] Some vehicles include a steering wheel that incorporates a heater and a hands-free detection (HD) sensor. The heater may include one or more electrical conductors attached / sewn to a fabric or other substrate. The electrical conductor generates heat when current flows through the heater.

[0044] The FD sensor determines and indicates whether a driver of the vehicle's hands are off the steering wheel, such as during autonomous or semi-autonomous driving of the vehicle. A control module may interrupt autonomous or semi-autonomous driving if the driver's hands are off the steering wheel for a predetermined period of time. One or more other actions may be taken additionally or alternatively if the driver's hands are off the steering wheel for a predetermined period of time. For example, one or more modules may provide a visible and / or audible output indicating that the driver's hands are off the steering wheel if the driver's hands are off the steering wheel for a predetermined period of time.

[0045] The FD sensor could comprise one or more electrical conductors attached / sewn to a fabric or other substrate. The FD sensor can determine and indicate whether the driver's hands are off the steering wheel based on a capacitance measured using the FD sensor and a compensator. However, parasitic capacitance of the sensor and compensator can change during heater temperature changes and can vary nonlinearly. A relatively complex compensator may be required to accurately detect whether the driver's hands are off the steering wheel, given the changes observed during heater use.

[0046] The present application includes a metallized sensor layer disposed on a first surface of a substrate and a metallized shielding layer disposed on a second surface of the substrate opposite the first surface. The metallized shielding layer is disposed between the metallized sensor layer and the heater layer. The metallized sensor and shielding layers may be deposited on the substrate (e.g., a plastic, a foam, a nonwoven, etc.) by vapor deposition, such as physical vapor deposition (PVD). Examples of PVD that may be used include evaporative PVD and sputter PVD.

[0047] The use of the metallized sensing layer and the metallized shielding layer reduces parasitic capacitance variation due to temperature changes, and the metallized shielding layer blocks heater switching noise. The use of the metallized shielding and sensing layers eliminates the need for complex compensation and increases the accuracy of a steering wheel's hands-free detection. Openings or slots can be created through the metallized layers and the substrate to increase the flexibility of the FD sensor without disrupting the metallized layer(s).

[0048] Fig. Figure 1 shows a steering wheel 100 of a vehicle. A driver rotates the steering wheel 100 to steer or turn the vehicle left and right. The steering wheel 100 is a toroid with two degrees of surface curvature.

[0049] A flexible circuit comprising a heater and a hands-free detection (FD) sensor may be flat and rectangular in shape (see, for example, Fig. 2) before being attached to the steering wheel 100. The flexible circuit may be covered with a covering material, such as leather or another suitable type of material.

[0050] Fig. 2 is an exploded perspective view of the heater 204 and the FD sensor 208 prior to attachment to the steering wheel 100. The heater 204 includes one or more electrical conductors 212. The electrical conductor(s) 212 may, for example, be woven into a fabric 216 or disposed on or in another suitable type of substrate. The electrical conductor(s) 212 form a resistive heater. A heater control module 220 controls the current through the electrical conductor(s) 212. For example, the heater control module 220 may apply power from a vehicle battery to the electrical conductor(s) 212. The electrical conductor(s) 212 generate(s) heat when current flows through the electrical conductor(s) 212.

[0051] The FD sensor 208 is located radially outside the heater 204 when it is part of the steering wheel 100. The FD sensor 208 may be attached directly to the heater 204 in various implementations. In other implementations, one or more other materials (e.g., one or more layers of foam) may be disposed between the FD sensor 208 and the heater 204. The one or more other layers may, for example, enhance a tactile experience (haptics) when touching the steering wheel 100.

[0052] Fig. 3 includes an exploded perspective view of the FD sensor 208. Fig. 4 includes a cross-sectional view of the FD sensor 208. Referring to Fig. 2 to 4, the FD sensor 208 includes a sensor metal film layer 304, a substrate 308, and a shielding metal film layer 312. The metal of layers 304 and 312 can be, for example, aluminum, copper, or another suitable electrically conductive material. The substrate 308 can be, for example, polyester (PET), polyurethane, a plastic, a foam, a nonwoven, a polymer film, or another suitable material.

