KR102511328B1 - Steering wheel capable of hands on/off sensing - Google Patents

Abstract

A driver grip sensing steering wheel is disclosed. A driver grip sensing steering wheel according to an embodiment of the present invention includes a rim base having a core having a rim shape and a base layer made of a polymer material surrounding the core; a capacitive sensor pad attached to the rim base to detect the driver's hands-off and hands-on signals; and a control unit receiving the signal detected by the sensor pad, processing a noise signal, and discriminating the hands-off state and the hands-on state of the driver based on the signal processed with the noise signal.

Description

Driver grip sensing steering wheel {STEERING WHEEL CAPABLE OF HANDS ON/OFF SENSING}

The present invention relates to a method of manufacturing a steering wheel capable of checking whether a driver's grip is detected and a method of manufacturing a driver's grip detection pad, and more particularly, a steering wheel equipped with a sensor pad capable of checking whether a user's grip is detected during autonomous driving, and It relates to a method of manufacturing a driver's grip sensing pad.

Self-driving vehicles self-recognize surrounding environments without driver's intervention, determine driving conditions, and control the vehicle. Recently, these self-driving cars have been attracting attention as a means of transportation that can reduce traffic accidents, increase traffic efficiency, save fuel, and increase driver convenience by substituting driving.

However, depending on driving conditions, there may be cases in which the driver's intervention is required. In this situation, the vehicle in the autonomous driving mode needs to immediately give the driver control over the vehicle.

Therefore, the self-driving car needs to check whether the driver is holding the steering wheel during autonomous driving, and when it is necessary to switch control to the driver, if the driver does not hold the steering wheel, a warning is issued to the driver for safety. Needs to be.

Conventionally, whether or not the driver is gripping the steering wheel is indirectly detected through a camera, an infrared sensor, or an MDPS torque sensor applied to parts around the steering wheel where gripping occurs, but misrecognition is often caused depending on the surrounding environment.

Accordingly, there is a need for a steering wheel with a function dedicated to gripping detection that accurately checks whether the driver is gripping the steering wheel and does not significantly change the structure and aesthetics of the existing steering wheel.

The present invention has been made to solve and improve the conventional problems, and is to provide a method of manufacturing a steering wheel equipped with a capacitive sensor pad and a driver's grip sensing pad that can accurately check whether the driver grips the steering wheel.

In addition, it is intended to provide a steering wheel capable of detecting whether a driver grips each area by separating the left area and the right area of the steering wheel.

In addition, it is intended to provide a steering wheel capable of robustly detecting a gripping signal by performing correction even when the ambient temperature changes.

In addition, when the steering wheel is wrapped, it is intended to provide a steering wheel capable of improving appearance quality and performance while facilitating mounting on the steering wheel by providing smooth extensibility in the circumferential direction and the steering axis direction.

A driver grip sensing steering wheel according to an embodiment of the present invention includes a rim base having a core having a rim shape and a base layer made of a polymer material surrounding the core; a capacitive sensor pad attached to the rim base to detect the driver's hands-off and hands-on signals; and a control unit receiving the signal detected by the sensor pad, processing a noise signal, and discriminating the hands-off state and the hands-on state of the driver based on the signal processed with the noise signal.

The controller may change a criterion for determining the hands-off state and the hands-on state according to whether the driver is wearing gloves.

In addition, the control unit may include a temperature sensor that detects a temperature, and may correct hands-off and hands-on signals of the driver according to the detected temperature.

In addition, the sensor pad, the base unit capable of extension; and a conductive sheet attached to the substrate and capable of stretching along with the substrate.

In addition, the sensor pad may include a position display unit for mounting at a predetermined position of the steering wheel so as to keep the degree of extension constant when it is mounted on the steering wheel and is stretched.

In addition, the sensor pad may be separated into a left pad for detecting whether the left area of the steering wheel is gripped and a right pad for detecting whether or not the right area of the steering wheel is gripped.

In addition, the control unit may determine left gripping, right gripping, or both-handed gripping depending on whether the signals detected by the left pad and the right pad are each equal to or greater than a first reference value.

In addition, when the detected signals of the left pad and the right pad are similar and each is half of a complete grip, it may be determined that the pad is gripped with one hand.

In addition, when both the detected signals of the left pad and the right pad are less than the first reference value, and the sum of the detected signals of the left pad and the right pad is higher than the second reference value, it is determined that the one-hand grip is held, and the higher It can be determined that the signal was gripped in the area where the signal was detected.

