Hands-off detection sensor on steering wheel

Abstract

A hands-off detection (HOD) sensor for a vehicle steering wheel includes 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 electrically connected directly to the first metal layer, wherein the first metal layer is attached to the first surface of the electrically insulating substrate without the use of an adhesive.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This 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.

[0002] The present disclosure relates to steering wheels, and more particularly to a hands-off detection sensor for a vehicle steering wheel. [Background technology]

[0003] The background discussion provided herein is intended to generally present the context for the present disclosure. The work of the currently named inventors to the extent described in this background section, and aspects of the description that may not otherwise qualify as prior art at the time of filing, are not admitted expressly or impliedly as prior art to the present disclosure.

[0004] Some vehicles have steering wheels equipped with heaters to warm the steering wheel. Additionally, steering wheels can include hands-on detection sensors (e.g., capacitance sensors) to detect whether one or both of a vehicle's occupants' hands are on the vehicle's steering wheel. For example, in a partially autonomous vehicle, an autonomous control system automatically controls vehicle operation under certain conditions, but certain situations may require the driver to intervene and / or take control of the vehicle. For example, driving on a highway may be handled by the autonomous control system, but driver intervention may be required if an accident or construction occurs on the road, or if the autonomous system is unable to function. Using a hands-on detection sensor in the steering wheel, the vehicle can detect whether one or both of a vehicle's occupants' hands are on the steering wheel before disengaging the autonomous control system. Summary of the Invention

[0005] In one aspect, a vehicle steering wheel hands-off detection (HOD) sensor is described, the sensor including 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 electrically connected directly to the first metal layer, wherein the first metal layer is attached to the first surface of the electrically insulating substrate without the use of an adhesive.

[0006] In a further feature, the first metal layer is a first metal film layer.

[0007] As a further feature, 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 electrically connected directly to the second metal film layer.

[0008] As a further feature, the first and second metal film layers are layers of aluminum film.

[0009] As a further feature, the first and second metal film layers are layers of copper film.

[0010] As a further feature, the electrically insulating substrate includes one of a polyester, a polyurethane, and a polymer film.

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

[0012] As a further feature, all of the openings are the same size.

[0013] As a further feature, the openings include at least two different sizes.

[0014] As a further feature, all of the openings are the same shape.

[0015] As a further feature, the opening comprises at least two different shapes.

[0016] As a further feature, the spacing between adjacent ones of the openings is the same.

[0017] As a further feature, the spacing between adjacent ones of the openings includes at least two different spacings.

[0018] As a further feature, a first end of the first conductor is bonded to the first metal film layer and a first end of the second conductor is bonded to the second metal film layer.

[0019] A further feature includes one of a conductive adhesive and a conductive glue that adheres the first end of the first conductor to the first metal film layer and adheres the first end of the second conductor to the second metal film layer.

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

[0021] As a further feature, the first and second thicknesses are less than 2 micrometers.

[0022] As a further feature, the first and second thicknesses are less than 1 micrometer.

[0023] As a further feature, the first and second thicknesses are less than 0.5 micrometers.

[0024] As a further feature, the first metal film layer and the second metal film layer are deposited on the electrically insulating substrate using a vapor deposition process.

[0025] As a further feature, the vapor deposition method is a physical vapor deposition method.

[0026] In one feature, the steering wheel includes an HOD 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] As a further feature, an electrical insulator is disposed between the second metal film layer and the electric heater.

[0028] As a further feature, the electrical insulator is a foam.

[0029] As a further feature, the system includes an HOD sensor; and a hands-off module electrically connected to second ends of the first and second electrical conductors; and configured to detect when the driver's hands are off the steering wheel based on the capacitance between the first and second metal film layers.

[0030] As a further feature, the first and second conductors are insulated conductors.

[0031] In one aspect, a hands-off detection (HOD) sensor for a vehicle steering wheel includes 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 includes 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.

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

[0033] As a further feature, the first metal film layer and the second metal film layer are deposited on the second electrically insulating substrate using a vapor deposition process.

[0034] As a further feature, the vapor deposition method is a physical vapor deposition method.

[0035] As a further feature, a linear slit extends through the first electrically insulating substrate, the first metal layer, and the second metal layer.

[0036] A further feature is that the linear slits are arranged in a V-shape.

[0037] As a further feature, the linear slits include a first row of linear slits arranged parallel to one another and a second row of linear slits forming a perpendicular angle with the first row of linear slits.

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

[0039] As a further feature, the second electrically insulating substrate is made of polyester and the first and second metal film layers include 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 purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]

[0041] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0042] [Figure 1] FIG. 1 is a perspective view of an example of a steering wheel of a vehicle.

