阅读说明：本技术 方向盘单元 (Steering wheel unit ) 是由 大馆正太郎 于 2018-07-23 设计创作，主要内容包括：本发明涉及一种方向盘、方向盘单元和传感片。在方向盘单元(12)中,在方向盘(26)的轮缘(42)的外周部(68)配置静电电容式传感器(56)而形成有检测人体与方向盘(26)的接触的感测区域(100),并且,在方向盘(26)处于中立状态时轮缘(42)中的相对位于左侧的左部(左轮辐连接部48L)和隔着轮缘(42)的中心部而与左部相向的右部(右轮辐连接部48R),分别形成有不检测人体与方向盘(26)的接触的盲区(102)。据此,能够防止误检测为方向盘正在被把持。(The invention relates to a steering wheel, a steering wheel unit and a sensor sheet. In a steering wheel unit (12), a capacitance sensor (56) is disposed on an outer peripheral portion (68) of a rim (42) of a steering wheel (26) to form a sensing region (100) for detecting contact between a human body and the steering wheel (26), and a blind region (102) for not detecting contact between a human body and the steering wheel (26) is formed in each of a left portion (left spoke connecting portion (48L)) of the rim (42) that is positioned on the left side relative to the rim and a right portion (right spoke connecting portion (48R)) of the rim (42) that faces the left portion across the center of the rim (42) when the steering wheel (26) is in a neutral state. This can prevent erroneous detection that the steering wheel is being gripped.)

1. A steering wheel unit that detects contact of a human body with a steering wheel of a vehicle by a sensor,

the steering wheel unit is characterized in that,

a capacitance sensor provided on the steering wheel for detecting a magnitude of capacitance accompanying contact between a human body and the steering wheel,

the capacitance type sensor is disposed on an outer peripheral portion of a rim of the steering wheel to form a sensing region for detecting contact between a human body and the steering wheel,

a blind area not detecting contact of a human body with the steering wheel is formed on at least a portion of the rim,

the vehicle is capable of switching between manual steering and automatic steering,

further comprising a contact detection unit for detecting whether or not a human body is in contact with the steering wheel based on the capacitance detected by the capacitance sensor,

the contact detection unit detects whether or not a human body is in contact with the steering wheel based on whether or not the capacitance detected by the capacitance sensor is equal to or greater than a first threshold value during manual steering,

the contact detection unit sets a second threshold value that is larger than the first threshold value when the automatic steering is returned to the manual steering, and detects whether a human body is in contact with the steering wheel based on whether or not the capacitance detected by the capacitance sensor is equal to or larger than the second threshold value.

2. Steering wheel unit according to claim 1,

in the steering wheel, a left portion of the rim, which is located on a left side with respect to the rim, and a right portion of the rim, which faces the left portion with respect to the center portion of the rim, are formed with blind areas, which do not detect contact between a human body and the steering wheel, respectively.

3. Steering wheel unit according to claim 2,

the lower portion of the rim, which is located relatively downward when the steering wheel is in the neutral state, is also formed with the blind area.

4. Steering wheel unit according to claim 2,

the blind area is formed at the connecting part of the spoke and the rim of the steering wheel.

5. Steering wheel unit according to claim 3,

the blind area is formed at the connecting part of the spoke and the rim of the steering wheel.

6. Steering wheel unit according to any of claims 1 to 5,

the electrostatic capacitance type sensor is sheet-shaped and is adhered to the rim.

7. Steering wheel unit according to any of claims 1 to 5,

the capacitance sensor is disposed at an outer edge portion of the rim where the blind area is formed.

Technical Field

The present invention relates to a steering wheel (steering wheel) installed in a vehicle, a steering wheel unit (steering wheel unit) for detecting contact between a human body and the steering wheel by a sensor, and a sensor sheet (sensor sheet) of an electrostatic capacitance sensor (electrostatic capacitance sensor) attached to the steering wheel.

Background

There is a vehicle that can switch between manual steering mainly performed by a driver and automatic steering mainly performed by a system. Such a vehicle detects whether or not the driver is in contact with (holding) the steering wheel at a predetermined time (timing), for example, when returning from automatic steering to manual steering. A capacitance sensor is used for detecting a touch on a steering wheel. A steering wheel having a capacitive sensor provided on a rim (rim) is shown in japanese patent application laid-open No. 5816827, 2015-131544 and 2015-147531.

Disclosure of Invention

For example, in the automatic steering, the driver may lie on the steering wheel due to a poor body or the like. It is envisioned that the driver's arm or elbow is in contact with the left and right portions of the rim. When switching from the automatic steering control to the manual steering control, the vehicle requests the driver to hold the steering wheel. At this time, if the electrostatic capacity sensor is provided at a contact position in the rim, which is in contact with the arm or elbow of the driver, the electrostatic capacity sensor detects that a human body is in contact with the steering wheel. As a result, the following false detections may occur: although the driver is not holding the steering wheel, it is detected that the driver is holding the steering wheel.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a steering wheel, a steering wheel unit, and a sensor sheet that prevent erroneous detection that the steering wheel is being gripped.

