Steering wheel assembly

Abstract

The purpose of the present invention is to provide a steering wheel assembly in which there is an insensitive region in which a sensor cannot be disposed due to restrictions on the planning and design of the steering wheel assembly, and thus it is possible to determine whether or not a hand of an operator is in contact with the steering wheel assembly even if there is no insensitive region of the sensor. In the steering wheel assembly, if the electrostatic capacitance measured by the capacitance measurement unit when the self-capacitance detection mode is set by the mode switching unit is equal to or greater than a first threshold value, it is determined that the hand of the operator is in contact with a position overlapping with at least one of the plurality of electrodes in the rim. When the capacitance is greater than or equal to a second threshold value smaller than the first threshold value and smaller than the first threshold value, if the capacitance measured by the capacitance measurement unit in the mutual capacitance detection mode is greater than or equal to a third threshold value after switching from the self-capacitance detection mode to the mutual capacitance detection mode. If so, it is determined that the hand of the operator is in contact with the position of the rim that overlaps the gaps between the plurality of electrodes.

Description

Technical Field

[0001] The present disclosure relates to a steering wheel assembly. Background Art

[0002] In the past, there has been a steering wheel assembly that detects a human body's contact with a vehicle's steering wheel by a sensor. There is a steering wheel assembly characterized in that it is provided with an electrostatic capacitance sensor disposed on the steering wheel to detect the size of an electrostatic capacitance accompanying a human body's contact with the steering wheel, the electrostatic capacitance sensor is disposed on the outer peripheral portion of the rim of the steering wheel to form a sensing area for detecting a human body's contact with the steering wheel, and when the steering wheel is in a neutral state, a left portion of the rim relatively located to the left and a right portion opposite to the left portion across the center portion of the rim form insensitive areas that do not detect a human body's contact with the steering wheel (for example, refer to Patent Document 1).

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: JP Patent Publication No. 2019-23009 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, if the position where the hand is touching is an insensitive zone, the existing steering wheel assembly does not detect that the hand is touching. In addition, the electrostatic capacitance sensor is a type that detects self-capacitance from the structure. That is, the existing steering wheel assembly is provided with an insensitive zone in order to avoid false detection and erroneous operation in the detection using self-capacitance, but the hand cannot be detected in the insensitive zone.

[0008] Since there is inevitably an insensitive zone where a sensor cannot be arranged due to planning and design constraints of a steering wheel assembly, an object is to provide a steering wheel assembly that can determine the presence or absence of contact by an operator's hand even in the insensitive zone where a sensor does not exist.

[0009] Means for solving problems

[0010] A steering wheel assembly according to an embodiment of the present disclosure includes: a steering wheel having a rim, spokes, and a plurality of electrodes arranged to cover the rim with gaps therebetween; a mode switching unit that switches the plurality of electrodes between a self-capacitance detection mode and a mutual-capacitance detection mode; a capacitance measuring unit that measures electrostatic capacitance based on the plurality of electrodes; and a contact determining unit that determines whether or not a hand of an operator is in contact with the steering wheel based on the electrostatic capacitance measured by the capacitance measuring unit, wherein the mode switching unit selects a driving electrode from the plurality of electrodes in the mutual-capacitance detection mode and selects an electrode adjacent to the selected driving electrode as a detection electrode, and when the mode switching unit is set to the self-capacitance detection mode, the contact determining unit performs the following processing: if the electrostatic capacitance measured by the capacitance measuring unit is greater than or equal to a first threshold value, determining that the hand of the operator is in contact with a position on the rim that overlaps with at least one of the plurality of electrodes, and when the electrostatic capacitance measured by the capacitance measuring unit is greater than or equal to a second threshold value that is less than the first threshold value and less than the first threshold value, after the mode switching unit switches from the self-capacitance detection mode to the mutual-capacitance detection mode. If the electrostatic capacitance measured by the capacitance measuring unit in the mutual capacitance detection mode is equal to or greater than a third threshold value, it is determined that the operator's hand is contacting a position of the rim that overlaps with the gaps between the plurality of electrodes.

[0011] Effects of the Invention

[0012] A steering wheel assembly is provided that can determine the presence or absence of contact by an operator's hand even when a sensor is not present on the rim of the steering wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram showing an example of a steering wheel included in the steering wheel assembly according to the embodiment.

[0014] Figure 2 Yes means Figure 1 A diagram showing an example of the structure of the AA cross section in FIG.

[0015] Figure 3 It is a diagram showing an example of the structure of a steering wheel assembly according to an embodiment.

[0016] Figure 4 This is a flowchart representing an example of processing executed by the HODECU.

[0017] Figure 5A This is a diagram showing the threshold value Th1 used by the contact determination unit.

[0018] Figure 5B This is a diagram showing the threshold value Th2 used by the contact determination unit.

[0019] Figure 6This is a diagram showing the threshold value Th4 used by the contact determination unit.

[0020] Fig. 7A 3 is a diagram showing the threshold value Th3 of the contact determination unit.

[0021] Figure 7B 3 is a diagram showing the threshold value Th5 of the contact determination unit.

[0022] Figure 8 It is a diagram showing the structure of a sensor according to a modified example of the embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, an embodiment of a steering wheel assembly to which the present disclosure is applied will be described.

[0024] <Implementation Method>

[0025] Figure 1 1 is a diagram showing an example of a steering wheel 110 included in a steering wheel assembly 100 of an embodiment. The steering wheel 110 has a rim 110A, a spoke 110B, a hub 110C, a steering wheel core 111, a cover 112, and sensors 113A, 113B, 113C, and 113D. Sensors 113A to 113D are examples of multiple electrodes. In addition, when describing the structure of the steering wheel 110 below, unless otherwise specified, the structure is described when the steering wheel 110 is installed in a vehicle and is in a neutral state and viewed from the driver's seat. In addition, the driver's seat side of the steering wheel 110 is referred to as the front side, and the vehicle side of the steering wheel 110 is referred to as the back side.

[0026] exist Figure 1 The steering wheel 110 is shown on the left side of FIG. Figure 1 The central exploded view shows the steering wheel 110. Figure 1 In the center, the skin 112 is omitted to facilitate the arrangement of the sensors 113A to 113D. Figure 1 The right side of FIG. 1 shows a portion of the rim 110A of the steering wheel 110 in an enlarged manner. Figure 1 On the right side, a portion of the rim 110A is shown in a straight line.

