Steering system

Abstract

To provide a steering device that can accurately detect the gripping state of an irregularly shaped steering wheel with an inexpensive configuration. [Solution] The steering device comprises a steering wheel 10 and a capacitive grip sensor having electrodes 51 provided on the spoke portion 40 to detect the gripping motion of the rim portion 30 by the occupant. The rim portion 30 has an upper rim portion 32 and a lower rim portion 31 extending substantially horizontally, and a pair of left and right vertical rim portions 33 connecting the left and right ends of the upper rim portion 32 and the lower rim portion 31. The vertical rim portion 33 has a lower vertical rim portion 331 and an upper vertical rim portion 332 below and above the spoke portion 40. The upper vertical rim portion 332 extends substantially vertically from the spoke portion 40 to the upper rim portion 32, and the angle of the upper vertical rim portion 332 with respect to the horizontal line is greater than or equal to a predetermined angle.

Description

Technical Field

[0001] The present invention relates to a steering device capable of detecting the gripping state of a steering wheel.

Background Art

[0002] In recent years, efforts to provide access to a sustainable transportation system that takes into account people in vulnerable positions among transportation participants have been actively pursued. Toward this realization, research and development on driving support technologies have been conducted. Under such a background, a device is known in which a gripping sensor is provided in the rim portion of a steering wheel, and the gripping state of the rim portion by a driver is detected by the gripping sensor (see, for example, Patent Document 1).

[0003] Patent Document 1 describes a non-circular, irregular-shaped steering wheel. The steering wheel described in this Patent Document 1 has a pair of left and right grips below a pair of left and right spoke portions, and gripping sensors are provided on the pair of left and right grips.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such a steering device having an irregular-shaped steering wheel, in order to improve the operability of the steering wheel, it is preferable to expand the gripping area of the steering wheel not only below the spoke portion but also above. However, when the gripping area of the steering wheel is expanded, the number and installation area of sensors for detecting the gripping state increase accordingly, resulting in an increase in cost.

Means for Solving the Problems

[0006] A steering device for a vehicle according to one aspect of the present invention comprises a steering wheel having a hub portion connected to a steering shaft, a rim portion extending around the hub portion over the entire circumference in the circumferential direction centered on the hub portion and gripped by the occupant, and spoke portions extending from the hub portion in the left-right direction and connecting the hub portion and the rim portion, and a non-contact type sensor portion provided on the hub portion or spoke portion to detect the occupant's gripping motion of the rim portion. The rim portion has an upper lateral rim portion and a lower lateral rim portion extending substantially horizontally above and below the hub portion, respectively, and a pair of left and right vertical rim portions connecting the left-right ends of the upper lateral rim portion and the lower lateral rim portion, the distance from the hub portion to the upper lateral rim portion is longer than the distance from the hub portion to the lower lateral rim portion, and the vertical rim portion has a first vertical rim portion below the spoke portion and a second vertical rim portion above the spoke portion. The second longitudinal rim section extends approximately vertically from the spoke section to the upper transverse rim section when the steering wheel is in a neutral position and not being steered, and the angle of the second longitudinal rim section with respect to the horizontal line is greater than or equal to a predetermined angle. [Effects of the Invention]

[0007] According to the present invention, the gripping state of an irregularly shaped steering wheel can be detected accurately without increasing the number of sensors or the installation area. [Brief explanation of the drawing]

[0008] [Figure 1] A side view showing a schematic configuration near the driver's seat of a vehicle having a steering device according to an embodiment of the present invention. [Figure 2] Viewpoint II in Figure 1. [Figure 3] Figure 2 shows a portion of the steering wheel. [Figure 4A] Enlarged view of the main part shown in Figure 3. [Figure 4B] Cross-sectional view along line BB in Figure 4A. [Figure 5] A diagram illustrating the principle of a torque sensor. [Figure 6]A block diagram showing the control configuration of a steering device according to an embodiment of the present invention. [Figure 7] A flowchart showing an example of the process executed by the controller in Figure 6. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to Figures 1 to 7. The steering device according to the embodiment of the present invention is mounted on a vehicle. The vehicle is, for example, an autonomous vehicle having an automatic driving function that does not require driving operations by a driver. The vehicle may also be a manually driven vehicle that requires driving operations by a driver. Below, an example in which the steering device is applied to an autonomous vehicle will be described. This autonomous vehicle is configured to be able to switch between an autonomous driving mode that does not require driving operations by a driver and a manual driving mode that requires driving operations by a driver.