The first technical means is a steering wheel unit which detects contact of a human body with a steering wheel of a vehicle by a sensor,

the steering wheel unit is characterized in that,

the steering apparatus includes a capacitance sensor that is provided on the steering wheel and detects a magnitude of capacitance (capacitance) associated with contact between a human body and the steering wheel,

the capacitive sensor is disposed on an outer peripheral portion of a rim of the steering wheel to form a sensing area (sensing area) for detecting contact between a human body and the steering wheel,

in addition, a left portion of the rim, which is located on a left side with respect to the rim, and a right portion of the rim, which faces the left portion with the center of the rim interposed therebetween, are formed with blind areas, which do not detect contact between a human body and the steering wheel when the steering wheel is in the neutral state.

As in the above configuration, if a dead zone (dead zone) is formed in the left portion of the rim, which is located on the left side, and the right portion of the rim, which is located opposite to the left portion, when the steering wheel is in the neutral state, the capacitance sensor does not detect the magnitude of the capacitance accompanying the contact of the human body with the steering wheel even if the arm or the elbow of the driver comes into contact with the left portion and the right portion of the rim. Therefore, it is possible to prevent erroneous detection that the steering wheel is being gripped.

In the first technical means, the following may be applied: the lower portion of the rim, which is located relatively downward when the steering wheel is in the neutral state, is also formed with the blind area.

If the driver presses the steering wheel with his legs, sometimes the legs come into contact with the lower part of the rim. At this time, the capacitance sensor detects the magnitude of capacitance accompanying the contact of the human body with the steering wheel. This causes erroneous detection that the steering wheel is being gripped even if the driver does not grip the steering wheel. If a blind spot is formed in the lower portion of the rim that is relatively located downward when the steering wheel is in the neutral state as in the above-described configuration, the capacitance-type sensor does not detect the magnitude of the capacitance accompanying the contact of the human body with the steering wheel even if the legs of the driver contact the lower portion of the rim. Therefore, it is possible to prevent erroneous detection that the steering wheel is being gripped.

In the first technical means, the following may be applied: the blind area is formed at a connection portion of a spoke (spoke) of the steering wheel and the rim (rim).

When the driver lies prone on the steering wheel due to a poor body or the like, the driver tends to lean the body weight against a portion of the steering wheel having high rigidity, that is, a portion where the spoke and the rim are connected, by bringing the arm or the elbow into contact with the portion. If a blind spot is formed in a portion where the driver is likely to bring the arm or the elbow into contact with the driver as in the above configuration, the capacitance type sensor does not detect the magnitude of the capacitance generated as the human body comes into contact with the steering wheel even if the driver lies on the front of the steering wheel. Therefore, it is possible to prevent erroneous detection that the steering wheel is being gripped.

The second technical means is a steering wheel unit which detects contact of a human body with a steering wheel of a vehicle by a sensor,

the steering wheel unit is characterized in that,

a capacitance sensor provided on the steering wheel for detecting capacitance accompanying contact between a human body and the steering wheel,

the capacitance type sensor is disposed on an outer peripheral portion of a rim of the steering wheel to form a sensing region for detecting contact between a human body and the steering wheel,

and a blind area which does not detect contact between a human body and the steering wheel is formed at a connection portion between the spoke and the rim of the steering wheel.

When the driver lies prone on the steering wheel due to a poor body or the like, the driver tends to lean the body weight against a portion of the steering wheel having high rigidity, that is, a portion where the spoke and the rim are connected, by bringing the arm or the elbow into contact with the portion. If a blind spot is formed in a portion where the driver is likely to bring the arm or the elbow into contact with the driver as in the above configuration, the capacitance type sensor does not detect the magnitude of the capacitance generated as the human body comes into contact with the steering wheel even if the driver lies on the front of the steering wheel. Therefore, it is possible to prevent erroneous detection that the steering wheel is being gripped.

In the first or second aspect, the following may be applied: the electrostatic capacitance type sensor is sheet-shaped and is adhered to the rim.

According to the above structure, the sensing region and the blind region can be formed on the rim by a simple structure and operation of attaching the sensing sheet, and thus the manufacturing cost is reduced.

In the first or second aspect, the following may be applied: the capacitance sensor is disposed at an outer edge portion of the rim where the blind area is formed.

If the capacitance type sensor is disposed at the outer edge of the rim where the blind area is formed as in the above configuration, the driver can detect that the steering wheel is being gripped by correctly gripping the rim. Thus, the grip state of the steering wheel can be accurately detected.