[0053] The sensor metal film layer 304 is disposed on a first surface 316 of the substrate 308. The shielding metal film layer 312 is disposed on a second surface 320 of the substrate 308. The second surface 320 is opposite the first surface 316. The second surface 320 faces the heater 204.

[0054] The Fig. The thicknesses illustrated in Figure 4 may not be to scale. However, the thickness 404 of the sensor metal film layer 304 and the thickness 408 of the shield metal film layer 312 are less than the thickness 412 of the substrate 308. The thicknesses 404 and 408 of the shield and metal film layers 304 and 312 may, for example, be between approximately 30 nanometers (nm) and 2 micrometers or another suitable thickness. The thickness 412 of the substrate 308 may, for example, be approximately 10 to 20 micrometers or another suitable thickness. The substrate 308 electrically separates the sensor metal film layer 304 from the shield metal film layer 312.

[0055] The sensor metal film layer 304 and the shield metal film layer 312 may be disposed on the substrate 308, for example, using chemical vapor deposition. The chemical vapor deposition may be, for example, physical vapor deposition (PVD) or another suitable form of chemical vapor deposition. While the chemical vapor deposition example is provided, the sensor and shield metal film layers 304 and 312 may be attached to the substrate 308 by lamination or in another suitable manner.

[0056] A first electrical conductor 340 (e.g., an insulated wire) is electrically connected to the sensor metal film layer 304. A second electrical conductor 344 (e.g., an insulated wire) is electrically connected to the shield metal film layer 312.

[0057] The first and second electrical conductors 344 may each be attached to the sensor and shield metal film layers 304 and 312 via an electrically conductive adhesive or bonding material or in another suitable manner, as illustrated by 348 and 352.

[0058] As in Fig. 4, a hands-free module 450 is electrically connected to the first and second electrical conductors 340 and 344 and measures a capacitance between the sensor and metal film layers 304 and 312. Touching the steering wheel 100 changes the capacitance measured by the hands-free module 450. The hands-free module 450 determines and indicates whether or not the driver's hands are released from the steering wheel 100 based on the capacitance. For example, the hands-free module 450 may determine that the driver's hands are released from the steering wheel 100 when the capacitance is less than a predetermined capacitance or decreases by at least a predetermined capacitance change.

[0059] Fig. 5 is a perspective view of an exemplary implementation of the FD sensor 208 looking toward the sensor metal film layer 304. As in Fig. 5, openings 504 may be formed through the FD sensor 208 and extend through the sensor metal film layer 304, the substrate 308, and the shield metal film layer 312.

[0060] Fig. 6 is a close-up perspective view of some of the openings 504. While the example of rectangular (or square) shaped openings is provided, the present application is also applicable to other shapes, such as triangular, circular, hexagonal, octagonal, ovoid, diamond-shaped, etc. Fig. 7 is another perspective view of an exemplary implementation of the FD sensor 208 looking at the sensor metal film layer 304. In the examples of Fig. 7, Fig. 13 and Fig. 14, the openings 504 are linear slits. The openings 504 increase the flexibility of the FD sensor 208 and allow stretching without breaking the metal of the metal film layers.

[0061] In the example of Fig. 7, the slots 504 are parallel to each other. In the example of Fig. 13, rows of slots 504 are arranged orthogonally, with each slot being arranged orthogonally to four adjacent slots. Slots of a first row 1304 are arranged orthogonally to slots of a second row 1308, and slots of other rows are parallel to the second row 1308. Slots of other rows are also parallel to the slots of the first row 1304.

[0062] In the example of Fig. 14, the slots 504 are arranged in V-shapes and intersect, forming obtuse angles θ. First edges 1404 of the slots 504 are wrapped around the steering wheel and touch second edges 1408 of the slots 504. A curve connecting the points of the V-shapes is illustrated by a dashed line in Fig. 14, forms the same shape as the steering wheel and is arranged radially outside the steering wheel core 804. The slots discussed here can be produced mechanically (e.g., by means of a knife), by laser cutting, or in another suitable manner.