A driver grip sensing steering wheel according to an embodiment of the present invention includes a rim base having a core having a rim shape and a base layer made of a polymer material surrounding the core; and a sensor pad attached to the rim base to detect the driver's hands-off and hands-on states, wherein the sensor pad can be stretched to be attached along the circumference of the rim base. there is.

In addition, the sensor pad, the base unit capable of extension; and an electrode unit attached to the base unit, and the electrode unit may have a structure capable of being extended in a circumferential direction of the steering wheel and an axial direction of the steering wheel.

In addition, the electrode unit, as a vertical branch extending in the width direction of the substrate portion having a meandering wave shape, a plurality of vertical branches spaced apart from each other in the circumferential direction of the steering wheel are installed; and one or more transverse branches extending in the circumferential direction of the steering wheel and having a meandering wave shape so as to electrically connect the plurality of vertical branches to each other.

Further, in a portion corresponding to the stitch portion of the steering wheel, a gap between the vertical branches may be wider than other portions.

In addition, the distance between the vertical branches may be 0.1 mm to 10.0 mm, and the distance between the widths of the vertical branches may be 0.5 mm to 10 mm.

In addition, the electrode part may be a metal such as aluminum or copper, and the substrate part may be nonwoven fabric or foam.

In addition, the electrode part is formed of a conductive paste, The substrate may be a non-woven fabric or foam.

In addition, the base unit may include a position display unit for mounting at a predetermined position of the steering wheel so as to keep the degree of elongation constant when the base unit is elongated to be mounted on the steering wheel.

In addition, the vertical branches, a first portion extending in a straight line form in a first direction at a predetermined angle in the longitudinal direction of the substrate portion; a second portion extending in a straight line at a predetermined angle in a direction opposite to the first direction in the longitudinal direction of the substrate; and a third portion connecting the first portion and the second portion, wherein the third portion may be rounded.

In addition, one horizontal branch is provided at each of the upper and lower ends of the vertical branch, so that even if one horizontal branch is cut, the other horizontal branch can electrically connect the vertical branch.

A method of manufacturing a driver grip detection pad mounted on a steering wheel according to an embodiment of the present invention includes preparing an electrode pad for detecting a driver's hands off and hands on state; preparing a non-woven fabric for supporting the electrode pad; Non-woven fabric lamination step of attaching the electrode pad and the non-woven fabric to each other; A cutting step of cutting together the laminated electrode pad and the nonwoven fabric into a shape for attaching to the steering wheel; and a terminal attachment step of attaching a terminal for applying a current to the electrode pad to the cut electrode pad and the nonwoven fabric.

In addition, the electrode pad is a stretchable conductive sheet, and the nonwoven fabric may be stretchable.

In addition, the electrode pad preparation step includes an electrode pad separation step of cutting a central portion of the elongated electrode pad and separating it into two parts, a left region pad and a right region pad, and the nonwoven fabric lamination step includes the separation of the nonwoven fabric. can be attached to the electrode pad.

In addition, the nonwoven fabric and the electrode pad It can be attached by double-sided tape.

In addition, in the cutting step, the laminated electrode pad and the nonwoven fabric may be cut using a hydraulic press or laser cutting.

In addition, the cutting step may include cutting a position display unit for mounting at a predetermined position of the steering wheel so as to make the extent of the extension constant when the steering wheel is elongated to be mounted on the steering wheel.

In addition, in the terminal attaching step, the terminal may be pressed to the electrode pad using a terminal press.

A method of manufacturing a driver grip detection pad mounted on a steering wheel according to an embodiment of the present invention includes preparing an electrode pad for detecting a driver's hands off and hands on state; preparing a non-woven fabric for supporting the electrode pad; Non-woven fabric lamination step of attaching the electrode pad and the non-woven fabric to each other; A cutting step of cutting together the laminated electrode pad and the nonwoven fabric into a shape for attaching to the steering wheel; and a terminal attachment step of attaching a terminal for applying a current to the electrode pad to the cut electrode pad and the nonwoven fabric, wherein the electrode pad preparation step may include forming a predetermined electrode pattern. .

In addition, the electrode pad preparation step may include a pattern mask printing step of printing an electrode pattern on a metal thin film; An etching step of forming an electrode pattern by performing an etching operation; and a peeling step of removing the remaining mask ink.

In addition, in the electrode pad preparation step, based on the central portion of the long electrode pad A step of separating the electrode pad into two, a left region pad and a right region pad, may be included, and the nonwoven fabric lamination step may attach the nonwoven fabric to the separated electrode pad.