In the first or second aspect, the following may be applied: the vehicle is capable of switching between manual steering and automatic steering,

further comprising a contact detection unit for detecting whether or not a human body is in contact with the steering wheel based on the capacitance detected by the capacitance sensor,

the contact detection unit detects whether or not a human body is in contact with the steering wheel based on whether or not the capacitance detected by the capacitance sensor is equal to or greater than a first threshold value during manual steering,

the contact detection unit sets a second threshold value that is larger than the first threshold value when the automatic steering is returned to the manual steering, and detects whether a human body is in contact with the steering wheel based on whether or not the capacitance detected by the capacitance sensor is equal to or larger than the second threshold value.

In a vehicle capable of switching between manual steering and automatic steering, a driver is required to hold a steering wheel when returning from automatic steering to manual steering. As in the above configuration, if it is detected whether or not a human body is in contact with the steering wheel by comparison with the second threshold value that is larger than the first threshold value set at the time of manual steering when returning from automatic steering to manual steering, the recognition accuracy of gripping is improved.

In the first or second aspect, the following may be applied: the wheel rim is composed of a plurality of spoke connecting parts and spoke non-connecting parts, wherein the spoke connecting parts are connected with the spokes; the spoke non-connecting portions are interposed between the spoke connecting portions adjacent to each other and are not connected to the spokes,

the capacitance type sensor is provided on an outer peripheral portion of the rim along a cross-sectional circumferential direction of the rim,

the width of the capacitive sensor in the circumferential direction of the cross section of the capacitive sensor provided in the spoke connecting portion is narrower than the width of the capacitive sensor in the circumferential direction of the cross section of the capacitive sensor provided in the spoke non-connecting portion.

In the first or second aspect, the following may be applied: the electrostatic capacitance type sensor is composed of a first part, a second part, a third part, a fourth part and a fifth part, wherein,

the first portion extends from the center of the sheet in the longitudinal direction to both ends;

the second portion extends from one end portion toward the center;

the third portion extends from the other end toward the center;

the fourth portion is located between the first portion and the second portion;

the fifth location is located between the first location and the third location,

the first portion, the second portion, and the third portion have a first width in a width direction of the sheet,

the fourth portion and the fifth portion have a second width in a width direction of the sheet,

the second width is narrower than the first width.

A third technical solution is a steering wheel, having a rim and spokes,

the steering wheel is characterized in that it is,

the rim is composed of a plurality of spoke connecting parts and spoke non-connecting parts, wherein,

a plurality of spoke connecting parts are connected with the spokes;

the spoke non-connecting portions are interposed between the spoke connecting portions adjacent to each other and are not connected to the spokes,

an electrostatic capacity type sensor is provided on an outer peripheral portion of the rim along a cross-sectional circumferential direction of the rim,

the width of the capacitive sensor in the circumferential direction of the cross section of the capacitive sensor provided in the spoke connecting portion is narrower than the width of the capacitive sensor in the circumferential direction of the cross section of the capacitive sensor provided in the spoke non-connecting portion.

As in the above configuration, if the width of the capacitance sensor provided in a portion where the driver is likely to bring the arm or the elbow into contact with the capacitance sensor is narrower than the width of the capacitance sensor provided in another portion, the capacitance sensor does not detect the capacitance accompanying the contact of the human body with the steering wheel even if the driver is lying on his/her stomach on the steering wheel. Therefore, it is possible to prevent erroneous detection that the steering wheel is being gripped.

The fourth technical means is a sensor sheet which is made of a conductive material and is adhered to a rim of a steering wheel to form an electrostatic capacity type sensor,

the sensor sheet is characterized in that,

comprises a first part, a second part, a third part, a fourth part and a fifth part, wherein,

the first portion extends from the center of the sheet in the longitudinal direction to both ends;

the second portion extends from one end portion toward the center;

the third portion extends from the other end toward the center;

the fourth portion is located between the first portion and the second portion;

the fifth location is located between the first location and the third location,

the first portion, the second portion, and the third portion have a first width in a width direction of the sheet,

the fourth portion and the fifth portion have a second width in a width direction of the sheet,

the second width is narrower than the first width.

According to the above structure, the sensing region and the blind region can be formed on the rim by such a simple structure and operation as to attach the sensing sheet, and thus the manufacturing cost is reduced.

According to the present invention, it is possible to prevent erroneous detection that the steering wheel is being gripped.

The above objects, features and advantages should be readily understood from the following description of the embodiments with reference to the accompanying drawings.

Drawings

Fig. 1 is a configuration diagram of a vehicle including a steering wheel unit according to the present embodiment.

Fig. 2 is a front view of the steering wheel according to the present embodiment.

Fig. 3 is a rear view of the steering wheel according to the present embodiment.

Fig. 4 is a sectional view IV-IV of the steering wheel shown in fig. 2.

Fig. 5 is a V-V sectional view of the steering wheel shown in fig. 2.

Fig. 6 is an expanded view of the sensor sheet.

Fig. 7 is a flowchart of a processing operation performed by the steering wheel unit.

Detailed Description

The steering wheel, the steering wheel unit, and the sensor sheet according to the present invention will be described in detail below with reference to the accompanying drawings by referring to preferred embodiments.