[0063] The openings 504 may each have the same dimensions, and the spacing between adjacent ones of the openings 504 may be identical. In various implementations, the openings 504 may include openings with different dimensions. In various implementations, the spacing between adjacent openings 504 may vary. In various implementations, the openings 504 may include two or more different shapes and / or sizes.

[0064] The openings 504 may extend to peripheral edges of the FD sensor 208, or a boundary of the metal film without openings may be included. The openings 504 may be formed, for example, by cutting, laser cutting, punching, or another suitable manner.

[0065] In the example of Fig. 6, a length 604 and a width 608 of the openings 504 may be approximately 6 millimeters, 8 millimeters, or another suitable length. A first distance 612 between adjacent openings in a first direction may be, for example, approximately 3 millimeters or another suitable length. A second distance 616 between adjacent openings in a second direction (e.g., perpendicular to the first direction) may be equal to the first distance 612 and may be, for example, 3 millimeters or another suitable length. In various implementations, the length and width 604 and 608 of the openings may be at least twice the first distance 612 and / or twice the second distance 616.

[0066] An element that extends vertically upwards from a second element in Fig. 8, is disposed radially outward of the second element. A steering wheel core 804 may be a radially innermost portion of the steering wheel 100. A first (lower) electrical insulator 808 may be disposed radially outward of the steering wheel core 804 and may be, for example, a foam or other suitable type of electrically insulating / isolating material.

[0067] The heater 204 may be arranged radially outward from the first insulator 808. A second electrical insulator 812 may be arranged between the FD sensor 208 and the heater 204. The second electrical insulator 812 may be, for example, a foam or another suitable type of electrically insulating / isolating material. The FD sensor 208 may be arranged radially outward from the second insulator 812.

[0068] A third electrical insulator 816 may be disposed radially outward of the FD sensor 208. The third electrical insulator 816 may be, for example, a foam or other suitable type of electrically insulating / isolating material. An outer cover material 820 is disposed radially outward of the third electrical insulator 816 and may be contacted by the driver's hands. The outer cover material 820 may be, for example, leather or another suitable material. In various implementations, one or more of the layers may be adhered to one another, such as using one or more adhesives and / or glues. In various implementations, the second electrical insulator 812 and / or the third electrical insulator 816 may be an adhesive, such as a pressure-sensitive adhesive tape.

[0069] As in Fig. As shown in Figure 9, an engine control module 904 may control the torque output of an internal combustion engine 908 based on one or more driver inputs, such as an accelerator pedal position (APP). The engine control module 904 may control the torque output of the engine by controlling one or more actuators of the engine 908. The engine 908 may transfer torque to two or more wheels of the vehicle via a transmission. In various implementations, such as the pure electric vehicle example, the engine 908 may be omitted.

[0070] A motor control module 912 may control the torque output of the electric motor 916 based on one or more of the driver inputs, such as the APP. While the example of one electric motor is provided, the vehicle may include more than one electric motor. An electric motor may output torque directly to one wheel of a vehicle or indirectly to two or more wheels of the vehicle.

[0071] A brake control module 920 controls the application of friction brakes 924 of the vehicle based on a brake pedal position (BPP). Application of the friction brakes 924 decelerates the vehicle.

[0072] A steering control module 928 controls a steering system 932 of the vehicle to control steering and wheel turning. The steering control module 928 controls the steering system based on a steering wheel angle (SWA) of the steering wheel 100.

[0073] In various implementations, the engine control module 904, the motor control module 912, the brake control module 920, and / or the steering control module 928 may control the engine 908, the electric motor 916, the friction brakes 924, and the steering system 932 based on commands from an autonomous driving module 936 for autonomous or semi-autonomous driving. The autonomous driving module 936 may generate the commands based on input from one or more external cameras and / or sensors 940. Examples of external cameras and sensors include one or more forward-facing cameras, one or more light detection and ranging (LIDAR) sensors, one or more radar sensors, one or more ultrasonic sensors, and / or one or more other types of sensors that sense features external to the vehicle.