[0010] Figure 1 is a side view showing a schematic configuration near the driver's seat of a vehicle 1 having a steering device 100 according to an embodiment of the present invention. In the following, the front-rear direction, left-right direction, and up-down direction are defined as shown in the figure, and the configuration of each part will be described according to these definitions. The front-rear direction, left-right direction, and up-down direction correspond to the front-rear direction (length direction), left-right direction (width direction), and up-down direction (height direction) of the vehicle 1.

[0011] Figure 1 shows a vehicle 1 with an occupant PS seated in the driver's seat 2. As shown in Figure 1, the steering device 100 has a steering wheel 10 positioned facing the driver's seat 2 and operated by the occupant PS. The steering wheel 10 is supported at the tip (rear end) of a steering shaft 11 that extends from the front to the rear of the vehicle, inclined upward along the centerline CL0. The steering shaft 11 rotates integrally with the steering wheel 10 in response to the operation of the steering wheel 10.

[0012] Although detailed illustrations are omitted, the steering device 100 includes a telescopic mechanism 12 and a tilt mechanism 13. The steering wheel 10 is movable in the forward / backward direction (direction of arrow A in Figure 1) by the telescopic mechanism 12 and in the vertical direction by the tilt mechanism 13. This allows the occupant PS to move the steering wheel 10 to any position. The telescopic mechanism 12 and the tilt mechanism 13 are driven by manual operation by the occupant. At least one of the telescopic mechanism 12 and the tilt mechanism 13 may be driven by an actuator (e.g., an electric motor).

[0013] Figure 2 is a front view of the steering wheel 10 in the neutral position (viewpoint II in Figure 1). The neutral position is when the steering wheel 10 is not being steered and the vehicle is traveling in a straight line. As shown in Figure 2, the steering wheel 10 has a hub portion 20 connected to the steering shaft 11, a rim portion 30 arranged around the hub portion 20 so as to surround the hub portion 20, and spokes 40 connecting the hub portion 20 and the rim portion 30. The rim portion 30 is gripped by the occupant PS, and the steering wheel 10 is rotated around the center line CL0.

[0014] The center line CL0 passes through the center of the hub portion 20 (for example, the center of the hub portion 20), and the steering wheel 10 extends along a plane perpendicular to the center line CL0. The steering wheel 10 is constructed symmetrically with respect to the center line CL1, which extends vertically through the center line CL0. Hereinafter, the direction away from the center line CL0 will be referred to as the left-right outward direction or left-right outer direction, and the direction toward the center line CL0 will be referred to as the left-right inward direction or left-right inner direction.

[0015] The rim portion 30 is entirely non-circular, and the steering wheel 10 is configured as an irregular-shaped steering wheel. More specifically, the rim portion 30 includes a lower rim portion 31 that extends in the left-right direction below the hub portion 20, an upper rim portion 32 that extends in the left-right direction above the hub portion 20, and a pair of left and right vertical rim portions 33, 33 that extend substantially in the up-down direction on the right and left sides of the hub portion 20 respectively and connect the left and right ends in the left-right direction of the lower rim portion 31 and the left and right ends in the left-right direction of the upper rim portion 32. By these lower rim portion 31, upper rim portion 32, and the pair of left and right vertical rim portions 33, 33, the rim portion 30 generally呈 a substantially rectangular or substantially D-shaped configuration.

[0016] The distance from the hub portion 20 (e.g., the center line CL0) to the lower rim portion 31 is shorter than the distance from the hub portion 20 to the upper rim portion 32. For this reason, the hub portion 20 is located below the center of the steering wheel 10 (the center of the rim portion 30). The spoke portion 40 includes a left spoke portion 41 that extends from the hub portion 20 to the left, a right spoke portion 42 that extends to the right, and a lower spoke portion 43 that extends downward, and is configured as three spokes. Thereby, the substantially donut-shaped space between the hub portion 20 and the rim portion 30 is divided into three through the spoke portion 40. That is, it is divided into the lower left space SP1, the lower right space SP2, and the upper space SP3 of the hub portion 20. Note that the number of spoke portions 40 may be two or four, and the configuration of the spoke portion 40 is not limited to that shown.

[0017] The configuration of the rim portion 30 will be described in more detail. FIG. 3 is a front view showing the configuration of the steering wheel 10 on the right side of the center line CL1. As shown in FIG. 3, among the vertical rim portions 33, the portion below the connection portion 33a to which the right spoke portion 42 is connected is called the lower vertical rim portion 331, and the portion above the connection portion 30a is called the upper vertical rim portion 332.