[0043] [Figure 2]FIG. 1 is an exploded perspective view of a heater and hands-off detection (HOD) sensor prior to application to a steering wheel.

[0044] [Figure 3] FIG. 2 is a diagram including an exploded perspective view of an HOD sensor.

[0045] [Figure 4] FIG. 1 is a diagram including a cross-sectional view of an HOD sensor.

[0046] [Figure 5] FIG. 2 is a perspective view of one implementation of the HOD sensor 208, viewed from the perspective of looking toward the sensor metal film layer.

[0047] [Figure 6] FIG. 10 is an enlarged perspective view of an opening through the HOD sensor.

[0048] [Figure 7] FIG. 10 is another perspective view of an example implementation of an HOD sensor, viewed from the perspective of the sensor metal film layer.

[0049] [Figure 8] FIG. 1 is a diagram including a cross-sectional view of an example portion of a steering wheel.

[0050] [Figure 9] FIG. 1 is a functional block diagram of an example vehicle control system.

[0051] [Figure 10] 1 is a diagram including a cross-sectional view of an example portion of a steering wheel. [Figure 11] 1 is a diagram including a cross-sectional view of an example portion of a steering wheel. [Figure 12] 1 is a diagram including a cross-sectional view of an example portion of a steering wheel.

[0052] [Figure 13]FIG. 1 is a perspective view of an example implementation of an HOD sensor, viewed from the perspective of the sensor metal film layer. [Figure 14] FIG. 1 is a perspective view of an example implementation of an HOD sensor, viewed from the perspective of the sensor metal film layer.

[0053] [Figure 15] FIG. 2 is a diagram including an exploded perspective view of an HOD sensor.

[0054] [Figure 16] FIG. 1 is a diagram including a cross-sectional view of an HOD sensor.

[0055] [Figure 17] FIG. 2 is an exploded perspective view of a sensor metal layer or a shield metal layer.

[0056] [Figure 18] FIG. 10 includes a cross-sectional view of a sensor metal layer or a shield metal layer.

[0057] [Figure 19] 1 is a diagram including a cross-sectional view of an example portion of a steering wheel.

[0058] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE INVENTION

[0059] Some vehicles are equipped with steering wheels that include a heater and a hands-off detection (HOD) sensor. The heater may include one or more electrical conductors attached / sewn into fabric or another retaining material. The conductors generate heat when an electric current is passed through the heater.

[0060] The HOD sensor determines and indicates whether a vehicle driver's hands are off the steering wheel, such as during autonomous or semi-autonomous operation of the vehicle. If the driver's hands are off the steering wheel for a predetermined period of time, the control module may suspend autonomous or semi-autonomous operation. If the driver's hands are off the steering wheel for a predetermined period of time, one or more other actions may additionally or alternatively be taken. For example, if the driver's hands are off the steering wheel for a predetermined period of time, one or more modules may provide a visual and / or audible output indicating that the driver's hands are off the steering wheel.

[0061] The HOD sensor may include one or more conductors attached / sewn to fabric or another retaining material. The HOD sensor can determine and indicate whether the driver's hands are off the steering wheel based on the capacitance measured using the HOD sensor and a compensator. However, while the heater temperature changes, the parasitic capacitance of the sensor and compensator may change, which may change nonlinearly. Given the changes observed during heater use, a relatively complex compensator may be required to accurately detect whether the driver's hands are off the steering wheel.

[0062] The present application includes a metallized sensor layer disposed on a first surface of a substrate, and a metallized shield layer disposed on a second surface of the substrate opposite the first surface. The metallized shield layer is disposed between the metallized sensor layer and the heater layer. The metallized sensor layer and the metallized shield layer may be deposited on the substrate (e.g., plastic, foam, fleece, etc.) using a vapor deposition method such as physical vapor deposition (PVD). Examples of PVD that may be used include evaporation PVD and sputter PVD.

[0063] The use of a metalized sensor layer and a metalized shield layer reduces variations in parasitic capacitance due to temperature changes, and the metalized shield layer blocks heater switching noise. The use of a metalized shield layer and a metalized sensor layer eliminates the need for complex compensation and improves the accuracy of hand-off detection. Openings or slits may be formed through the metallization layer and substrate, which increases the flexibility of the HOD sensor without tearing the metallization layer.

[0064] 1 shows a vehicle steering wheel 100. A driver steers or turns the vehicle left and right by turning the steering wheel 100. The steering wheel 100 is a toroidal body with two surface curvatures.

[0065] The flexible circuit containing the heater and hands-off detection (HOD) sensor may have a flat rectangular shape (see, for example, FIG. 2) before being applied to the steering wheel 100. The flexible circuit may be covered with a covering material (e.g., leather or another suitable type of material).