In addition, in the nonwoven fabric lamination step, the electrode pad and the nonwoven fabric may be laminated by seating the electrode pad and the nonwoven fabric on a vacuum adsorption jig, respectively, and then bonding the top and bottom of the vacuum adsorption jig.

According to the driver's grip sensing steering wheel according to an embodiment of the present invention, a capacitive sensor pad is mounted to accurately check whether the driver is gripping the steering wheel.

In addition, since the left and right areas of the steering wheel are separated, whether or not the driver grips each area can be detected.

In addition, even if the ambient temperature changes, the gripping signal can be robustly detected by performing correction.

In addition, when the steering wheel is wrapped, it is possible to improve appearance quality and performance while facilitating mounting on the steering wheel by providing smooth extensibility in the circumferential direction and the steering axis direction.

In addition, since the sensor pad has an elastic material or shape, when the steering wheel is attached, it is easily expanded to prevent damage.

1 is a diagram showing the structure of a driver grip sensing steering wheel according to an embodiment of the present invention.
2 is a block diagram showing the configuration of a driver grip sensing steering wheel according to an embodiment of the present invention.
3 is a diagram schematically showing the structure of a sensor pad according to an embodiment of the present invention.
4 is a diagram illustrating a change in capacitance of a sensor pad according to a driver's grip detection.
5 is a diagram showing a change in capacitance of a sensor pad according to a temperature change before and after correction.
6 is a view for explaining situations of two-handed gripping and one-handed gripping of the steering wheel.
7 is a flowchart schematically illustrating steps of determining two-hand gripping and one-hand gripping in a driver grip sensing steering wheel according to an embodiment of the present invention.
8 is a diagram schematically illustrating a structure of a cross section of a driver grip sensing steering wheel according to an embodiment of the present invention.
9 is a view for explaining in detail the overall arrangement and shape of the electrode unit in the embodiment of FIG. 8 .
10 and 11 are diagrams illustrating detailed shapes of the electrode part in FIG. 9 .
FIG. 12 is a view showing that, in FIG. 9, only one horizontal branch is disposed at the lower portion.
13 is a diagram illustrating a method of manufacturing a driver's grip sensing pad according to an embodiment of the present invention.
14 is a diagram illustrating a method of manufacturing a driver's grip sensing pad according to another embodiment of the present invention.
15 is a diagram illustrating a method of manufacturing a driver's grip sensing pad according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the embodiment of the present invention in the drawings, parts irrelevant to the description are omitted.

Terms used in this specification are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions may include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as "include", "have" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one Or it may be understood that it does not exclude in advance the possibility of the existence or addition of other features, numbers, steps, operations, components, parts, or combinations thereof.

In addition, it does not mean that all of the objects or effects presented in the present invention should be included in a specific embodiment or only such effects should not be included, so it should not be understood that the scope of the present invention is limited by the specific embodiment. Meanwhile, among the technical configurations described in the present invention and the functions exhibited by the technical configurations, detailed descriptions of widely known and applied technical configurations and functions will be omitted.

In addition, the following embodiments are provided to more clearly explain to those with average knowledge in the art, and the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Hereinafter, with reference to the accompanying drawings, it will be described with respect to preferred embodiments according to the present invention.

Driver grip monitoring steering wheel

1 is a diagram showing the structure of a driver grip sensing steering wheel according to an embodiment of the present invention, and FIG. 2 is a block diagram showing the structure of a driver grip sensing steering wheel according to an embodiment of the present invention. 3 is a diagram schematically showing the structure of a sensor pad according to an embodiment of the present invention, and FIG. 4 is a diagram showing a change in capacitance of the sensor pad according to a driver's grip detection.

1 to 3, the driver's grip sensing steering wheel 100 according to an embodiment of the present invention determines whether the driver grips the steering wheel, that is, in a hands-on and hands-off state. A capacitive sensor pad can be used to determine . The steering wheel 100 may include a rim base 110, a sensor pad 120, and a controller 130.

In the steering wheel 100, a sensor pad 120 is wrapped around a rim base 110 manufactured by molding a polymer material such as polyurethane foam 114 on a core 112, and then leather 140 is used. Thus, the exterior can be finished. In this embodiment, the sensor pad 120 is shown as surrounding the entire rim base 110, but it goes without saying that only a part of the circumference that the driver's hand touches a lot may be wrapped.

The sensor pad 120 is attached to the rim base 110 and is provided to detect the driver's hands-on and hands-off signals, and a capacitive sensor may be provided. When the user grips or releases the grip of the steering wheel 100, the capacitance detected by the sensor pad 120 may change.