[0027] exist Figure 1 , two spokes 110B extending to the left and right from the wheel axis 110C at the center of the steering wheel 110 are shown, but the number of spokes 110B may be any number. In addition, the rim 110A may not be in a circular shape, but may be in a rectangular ring shape, a D-shape, etc., or may not be in a ring shape. In addition, the steering wheel core 111 has the same shape as the steering wheel 110, and has a rim and spokes. The rim and spokes of the steering wheel core 111 are portions corresponding to the rim 110A and spokes 110B of the steering wheel 110.

[0028] The cover 112 is a member covering the rim of the steering wheel core 111 and is a portion that the hands of the operator (driver) of the vehicle directly touch. As an example, the cover 112 is made of genuine leather, artificial leather, or resin.

[0029] As an example, the cover 112 is integrated with the sensors 113A to 113D, and the rim of the steering wheel core 111 is covered with the sensors 113A to 113D provided between the cover 112 and the rim of the steering wheel core 111. When the rim of the steering wheel core 111 is covered with the cover 112 integrated with the sensors 113A to 113D, the rim 110A of the steering wheel 110 is formed. In addition, the spokes of the steering wheel core 111 are formed into the spokes 110B of the steering wheel 110 by attaching a decorative member made of resin or the like.

[0030] The skin 112 integrated with the sensors 113A to 113D is a sheet-like member before being mounted on the rim of the steering wheel core 111. The skin 112 integrated with the sensors 113A to 113D is sewn while covering the rim of the steering wheel core 111, thereby forming a stitch 112A. The stitch 112A is formed along the circumferential direction of the rim 110A of the steering wheel 110. The stitch 112A is formed, for example, on the inner peripheral side, the inner peripheral side and the outer peripheral side, or the outer peripheral side of the rim 110A of the steering wheel 110.

[0031] Sensors 113A to 113D are electrodes containing a conductor, and are provided to detect whether the operator's hand is touching the steering wheel 110. Cables 114 connected to HODECU (Hands Off Detection Electronic Control Unit) and the like are connected to sensors 113A to 113D. Sensors 113A to 113D may be, for example, sensors obtained by applying silver paste on a resin film or the like, or electrodes obtained by forming aluminum foil or copper foil on a resin film or the like.

[0032] As an example, sensor 113A is located on the front side of the right half of rim 110A, and as an example, sensor 113B is located on the front side of the left half of rim 110A. In addition, as an example, sensor 113C is located on the back side of the right half of rim 110A, and as an example, sensor 113D is located on the back side of the left half of rim 110A.

[0033] The electrostatic capacitance between the sensors 113A to 113D and the operator's hand changes depending on whether the operator's hand is touching the rim 110A of the steering wheel 110. In addition, the electrostatic capacitance between the sensors 113A to 113D and the operator's hand is different when the operator's hand is gripping the rim 110A of the steering wheel 110 and when the operator's hand is lightly touching it. For example, the electrostatic capacitance when gripping is greater than the electrostatic capacitance when lightly touching it.

[0034] If the skin 112 integrated with the sensors 113A to 113D is mounted on the rim of the steering wheel core 111, since the sensors 113A to 113D do not exist in the trace 112A, the electrostatic capacitance between the sensors 113A to 113D and the operator's hand is different when the operator's hand is in contact with the trace 112A of the rim 110A of the steering wheel 110 and when the operator's hand is in contact with a portion other than the trace 112A of the rim 110A (a portion overlapping with at least one of the sensors 113A to 113D). The portion where the sensors 113A to 113D do not exist, such as the trace 112A, is an example of a position in the rim 110A of the steering wheel 110 that overlaps with the gaps between the plurality of electrodes.

[0035] In addition, here, the case where the portion of the rim 110A of the steering wheel 110 where the sensors 113A to 113D do not exist is the stitch 112A, but there may be portions other than the stitch 112A where the sensors 113A to 113D do not exist. For example, when the cover 112 is bonded instead of being sewn, the portion shown as the stitch 112A becomes the seam of the cover 112, and portions where the sensors 113A to 113D do not exist may occur in the seam.

[0036] In addition, for example, in a case where the decorative component of the spoke 110B of the steering wheel 110 is arranged to wrap around the rim 110A, since the skin 112 integrated with the sensors 113A to 113D cannot be installed on a part of the rim 110A of the steering wheel 110, even if there is no stitch 112A, a part where the sensors 113A to 113D do not exist will be generated on the rim 110A of the steering wheel 110.

[0037] In addition, when the stitch 112A does not exist on the outer peripheral side of the rim 110A, the gap between the sensor 113A located on the front side of the right half of the rim 110A and the sensor 113C located on the back side of the right half of the rim 110A becomes the portion where the sensor does not exist. In addition, when the stitch 112A does not exist on the outer peripheral side of the rim 110A, the gap between the sensor 113B located on the front side of the left half of the rim 110A and the sensor 113D located on the back side of the left half of the rim 110A becomes the portion where the sensor does not exist. In addition, the gap between the sensors 113A and 113C located on the front side of the rim 110A and the gap between the sensors 113B and 113D located on the back side of the rim 110A also become the portion where the sensor does not exist.

[0038] The steering wheel assembly 100 of the embodiment can detect that the operator's hand is touching the rim 110A of the steering wheel 110 even when the operator's hand is touching a portion of the rim 110A of the steering wheel 110 where the sensors 113A to 113D are not present, such as the stitch 112A.

[0039] <Outline of the Method for Detecting Electrostatic Capacitance in the Steering Wheel Assembly 100 of the Embodiment>

[0040] Figure 2 Yes means Figure 1 Here, the structure of the AA section in FIG. Figure 2 The following will describe the outline of a method for detecting electrostatic capacitance in the steering wheel assembly 100 of the embodiment. Figure 2 In the figure, since the electrostatic capacitance between the operator's hand H and the sensor 113A or 113C is represented by the symbol of a capacitor, the hand H is shown separated from the epidermis 112 or the trace 112A, indicating that the hand is in contact with the epidermis 112 or the trace 112A.