[0066] 2 is an exploded perspective view of the heater 204 and the HOD sensor 208 prior to application to the steering wheel 100. The heater 204 includes one or more electrical conductors 212. The electrical conductors 212 may be woven into a fabric 216, for example, or disposed on or within another suitable type of substrate. The electrical conductors 212 form a resistive heater. The current flowing through the electrical conductors 212 is controlled by a heater control module 220. For example, the heater control module 220 may apply power to the electrical conductors 212 from the vehicle battery. When a current flows through the electrical conductors 212, the electrical conductors 212 generate heat.

[0067] When the HOD sensor 208 is part of the steering wheel 100, it is located radially outward of the heater 204. In various implementations, the HOD sensor 208 may be applied directly to the heater 204. In other implementations, one or more other materials (e.g., one or more layers of foam) may be disposed between the HOD sensor 208 and the heater 204. The one or more other layers may, for example, enhance the haptic experience when touching the steering wheel 100.

[0068] FIG. 3 includes an exploded perspective view of HOD sensor 208. FIG. 4 includes a cross-sectional view of HOD sensor 208. Referring to FIGS. 2-4, HOD sensor 208 includes a sensor metal film layer 304, a substrate 308, and a shield metal film layer 312. The metal of layers 304 and 312 may be, for example, aluminum, copper, or another suitable conductive material. Substrate 308 may be, for example, polyester (PET), polyurethane, plastic, foam, fleece, polymer film, or another suitable material.

[0069] The sensor metal film layer 304 is disposed on a first surface 316 of the substrate 308. The shield metal film layer 312 is disposed on a second surface 320 of the substrate 308. The second surface 320 is located opposite the first surface 316. The second surface 320 faces the heater 204.

[0070] The thicknesses illustrated in FIG. 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 sensor and shield metal film layers 304 and 312 may be, for example, between approximately 30 nanometers (nm) and 2 micrometers, or may be another suitable thickness. The thickness 412 of the substrate 308 may be, for example, between approximately 10 and 20 micrometers, or may be another suitable thickness. The substrate 308 electrically insulates the sensor metal film layer 304 from the shield metal film layer 312.

[0071] The sensor metal film layer 304 and the shield metal film layer 312 may be disposed on the substrate 308 using, for example, a vapor deposition process. The vapor deposition process may be, for example, physical vapor deposition (PVD) or another suitable type of vapor deposition process. Although an example of a vapor deposition process is provided, the sensor and shield metal film layers 304 and 312 may also be applied to the substrate 308 using a lamination process or in another suitable manner.

[0072] 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. The first and second electrical conductors 340 and 344 may be attached to the sensor and shield metal film layers 304 and 312, respectively, using a conductive glue or adhesive, or in another suitable manner, as illustrated at 348 and 352.

[0073] 4, hands-off module 450 is electrically connected to first and second electrical conductors 340 and 344 and measures the capacitance between the sensor and metal film layers 304 and 312. Touching the steering wheel 100 changes the capacitance measured by hands-off module 450. Based on this capacitance, hands-off module 450 determines whether the driver's hands have been removed from steering wheel 100. For example, hands-off module 450 may determine that the driver's hands have been removed from steering wheel 100 if the capacitance is less than a predetermined capacitance or has decreased by at least a predetermined capacitance change.

[0074] 5 is a perspective view of one implementation of the HOD sensor 208, looking at the sensor metal film layer 304. As illustrated in FIG. 5, an opening 504 may be formed through the HOD sensor 208 and extend through the sensor metal film layer 304, the substrate 308, and the shield metal film layer 312.

[0075] FIG. 6 is an enlarged perspective view of a portion of the opening 504. While an example of a rectangular (or square) shaped opening is provided, the present application is applicable to other shapes, such as triangular, circular, hexagonal, octagonal, oval, diamond, etc. FIG. 7 is another perspective view of one implementation of the HOD sensor 208, looking toward the sensor metal film layer 304. In the examples of FIGS. 7, 13, and 14, the opening 504 is a linear slit. The opening 504 improves the flexibility of the HOD sensor 208, allowing the metal in the metal film layer to stretch without breaking.

[0076] In the example of Figure 7, the slits 504 are parallel to one another. In the example of Figure 13, the rows of slits 504 are arranged orthogonally, with each slit arranged orthogonally to four adjacent slits. The slits in a first row 1304 are arranged orthogonally to the slits in a second row 1308, with the slits in the other rows being parallel to the second row 1308. The slits in the other rows are also parallel to the slits in the first row 1304.