[1 Structure of vehicle 10 ]

As shown in fig. 1, the steering wheel unit 12 according to the present embodiment is provided in a vehicle 10. The vehicle 10 can appropriately switch between manual steering in which steering is performed mainly by the driver and automatic steering in which steering is performed mainly by the system (the automatic steering device 14). In the present embodiment, an autonomous vehicle is assumed as the vehicle 10, which can perform driving and braking operations mainly on the system in addition to steering mainly on the system. The vehicle 10 includes an automatic steering device 14, a travel device 16, and a notification device 18, in addition to the steering wheel unit 12.

The autopilot unit 14 is constituted by an ECU, and includes an arithmetic unit such as a processor and a storage unit such as a ROM and a RAM. The automatic driving device 14 realizes various functions by executing a program stored in the storage device by the arithmetic device. The automatic driving device 14 acquires information required for automatic driving, for example, external information (detection results of a camera, a radar, and the like), driving state information (a driving speed, an acceleration/deceleration), navigation information, and the like of the vehicle 10 from various sensors or devices, and outputs a control instruction for automatically performing operations of driving, steering, and braking to the driving device 16.

The running device 16 includes a driving force device 20, a steering device 22, and a brake device 24. The driving force device 20 has a driving force ECU and a driving source including an engine and/or a driving motor. The driving force device 20 generates driving force in accordance with a control instruction of driving by the driver operating an accelerator pedal or output from the automatic driving device 14. The steering device 22 has an Electric Power Steering (EPS) ECU and an EPS actuator. The steering device 22 generates a steering force in accordance with an operation of a steering wheel 26 by a driver or a control instruction for steering output from the autopilot 14. The brake device 24 has a brake ECU and a brake actuator. The brake device 24 generates a braking force in accordance with an operation of a brake pedal by a driver or a control instruction of braking output from the automatic driving device 14.

The notification device 18 includes a notification ECU, a display device, an audio device, and a tactile device. The notification device 18 notifies the driver in accordance with a notification instruction output from the autopilot device 14 or a contact determination device 28 described later.

[2 Structure of steering wheel Unit 12 ]

The steering wheel unit 12 includes a steering wheel 26 and a contact determination device 28.

The contact determination device 28 is constituted by an ECU, and includes a sensor circuit 30, an arithmetic device 32 such as a processor, and a storage device 34 such as a ROM and a RAM.

The sensor circuit 30 is electrically connected to a capacitance sensor 56 provided on the steering wheel 26. The sensor circuit 30 includes: a power supply that supplies power to the capacitance sensor 56; a measuring device (e.g., a current sensor or the like) that measures a detection value C corresponding to the magnitude of capacitance detected by the capacitance sensor 56; and a switch that switches on/off of energization to the electrostatic capacitance sensor 56.

The arithmetic device 32 realizes various functions by executing programs stored in the storage device 34. In the present embodiment, the arithmetic device 32 functions as an integrated control unit 36, a contact detection unit 38, and a notification instruction unit 40. In the contact detection process between the human body and the steering wheel 26, the integrated control unit 36 performs processes other than those performed by the contact detection unit 38 and the notification instruction unit 40. The contact detection unit 38 detects whether or not a human body is in contact with the steering wheel 26, based on a detection value C of the measurement device of the sensor circuit 30. When the contact detection unit 38 does not detect that a human body (driver) is in contact with the steering wheel 26 while the driver must hold the steering wheel 26, the notification instruction unit 40 outputs a notification instruction to the notification device 18.

The storage device 34 stores, in addition to various programs, a first threshold value and a second threshold value (> first threshold value) as determination threshold values for whether or not a human body is in contact with the steering wheel 26.

[3 Structure of steering wheel 26 ]

The front view and the rear view of the steering wheel 26 shown in fig. 2 and 3 show the operation state (posture) of the steering wheel 26 when the vehicle 10 is running straight. This operation state (posture) is hereinafter referred to as a neutral state. In fig. 2, the vertical direction on the paper surface is taken as the vertical direction of the steering wheel 26 in the neutral state, and the horizontal direction on the paper surface is taken as the horizontal direction of the steering wheel 26 in the neutral state. The front direction of the paper is defined as the front direction of the steering wheel 26 in the neutral state, and the back direction of the paper is defined as the back direction of the steering wheel 26 in the neutral state. In fig. 3, the front, rear, left, and right directions are opposite to those of fig. 2. In fig. 2 and 3, in order to facilitate understanding of the arrangement of the electrodes, which is one of the features of the present invention, a state is shown in which the rim leather 60 of the substantially left half portion of the rim 42 is removed. The structure of the rim 42 of the steering wheel 26 is the same on both the left and right sides.