[0074] The autonomous driving module 936 may generate one or more commands for the engine control module 904, the motor control module 912, and / or the brake control module 920, for example, to accelerate or decelerate the vehicle during autonomous or semi-autonomous driving (e.g., to maintain a predetermined following distance, etc.). The autonomous driving module 936 may generate a command for the steering control module 928, for example, to accelerate or decelerate the vehicle's steering to the right or left (e.g., for object avoidance, lane keeping, route following, etc.).

[0075] If the hands-free module 450 detects, using the FD sensor 208, that the driver's hands are released from the steering wheel 100, one or more actions may be taken. For example, the autonomous driving module 936 may terminate autonomous or semi-autonomous driving if the hands-free module 450 detects that the driver's hands are released from the steering wheel 100 (e.g., for a predetermined period of time). The engine control module 904, the motor control module 912, the brake control module 920, and / or the steering control module 928 may then control the engine 908, the electric motor 916, the friction brakes 924, and the steering system 932, for example, based on the APP, the BPP, and the SWA, as described above. The autonomous driving module 936 may enable autonomous or semi-autonomous driving to continue when the hands-free module 450 detects, using the FD sensor 208, that the driver's hands are released from the steering wheel 100.

[0076] When the hands-free module 450 detects, using the FD sensor 208, that the driver's hands are released from the steering wheel 100, an indicator module 944 may output one or more indicators via one or more output devices 948 of the vehicle. Examples of output devices include displays, lights, speakers, haptic (vibrating) devices, and other devices within the passenger compartment of the vehicle. For example, when the hands-free module 450 detects that the driver's hands are released from the steering wheel 100, the indicator module 944 may output an audible indicator via one or more speakers, a visual indicator via one or more displays and / or lights, and / or output a haptic indicator via one or more haptic devices.

[0077] Fig. 10 to 12 include cross-sectional views of exemplary portions of the steering wheel. As in Fig. 10, the insulator 816 may be omitted. In the example of Fig. 10, the sensor layer 304 and the shielding layer 312 are arranged radially outward from the heater 204.

[0078] In the example of Fig. 11 may include a combination sensor / heater 1104. The sensor / heater 1104 may comprise an electrically conductive wire or a metal layer, as described above. A selection module 1108 may connect either the heater control module 220 or the hands-free module 450 to the sensor / heater 1104 at any given time. The heater control module 220 applies power to the sensor / heater 1104 when the heater control module is connected to the sensor / heater 1104 via the selection module 1108. The sensor / heater 1104 then generates heat. When the hands-free module 450 is connected to the sensor / heater 1104 via the selection module 1108, it measures via the sensor / heater 1104.

[0079] The selection module 1108 selects to connect either the heater control module 220 or the hands-free module 450 based on a state of a signal from a selection control module 1112. For example, the selection module 1108 may connect the heater control module 220 to the sensor / heater 1104 when the signal is in a first state. The selection module 1108 may connect the hands-free module 450 to the sensor / heater 1104 when the signal is in a second state. In various implementations, the selection control module 1112 may toggle the signal between the first state and the second state. For example, the selection control module 1112 may set the signal to the first state for a predetermined period of time, then toggle the signal to the second state, set the signal to the second state for a predetermined period of time, then toggle the signal back to the first state, etc.However, the present application is also applicable to setting the signal in any other suitable manner.

[0080] As in Fig. 12, the heater 204 may be omitted.

[0081] Fig. 15 to 16 illustrate an example of the FD sensor 208. Fig. 15 includes an exploded perspective view of the FD sensor 208. Fig. 16 includes a cross-sectional view of the FD sensor 208. Referring to Fig. 15 to 16, the FD sensor 208 includes a sensor metal layer 1504, a substrate 1508, and a shielding metal layer 1512. The substrate 1508 may be, for example, polyester (PET), polyurethane, a plastic, a foam (e.g., polyethylene foam), a nonwoven, a polymer film, or other suitable material.