[0077] In the example of Figure 14, the slits 504 are arranged in a V-shape and intersect with each other to form an obtuse angle θ. A first end 1404 of the slits 504 wraps around the steering wheel and meets a second end 1408 of the slits 504. The curves connecting the points of the V-shape, illustrated by the dashed lines in Figure 14, form the same shape as the steering wheel and are located radially outward of the steering wheel core 804. The slits described herein may be made mechanically (e.g., with a knife), by laser cutting, or in another suitable manner.

[0078] The openings 504 may each have the same dimensions, and adjacent openings 504 may be spaced the same apart. In various implementations, the openings 504 may include openings of different dimensions. In various implementations, adjacent openings 504 may be spaced differently apart. In various implementations, the openings 504 may include two or more different shapes and / or sizes.

[0079] The opening 504 may extend to the peripheral edge of the HOD sensor 208, or may include a border of the metal film without an opening. The opening 504 may be formed, for example, by die cutting, laser cutting, stamping, or another suitable method.

[0080] 6 , the length 604 and width 608 of the opening 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, for example, 3 millimeters, or another suitable length. In various implementations, the length and width 604 and 608 of the opening may be at least twice as large as the first distance 612 and / or may be twice as large as the second distance 616.

[0081] 8 is disposed radially outward of the second element. The steering wheel core 804 may be the radially innermost portion of the steering wheel 100. A first (bottom) electrical insulator 808 may be disposed radially outward of the steering wheel core 804 and may be, for example, foam or another suitable type of electrically insulating / isolating material.

[0082] The heater 204 may be disposed radially outward of the first insulator 808. A second electrical insulator 812 may be disposed between the HOD sensor 208 and the heater 204. The second electrical insulator 812 may be, for example, foam or another suitable type of electrically insulating / isolating material. The HOD sensor 208 may be disposed radially outward of the second insulator 812.

[0083] A third electrical insulator 816 may be disposed radially outward of the HOD sensor 208. The third electrical insulator 816 may be, for example, foam or another suitable type of electrically insulating / isolating material. An outer covering material 820 may be disposed radially outward of the third electrical insulator 816 and may come into contact with the driver's hands. The outer covering material 820 may be, for example, leather or another suitable material. In various implementations, one or more of these layers may be adhered together, such as with 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.

[0084] As shown in FIG. 9 , engine control module 904 can control the torque output of an internal combustion engine 908 based on one or more driver inputs (such as accelerator pedal position (APP)). Engine control module 904 can control the torque output of the engine by controlling one or more actuators of the engine 908. The engine 908 can transfer torque to two or more wheels of the vehicle using a transmission. In various implementations, for example, in an all-electric vehicle example, the engine 908 can be omitted.

[0085] The motor control module 912 may control the torque output of the electric motor 916 based on one or more driver inputs, such as an APP. Although an example of one electric motor is provided, a vehicle may have more than one electric motor. The electric motor may output torque directly to one wheel of the vehicle or indirectly to two or more wheels of the vehicle.

[0086] The brake control module 920 controls the application of the vehicle's friction brakes 924 based on the brake pedal position (BPP). Application of the friction brakes 924 slows the vehicle.

[0087] The steering control module 928 controls the vehicle's steering system 932 to control the steering and rotation of the wheels. The steering control module 928 controls the steering system based on the steering wheel angle (SWA) of the steering wheel 100.

[0088] In various implementations, engine control module 904, motor control module 912, brake control module 920, and / or steering control module 928 can control engine 908, electric motor 916, friction brakes 924, and steering system 932 based on commands from an autonomous driving module 936 for autonomous or semi-autonomous driving. Autonomous driving module 936 may generate 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 detect features outside the vehicle.

[0089] The autonomous driving module 936 may issue one or more commands to 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 issue commands to the steering control module 928, for example, to accelerate or decelerate the vehicle steering right or left (e.g., for object avoidance, lane keeping, route following, etc.).

[0090] When hands-off module 450 detects using HOD sensor 208 that the driver's hands are off steering wheel 100, one or more actions may be taken. For example, if hands-off module 450 detects that the driver's hands are off steering wheel 100 (e.g., for a predetermined period of time), autonomous driving module 936 may terminate autonomous or semi-autonomous driving. Engine control module 904, motor control module 912, brake control module 920, and / or steering control module 928 may then control engine 908, electric motor 916, friction brake 924, and steering system 932, for example, based on the APP, BPP, and SWA described above. When hands-off module 450 detects using HOD sensor 208 that the driver's hands are on steering wheel 100, autonomous driving module 936 may allow autonomous or semi-autonomous driving to continue.