As shown in fig. 2 and 3, the steering wheel 26 has a rim 42 formed in a ring shape; a hub (hub)44 connected to a steering shaft (steering shaft), not shown; and spokes (spokes) 46 interposed between the rim 42 and the hub 44. The steering wheel 26 of the present embodiment has 3 spokes 46 extending in the left-right direction and downward from the boss 44 toward the rim 42. The number of spokes 46 may be other than 3, and the extending direction thereof may not be the left-right direction and the lower direction.

The rim 42 is composed of three spoke connecting parts 48 and spoke non-connecting parts 50, wherein the three spoke connecting parts 48 are connected with the spokes 46; the spoke non-connecting portions 50 are interposed between the spoke connecting portions 48 adjacent to each other and are not connected to the spokes 46. In fig. 2 and 3, a boundary between the spoke connecting portion 48 and the spoke non-connecting portion 50 is indicated by a single-dot chain line. In the neutral state, the spoke connection portion 48 located at the left portion of the rim 42 is referred to as a left spoke connection portion 48L, the spoke connection portion 48 located at the right portion is referred to as a right spoke connection portion 48R, and the spoke connection portion 48 located at the lower portion is referred to as a lower spoke connection portion 48B. The rigidity of the spoke connecting portion 48 is higher than that of the spoke non-connecting portion 50.

The rim 42 has a laminated structure having a cross section (a cross section parallel to the central axis of the steering wheel 26) composed of a plurality of layers. As shown in fig. 4, in the spoke non-connecting portion 50, the rim resin 54 covers the entire rim core 52 corresponding to the skeleton, the capacitance type sensor 56 covers a part of the rim resin 54, the elastic member 58 covers the remaining part of the rim resin 54, and the rim leather 60 covers the capacitance type sensor 56 and the elastic member 58. The capacitance sensor 56 corresponds to an electrode made of a conductive member, and is insulated from surrounding members. The capacitance sensor 56 and the elastic member 58 have substantially the same thickness.

As shown in fig. 5, the right spoke connecting portion 48R and the left spoke connecting portion 48L (hereinafter referred to as the right spoke connecting portion 48R or the like) have a rim core 52, a rim resin 54, a capacitance sensor 56, an elastic member 58, and a rim leather 60, as in the spoke non-connecting portion 50. In the right spoke connecting portion 48R and the like, the rim core metal 52 is connected to the spoke core metal 62, the rim resin 54 is connected to the spoke resin 64, the rim leather 60 is connected to the spoke leather 66, and the elastic member 58 is provided on a part of the front surface side and the back surface side. The lower spoke connecting portion 48B, not shown in cross section, is substantially the same as the right spoke connecting portion 48R and the like, except that the capacitance sensor 56 is not provided.

As shown in fig. 4 and 5, a portion located on the outer peripheral side of the rim 42 is referred to as an outer peripheral portion 68, and a portion located on the inner peripheral side of the rim 42 is referred to as an inner peripheral portion 70, with a plane S spreading in the front-rear direction (front-rear direction) from a center portion O2 of the cross section of the rim 42 as a boundary. The outermost portion of each member is referred to as an outer edge portion 72.

As shown in fig. 4, in the spoke non-connection portion 50, the capacitance type sensor 56 is formed in a part (partial) of the inner peripheral portion 70 and the outer peripheral portion 68 of the rim 42. The capacitance type sensor 56 is spread out in the cross-sectional circumferential direction of the rim resin 54 around the outer edge portion 72 of the rim resin 54, and covers the surface of the outer peripheral portion 68 and a part of the surface of the inner peripheral portion 70 of the rim resin 54. That is, in the spoke non-connection portion 50, the capacitance type sensor 56 covers the entire surface of the rim resin 54 on the outer circumferential side of the surface S and a part of the surface of the rim resin 54 on the inner circumferential side of the surface S.

As shown in fig. 5, in the right spoke connection portion 48R and the like, the capacitance type sensor 56 is formed in a part of the outer peripheral portion 68 of the rim 42. The capacitance sensor 56 extends in the cross-sectional circumferential direction of the rim resin 54 around the outer edge portion 72 of the rim resin 54, and covers a part of the surface of the outer peripheral portion 68 of the rim resin 54. That is, in the right spoke connecting portion 48R and the like, the capacitance type sensor 56 covers only a part of the surface of the rim resin 54 on the outer circumferential side of the surface S, and does not cover the surface of the rim resin 54 on the inner circumferential side of the surface S.

The second width W2 in the cross-sectional circumferential direction of the capacitive sensor 56 provided at the spoke connection portion 48 is narrower than the first width W1 in the cross-sectional circumferential direction of the capacitive sensor 56 provided at the spoke non-connection portion 50 (fig. 6).

A portion of the rim 42 where the capacitance type sensor 56 is disposed serves as a sensing region 100 for detecting contact of a human body with the steering wheel 26. Further, a portion where the capacitance sensor 56 is not disposed becomes a blind area 102 where contact of a human body with the steering wheel 26 is not detected.