[0041] like Figure 2 As shown in the figure, as an example, in the rim 110A of the steering wheel 110, on the inner circumference side ( Figure 2 The left side of the figure) is provided with a stitch 112A, and the outer peripheral side ( Figure 2 The insensitive zone without a sensor is provided on the right side of the steering wheel 110. The inner circumference side trace 112A and the outer circumference side insensitive zone without a sensor correspond to the position of the gap between sensors 113A and 113C. In addition, here, the right half of the steering wheel 110 with sensors 113A and 113C is described, but the same is true for the left half with sensors 113B and 113D, the front side with sensors 113A and 113B, and the back side with sensors 113C and 113D.

[0042] In the self-capacitance detection mode, the steering wheel assembly 100 selects the sensor 113A or 113C as the detection electrode and measures the electrostatic capacitance between the detection electrode and the ground. In the self-capacitance detection mode, the detection electrode also has the function of a drive electrode. When a certain degree of electrostatic capacitance can be measured in the self-capacitance detection mode, it is determined that the hand H is contacting the steering wheel 110 at a position overlapping with the sensor 113A or 113C.

[0043] In addition, when a certain large static capacitance cannot be measured by sensor 113A or 113C in the self-capacitance detection mode, the steering wheel assembly 100 switches to the mutual capacitance detection mode. Then, the steering wheel assembly 100 selects one of the sensors 113A and 113C as the driving electrode, and selects the electrode adjacent to the driving electrode (the other of the sensors 113A and 113C) as the detection electrode, and measures the static capacitance between the driving electrode and the detection electrode. When a certain large static capacitance cannot be measured in the mutual capacitance detection mode, the steering wheel assembly 100 determines that the hand H is contacting the steering wheel 110 at a position overlapping with the trace 112A or the insensitive zone where there is no sensor.

[0044] <Structure of Steering Wheel Assembly 100>

[0045] Figure 3 : is a diagram showing an example of the structure of a steering wheel assembly 100 of an implementation scheme. The steering wheel assembly 100 includes a steering wheel 110, a capacitance measuring unit 120, and a HODECU 130. The HODECU 130 has a mode switching unit 131 and a contact determination unit 132. The HODECU 130 is connected to an ADASECU (Advanced Driver-Assistance System Electronic Control Unit) 200. As an example, the ADASECU 200 is a device that controls a system that performs advanced driving assistance, such as an autonomous driving system. As an example, the autonomous driving system can be a system of level 3 or above among the levels 0 to 5 of autonomous driving specified by the JSAE (Japan Society of Automotive Engineers).

[0046] exist Figure 3 , only sensors 113A to 113D and trace 112A are shown with respect to steering wheel 110. Trace 112A is a dead zone where sensors 113A to 113D do not exist.

[0047] The capacitance measuring unit 120 is provided between the sensors 113A to 113D and the contact determination unit 132 of the HODECU 130, and is a measuring circuit that converts the analog outputs from the sensors 113A to 113D into digital form and outputs the digital output to the contact determination unit 132. The static capacitance output by the capacitance measuring unit 120 after digital conversion is a digital conversion value (Raw value) before the HODECU 130 obtains a differential value (ΔAD) from a given reference value.

[0048] The HODECU 130 is implemented by a computer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output interface, an internal bus, etc. The mode switching unit 131 and the contact determination unit 132 show the functions of the program executed by the HODECU 130 as functional blocks.

[0049] The mode switching unit 131 selects the sensors 113A to 113D as driving electrodes or detection electrodes, and switches between the self-capacitance detection mode and the mutual capacitance detection mode. In the self-capacitance detection mode, the mode switching unit 131 selects the sensors 113A to 113D as detection electrodes in a time-division manner, and the capacitance measuring unit 120 measures the electrostatic capacitance as the self-capacitance. At this time, the remaining three sensors not used in the detection of the electrostatic capacitance are used as shields.

[0050] Alternatively, the sensors 113A to 113D may be simultaneously selected as detection electrodes, and the electrostatic capacitance may be measured as self-capacitance by the capacitance measuring unit 120. In this case, shielding is not set.

[0051] Here, shielding means driving the sensor which is not set as a detection electrode and is not used in electrostatic capacitance detection at an arbitrary potential, which may be a ground level (0 V).

[0052] In addition, in the mutual capacitance detection mode, the mode switching unit 131 selects a driving electrode from the sensors 113A to 113D, and selects a sensor adjacent to the selected driving electrode as a detection electrode. The sensors 113A to 113D are adjacent to each other in the direction connecting the front and back of the steering wheel 110, or in the circumferential direction of the steering wheel 110. Therefore, the mode switching unit 131 selects any one of the sensors 113A to 113D as the driving electrode, and selects the sensor adjacent to the selected driving electrode as the detection electrode. In the mutual capacitance detection mode, the electrostatic capacitance between the driving electrode and the detection electrode is measured by the capacitance measuring unit 120 as the mutual capacitance.

[0053] The contact determination unit 132 determines whether the operator's hand H is in contact with the rim 110A of the steering wheel 110 based on the electrostatic capacitance measured by the capacitance measurement unit 120. Figure 4 The details of the processing performed by the contact determination unit 132 are described with reference to the flowchart of FIG.

[0054] <Flowchart>

[0055] Figure 4This is a flowchart representing an example of processing executed by the HODECU 130 .

[0056] When the contact determination unit 132 starts the process, it sets the mode switching unit 131 to the self-capacitance detection mode, and the capacitance measuring unit 120 obtains the static capacitance measured sequentially in time division in each of all sensors 113A to 113D (step S1). In step S1, the contact determination unit 132 obtains the static capacitance obtained by the capacitance measuring unit 120, that is, the digital conversion value (Raw value).

[0057] In addition, in step S1, the mode switching unit 131 may drive the three sensors other than the sensor for detecting electrostatic capacitance as shields. The contact determination unit 132 may cause the mode switching unit 131 to perform such processing. By driving the three sensors other than the sensor for detecting electrostatic capacitance as shields, the influence of the grounding around the sensor for detecting electrostatic capacitance can be suppressed, and the electrostatic capacitance can be stably detected.