[0091] When the hands-off module 450 detects using the HOD sensor 208 that the driver's hands have been removed from the steering wheel 100, the indicator module 944 may output one or more indicators using one or more output devices 948 of the vehicle. Examples of output devices include displays, lights, speakers, haptic (vibration) devices, and other devices within the passenger compartment of the vehicle. For example, when the hands-off module 450 detects that the driver's hands have been removed from the steering wheel 100, the indicator module 944 may output an audible indicator using one or more speakers, a visual indicator using one or more displays and / or lights, and / or a tactile indicator using one or more haptic devices.

[0092] 10-12 include cross-sectional views of example portions of a steering wheel. As shown in FIG. 10, the insulator 816 may be omitted. In the example of FIG. 10, the sensor layer 304 and the shield layer 312 are disposed radially outward of the heater 204.

[0093] 11 may include a sensor / heater 1104 combination. The sensor / heater 1104 may include conductive wires or metal layers as described above. A selection module 1108 may connect either the heater control module 220 or the hands-off module 450 to the sensor / heater 1104 at any time. When the heater control module is connected to the sensor / heater 1104 via the selection module 1108, the heater control module 220 applies power to the sensor / heater 1104. The sensor / heater 1104 then generates heat. When the hands-off module 450 is connected to the sensor / heater 1104 via the selection module 1108, a measurement is taken by the sensor / heater 1104.

[0094] The selection module 1108 selects to connect either the heater control module 220 or the hands-off module 450 based on the state of the signal from the selection control module 1112. For example, when the signal is in a first state, the selection module 1108 may connect the heater control module 220 to the sensor / heater 1104. When the signal is in a second state, the selection module 1108 may connect the hands-off module 450 to the sensor / heater 1104. In various implementations, the selection control module 1112 may alternately switch 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 switch the signal to the second state, set the signal to the second state for a predetermined period of time, and then switch the signal back to the first state. However, the present application is also applicable to setting the signal in another suitable manner.

[0095] As illustrated in FIG. 12, the heater 204 may be omitted.

[0096] 15-16 illustrate an example of an HOD sensor 208. FIG. 15 includes an exploded perspective view of the HOD sensor 208. FIG. 16 includes a cross-sectional view of the HOD sensor 208. Referring to FIGS. 15-16, the HOD sensor 208 includes a sensor metal layer 1504, a substrate 1508, and a shield metal layer 1512. The substrate 1508 may be, for example, polyester (PET), polyurethane, plastic, foam (e.g., polyethylene foam), fleece, a polymer film, or another suitable material.

[0097] The sensor metal layer 1504 is disposed on a first surface 1516 of the substrate 1508. The shield metal layer 1512 is disposed on a second surface 1520 of the substrate 1508. The second surface 1520 is located opposite the first surface 1516. The second surface 1520 faces the heater 204.

[0098] The thicknesses illustrated in FIG. 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 sensor and shield metal layers 1504 and 1512 may be, for example, between approximately 1 micrometer and 30 micrometers (e.g., approximately 25 micrometers) or another suitable thickness. The thickness 1612 of the substrate 1508 may be, for example, between approximately 0.1 and 1 millimeter (e.g., approximately 0.55 mm) or another suitable thickness. The substrate 1508 electrically insulates the sensor metal layer 1504 from the shield metal layer 1512.

[0099] Figure 17 is an exploded perspective view of the sensor metal layer 1504. Figure 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 illustrated in Figures 17 and 18.

[0100] 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 may be, for example, aluminum, copper, or another suitable conductive material. The substrate 1708 may be, for example, polyester (PET), polyurethane, plastic, foam, fleece, polymer film, or another suitable material.

[0101] 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 located opposite the first surface 1716. The second surface 1720 faces the substrate 1508.

[0102] The thicknesses illustrated in FIG. 18 may not be to scale. However, thickness 1804 of first metal film layer 1704 and thickness 1808 of second metal film layer 1712 are less than thickness 1812 of substrate 1708. Thicknesses 1804 and 1812 of first and second metal film layers 1704 and 1712 may be, for example, between approximately 10 micrometers and 40 micrometers (e.g., 25 micrometers) or another suitable thickness. Thickness 1812 of substrate 1708 may be, for example, between approximately 0.4 millimeters and 0.7 millimeters (e.g., 0.55 millimeters) or another suitable thickness. Substrate 1708 electrically insulates first metal film layer 1704 from second metal film layer 1712.

[0103] The first metal film layer 1704 and the second metal film layer 1712 may be disposed on the substrate 1708 using, for example, a vapor deposition process. The vapor deposition process may be, for example, PVD, or another suitable type of vapor deposition process. Although an example of a vapor deposition process is provided, the first and second metal film layers 1704 and 1712 may also be applied to the substrate 1708 using a lamination process or in another suitable manner.