The control unit 130 may be provided on an armature portion of the steering wheel 100, receive a signal detected by the sensor pad 120, detect capacitance, and process a noise signal. Based on the processed signal of the noise signal, the controller 130 may determine the hands-on and hands-off states of the driver.

When gripping the steering wheel 100, the driver may grip the steering wheel 100 with bare hands or may grip the steering wheel 100 while wearing gloves. In addition, the temperature and humidity of the hand may be different according to the driver's condition. The capacitance detected by the sensor pad 120 may vary according to the state of the driver's hand. The control unit 130 may vary the criteria for processing the noise signal according to various states of the driver's hand.

As shown in FIG. 3 , the sensor pad 120 may be configured by being separated into a left pad for detecting whether or not the left area of the steering wheel 100 is gripped and a right pad for detecting whether or not the right area of the steering wheel 100 is gripped. there is. The separated gap is for example 0.5 mm to 10 mm , which may be an area corresponding to the 12 o'clock part or the 6 o'clock part of the steering wheel 100 .

More specifically, the sensor pad 120 may include an extensible base unit 128 and a conductive sheet 122 attached to the base unit 128 and capable of stretching together with the base unit 128 . Here, the base unit 128 may be formed of a stretchable material such as nonwoven fabric as a whole, and the conductive sheet may have, for example, a structure in which a metal such as silver or copper is deposited on a stretchable fabric such as nylon. Here, the conductive sheet 122 may be divided into a left conductive sheet 122L and a right conductive sheet 122R.

The sensor pad 120 may extend in the circumferential and axial directions of the steering wheel 100 to be mounted on the rim base 110 of the steering wheel 100 . In this case, it is ensured that the degree of elongation of the sensor pad 120 is uniform for each product, and the signal of the sensor pad 120 is stable over the entire area of the sensor pad 120 only when it is elongated to a predetermined extent for each section. can be uniform. To this end, a plurality of position display units 129 to be mounted at a predetermined position of the steering wheel 100 may be provided on the sensor pad 120 so as to keep the degree of elongation constant. The position display unit 129 may be provided in an embossed, intaglio, or concave-convex shape, and may be provided in a 'V'-shaped cut shape as in the present embodiment. When mounting the sensor pad 120 on the rim base 110 by using the position display unit 129, the operator can extend the sensor pad 120 by the corresponding position of the rim base 110 and mount it.

Referring to FIG. 4 , when the driver grips any one of the left regions of the steering wheel 100, the detection signal L_S of the sensor pad 120 corresponding to the left region is the first step for determining whether the driver grips or not. It may appear as greater than the reference value (L_T), for example, 50 pF. Here, the first reference value (L_T) may be set to 25 pF, and when the detection signal (L_S) of the sensor pad 120 is detected to be greater than or equal to the first reference value (L_T), the control unit 130 for the left area It can be judged by hands-on.

Meanwhile, when the driver does not grip the right side of the steering wheel 100, the detection signal R_S of the sensor pad 120 corresponding to the right side may appear as OpF lower than the first reference value R_T. there is. Accordingly, the control unit 130 may determine that the hands are off for the right area. Here, the first reference value (R_T) corresponding to the right region and the first reference value (L_T) corresponding to the left region may be set to be the same or may be set with a predetermined difference.

5 is a diagram illustrating a change in capacitance of a sensor pad according to a temperature change before and after correction.

The control unit 130 provided on the armature of the steering wheel 100 processes the signal detected from the sensor pad 120. The capacitance of may exhibit an increasing tendency as shown in FIG. 5 . This may actually cause an error in capacitance of the sensor pad 120 . In this embodiment, a temperature sensor (not shown) may be provided in the control unit 130 to minimize a measurement error due to a temperature change of the surrounding environment and the steering wheel 100 . The control unit 130 can actively correct an error in the detection signal of the sensor pad 120 according to the detected temperature and maintain it constant even when the temperature changes.

FIG. 6 is a view for explaining situations of two-hand gripping and one-hand gripping of a steering wheel, and FIG. 7 schematically illustrates a step of determining two-hand gripping and one-hand gripping in a driver grip sensing steering wheel according to an embodiment of the present invention. It is a flowchart showing

Referring to FIGS. 6 and 7 , the controller 130 measures the capacitance of the left sensor pad in step S110 and measures the capacitance of the right sensor pad in step S120.

The control unit 130 determines that the driver holds the steering wheel 100 with both hands (S140, FIG. 6A reference).