As shown in fig. 2 to 5, a sensing region 100 is formed on the outer peripheral side of the rim 42 except for the lower spoke attachment portion 48B that is relatively located below in the rim 42 when the steering wheel 26 is in the neutral state. On the other hand, the left spoke attachment portion 48L, which is the left portion of the rim 42 located on the left side with respect to the neutral state of the steering wheel 26, and the right spoke attachment portion 48R, which is the right portion facing the left portion with the center portion O1 of the front surface of the rim 42 interposed therebetween, form a blind area 102.

In the present embodiment, the spoke non-connection portion 50 forms a sensing region 100 in a part of the inner peripheral portion 70 and the outer peripheral portion 68, while the right spoke connection portion 48R and the like form a blind region 102 in a part of the outer peripheral portion 68 and the inner peripheral portion 70. In other words, in the present embodiment, the front surface (right in front) of the spoke non-connection portion 50 is the sensing region 100, while the front surface of the right spoke connection portion 48R and the like is the blind region 102.

In the present embodiment, the left portion includes the leftmost portion in the neutral state. Here, the left portion is defined as a portion sandwiched between a portion shifted upward by about 40 ° from the leftmost portion along the rim 42 and a portion shifted downward by about 40 ° from the leftmost portion along the rim 42. Similarly, the right portion includes the rightmost portion in the neutral state. Here, the right portion is defined as a portion sandwiched between a portion shifted upward by about 40 ° from the rightmost portion along the rim 42 and a portion shifted downward by about 40 ° from the rightmost portion along the rim 42.

[4 sensor sheet 74]

As shown in fig. 6, the capacitance sensor 56 is formed of a planar sensor sheet 74 including a conductive member such as a metal. Let the center line of the sensor sheet 74 in the longitudinal direction be C1, and let the center line parallel to the surface of the spread sheet and orthogonal to the center line C1 be C2. The sensor sheet 74 is substantially axisymmetric about the center line C2.

Here, 5 portions of the sensor sheet 74 that are aligned from one direction to the other in the longitudinal direction thereof are defined. Specifically, a portion extending from the center line C2 to both end portions 76, 76 is defined as a first portion 80, a portion extending from one end portion 76 to the center line C2 is defined as a second portion 82, a portion extending from the other end portion 76 to the center line C2 is defined as a third portion 84, a portion between the first portion 80 and the second portion 82 is defined as a fourth portion 86, and a portion between the first portion 80 and the third portion 84 is defined as a fifth portion 88.

The length of each portion in the longitudinal direction can be appropriately set according to the position and size of the spoke non-connecting portion 50 and the spoke connecting portion 48 of the rim 42. In the present embodiment, the length is (L1 of the first region 80) ≥ L (L2 of the second region 82 + L3 of the third region 84) ≥ L (L4 of the fourth region 86 + L5 of the fifth region 88).

The first portion 80, the second portion 82, and the third portion 84 have substantially the same length in the width direction (length in the direction orthogonal to the longitudinal direction). The length corresponds to the first width W1. The fourth portion 86 and the fifth portion 88 have substantially the same length in the width direction. The length corresponds to the second width W2. The fourth portion 86 and the fifth portion 88 form a recess 90 on both sides in the width direction. Therefore, the second width W2 is narrower than the first width W1.

The sensor sheet 74 is adhered to the surface of the rim resin 54 such that the center line C1 is along the outer edge portion 72 of the rim resin 54. When the steering wheel 26 is in the neutral state, the first portion 80 is located at the upper and left and right upper portions of the rim 42, the second portion 82 is located at the left lower portion of the rim 42, the third portion 84 is located at the right lower portion of the rim 42, the fourth portion 86 is located at the left portion of the rim 42, and the fifth portion 88 is located at the right portion of the rim 42.

The first, second and third portions 80, 82 and 84 are located at the spoke non-connecting portions 50 of the rim 42, the fourth portion 86 is located at the left spoke connecting portion 48L of the rim 42, and the fifth portion 88 is located at the right spoke connecting portion 48R of the rim 42. The two end portions 76, 76 face each other with the lower spoke attachment portion 48B interposed therebetween. The region of the rim 42 where the sensor chip 74 is provided becomes a sensing region 100, and the region where the sensor chip 74 is not provided becomes a blind region 102.

In addition to the sensor sheet 74 forming the capacitance sensor 56, the capacitance sensor 56 may be formed by applying and forming a conductive member on the surface of the rim resin 54.

[5 operation of steering wheel unit 12 ]

The operation of the steering wheel unit 12 will be described with reference to fig. 7. A series of processing described below is repeatedly executed at predetermined time intervals.

In step S1, the integrated control unit 36 determines whether or not it is time to perform gripping determination (contact determination). The time for performing the grip determination is arbitrarily set. For example, when the vehicle 10 is traveling by automatic steering, the driver does not need to hold the steering wheel 26. At this time, the grip determination may not be performed. In contrast, when the vehicle 10 travels by manual steering, the driver needs to hold the steering wheel 26. At this time, the grip determination may be performed. If it is time to perform the grip determination (yes in step S1), the process proceeds to step S2. On the other hand, if the time is not the time for performing the grip determination (no in step S1), the series of processing ends and the process waits until the next series of processing starts.