[0104] 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. These electrical conductors may be attached to the sensor and shield metal layers, respectively, using conductive glue or adhesive 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.

[0105] Hands-off module 450 is electrically connected to metal film layers 1504 and 1512 and measures the capacitance therebetween. Touching steering wheel 100 changes the capacitance measured by hands-off module 450. Based on this capacitance, hands-off module 450 determines whether the driver's hands have been removed from steering wheel 100. For example, hands-off module 450 may determine that the driver's hands have been removed from steering wheel 100 if the capacitance is less than a predetermined capacitance or has decreased by at least a predetermined capacitance change.

[0106] 19 is a cross-sectional view of an example portion of a 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 outward of 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 as described in conjunction with FIGS. 16-18.

[0107] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the present disclosure may be implemented in a variety of forms. Accordingly, while the present disclosure includes specific examples, the true scope of the disclosure should not be so limited, as other variations will become apparent upon study of the drawings, this specification, and the following claims. It should be understood that one or more steps in a method may be performed in a different order (or simultaneously) without altering the principles of the disclosure. Furthermore, although each of the embodiments is described above as having particular features, any one or more of these features described in connection with any embodiment of the present disclosure may also be implemented with and / or in combination with any feature of any other embodiment (even if the combination is not explicitly stated). That is, the described embodiments are not mutually exclusive, and combinations of one or more embodiments with each other remain within the scope of the present disclosure.

[0108] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed on." Except as expressly described as "direct," when a relationship between first and second elements is described in the above disclosure, the relationship may be a direct relationship where no other intervening elements exist between the first and second elements, but may also be an indirect relationship where one or more intervening elements (either spatially or functionally) exist between the first and second elements. In this specification, the phrase "at least one of A, B, and C" should be interpreted to mean the logic (A OR B OR C) using a non-exclusive logical OR, and not to mean "at least one of A, at least one of B, and at least one of C."

[0109] In the drawings, the direction of the arrows, as indicated by the arrowhead, generally indicates the flow of information (e.g., data or instructions) being discussed. For example, even if elements A and B exchange various information, an arrow may point from element A to element B if the information being discussed is related to the information being sent from element A to element B. This unidirectional arrow does not imply that there is no other information being sent from element B to element A. Furthermore, for information sent from element A to element B, element B may send a request for that information or an acknowledgment of receipt of that information to element A.

[0110] In this application, including the definitions below, the term "module" or "controller" may be interchanged with the term "circuitry." The term "module" may refer to, be a part of, or include: an application specific integrated circuit (ASIC); digital, analog, or mixed analog / digital discrete circuitry; digital, analog, or mixed analog / digital integrated circuitry; combinatorial logic circuitry; 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 a chip.

[0111] A module may include one or more interface circuits. In some examples, the interface circuit may include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any module related to the present disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may enable load balancing. In a further example, a server (also known as a remote or cloud) module may perform some functionality on behalf of a client module.

[0112] The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit includes a single processor circuit that executes some or all code from multiple modules. The term group processor circuit includes a processor circuit that executes some or all code from one or more modules in combination with additional processor circuits. References to multiple processor circuits include multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores within a single processor circuit, multiple threads within a single processor circuit, or combinations of the above. The term shared memory circuit includes a single memory circuit that stores some or all code from multiple modules. The term group memory circuit includes a memory circuit that stores some or all code from one or more modules in combination with additional memory.

[0113] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not include transitory electrical or electromagnetic signals propagated through a medium (such as by carrier wave); therefore, the term computer-readable medium may be considered to be tangible and non-transitory. Non-limiting examples of non-transitory tangible computer-readable media include non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or masked read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0114] The apparatus and methods described herein may be implemented, in part or entirely, by a special-purpose computer constructed by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks, flowchart components, and other elements described above function as software specification items and can be converted into a computer program by the routine work of a skilled engineer or programmer.