If it is not the case that the detection signals of both sensor pads in step S130 are equal to or greater than the first reference value, it is determined whether one of the two sensor pads outputs an output greater than or equal to the first reference value (S150). If any one sensor pad is greater than the first reference value, the controller 130 determines that the driver grips the steering wheel 100 with one hand (S160).

Meanwhile, in step S150, if signals from both sensor pads are less than the first reference value, the control unit 130 may determine whether detection signals from both sensor pads are similar to each other. As shown in FIG. 6B , when the steering wheel 100 is gripped with one hand at the 12 o'clock direction, the 12 o'clock direction of the steering wheel 100 may be an area corresponding to the boundary surface of the two separated sensor pads. In this case, when the driver holds the corresponding part with one hand, the output signal in the left area and the output signal in the right area of the steering wheel 100 are similar to each other according to the size of the area that the driver's hand touches. can appear In addition, even if the output signal in the left area and the output signal in the right area are not similar to each other, the signals of the both sensor pads are smaller than the first reference value, but the sum of the signals of the both sensor pads is greater than the second reference value. If it is large, it is determined that the boundary of the 12 o'clock or 6 o'clock is gripped with one hand (S180). If the sum of the signals of both sensor pads is smaller than the second reference value, the controller 130 determines that both hands are not gripped (S190).

Sensor pad detecting Hands Off and Hands On status

8 is a diagram for schematically explaining the structure of a cross section of a driver grip sensing steering wheel according to an embodiment of the present invention, and FIG. 9 is a diagram for explaining in detail the overall arrangement and shape of electrode units in the embodiment of FIG. 8 . It is a drawing for 10 and 11 are views for showing detailed shapes of the electrode part in FIG. 9 .

First, referring to FIG. 8A , a driver grip sensing steering wheel according to an embodiment of the present invention may include a rim base 110 and a sensor pad 120 . The rim base 110 may be composed of a core having a rim shape of a steering wheel and a polymer material surrounding the core. The sensor pad 120 is attached to the rim base 110 to detect the driver's hands off and hands on state. Here, the sensor pad 120 may be stretchable so as to be attached along the circumference of the rim base 110 .

Specifically, the sensor pad 120 may include a nonwoven fabric 128 as an extensible base unit and an electrode unit 122 that is elastically coupled to the nonwoven fabric 128 . The electrode unit 122 may have a shape having a predetermined meandering pattern as a whole, and may be made of, for example, a metal material such as copper or aluminum. The electrode unit 122 may be elongated in the circumferential direction and the axial direction of the steering wheel 100 thanks to its meandering shape. In addition, the electrode part 122 is formed of conductive paste, and the base part may be foam instead of nonwoven fabric.

In one embodiment, the electrode part 122 in the form of a thin plate having a predetermined pattern of copper or aluminum material may be prepared through a process such as etching, which will be described later. Then, a polymer substrate 126 may be attached to one surface of the electrode unit 122 . The polymer substrate 126 may serve to support the electrode unit 122 having a predetermined pattern. In addition, an inorganic double-sided tape 125 may be attached to one surface of the polymer substrate 126 to which the electrode unit 122 is not attached. The double-sided tape 125 may then be used for coupling with the rim base 110 . Meanwhile, a double-sided tape 123 may be provided on the other surface of the electrode unit 122 and may be used to couple the electrode unit 122 and the skin layer 140 . In addition, a terminal 121 for measuring capacitance may be connected to the metal layer 122 at a predetermined position. The terminal 121 may be provided in the form of a Kapton film, which is a form of a reinforcing film.

Compared to FIG. 8A, FIG. 8B is similar to FIG. 8A except that the electrode part 122 is bonded close to the leather layer 140 by a polymer substrate and the nonwoven fabric 128 is attached to the rim base 110. A detailed description will be omitted.

Referring to FIG. 9A , the electrode unit 122 may include a plurality of vertical branches 122V and one or more horizontal branches 122H. FIG. 9B is a diagram showing a more enlarged left area of the electrode part shown in FIG. 9A.

The vertical branches 122V extend in the width direction of the nonwoven fabric 128, which is the base unit, and have a wave shape meandering left and right, and when mounted, a plurality of them are spaced apart from each other in the circumferential direction of the steering wheel 100. Can be installed. In addition, the plurality of vertical branches 122V need to be electrically connected to each other, and the horizontal branches 122H extending in the circumferential direction (lateral direction in the drawing) of the steering wheel 100 but having a wavy shape meandering up and down It may be connected to a plurality of vertical branches (122V). In this embodiment, the horizontal branches 122H may be provided as a pair and provided one by one on the upper and lower portions of the nonwoven fabric 128.