[0058] The contact determination unit 132 obtains the electrostatic capacitance as a differential value (ΔAD) by subtracting a given reference value from the digital conversion value (Raw value), and determines whether there is an electrostatic capacitance greater than the threshold value Th2 in the obtained electrostatic capacitance (step S2). The threshold value Th2 is an example of a second threshold value, and is set to be able to determine in the self-capacitance detection mode that the hand H is in contact with the electrostatic capacitance of a certain portion of the rim 110A of the steering wheel 110, including the trace 112A and the insensitive zone where no sensor exists. Since the electrostatic capacitance of at least any one of the sensors 113A to 113D increases to some extent even when the hand H is in contact with the insensitive zone of the rim 110A of the steering wheel 110, the threshold value Th2 is used to detect that the hand H is in contact with a certain portion of the rim 110A of the steering wheel 110, including the trace 112A and the insensitive zone where no sensor exists.

[0059] If the contact determination unit 132 determines that there is a capacitance greater than the threshold value Th2 among the obtained capacitances (S2: Yes), it determines whether the capacitance (ΔAD) is greater than the threshold value Th1 (step S3). The threshold value Th1 is an example of a first threshold value, and is set to be a capacitance that can determine that the hand H is in contact with the position of the rim 110A of the steering wheel 110 that overlaps with at least one of the sensors 113A to 113D. Here, the position of the rim 110A that overlaps with at least one of the sensors 113A to 113D is the portion of the rim 110A other than the dead zone where there is no sensor, and the trace 112A.

[0060] In particular, the threshold value Th1 is set by assuming that the hand H is firmly holding the trace 112A of the rim 110A and there is no portion other than the insensitive zone of the sensor. In the state where the hand H is firmly holding the trace 112A of the rim 110A and there is no portion other than the insensitive zone of the sensor, a very large static capacitance can be obtained, so in order to determine that the hand H is in contact with the steering wheel 110, the processing of step S3 is provided.

[0061] In addition, in step S2, after determining that the hand H is touching a certain part of the rim 110A of the steering wheel 110 including the trace 112A and the insensitive zone where there is no sensor (S2: Yes), it is determined whether the hand H is touching a part of the rim 110A other than the trace 112A and the insensitive zone where there is no sensor, thereby being able to determine whether the position that the hand H is touching is the trace 112A and the insensitive zone where there is no sensor.

[0062] If the contact determination unit 132 determines that the electrostatic capacitance is greater than or equal to the threshold value Th1 (S3: YES), it determines that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4). When the contact determination unit 132 completes the processing of step S4, the HODECU 130 sends the determination result to the ADASECU 200, and the process returns to the beginning.

[0063] Furthermore, if the contact determination unit 132 determines in step S3 that the electrostatic capacitance is not greater than the threshold value Th1 (S3: No), the mode switching unit 131 switches to the mutual capacitance detection mode (step S5). The mode switching unit 131 selects the sensor 113A to 113D that detects an electrostatic capacitance greater than the threshold value Th2 in step S2 as a driving electrode, and selects a sensor adjacent to the sensor serving as the driving electrode as a detection electrode.

[0064] For example, when sensor 113A is selected as the driving electrode, sensor 113C adjacent to sensor 113A across the rim of steering wheel core 111 or sensor 113B located on the opposite side of the rim of steering wheel core 111 may be selected as the detection electrode. Furthermore, when sensor 113C is selected as the driving electrode, sensor 113A adjacent to sensor 113C across the rim of steering wheel core 111 or sensor 113D located on the opposite side of the rim of steering wheel core 111 may be selected as the detection electrode. Similarly, when sensor 113B is selected as the driving electrode, sensor 113D adjacent to sensor 113B across the rim of steering wheel core 111 or sensor 113A located on the opposite side of the rim of steering wheel core 111 may be selected as the detection electrode. When sensor 113D is selected as the driving electrode, sensor 113B adjacent to sensor 113D across the rim of steering wheel core 111 or sensor 113C located on the opposite side of the rim of steering wheel core 111 may be selected as the detecting electrode.

[0065] In addition, the process proceeds to step S5 when the static capacitance in step S2 is greater than the threshold value Th2 and the static capacitance in step S3 is less than the threshold value Th1. A certain degree of large static capacitance can be obtained, but there is a possibility that the hand H does not touch the part of the rim 110A of the steering wheel 110 that overlaps with the sensors 113A~113D, such as the positive contact trace 112A, and there is no possibility of an insensitive area of ​​the sensor.

[0066] The contact determination unit 132 obtains the electrostatic capacitance between the driving electrode and the detecting electrode using the driving electrode and the detecting electrode selected in step S5 (step S6 ).

[0067] In addition, in step S5, instead of selecting the sensor that detects the electrostatic capacitance above the threshold value Th2 in step S2 as the driving electrode, the sensors 113A to 113D may be selected as the driving electrodes, and the driving electrodes and the detection electrodes may be selected in a round robin manner. In this case, the process of selecting the driving electrodes and the detection electrodes in step S5 and the process of detecting the electrostatic capacitance between the driving electrodes and the detection electrodes in step S6 may be repeatedly performed.

[0068] Here, the so-called selecting the driving electrodes and the detecting electrodes in a cyclic form means selecting all sensors as driving electrodes in sequence, and selecting sensors adjacent to the selected driving electrodes as detecting electrodes, thereby measuring the electrostatic capacitance (mutual capacitance) between the driving electrodes and the detecting electrodes when all sensors are selected as driving electrodes.

[0069] The contact determination unit 132 determines whether the obtained electrostatic capacitance is greater than or equal to a threshold value Th3 (step S7). The threshold value Th3 is an example of a third threshold value, and is set to be an electrostatic capacitance that can determine whether the hand H is in contact with the trace 112A in the rim 110A of the steering wheel 110 in the mutual capacitance detection mode and does not have a dead zone of the sensor.

[0070] If the contact determination unit 132 determines that the acquired electrostatic capacitance is greater than or equal to the threshold value Th3 (S7: Yes), it is determined that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4). The process proceeds to step S4 via step S7, which means that the hand H is in contact with the trace 112A in the rim 110A of the steering wheel 110 and there is no dead zone of the sensor.