[0082] The sensor metal layer 1504 is disposed on a first surface 1516 of the substrate 1508. The shielding metal layer 1512 is disposed on a second surface 1520 of the substrate 1508. The second surface 1520 is opposite the first surface 1516. The second surface 1520 faces the heater 204.

[0083] The Fig. The thicknesses illustrated in Figure 16 may not be to scale. However, the thickness 1604 of the sensor metal layer 1504 and the thickness 1608 of the shield metal layer 1512 are less than the thickness 1612 of the substrate 1508. The thicknesses 1604 and 1608 of the shield and metal layers 1504 and 1512 may be, for example, between approximately 1 micrometer and 30 micrometers, such as approximately 25 micrometers, or another suitable thickness. The thickness 1612 of the substrate 1508 may be, for example, approximately 0.1-1 millimeter, such as approximately 0.55 mm, or another suitable thickness. The substrate 1508 electrically insulates the sensor metal layer 1504 from the shield metal layer 1512.

[0084] Fig. 17 is an exploded perspective view of the sensor metal layer 1504. Fig. 18 includes a cross-sectional view of the sensor metal layer 1504. The shield metal layer 1512 may be the same as the sensor metal layer 1504, as shown in Fig. 17 and Fig. 18 illustrates.

[0085] The sensor metal layer 1504 includes a first metal film layer 1704, a substrate 1708, and a second metal film layer 1712. The metal of layers 1704 and 1712 can be, for example, aluminum, copper, or another suitable electrically conductive material. The substrate 308 can be, for example, polyester (PET), polyurethane, a plastic, a foam, a nonwoven, a polymer film, or another suitable material.

[0086] The first metal film layer 1704 is disposed on a first surface 1716 of the substrate 1708. The second metal film layer 1712 is disposed on a second surface 1720 of the substrate 1708. The second surface 1720 is opposite the first surface 1716. The second surface 1720 faces the substrate 1708.

[0087] The Fig. The thicknesses illustrated in Figure 18 may not be to scale. However, the thickness 1804 of the first metal film layer 1704 and the thickness 1808 of the second metal film layer 1712 are less than the thickness 1812 of the substrate 1708. The thicknesses 1804 and 1812 of the first and second metal film layers 1704 and 1712 may be, for example, between approximately 10 micrometers and 40 micrometers, such as 25 micrometers, or another suitable thickness. The thickness 1812 of the substrate 1708 may be, for example, approximately 0.4 millimeters to 0.7 millimeters, such as 0.55 millimeters, or another suitable thickness. The substrate 1708 electrically insulates the first metal film layer 1704 from the second metal film layer 1712.

[0088] The first metal film layer 1704 and the second metal film layer 1712 may be disposed on the substrate 1708, for example, using chemical vapor deposition. The chemical vapor deposition may be, for example, PVD or another suitable form of chemical vapor deposition. While the chemical vapor deposition example is provided, the first and second metal film layers 1704 and 1712 may be attached to the substrate 1708 by lamination or in another suitable manner.

[0089] A first electrical conductor (e.g., an insulated wire) may be connected to the first metal film layer 1704 of the sensor metal layer 1504. In various implementations, a second electrical conductor (e.g., an insulated wire) may be connected to the second metal film layer 1712 of the sensor metal layer 1504. A third electrical conductor (e.g., an insulated wire) may be electrically connected to the first metal film layer 1704 of the shield metal layer 1512. A fourth electrical conductor (e.g., an insulated wire) may be electrically connected to the second metal film layer 1712 of the shield metal layer 1512. The electrical conductors may each be attached to the sensor and shield metal layers via an electrically conductive adhesive or bonding material or in another suitable manner.In various implementations, only one electrical conductor may be connected to one of the metal film layers of the shield metal layer 1504, and one electrical conductor may be connected to one of the metal film layers of the shield metal layer 1512.

[0090] The hands-free module 450 is electrically connected to the metal film layers 1504 and 1512 and measures a capacitance between them. Touching the steering wheel 100 changes the capacitance measured by the hands-free module 450. The hands-free module 450 determines and indicates whether or not the driver's hands are released from the steering wheel 100 based on the capacitance. For example, the hands-free module 450 may determine that the driver's hands are released from the steering wheel 100 when the capacitance is less than a predetermined capacitance or decreases by at least a predetermined capacitance change.