[0115] A computer program includes processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. A computer program may include or depend on stored data. A computer program may include a basic input / output system (BIOS) that interacts with hardware in a special-purpose computer, device drivers that interact with specific devices in a special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0116] A computer program may include (i) parsed text, 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 in the following languages: That is, languages ​​such as C, C++, C#, Objective-C, Swift (registered trademark), Haskell, Go, SQL, R, Lisp, Java (registered trademark), Fortran, Perl, Pascal, Curl, OCaml, Javascript (registered trademark), HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (Hypertext Preprocessor), Scala, Eiffel, Smalltalk (registered trademark), Erlang, Ruby, Flash (registered trademark), Visual Basic (registered trademark), Lua, MATLAB (registered trademark), SIMULINK, and Python (registered trademark). (Other possible items) (Item 1) A hands-off detection (HOD) sensor for a steering wheel of a vehicle, the HOD 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 conductor having a first end electrically connected directly to the first metal layer; Equipped with wherein the first metal layer is attached to the first surface of the electrically insulating substrate without the use of an adhesive. (Item 2) Item 2. The HOD sensor of item 1, wherein the first metal layer is a first metal film layer. (Item 3) a second metal film layer disposed on the second surface of the electrically insulating substrate; and a second conductor having a first end electrically connected directly to the second metal film layer; Item 3. The HOD sensor according to item 2, further comprising: (Item 4) Item 4. The HOD sensor according to item 3, wherein the first and second metal film layers are layers of aluminum film. (Item 5) Item 4. The HOD sensor of item 3, wherein the first and second metal film layers are layers of copper film. (Item 6) Item 2. The HOD sensor according to item 1, wherein the electrically insulating substrate comprises one of polyester, polyurethane, and polymer film. (Item 7) 4. The HOD sensor of 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. (Item 8) 8. The HOD sensor of claim 7, wherein the openings are all the same size. (Item 9) 8. The HOD sensor of item 7, wherein the openings include at least two different sizes. (Item 10) 8. The HOD sensor according to item 7, wherein the openings are all the same shape. (Item 11) Item 8. The HOD sensor according to item 7, wherein the opening comprises at least two different shapes. (Item 12) 8. The HOD sensor according to item 7, wherein the intervals between adjacent ones of the openings are the same. (Item 13) 8. The HOD sensor according to item 7, wherein the spacing between adjacent ones of the openings includes at least two different spacings. (Item 14) 4. The HOD sensor of claim 3, wherein the first end of the first conductor is bonded to the first metal film layer, and the first end of the second conductor is bonded to the second metal film layer. (Item 15) 4. The HOD sensor of item 3, further comprising one of a conductive adhesive and a conductive glue that adheres the first end of the first conductor to the first metal film layer and adheres the first end of the second conductor to the second metal film layer. (Item 16) 4. The HOD sensor according to item 3, wherein a first thickness of the first metal film layer and a second thickness of the second metal film layer are smaller than a third thickness of the electrically insulating substrate. (Item 17) Item 17. The HOD sensor of item 16, wherein the first and second thicknesses are less than 2 micrometers. (Item 18) Item 17. The HOD sensor of item 16, wherein the first and second thicknesses are less than 1 micrometer. (Item 19) Item 17. The HOD sensor of item 16, wherein the first and second thicknesses are less than 0.5 micrometers. (Item 20) 4. The HOD sensor according to item 3, wherein the first metal film layer and the second metal film layer are deposited on the electrically insulating substrate using a vapor deposition method. (Item 21) 21. The HOD sensor according to item 20, wherein the vapor deposition method is a physical vapor deposition method. (Item 22) The HOD sensor according to item 3; and electric heater Equipped with wherein the second metal film layer is disposed radially between the first metal film layer and the electric heater. (Item 23) Item 23. The steering wheel of item 22, further comprising an electrical insulator disposed between the second metal film layer and the electric heater. (Item 24) Item 24. The steering wheel of item 23, wherein the electrical insulator is foam. (Item 25) The HOD sensor according to item 3; and A hands-off module, electrically connecting the second ends of the first and second conductors; and Detecting when the driver's hands are off the steering wheel based on the capacitance between the first and second metal film layers. Hands-off module configured for A system comprising: (Item 26) Item 4. The HOD sensor according to item 3, wherein the first and second conductors are insulated conductors. (Item 27) A hands-off detection (HOD) sensor for a steering wheel of a vehicle, the HOD 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; Equipped with Here, each of the first metal layer and the second metal layer is 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; The HOD sensor has: (Item 28) 28. The HOD sensor of item 27, wherein the first thickness of the second electrically insulating substrate is greater than the second thickness of the first metal film layer and greater than the third thickness of the second metal film layer. (Item 29) 28. The HOD sensor according to item 27, wherein the first metal film layer and the second metal film layer are deposited on the second electrically insulating substrate using a vapor deposition method. (Item 30) Item 30. The HOD sensor according to item 29, wherein the vapor deposition method is a physical vapor deposition method. (Item 31) Item 28. The HOD sensor of item 27, further comprising a linear slit extending through the first electrically insulating substrate, the first metal layer, and the second metal layer. (Item 32) Item 32. The HOD sensor according to item 31, wherein the linear slits are arranged in a V-shape. (Item 33) Item 32. The HOD sensor of item 31, wherein the linear slits include a first row of parallel linear slits and a second row of linear slits that form a perpendicular angle with the linear slits of the first row. (Item 34) 28. The HOD sensor of item 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. (Item 35) 28. The HOD sensor of item 27, wherein the second electrically insulating substrate is made of polyester and the first and second metal film layers include aluminum.