Meanwhile, in the electrode unit 122 , one terminal 121 may be provided in a lower left area and a lower right area of the sensor pad 120 , respectively. The corresponding area may be an area corresponding to the 6 o'clock position when mounted on the steering wheel 10 .

In addition, as shown in FIG. 9B, the degree of elongation of the sensor pad 120 should be uniform for each product and a predetermined degree for each section so that the signal can be stable and uniform over the entire area of the sensor pad 120. To this end, a plurality of position display units 129 to be mounted at a predetermined position of the steering wheel 100 may be provided on the sensor pad 120 so as to keep the degree of elongation constant. The position display unit 129 may be provided in an embossed, intaglio, or concave-convex shape, and may be provided in a 'V'-shaped cut shape as in the present embodiment.

Meanwhile, when the steering wheel 100 is finished with leather or the like, a plurality of seams for finishing the leather may be provided in the middle of the steering wheel 100 . If the vertical branches 122V of the electrode part 122 are also provided in the region B corresponding to the stitching part, the disconnection of the electrode 122 due to breakage or cutting due to folding of the electrode part 122 in the corresponding part can happen As a result, the sensor pad 120 is damaged, making it impossible to detect whether or not the driver is gripping the steering wheel 100 . Therefore, in the present embodiment, in the area (B) corresponding to the stitch portion, the distance between the vertical branches (122V) is much wider than other parts, so that when the sensor pad 120 is mounted on the steering wheel 100, Substantially, in the region (B), the vertical branch (122V) may be omitted.

10 and 11 are views for showing detailed shapes of the electrode part in FIG. 9 .

Referring to Figure 10, the interval between the vertical branches (122V) according to an embodiment of the present invention is 0.1mm to 10.0mm, the vertical branch width may be in the range of 0.5mm to 10mm. In addition, in the repeated moire pattern, the height of the pattern may be between 3 mm and 20 mm. Thanks to these wavy patterns, even if the stretchable substrate nonwoven fabric 128 is stretched in the transverse direction or the longitudinal direction, that is, in the circumferential and axial directions when mounted on the steering wheel 100, the electrode unit 122 can also be stretched, resulting in disconnection can prevent

Of course, as shown in FIG. 10 , the electrode unit 122 may not be meandering in a curved shape, but may be provided with a zigzag electrode unit 122 in a straight line shape as shown in FIG. 11 . Specifically, the first portion (122V_1) in which the vertical branches (122V) extend linearly in the first direction at a predetermined angle in the longitudinal direction of the substrate portion (128), and the first portion (122V_1) in the longitudinal direction of the substrate portion (128) It may include a second part 122V_2 extending in a straight line at a predetermined angle in a direction opposite to the direction, and a third part 122V_3 connecting the first part 122V_1 and the second part 122V_2. . Here, the third portion 122V_3 may have rounded edges to gently connect the first portion 122V_1 and the second portion 122V_2 and prevent damage during extension.

FIG. 12 is a view showing that only one horizontal branch is disposed at the lower portion in FIG. 9 .

Referring to FIG. 12, when compared to FIG. 9, only one horizontal branch (122H) is provided at the bottom or top to connect a plurality of vertical branches (122V). On the other hand, in FIG. 9, one horizontal branch (122H) is provided at the top and bottom of each vertical branch (122V), so even if one horizontal branch (122H) is cut, the other horizontal branch (122H) is the vertical branch ( 122V) may be electrically connected to stably maintain the function of the sensor pad 120 .

Manufacturing method of driver's grip sensing pad

13 to 15 are views illustrating a method of manufacturing a driver's grip sensing pad according to an embodiment of the present invention. 13 and 14 are flowcharts for manufacturing a gripping sensing pad using an electrode pad composed of a conductive sheet without a pattern, and FIG. 15 is a flowchart composed of a thin metal plate such as copper or aluminum on which a pattern is formed, as shown in FIG. It is a flow chart of a method for manufacturing a phage sensing pad.

First, referring to FIG. 13 , in the manufacturing method of the driver's grip sensing pad according to an embodiment of the present invention, in the raw material preparation step (S210), first, the driver's hands off state and hands on state An electrode pad for detecting and a nonwoven fabric supporting the electrode pad are prepared in a predetermined standard. Here, the electrode pad may be a fabric having elasticity and conductivity, and may have, for example, a structure in which a conductive material such as silver is laminated on nylon. In addition, the nonwoven fabric may also be a stretchable material. The nonwoven fabric and the electrode pad may be prepared by being cut into a rectangular shape having the same standard. In addition, double-sided tape may be provided on the electrode pad.