In step S2, the integrated control unit 36 determines whether or not it is a return time to the manual steering. When it is necessary to return to the manual steering in the automatic steering state, for example, when the vehicle 10 approaches the end position of the automatic driving link, the automatic driving device 14 outputs a notification instruction to the notification device 18 to urge the driver to perform the manual steering. At this time, the autopilot device 14 outputs a return signal indicating a return time to return to the manual steering to the contact determination device 28. When the contact determination device 28 receives the return signal output from the automatic driving device 14, the integrated control unit 36 determines that it is the return time to return the manual steering, and when the contact determination device 28 does not receive the return signal output from the automatic driving device 14, the integrated control unit 36 determines that it is not the return time to return the manual steering. If it is the return time to return to the manual steering (yes in step S2), the process proceeds to step S3. On the other hand, if the return time for returning the manual steering is not reached (no in step S2), the process proceeds to step S4.

In step S3, the contact detection unit 38 reads the second threshold (> first threshold) from the storage device 34. Then, whether or not the driver is gripping the steering wheel 26 is detected by comparison with the detection value C of the capacitance sensor 56.

In step S4, the contact detection unit 38 reads out the first threshold value (< second threshold value) from the storage device 34. Then, whether or not the driver is gripping the steering wheel 26 is detected by comparison with the detection value C of the capacitance sensor 56.

When the driver does not hold the steering wheel 26, the notification instruction unit 40 outputs a notification instruction for urging manual steering to the notification device 18. When the driver does not grip the steering wheel 26 even after a certain time has elapsed, the contact detection unit 38 outputs non-grip information indicating that the steering wheel 26 is not gripped to the automatic driving device 14. When the automatic driving device 14 inputs the non-grip information, the vehicle 10 is decelerated or stopped by leaning on the shoulder.

[6 summary of the present embodiment ]

[6.1 summary of steering wheel unit 12 ]

The steering wheel unit 12 includes a capacitance sensor 56, and the capacitance sensor 56 is provided on the steering wheel 26 and detects the magnitude of capacitance associated with contact between a human body and the steering wheel 26. In the steering wheel unit 12, the capacitance type sensor 56 is disposed in the outer peripheral portion 68 of the rim 42 of the steering wheel 26, and a sensing region 100 that detects contact between a human body and the steering wheel 26 is formed, and a blind region 102 that does not detect contact between a human body and the steering wheel 26 is formed in each of a left portion (left spoke connecting portion 48L) of the rim 42 that is located on the left side and a right portion (right spoke connecting portion 48R) of the rim 42 that faces the left portion with the center portion O1 of the rim 42 interposed therebetween when the steering wheel 26 is in the neutral state.

As in the above configuration, if the blind area 102 is formed in the left portion (left spoke connecting portion 48L) of the rim 42 that is located on the left side relative to the left portion and the right portion (right spoke connecting portion 48R) that is located on the right portion relative to the left portion when the steering wheel 26 is in the neutral state, the capacitance sensor 56 does not detect the magnitude of the capacitance accompanying the contact of the human body with the steering wheel 26 even if the arm or the elbow of the driver comes into contact with the left and right portions of the rim 42. Therefore, it is possible to prevent erroneous detection that the steering wheel 26 is being gripped.

In addition, a blind area 102 is also formed in a lower portion (lower spoke attachment portion 48B) of the rim 42 that is relatively located downward when the steering wheel 26 is in the neutral state. If the driver presses the steering wheel 26 with the legs, sometimes the legs come into contact with the lower portion of the rim 42. At this time, the capacitance sensor 56 detects the magnitude of capacitance accompanying the contact of the human body with the steering wheel 26. Thus, even if the driver does not grip the steering wheel 26, it is erroneously detected that the steering wheel 26 is being gripped. As in the above configuration, if the blind area 102 is formed in the lower portion of the rim 42 that is relatively located downward when the steering wheel 26 is in the neutral state, the capacitance type sensor 56 does not detect the magnitude of the capacitance caused by the contact between the human body and the steering wheel 26 even if the driver's leg contacts the lower portion (lower spoke connecting portion 48B) of the rim 42. Therefore, it is possible to prevent erroneous detection that the steering wheel 26 is being gripped.

The steering wheel unit 12 includes a capacitance sensor 56, and the capacitance sensor 56 is provided on the steering wheel 26 and detects capacitance accompanying contact between a human body and the steering wheel 26. In the steering wheel unit 12, the capacitance type sensor 56 is disposed in the outer peripheral portion 68 of the rim 42 of the steering wheel 26, and a sensing region 100 that detects contact between a human body and the steering wheel 26 is formed, and a blind region 102 that does not detect contact between a human body and the steering wheel 26 is formed in a connecting portion (the right spoke connecting portion 48R and the like, the lower spoke connecting portion 48B) between the spokes 46 of the steering wheel 26 and the rim 42.