Claims

1. A hands-off detection (HOD) sensor for a steering wheel of a vehicle, the HOD 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; a first conductor having a first end electrically connected directly to the first metal layer; wherein the first metal layer is attached to the first surface of the electrically insulating substrate without the use of an adhesive; and a plurality of openings extending through the electrically insulating substrate, the first metal layer, and the second metal layer; wherein the openings include at least two different sizes. An HOD sensor comprising:

2. The HOD sensor of claim 1 , wherein the first metal layer is a first metal film layer.

3. a second metal film layer disposed on the second surface of the electrically insulating substrate; and a second conductor having a first end electrically connected directly to the second metal film layer; The HOD sensor of claim 2 further comprising:

4. The HOD sensor of claim 3 , wherein the first metal film layer and the second metal film layer are layers of aluminum film.

5. The HOD sensor of claim 3 , wherein the first metal film layer and the second metal film layer are layers of copper film.

6. The HOD sensor of claim 1 , wherein the electrically insulating substrate comprises one of polyester, polyurethane, and polymer film.

7. The HOD sensor of claim 1 , wherein the openings are all the same shape.

8. The HOD sensor of claim 1 , wherein the opening comprises at least two different shapes.

9. The HOD sensor of claim 1 , wherein the spacing between adjacent ones of the openings is the same.

10. The HOD sensor of claim 1 , wherein the spacing between adjacent ones of the openings includes at least two different spacings.

11. 4. The HOD sensor of claim 3, wherein the first end of the first conductor is bonded to the first metal film layer and the first end of the second conductor is bonded to the second metal film layer.

12. 4. The HOD sensor of claim 3, further comprising one of a conductive adhesive and a conductive glue that adheres the first end of the first conductor to the first metal film layer and adheres the first end of the second conductor to the second metal film layer.

13. The HOD sensor of 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.

14. The HOD sensor of claim 13 , wherein the first thickness and the second thickness are less than 2 micrometers.

15. The HOD sensor of claim 13 , wherein the first thickness and the second thickness are less than 1 micrometer.

16. The HOD sensor of claim 13 , wherein the first thickness and the second thickness are less than 0.5 micrometers.

17. The HOD sensor of claim 3 , wherein the first metal film layer and the second metal film layer are deposited on the electrically insulating substrate using a vapor deposition method.

18. 18. The HOD sensor of claim 17, wherein the vapor deposition method is a physical vapor deposition method.

19. A HOD sensor according to any one of claims 3 to 5 or 11 to 18; and electric heater Equipped with wherein the second metal film layer is radially disposed between the first metal film layer and the electric heater.

20. 20. The steering wheel of claim 19, further comprising an electrical insulator disposed between the second metal film layer and the electric heater.

21. 21. The steering wheel of claim 20, wherein the electrical insulator is foam.

22. A HOD sensor according to any one of claims 3 to 5 or 11 to 18; and A hands-off module, electrically connecting the second ends of the first conductor and the second conductor; and Detecting when the driver's hands are off the steering wheel based on the capacitance between the first metal film layer and the second metal film layer. Hands-off module configured for A system comprising:

23. 19. The HOD sensor of claim 3, wherein the first conductor and the second conductor are insulated conductors.

24. A hands-off detection (HOD) sensor for a steering wheel of a vehicle, the HOD sensor comprising: a first 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 first electrically insulating substrate; and a second metal layer disposed on the second surface of the first electrically insulating substrate; Equipped with Here, each of the first metal layer and the second metal layer is 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; The HOD sensor has:

25. 25. The HOD sensor of claim 24, wherein the first thickness of the second electrically insulating substrate is greater than the second thickness of the first metal film layer and greater than the third thickness of the second metal film layer.

26. 25. The HOD sensor of claim 24, wherein the first metal film layer and the second metal film layer are deposited on the second electrically insulating substrate using a vapor deposition method.

27. 27. The HOD sensor of claim 26, wherein the vapor deposition method is a physical vapor deposition method.

28. 25. The HOD sensor of claim 24, further comprising a linear slit through the first electrically insulating substrate, the first metal layer, and the second metal layer.

29. 30. The HOD sensor of claim 28, wherein the linear slits are arranged in a V-shape.

30. 30. The HOD sensor of claim 28, wherein the linear slits include a first row of parallel linear slits and a second row of linear slits that form a perpendicular angle with the first row of linear slits.

31. 31. The HOD sensor of claim 24, 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.

32. 31. The HOD sensor of any one of claims 24 to 30, wherein the second electrically insulating substrate is made of polyester and the first and second metal film layers comprise aluminum.

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