[0018] The lower rim portion 31 and the upper rim portion 32 each extend along the horizontal line L0. The lower vertical rim portion 331 extends upward from the right end portion (outer end portion in the left-right direction) of the lower rim portion 31, strictly speaking, upward and slightly rightward (outward in the left-right direction). That is, the lower vertical rim portion 331 extends along a straight line L1 that goes upward and slightly rightward. Therefore, the angle θ1 formed between the lower rim portion 31 and the lower vertical rim portion 331 (the angle formed between the horizontal line L0 and the straight line L1) is greater than 90 degrees by a predetermined angle (for example, about 5 degrees to 15 degrees). The connection portion between the lower rim portion 31 and the lower vertical rim portion 331 is configured in a smooth curved surface shape.

[0019] The upper vertical rim portion 332 has a lower upper vertical rim portion 332A that extends upward from the connection portion 33a between the right spoke portion 42 and the vertical rim portion 33, and an upper upper vertical rim portion 332B that extends upward and leftward from the upper end portion of the lower upper vertical rim portion 332A. In other words, the upper vertical rim portion 332 has a lower upper vertical rim portion 332A that extends along a straight line L2 extending in the vertical direction, and an upper upper vertical rim portion 332B that extends along a straight line L3 extending upward and leftward.

[0020] The angle θ2 formed by the lower upper vertical rim portion 332A with respect to the horizontal line is 90 degrees or approximately 90 degrees, and the lower upper vertical rim portion 332A rises more steeply than the lower vertical rim portion 331. The angle θ3 formed by the upper upper vertical rim portion 332B with respect to the horizontal line is smaller than θ2. Specifically, the angle θ3 is greater than 45 degrees, for example, about 60 degrees to 80 degrees. The connection portion between the lower upper vertical rim portion 332A and the upper upper vertical rim portion 332B, and the connection portion between the upper upper vertical rim portion 332B and the upper rim portion 32 are configured in a smooth curved surface shape. The entire portion from the connection portion 33a to the right end portion of the upper rim portion 32 may be configured in a smooth curved surface shape.

[0021] The right spoke portion 42 has an enlarged portion 420 whose vertical length (width) increases towards the left (inward in the left-right direction). The upper edge 421 of the enlarged portion 420 extends diagonally upward towards the left, and the lower edge 422 of the right spoke portion 42 extends diagonally downward towards the left. The vertical length of the enlarged portion 420 is longer than its horizontal length, so the enlarged portion 420 is configured to be elongated in the vertical direction. A pair of upper and lower switches 45 (steering switches) are arranged on the enlarged portion 420. The switches 45 are toggle switches or push-button switches. The driver can operate the switches 45 (for example, with their thumb) while gripping the rim portion 30.

[0022] The steering device 100 according to this embodiment has a capacitive gripping sensor 50 that detects the driver's gripping motion of the rim portion 30. The gripping sensor 50 includes a power supply (not shown), an electrode 51 arranged in the enlarged portion 420, and a detection circuit 52 (Figure 6) that detects the capacitance of the electrode 51 or a change in capacitance. The detection circuit 52 detects, for example, the electrical characteristics of the electrode 51, that is, the magnitude of the capacitance between the electrode 51 and the ground (vehicle body). The capacitance detected by the detection circuit 52 increases when the object to be detected (occupant's body) approaches the electrode 51 and decreases when it moves away.

[0023] Figure 4A is an enlarged view of the main part of Figure 3 showing the arrangement of the electrode 51, and Figure 4B is a cross-sectional view along line BB in Figure 4A. As shown in Figure 4A, the electrode 51 is housed inside the enlarged portion 420 of the right spoke portion 42. Therefore, the electrode 51 is not exposed and is covered by the surface 42a of the right spoke portion 42 facing the driver. The electrode 51 is constructed by bending a conductive plate-like member and is positioned around the switch 45 so as not to interfere with the switch 45.

[0024] More specifically, the electrode 51 has a central electrode portion 511 extending vertically to the right of the switch 45, a lower electrode portion 512 extending inclined to the left and downward from the lower end of the central electrode portion 511, and an upper electrode portion 513 extending inclined to the left and upward from the upper end of the central electrode portion 511. The lower electrode portion 512 extends along the lower edge 422 of the right spoke portion 42, approximately parallel to the lower edge 422. The upper electrode portion 513 extends along the upper edge 421 of the right spoke portion 42, approximately parallel to the upper edge 421.

[0025] As shown in Figure 4B, the electrode 51 has a pair of substantially thin electrode layers (inner electrode layer 51a, outer electrode layer 51b) and an insulating layer 51c interposed between the pair of electrode layers 51a and 51b. The inner electrode layer 51a is positioned opposite the switch 45 (Figure 4A). At least a portion of the ends of the inner electrode layer 51a and the outer electrode layer 51b are connected via a connecting portion 51d (dotted line), and the electrode 51 is formed by bending at the connecting portion 51d.