Next, in the double-sided tape laminating step (S220), one side of the double-sided tape may be attached to the lower surface of the electrode pad. In this process, the electrode pad and the double-sided tape can be managed so that wrinkles do not occur. Next, in the cutting step (S230), the central portion of the laminated electrode pad and the double-sided tape may be cut and separated into two. The two separated sets may serve to sense the grip of the left and right areas of the steering wheel, respectively.

Next, in the double-sided tape laminating step (S240), the two electrode pads separated in the step (S230) are spaced apart at intervals of about 1 mm to 10 mm, and then the double-sided tape is attached to the top. Here, the double-sided tape may be attached to both of the two spaced apart electrode pads.

Next, in the non-woven fabric lamination step (S250), the non-woven fabric having a size to cover all lower portions of the two spaced apart electrode pads is attached. Then, in the cutting step (S260), the laminated electrode pad and the nonwoven fabric are cut together into a shape for attaching to a steering wheel to be mounted. Here, the laminated electrode pad and the nonwoven fabric may be cut using a hydraulic press or laser cutting.

In addition, the cutting step (S260) may include cutting a position display unit for mounting at a predetermined position of the steering wheel so that the extent of the extension is constant when the extension is performed to mount on the steering wheel. .

Here, a leather layer may be provided on the other surface of the non-woven fabric when mounted on a steering wheel, and the separated electrode pad wraps the rim base made of polyurethane or the like using the double-sided tape provided on the upper portion of the rim. Can be attached to the base.

Next, in the terminal crimping step (S270), terminals (terminals) to measure capacitance may be attached to both sides of the laminated and cut electrode pad and the nonwoven fabric through crimping pressure. Finally, in step S280, the specifications and appearance of the completed touchpad are inspected and packaged.

In the manufacturing method of the driver's grip sensing pad according to the above-described embodiment, a nonwoven fabric standardized to a predetermined size, an electrode pad, and a double-sided tape are used, and after bonding the nonwoven fabric and the electrode pad, high-pressure hydraulic press or laser cutting is performed. Since it is cut into a shape attached to the steering wheel using a back, it is easy to manage the size, and it is possible to prevent the nonwoven fabric from being different in size from the electrode pad or wrinkles from being formed.

14 shows a method of manufacturing a driver's grip sensing pad according to another embodiment of the present invention. Compared with FIG. 13, the manufacturing method of the gripping sensing pad shown in FIG. 14 is the same up to the cutting step (S330), and after the cutting step (S330), the two separated electrode pads are spaced apart and both sides are placed on the top. Only the process of attaching the nonwoven fabric using the tape is different.

More specifically, in the manufacturing method shown in FIG. 14, the two separated electrode pads are spaced apart at intervals of about 1 mm to 10 mm, and double-sided tape is attached. Here, the double-sided tape may be attached to both of the two spaced apart electrode pads. Here, a leather layer may be provided on the other surface of the nonwoven fabric when mounted on a steering wheel, and the separated electrode pad may be attached to the rim base while surrounding a rim base made of polyurethane or the like.

Referring to FIG. 15 , a method of manufacturing a driver's grip sensing pad according to another embodiment of the present invention includes an electrode pad preparation step (S410), a nonwoven fabric preparation step (S420), a nonwoven fabric lamination step (S430), and a cutting step (S440). can include

First, the electrode pad preparation step (S410) is a step of preparing an electrode pad for detecting the driver's hands off and hands on states. As shown in FIG. 9, patterned copper or aluminum, etc. and manufacturing a gripping sensing pad composed of a thin metal plate of

Specifically, the electrode pad preparation step (S410) may include an electrode pattern mask printing step (S412), an etching step (S414), a peeling step (S416), and an external processing step (S418). In the electrode pattern mask printing step (S412), a metal thin film such as copper or aluminum is prepared in a predetermined size, and then a pattern mask for forming a wavy electrode pattern is laminated as shown in FIG. 9 .

In the etching step (S414), a pattern is formed by etching the metal portion of the region without the pattern mask using an etching solution or gas. Next, mask ink remaining in the peeling step (S416) is removed.

The nonwoven fabric preparation step (S420) may be performed in parallel with the electrode pad preparation step (S410). A nonwoven fabric having a predetermined size suitable for the size of the electrode pad is prepared. Here, the non-woven fabric has elongation and may be a material with elasticity.