When the driver lies prone on the steering wheel 26 due to a poor body, for example, the driver tends to lean his or her body against a portion of the steering wheel 26 where the rigidity is high, that is, a portion (e.g., the right spoke connecting portion 48R) between the spokes 46 and the rim 42, by bringing the arms or elbows into contact with the portion. If the blind spot 102 is formed in a portion where the driver is likely to contact the arm or the elbow as in the above configuration, the capacitance sensor 56 does not detect the magnitude of the capacitance generated as the human body contacts the steering wheel 26 even if the driver lies on the front of the steering wheel 26. Therefore, it is possible to prevent erroneous detection that the steering wheel 26 is being gripped.

The electrostatic capacity sensor 56 is in the form of a sheet, and is adhered to the rim 42. According to the above structure, the sensing region 100 and the dead zone 102 can be formed on the rim 42 by a simple structure and operation of attaching the sensing sheet, and thus the manufacturing cost is reduced.

In the steering wheel unit 12, the capacitance sensor 56 is disposed at the outer edge portion 72 of the rim 42 where the blind area 102 is formed. As in the above configuration, if the capacitance sensor 56 is disposed in the outer edge portion 72 of the rim 42 in which the blind area 102 is formed, the driver can detect that the steering wheel 26 is being gripped by correctly gripping the rim 42. In this way, the grip state of the steering wheel 26 can be accurately detected.

The steering wheel unit 12 is provided in the vehicle 10 that can switch between manual steering and automatic steering. The steering wheel unit 12 includes a contact detection unit 38, and the contact detection unit 38 detects whether or not a human body is in contact with the steering wheel 26 based on the magnitude of the capacitance detected by the capacitance sensor 56. The contact detection unit 38 detects whether or not a human body is in contact with the steering wheel 26 based on whether or not the magnitude of the capacitance detected by the capacitance sensor 56 is equal to or greater than a first threshold value during manual steering. The contact detection unit 38 sets a second threshold value larger than the first threshold value when returning from the automatic steering to the manual steering, and detects whether or not a human body is in contact with the steering wheel 26 based on whether or not the magnitude of the capacitance detected by the capacitance sensor 56 is equal to or larger than the second threshold value. In the vehicle 10 capable of switching between the manual steering and the automatic steering, the driver is required to hold the steering wheel 26 when returning from the automatic steering to the manual steering. As in the above configuration, if it is detected whether or not the human body is in contact with the steering wheel 26 by comparison with the second threshold value that is larger than the first threshold value set at the time of manual steering when returning from automatic steering to manual steering, the recognition accuracy of gripping is improved.

[6.2 summary of steering wheel 26 ]

The steering wheel 26 has a rim 42 and spokes 46. The rim 42 is configured by a plurality of spoke connecting portions 48 and spoke non-connecting portions 50, wherein the plurality of spoke connecting portions 48 are connected to the spokes 46, and the spoke non-connecting portions 50 are interposed between mutually adjacent spoke connecting portions 48 and are not connected to the spokes 46. The capacitance type sensor 56 is provided in the outer peripheral portion 68 of the rim 42 along the cross-sectional circumferential direction of the rim 42. The second width W2 in the cross-sectional circumferential direction of the capacitive sensor 56 provided at the spoke connecting portion 48 is narrower than the first width W1 in the cross-sectional circumferential direction of the capacitive sensor 56 provided at the spoke non-connecting portion 50.

As in the above configuration, if the second width W2 of the capacitive sensor 56 provided in the spoke connection portion 48 is narrower than the first width W1 of the capacitive sensor 56 provided in another portion, the capacitive sensor 56 does not detect the capacitance accompanying the contact of the human body with the steering wheel 26 even if the driver is lying on his/her stomach on the steering wheel 26, and there is a high possibility that the driver may contact the arm or elbow with the spoke connection portion 48. Therefore, it is possible to prevent erroneous detection that the steering wheel 26 is being gripped.

[6.3 summary of sensor sheet 74]

The sensor sheet 74 includes a first portion 80, a second portion 82, a third portion 84, a fourth portion 86, and a fifth portion 88, wherein the first portion 80 extends from the center in the longitudinal direction to both end portions 76, 76; the second portion 82 extends from one end 76 toward the center; the third portion 84 extends from the other end 76 toward the center; the fourth portion 86 is located between the first portion 80 and the second portion 82; the fifth region 88 is located between the first region 80 and the third region 84, the first region 80, the second region 82, and the third region 84 have a first width W1 in the width direction of the sheet, and the fourth region 86 and the fifth region 88 have a second width W2 in the width direction of the sheet. The second width W2 is narrower than the first width W1.

According to the above structure, the sensing region 100 and the dead zone 102 can be formed on the rim 42 by a simple structure and operation of attaching the sensing sheet 74, and thus the manufacturing cost is reduced.