[0091] Fig. 19 is a cross-sectional view of an exemplary portion of the steering wheel. As illustrated, the shield metal layer 1512 may be disposed radially outward of the insulator 812. The substrate 1508 may be disposed radially outside the shield metal layer 1512. The sensor metal layer 1504 may be disposed radially outward of the substrate 1508 and radially inward of the insulator 816. The sensor metal layer 1504 and the shield metal layer 1512 may be formed as described in connection with Fig. 16 to 18 are described.

[0092] The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure may be embodied in a variety of forms. Therefore, while this disclosure includes specific examples, the true scope of the disclosure should not be so limited, since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It is understood that one or more steps within a method may be performed in different orders (or simultaneously) without altering the principles of the present disclosure.Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure may be implemented in and / or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of this disclosure.

[0093] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaging," "coupled," "adjacent," "beside," "on top of," "over," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first and a second element is described in the above disclosure, that relationship may be a direct relationship in which no other intervening elements are present between the first and second elements, but may also be an indirect relationship in which one or more intervening elements (either spatial or functional) are present between the first and second elements.As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C) using a non-exclusive logical OR, and should not be construed to mean "at least one of A, at least one of B, and at least one of C."

[0094] In the figures, the direction of an arrow, as indicated by the arrowhead, generally shows the flow of information (such as data or instructions) of interest to the illustration. For example, if element A and element B exchange a lot of information, but information being passed from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is being passed from element B to element A. Further, for information being sent from element A to element B, element B may send requests for or acknowledgments of receipt of the information to element A.

[0095] Throughout this application, including the definitions below, the term "module" or the term "controller" may be replaced with the term "circuit." The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or group) that executes code; memory circuitry (shared, dedicated, or group) that stores code executed by the processor circuitry; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

[0096] The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may enable load balancing. In another example, a server module (also known as a remote or cloud module) may perform some functionality for a client module.

[0097] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuitry includes a single processor circuitry that executes some or all of the code from multiple modules. The term group processor circuitry includes a processor circuitry that, in combination with additional processor circuitry, executes some or all of the code from one or more modules. References to multiple processor circuitry include multiple processor circuitry on discrete dies, multiple processor circuitry on a single die, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination of the above.The term shared memory circuit refers to a single memory circuit that stores some or all of the code from multiple modules. The term group memory circuit refers to a memory circuit that, in combination with additional memories, stores some or all of the code from one or more modules.

[0098] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not include transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); therefore, the term computer-readable medium can be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0099] The devices and methods described in this application may be implemented, in part or in whole, by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a skilled technician or programmer.

[0100] The computer programs include processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. The computer programs may also include or be based on stored data. The computer programs may include a basic input / output system (BIOS) that interacts with hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0101] The computer programs may comprise: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language) or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, source code may be written using syntax from languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK and Python®. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 428,265

[0001]