In the non-woven fabric lamination step (S430), the prepared non-woven fabric and the electrode pad are attached to each other using double-sided tape, etc. In this case, the non-woven fabric and the electrode pad have a positioning hole for positioning when attaching to each other in advance. can be processed.

In the cutting step (S440), the laminated electrode pad and the nonwoven fabric may be cut together into a shape for attaching to a steering wheel. Here, the laminated electrode pad and the nonwoven fabric may be cut using a hydraulic press or laser cutting. Here, the step of cutting a position display unit for mounting at a predetermined position of the steering wheel so as to make the extent of the extension constant when it is elongated to be mounted on the steering wheel.

Next, in the terminal compression step, terminals (terminals) to measure capacitance may be attached to both sides of the laminated and cut electrode pad and the nonwoven fabric through compression pressure.

In the above-described embodiments, for example, in the nonwoven fabric lamination step (S430), the electrode pad and the nonwoven fabric are seated on a vacuum adsorption jig, and then the electrode pad and the nonwoven fabric are laminated by combining the top and bottom of the vacuum adsorption jig. You can do it.

According to the driver's grip sensing steering wheel according to the above-described embodiments, a capacitive sensor pad is mounted to accurately check whether the driver is gripped.

In addition, since the left and right areas of the steering wheel are separated, whether or not the driver grips each area can be detected, and the gripping signal can be robustly detected by correcting even when the ambient temperature changes.

In addition, when wrapping the steering wheel, it is possible to improve the appearance quality and performance while facilitating mounting on the steering wheel by providing smooth extensibility in the circumferential direction and the steering axis direction, and the sensor pad is made of an elastic material or shape When the steering wheel is attached by having a, it is easily expanded to prevent damage.

Representative embodiments of the present invention have been described in detail above, but those skilled in the art will understand that various modifications are possible to the above-described embodiments without departing from the scope of the present invention. .

Therefore, the scope of the present invention should not be limited to the described embodiments and should not be defined, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

100: steering wheel, 110: rim base
120: sensor pad 130: control unit
112: core 114: polyurethane foam
122: conductive sheet, electrode unit 129: position display unit
128: substrate, non-woven fabric 123, 125: double-sided tape
126: polymer substrate 140: leather layer (skin side)
121: terminal 122H: transverse branch
122V: vertical branch

Claims (9)

As a driver grip sensing steering wheel,
A rim base having a core having a rim shape and a base layer made of a polymer material surrounding the core;
a capacitive sensor pad attached to the rim base to detect the driver's hands-off and hands-on signals; and
A control unit receiving the signal detected by the sensor pad, processing a noise signal, and determining the hands-off state and the hands-on state of the driver based on the signal processed with the noise signal;
The sensor pad is divided into a left pad for detecting whether the left area of the steering wheel is gripped and a right pad for detecting whether or not the right area of the steering wheel is gripped.
The control unit,
Depending on whether the signals detected from the left pad and the right pad are equal to or greater than a first reference value, it is determined that the left grip, the right grip, or both-hand grip is performed,
When the detected signals of the left pad and the right pad are similar, and each is half of the complete grip, it is determined that the one-hand grip is held;
When both the detected signals of the left pad and the right pad are less than the first reference value and the sum of the detected signals of the left pad and the right pad is higher than a second reference value, it is determined that the driver grips with one hand. steering wheel.
According to claim 1,
The control unit,
The driver's grip sensing steering wheel, wherein a criterion for determining the hands-off state and the hands-on state is changed according to whether the driver is wearing gloves.
According to claim 1,
The control unit,
Including a temperature sensor for detecting the temperature,
A driver's grip sensing steering wheel that corrects the driver's hands-off and hands-on signals according to the detected temperature.
According to claim 1,
The sensor pad,
Extensible base unit; and
A driver's grip sensing steering wheel comprising a; conductive sheet attached to the substrate and capable of stretching along with the substrate.
According to claim 4,
The sensor pad includes a position display unit for mounting at a predetermined position of the steering wheel so as to maintain a constant degree of extension when the sensor pad is mounted on the steering wheel and is elongated.
delete delete delete According to claim 1,
When both the detected signals of the left pad and the right pad are less than the first reference value, and the sum of the detected signals of the left pad and the right pad is higher than the second reference value, it is determined that the grip is held with one hand, and the higher signal is higher than the second reference value. A driver grip sensing steering wheel that is determined to be gripped in the detected area.

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