[0071] In addition, if the contact determination unit 132 determines in step S7 that the acquired electrostatic capacitance is not greater than the threshold value Th3 (S7: No), it determines that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8). For example, when the electrostatic capacitance is acquired in step S1, the hand H is in contact with the stitch 112A in the rim 110A of the steering wheel 110 and there is no dead zone of the sensor, but when the electrostatic capacitance is acquired in step S6, when the hand H is no longer in contact with the rim 110A of the steering wheel 110, the process proceeds from step S7 to step S8. When the contact determination unit 132 finishes the processing of step S8, the HODECU 130 sends the determination result of the contact determination unit 132 to the ADASECU 200, and the process returns to the beginning.

[0072] In addition, if the contact determination unit 132 determines in step S2 that there is no electrostatic capacitance greater than the threshold value Th2 in the obtained electrostatic capacitance (ΔAD) (S2: No), it determines whether there is an electrostatic capacitance greater than the threshold value Th4 greater than the initial value in the electrostatic capacitance (Raw value) of the sensors 113A to 113D obtained in step S1 (step S9). Threshold Th4 is an example of the fourth threshold. The so-called initial value is the output value of each of the sensors 113A to 113D when the hand H is not in contact with the steering wheel 110. Such an initial value is a value determined by the structure of the sensors 113A to 113D, and as an example, the HODECU 130 can maintain it in the internal memory. In addition, each time the value of the threshold value Th4 is set, the sensitivity when determining whether the hand H is in contact with the steering wheel 110 can be adjusted according to the degree of estimated increase relative to the initial value.

[0073] Threshold Th4 is set to the electrostatic capacitance that can determine that hand H is lightly touching a certain part of the rim 110A of the steering wheel 110, including the trace 112A and the insensitive area where there is no sensor in the self-capacitance detection mode. Step S9 is the following processing: by looking at the increase in the electrostatic capacitance (Raw value) of sensors 113A to 113D obtained in step S1, if hand H is lightly touching a certain part of the rim 110A, it is determined which sensor (one of 113A to 113D) is close to. In the case where hand H is lightly touching a certain part of the rim 110A, or hand H is close to the rim 110A of the steering wheel 110, in step S9, the range is narrowed down to one sensor.

[0074] If the contact determination unit 132 determines that there is an electrostatic capacitance greater than the threshold value Th4 among the electrostatic capacitances of the sensors 113A to 113D (S9: Yes), the mode switching unit 131 switches to the mutual capacitance detection mode (step S10). The mode switching unit 131 selects the sensor determined to be greater than the threshold value Th4 in step S9 among the sensors 113A to 113D as a driving electrode, and selects a sensor adjacent to the sensor serving as the driving electrode as a detection electrode.

[0075] The contact determination unit 132 obtains the electrostatic capacitance between the driving electrode and the detecting electrode using the driving electrode and the detecting electrode selected in step S10 (step S11 ).

[0076] The contact determination unit 132 determines whether the obtained electrostatic capacitance is greater than the threshold value Th5 (step S12). Threshold value Th5 is an example of the fifth threshold value, and is set to be able to determine whether the hand H is in contact with the electrostatic capacitance of the trace 112A in the rim 110A of the steering wheel 110 or the insensitive zone where there is no sensor in the mutual capacitance detection mode. The processing of step S12 is the same as that of step S7, but the threshold value is different. The process proceeds to step S12 when it is determined in step S2 that there is no electrostatic capacitance greater than the threshold value Th2 in the obtained electrostatic capacitance (ΔAD) (S2: No), which is a case where the hand H is not in contact with any part of the rim 110A of the steering wheel 110, including the trace 112A and the insensitive zone where there is no sensor.

[0077] The threshold value Th3 used in step S7 is a static capacitance that can determine whether the hand H is touching the trace 112A in the rim 110A of the steering wheel 110 in the mutual capacitance detection mode and does not have a dead zone of the sensor. In contrast, the threshold value Th5 used in step S12 is a static capacitance that can determine whether the hand H is touching the trace 112A in the rim 110A of the steering wheel 110 in the mutual capacitance detection mode and does not have a dead zone of the sensor, and is therefore smaller than the threshold value Th3.

[0078] When the contact determination unit 132 determines that the acquired electrostatic capacitance is greater than or equal to the threshold value Th5 (S12: Yes), the HODECU 130 determines that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4). The process proceeds to step S4 via step S12 when the hand H is in contact with the insensitive area of ​​the rim 110A of the steering wheel 110 where there is no sensor trace 112A.

[0079] In addition, when the contact determination unit 132 determines that the acquired electrostatic capacitance is not equal to or greater than the threshold value Th5 (S12: No), the HODECU 130 determines that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8). For example, when the electrostatic capacitance is acquired in step S1, the hand H is very lightly in contact with the dead zone such as the stitch 112A in the rim 110A of the steering wheel 110 and there is no sensor, but when the electrostatic capacitance is acquired in step S11, the hand H is no longer in contact with the rim 110A of the steering wheel 110, and the process proceeds from step S12 to step S8.

[0080] Furthermore, when the contact determination unit 132 determines in step S9 that there is no electrostatic capacitance greater than or equal to the threshold value Th4 among the electrostatic capacitances of the sensors 113A to 113D (S9: No), the HODECU 130 determines that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8). For example, when the hand H is away from the rim 110A of the steering wheel 110, the flow proceeds from step S9 to step S8.

[0081] <Description of Each Threshold>

[0082] <Threshold Th1>

[0083] Figure 5A 1 is a diagram showing a threshold value Th1 used by the contact determination unit 132 in the process of step S3. Figure 5A In FIG. 1 , the vertical axis represents the electrostatic capacitance ΔAD as a difference value (ΔAD) obtained by subtracting a given reference value from a digital conversion value (Raw value).

[0084] The threshold Th1 is set based on the assumption that the hand H is firmly holding the trace 112A of the rim 110A in the self-capacitance detection mode and that there is no part other than the insensitive zone of the sensor. Therefore, the contact determination unit 132 is set to Figure 4 The maximum value among the thresholds used in the flowchart.

[0085] If the contact determination unit 132 determines in step S2 that the obtained electrostatic capacitance (ΔAD) has an electrostatic capacitance greater than or equal to the threshold value Th2 (S2: Yes), it determines whether the electrostatic capacitance is greater than or equal to the threshold value Th1 (step S3). Figure 5AIf the capacitance ΔAD1 is equal to or greater than the threshold value Th1 as shown in FIG. 1 , the contact determination unit 132 determines that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4 ).