Claims

[1] Hands-free detection sensor (FD sensor) of a steering wheel of a vehicle, the FD sensor comprising: an electrically insulating substrate having a first surface and a second surface opposite the first surface; a first metal layer disposed on the first surface of the electrically insulating substrate; and a first electrical conductor having a first end directly electrically connected to the first metal layer, wherein the first metal layer is attached to the first surface of the electrically insulating substrate without an adhesive. [2] The FD sensor according to claim 1, wherein the first metal layer is a first metal film layer. [3] The FD sensor of claim 2, further comprising: a second metal film layer disposed on the second surface of the electrically insulating substrate; and a second electrical conductor having a first end directly electrically connected to the second metal film layer. [4] The FD sensor according to claim 3, wherein the first and second metal film layers are layers of aluminum film. [5] The FD sensor according to claim 3, wherein the first and second metal film layers are layers of copper film. [6] The FD sensor according to claim 1, wherein the electrically insulating substrate comprises one of polyester, polyurethane, and a polymer film. [7] The FD sensor according to claim 3, further comprising a plurality of openings extending through the electrically insulating substrate, the first metal film layer and the second metal film layer. [8] The FD sensor of claim 7, wherein the openings are all of the same size. [9] The FD sensor of claim 7, wherein the openings comprise at least two different sizes. [10] The FD sensor of claim 7, wherein the openings all have the same shape. [11] The FD sensor of claim 7, wherein the openings comprise at least two different shapes. [12] The FD sensor according to claim 7, wherein the distance between adjacent ones of the openings is the same. [13] The FD sensor of claim 7, wherein the distance between adjacent ones of the openings comprises at least two different distances. [14] The FD sensor according to claim 3, wherein the first end of the first electrical conductor is adhered to the first metal film layer and the first end of the second electrical conductor is adhered to the second metal film layer. [15] The FD sensor according to claim 3, further comprising one of electrically conductive adhesive and electrically conductive glue that adheres the first end of the first electrical conductor to the first metal film layer, and the first end of the second electrical conductor is adhered to the second metal film layer. [16] The FD sensor according to claim 3, wherein a first thickness of the first metal film layer and a second thickness of the second metal film layer are less than a third thickness of the electrically insulating substrate. [17] The FD sensor of claim 16, wherein the first and second thicknesses are less than 2 micrometers. [18] The FD sensor of claim 16, wherein the first and second thicknesses are less than 1 micrometer. [19] The FD sensor of claim 16, wherein the first and second thicknesses are less than 0.5 micrometers. [20] The FD sensor according to claim 3, wherein the first metal film layer and the second metal film layer are deposited on the electrically insulating substrate using vapor deposition. [21] The FD sensor of claim 20, wherein the vapor deposition is a physical vapor deposition. [22] Steering wheel, comprising: the FD sensor according to claim 3 and an electric heater, wherein the second metal film layer is arranged radially between the first metal film layer and the electric heater. [23] The steering wheel of claim 22, further comprising an electrical insulator disposed between the second metal film layer and the electric heater. [24] A steering wheel according to claim 23, wherein the electrical insulator is a foam. [25] System comprising: the FD sensor according to claim 3 and a hands-free module configured to: to be electrically connected to second ends of the first and second electrical conductors; and based on a capacitance between the first and second metal film layers to detect when a driver's hands are released from the steering wheel. [26] The FD sensor of claim 3, wherein the first and second electrical conductors are insulated electrical conductors. [27] Hands-free detection sensor (FD sensor) of a steering wheel of a vehicle, the FD sensor comprising: an electrically insulating substrate having a first surface and a second surface opposite the first surface; a first metal layer disposed on the first surface of the electrically insulating substrate; and a second metal layer disposed on the second surface of the electrically insulating substrate, wherein each of the first metal layer and the second metal layer comprises: a second electrically insulating substrate having a third surface and a fourth surface opposite the third surface; a first metal film layer disposed on the third surface; and a second metal film layer disposed on the fourth surface. [28] The FD sensor according to claim 27, wherein a first thickness of the second electrically insulating substrate is greater than a second thickness of the first metal film layer and greater than a third thickness of the second metal film layer. [29] The FD sensor according to claim 27, wherein the first metal film layer and the second metal film layer are deposited on the second electrically insulating substrate using vapor deposition. [30] The FD sensor of claim 29, wherein the vapor deposition is a physical vapor deposition. [31] The FD sensor of claim 27, further comprising linear slits through the first electrically insulating substrate, the first metal layer, and the second metal layer. [32] The FD sensor according to claim 31, wherein the linear slits are arranged in a V-shape. [33] The FD sensor of claim 31, wherein the linear slits comprise first rows of linear slits that are parallel and second rows of linear slits that form orthogonal angles with the linear slits of the first rows. [34] The FD sensor according to claim 27, wherein a first thickness of the second electrically insulating substrate is greater than a second thickness of the first metal film layer and a third thickness of the second metal film layer. [35] The FD sensor according to claim 27, wherein the second electrically insulating substrate is made of polyester and the first and second metal film layers comprise aluminum.

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