[0086] On the other hand, if Figure 5A If the electrostatic capacitance ΔAD2 shown in FIG. 1 is smaller than the threshold value Th1 , the contact determination unit 132 determines that there is a possibility that the hand H is not in contact with the rim 110A of the steering wheel 110 , and advances the flow to step S5 .

[0087] <Threshold Th2>

[0088] Figure 5B 2 is a diagram showing a threshold value Th2 used by the contact determination unit 132 in the process of step S2. Figure 5B In FIG. 1 , the vertical axis represents the electrostatic capacitance ΔAD as a difference value (ΔAD) obtained by subtracting a given reference value from a digital conversion value (Raw value).

[0089] Threshold Th2 is set to be able to determine in the self-capacitance detection mode that the hand H is touching the static capacitance of a certain part of the rim 110A of the steering wheel 110 including the trace 112A and the insensitive zone where there is no sensor. Since it is also possible to determine that the hand H is touching the insensitive zone of the rim 110A, it is lower than threshold Th1. Figure 5B The threshold value Th1 is also shown in FIG.

[0090] The contact determination unit 132 determines in step S2 whether there is a capacitance greater than the threshold value Th2 among all the capacitances measured by the capacitance measurement unit 120 in step S1. Figure 5B If the capacitance ΔAD3 shown in FIG. 1 is greater than the threshold value Th2, the contact determination unit 132 advances the process to step S3. On the other hand, if the total capacitance measured by the capacitance measurement unit 120 in step S1 is as shown in FIG. Figure 5B If the contact determination unit 132 determines that the contact value is smaller than the threshold value Th2 as shown in the electrostatic capacitance ΔAD4, the contact determination unit 132 advances the flow to step S9.

[0091] <Threshold Th4>

[0092] Figure 6 4 is a diagram showing the threshold value Th4 used by the contact determination unit 132 in the process of step S9. Figure 6 In FIG. 1 , the vertical axis represents the electrostatic capacitance (Raw value) measured by the capacitance measurement unit 120 in the self-capacitance detection mode.

[0093] The threshold value Th4 is set to be a static capacitance that can determine that the hand H is lightly touching a certain point of the rim 110A of the steering wheel 110 in the self-capacitance detection mode, not a difference value (ΔAD) from a given reference value, but a digital conversion value (Raw value) before obtaining the difference value (ΔAD). This is to capture a slight change in the static capacitance (Raw value) output by the digital conversion of the capacitance measuring unit 120.

[0094] If the contact determination unit 132 determines in step S9 that the capacitance of the sensors 113A to 113D is greater than the threshold value Th4 (S9: Yes), the process proceeds to step S10 because there is a possibility that the hand H is lightly touching a certain part of the rim 110A of the steering wheel 110. Figure 6 If the capacitance Raw1 is equal to or greater than the threshold value Th4, as shown in FIG. 1 , the contact determination unit 132 advances the flow to step S10.

[0095] On the other hand, if Figure 6 If the hand H is smaller than the threshold value Th4 as shown in the electrostatic capacitance Raw2, the contact determination unit 132 determines that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8).

[0096] <Threshold Th3>

[0097] Fig. 7A 3 is a diagram showing a threshold value Th3 used by the contact determination unit 132 in the process of step S7. Fig. 7A In FIG. 1 , the vertical axis represents the electrostatic capacitance ΔAD measured by the capacitance measurement unit 120 in the mutual capacitance detection mode.

[0098] The threshold Th3 is set to an electrostatic capacitance capable of determining whether the hand H is touching the trace 112A in the rim 110A of the steering wheel 110 in the mutual capacitance detection mode and whether there is no dead zone of the sensor.

[0099] If the contact determination unit 132 determines in step S7 that Fig. 7A If the static capacitance ΔAD5 shown is greater than the threshold value Th3, it is determined that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4). In step S2, it is determined that the hand H is in contact with at least a certain part of the rim 110A, and in step S3, it is determined that the hand H is not in contact with a position overlapping with at least one of the sensors 113A to 113D, and then the hand H is in contact with the trace 112A in the rim 110A of the steering wheel 110 and the state where the dead zone of the sensor does not exist is detected.

[0100] Furthermore, if the contact determination unit 132 determines in step S7 that Fig. 7A If the electrostatic capacitance ΔAD6 is not equal to or greater than the threshold value Th3 ( S7 : NO), it is determined that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8 ).

[0101] <Threshold Th5>

[0102] Figure 7B 1 is a diagram showing the threshold value Th5 used by the contact determination unit 132 in the process of step S12. Figure 7B In FIG. 1 , the vertical axis represents the electrostatic capacitance ΔAD measured by the capacitance measurement unit 120 in the mutual capacitance detection mode.

[0103] The threshold Th5 is set to a static capacitance that can determine whether the hand H is touching the trace 112A in the rim 110A of the steering wheel 110 in the mutual capacitance detection mode and does not have a dead zone of the sensor. When the process proceeds to step S12, it is different from the process proceeding to step S7 in that it is determined that there is no static capacitance greater than the threshold Th2 in the static capacitance (ΔAD) obtained in step S2 (S2: No).

[0104] The threshold Th5 is used to detect that the hand H is only touching the trace 112A in the rim 110A of the steering wheel 110 and there is no insensitive area of ​​the sensor. Therefore, it is smaller than the threshold Th3 used to determine the state where the hand H is touching the trace 112A in the rim 110A and there is no insensitive area of ​​the sensor.

[0105] If the contact determination unit 132 determines in step S12 that Figure 7B If the static capacitance ΔAD7 shown is greater than the threshold Th5, it is determined that the hand H is in contact with the rim 110A of the steering wheel 110 (step S4). This indicates that the hand H is only in contact with the trace 112A in the rim 110A of the steering wheel 110 and there is no dead zone of the sensor.

[0106] Furthermore, if the contact determination unit 132 determines in step S12 that Figure 7B If the static capacitance ΔAD8 shown is not greater than the threshold value Th5, it is determined that the hand H is not in contact with the rim 110A of the steering wheel 110 (step S8). Thus, even if the hand H is only in contact with the trace 112A in the rim 110A of the steering wheel 110 and there is no dead zone of the sensor, it is known that there is no contact.

[0107] <Effect>

[0108] The steering wheel assembly 100 comprises: a steering wheel 110 having a rim 110A, spokes 110B, and sensors 113A to 113D arranged inside the rim 110A; a mode switching unit 131, which selects the sensors 113A to 113D as driving electrodes or detection electrodes and can switch between a self-capacitance detection mode and a mutual capacitance detection mode; a capacitance measuring unit 120, which measures the static capacitance detected in the driving electrode and the detection electrode; and a contact determination unit 132, which determines whether the operator's hand H is in contact with the steering wheel 110 based on the static capacitance measured by the capacitance measuring unit 120. In the mutual capacitance detection mode, the mode switching unit 131 selects a driving electrode from the sensors 113A to 113D, and selects an electrode adjacent to the selected driving electrode as a detection electrode. When the mode switching unit 131 is set to the self-capacitance detection mode, the contact determination unit 132 performs the following processing: If the static capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th1, it is determined that the operator's hand H is contacting a position in the rim 110A that overlaps with at least one of the sensors 113A to 113D. When the static capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th2 that is less than the threshold value Th1 and less than the threshold value Th1, after the mode switching unit 131 is switched from the self-capacitance detection mode to the mutual capacitance detection mode, if the static capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th3, it is determined that the operator's hand H is contacting a position in the rim 110A that overlaps with the gaps between the sensors 113A to 113D. Therefore, even when it is determined that the operator's hand H is not in contact with the rim 110A in the self-capacitance detection mode, the presence or absence of contact of the hand H can be determined by measuring the electrostatic capacitance in the mutual capacitance detection mode.

[0109] Therefore, it is possible to provide the steering wheel assembly 100 which can determine the presence or absence of contact by the operator's hand H in the dead zone of the rim 110A of the steering wheel 110 where no sensor is present.

[0110] If the electrostatic capacitance measured by the capacitance measuring unit 120 in the mutual capacitance detection mode is less than the threshold Th3, the contact determination unit 132 determines that the operator's hand H is not in contact with the rim 110A. Therefore, it can be determined that the operator's hand H is not in contact with the dead zone where there is no sensor.

[0111] In addition, when the static capacitance measured by the capacitance measuring unit 120 in the self-capacitance detection mode is less than the threshold value Th2 and the static capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th4, the contact determination unit 132 switches the mode switching unit 131 from the self-capacitance detection mode to the mutual capacitance detection mode. If the static capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th5, it is determined that the operator's hand H is contacting the position of the rim 110A that overlaps with the gap between the sensors 113A to 113D. Therefore, even when the static capacitance is small, such as when the static capacitance measured by the capacitance measuring unit 120 in the self-capacitance detection mode is determined to be less than the threshold value Th2, it can be determined that the operator's hand H is contacting the insensitive zone where there is no sensor.

[0112] If the static capacitance measured by the capacitance measuring unit 120 in the mutual capacitance detection mode is less than the threshold value Th5, the contact determination unit 132 determines that the operator's hand H does not contact the rim 110A. Therefore, even in the case where the static capacitance is small, such as when the static capacitance measured by the capacitance measuring unit 120 in the self-capacitance detection mode is determined to be less than the threshold value Th2, it can be determined that the operator's hand H does not contact the dead zone where there is no sensor.

[0113] In addition, the threshold value Th5 is smaller than the threshold value Th3. The threshold value Th5 is used to detect that the hand H is only touching the trace 112A in the wheel rim 110A of the steering wheel 110 and there is no insensitive area of ​​the sensor, and is smaller than the threshold value Th3 used to determine that the hand H is touching the trace 112A in the wheel rim 110A and there is no insensitive area of ​​the sensor.

[0114] The threshold value Th4 is a threshold value for comparison with a value (raw value) obtained by subtracting a reference value from the electrostatic capacitance measured by the capacitance measuring unit 120 in the self-capacitance detection mode. Therefore, it is possible to detect a slight change in the electrostatic capacitance (raw value) output by the capacitance measuring unit 120 after digital conversion, and determine whether the operator's hand H is touching a dead zone where no sensor exists.

[0115] Furthermore, when the electrostatic capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th2, the contact determining unit 132 determines whether the electrostatic capacitance measured by the capacitance measuring unit 120 is greater than the threshold value Th1. Therefore, it can be determined whether the position being touched by the hand H is the trace 112A and there is no dead zone of the sensor.

[0116] The gaps between the sensors 113A to 113D are located at the seams 112A or seams of the cover 112 covering the rim 110A. Therefore, the presence or absence of contact by the operator's hand H can be determined at the seams 112A or seams of the cover 112, which are insensitive areas.

[0117] <Modification>

[0118] Figure 8 FIG. 1 is a diagram showing a structure of a sensor 113 according to a modified example of the embodiment. Figures 1 to 3 In the above description, the steering wheel 110 is provided with four sensors 113A to 113D. However, the number of sensors is not limited to four, and may be larger, for example.

[0119] exist Figure 8 , 21 sensors 113 (3 rows and 7 columns) arranged with 7 sensors in the horizontal direction and 3 sensors in the vertical direction, and the initial values ​​(raw values) of the electrostatic capacitance of the 7 sensors in the second row measured by the capacitance measuring unit 120 are shown. Such 21 sensors 113 are provided on the sheet-like epidermis 112 (refer to Figure 1 ). The trace 112A as an insensitive area is provided in the portion of the 8th column of the sensor 113 corresponding to the configuration of 3 rows and 7 columns. For example, when wound around the rim of the steering wheel core 111, the trace 112A is located between the sensor 113 in the 1st column and the sensor 113 in the 7th column.

[0120] The following describes the processing executed by the HODECU 130 when the operator's hand H touches the trace 112A, which is a dead zone, located at a position corresponding to the eighth column of the second row.

[0121] When the contact determination unit 132 starts the process, it sets the mode switching unit 131 to the self-capacitance detection mode, and the capacitance measuring unit 120 obtains the static capacitance measured sequentially in time division at each of the 21 sensors 113 (step S1). In step S1, the contact determination unit 132 obtains the static capacitance obtained by the capacitance measuring unit 120, that is, the digital conversion value (Raw value).

[0122] In addition, in step S1, the mode switching unit 131 may drive the 20 sensors other than the sensor for detecting electrostatic capacitance as shields. The contact determination unit 132 may cause the mode switching unit 131 to perform such processing. By driving the 20 sensors other than the sensor for detecting electrostatic capacitance as shields, the influence of the grounding around the sensor for detecting electrostatic capacitance can be suppressed, and the electrostatic capacitance can be stably detected.

[0123] The contact determination unit 132 obtains the electrostatic capacitance as a differential value (ΔAD) by subtracting a given reference value from the digital conversion value (Raw value), and determines whether there is an electrostatic capacitance greater than a threshold value Th2 in the obtained electrostatic capacitance (step S2). Since the operator's hand H is touching the stitch 112A, the electrostatic capacitance becomes smaller than the threshold value Th2, and the process proceeds to step S9.

[0124] Here, the initial value (Raw value) of the electrostatic capacitance of each sensor acquired by the capacitance measurement unit 120 will be described.

[0125] The 21 sensors in the 1st to 7th columns have different positions from the trace 112A, and the number of sensors 113 located on the left and right in the horizontal direction is different. For example, the sensor in the 6th column of the 2nd row is the 2nd on the left and the 6th on the right from the trace 112A, and the initial value (Raw value) of the electrostatic capacitance is lower than that of the sensor in the 7th column of the 2nd row. This is because the more sensors there are between the trace 112A, the smaller the capacitive coupling with the ground around the steering wheel 110, etc., and the lower the initial value. Therefore, the initial values ​​of the electrostatic capacitance (Raw value) measured by the capacitance measuring unit 120 of the 21 sensors in the 1st to 7th columns and the 1st to 3rd rows are different. The initial value is the electrostatic capacitance (Raw value) when the hand H does not touch the trace 112A.

[0126] In step S9, the contact determination unit 132 uses the threshold Th4 to determine the sensors 113 in each row and column. If the electrostatic capacitance (Raw value) of the sensors 113 in the 1st column and the 7th column adjacent to the trace 112A exceeds the threshold Th4, the possibility of the hand H contacting the trace 112A can be detected, and the process proceeds to step S10.

[0127] The processing of steps S10 to S12 is as described above.

[0128] As mentioned above, the steering wheel assembly according to the exemplary embodiment of the present disclosure has been described, but the present disclosure is not limited to the specifically disclosed embodiment, and various modifications and changes can be made without departing from the scope of the claims.

[0129] In addition, the present international application claims priority based on Japanese Patent Application No. 2022-125647 filed on August 5, 2022, the entire contents of which are incorporated herein by reference.

[0130] Explanation of symbols

[0131] 100 Steering wheel assembly

[0132] 110 Steering Wheel

[0133] 110A rim

[0134] 110B Spoke

[0135] 111 Steering wheel core

[0136] 112 Epidermis

[0137] 112A trace (an example of a position overlapping with gaps between multiple electrodes)

[0138] 113, 113A to 113D Sensor (an example of multiple electrodes)

[0139] 120 Capacitance measurement unit

[0140] 130 HODECU

[0141] 131 Mode switching unit

[0142] 132 Contact determination unit

[0143] 200 ADASECU.

Claims

1. A steering wheel assembly comprising: A steering wheel having a rim, spokes, and a plurality of electrodes having gaps and configured to cover the rim; a mode switching unit configured to switch between a self-capacitance detection mode and a mutual capacitance detection mode for the plurality of electrodes; a capacitance measuring unit configured to measure an electrostatic capacitance based on the plurality of electrodes; and a contact determination unit that determines whether or not the operator's hand is in contact with the steering wheel based on the electrostatic capacitance measured by the capacitance measurement unit, The mode switching unit selects a driving electrode from the plurality of electrodes in the mutual capacitance detection mode, and selects an electrode adjacent to the selected driving electrode as a detection electrode. When the mode switching unit sets the self-capacitance detection mode, the contact determination unit performs the following processing: If the electrostatic capacitance measured by the capacitance measuring unit is equal to or greater than a first threshold value, it is determined that the operator's hand is in contact with a position on the rim that overlaps with at least one of the plurality of electrodes. When the electrostatic capacitance measured by the capacitance measuring unit is greater than or equal to the second threshold value which is less than the first threshold value and less than the first threshold value, if, after the mode switching unit switches from the self-capacitance detection mode to the mutual capacitance detection mode, the electrostatic capacitance measured by the capacitance measuring unit in the mutual capacitance detection mode is greater than or equal to the third threshold value, it is determined that the operator's hand is contacting a position on the rim that overlaps with the gaps between the multiple electrodes.

2. The steering wheel assembly according to claim 1, wherein: The contact determination unit performs a process of determining that the hand of the operator is not in contact with the rim when the electrostatic capacitance measured by the capacitance measurement unit in the mutual capacitance detection mode is smaller than the third threshold value.

3. The steering wheel assembly according to claim 1, wherein: The contact determination unit performs the following processing: when the electrostatic capacitance measured by the capacitance measuring unit in the self-capacitance detection mode is less than the second threshold value and the electrostatic capacitance measured by the capacitance measuring unit is greater than the fourth threshold value, if after the mode switching unit switches from the self-capacitance detection mode to the mutual capacitance detection mode, the electrostatic capacitance measured by the capacitance measuring unit is greater than the fifth threshold value, it is determined that the operator's hand is contacting a position in the rim that overlaps with the gaps between the multiple electrodes.

4. The steering wheel assembly according to claim 3, wherein: The contact determination unit performs a process of determining that the operator's hand is not in contact with the rim if the electrostatic capacitance measured by the capacitance measurement unit in the mutual capacitance detection mode is smaller than the fifth threshold value.

5. The steering wheel assembly according to claim 3, wherein: The fifth threshold is smaller than the third threshold.

6. The steering wheel assembly according to claim 3, wherein: The fourth threshold value is a threshold value for comparison with a value obtained by not subtracting a reference value from the electrostatic capacitance measured by the capacitance measuring unit in the self-capacitance detection mode.

7. The steering wheel assembly according to any one of claims 1 to 6, wherein: The contact determination unit executes a process of determining whether the electrostatic capacitance measured by the capacitance measurement unit is equal to or greater than the first threshold value when the electrostatic capacitance measured by the capacitance measurement unit is equal to or greater than the second threshold value.

8. The steering wheel assembly according to claim 1, wherein: The gaps between the multiple electrodes are located at the seams or seams of the skin covering the rim.

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