[0026] As shown in Figure 4A, insulating portions 515 and 516 are provided at the boundary between the central electrode portion 511 and the lower electrode portion 512, and at the boundary between the central electrode portion 511 and the upper electrode portion 513, respectively, to insulate the electrode portions from each other. As a result, electrode 51 is electrically divided into three parts corresponding to electrode portions 511 to 513 via the insulating portions 515 and 516. Therefore, the gripping operation of region AR1 can be detected by the central electrode portion 511, the gripping operation of region AR2 can be detected by the lower electrode portion 512, and the gripping operation of region AR3 can be detected by the upper electrode portion 513. Region AR1 includes the connection portion 33a and its vicinity in Figure 3, region AR2 includes the lower rim portion 31 and the lower vertical rim portion 331, and region AR3 includes the upper vertical rim portion 332. As a result, it is possible not only to determine whether the steering wheel 10 is gripped, but also to identify the gripping region of the steering wheel 10.

[0027] The maximum distance from the electrode 51 capable of detecting the gripping motion of the steering wheel 10 is defined as the detectable distance. As shown in Figure 3, in this embodiment, the enlarged portion 420 is configured to be vertically elongated in the vertical direction. Therefore, the distance from the electrode 51 (lower electrode portion 512) near the lower edge 422 of the right spoke portion 42 to the lower vertical rim portion 331 facing the lower electrode portion 512 is less than or equal to the detectable distance. As a result, the gripping motion of the lower vertical rim portion 331 can be detected by the gripping sensor 50. In addition, since the central electrode portion 511 is located to the right of the switch 45, the distance from the electrode 51 (central electrode portion 511) to the connection portion 33a and its vicinity is also less than or equal to the detectable distance. As a result, the gripping motion in the vicinity of the connection portion 33a can be detected by the gripping sensor 50.

[0028] Furthermore, the distance from the electrode 51 (upper electrode portion 513) near the upper edge 421 of the right spoke portion 42 to the lower upper vertical rim portion 332A of the upper vertical rim portion 332 facing the upper electrode portion 513 is less than or equal to the detectable distance. As a result, the gripping operation of the lower upper vertical rim portion 332A can be detected by the gripping sensor 50.

[0029] On the other hand, the distance from the upper electrode portion 513 to the upper vertical rim portion 332B exceeds the detectable distance. Therefore, it is difficult for the gripping sensor 50 to detect the gripping operation of the upper vertical rim portion 332 (upper upper vertical rim portion 332B) that is more than a predetermined distance above the right spoke portion 42. For convenience, the upper vertical rim portion 332 that is more than a predetermined distance above the right spoke portion 42, i.e., the upper vertical rim portion 332 for which it is difficult to detect the gripping operation by the gripping sensor 50, will be referred to as the undetectable rim portion 30X.

[0030] The undetectable rim portion 30X may include the upper or upper end of the lower upper vertical rim portion 332A. The lower or lower end of the upper upper vertical rim portion 332B may be excluded from the undetectable rim portion 30X. In other words, the undetectable rim portion 30X may not start from the boundary between the lower upper vertical rim portion 332A and the upper upper vertical rim portion 332B, but may start above or below the boundary.

[0031] In this embodiment, the lower upper vertical rim portion 332A extends substantially vertically along the straight line L2, and the upper upper vertical rim portion 332B extends from the upper end of the lower upper vertical rim portion 332A along the straight line L3 at a predetermined angle θ3 with respect to the horizontal line. The predetermined angle θ3 is greater than 45 degrees, for example, 60 degrees or more. Therefore, the undetectable rim portion 30X is formed rising from the horizontal line at least at the predetermined angle θ3 or more. Consequently, when an occupant (driver) grasps the undetectable rim portion 30X (for example, area AR10 in Figure 2), the occupant needs to grip the undetectable rim portion 30X with a relatively large grip force against the weight of their hand, which is burdensome for the occupant.

[0032] Therefore, the time the occupant holds the undetectable rim portion 30X is short, and the frequency of holding the undetectable rim portion 30X is reduced. As a result, the occupant places their hand on the spoke portion 40 below the undetectable rim portion 30X, and with their hand supported by the spoke portion 40, they begin to hold the upper vertical rim portion 332 (lower upper vertical rim portion 332A) below the undetectable rim portion 30X (area AR20 in Figure 2). This allows the gripping motion of the rim portion 30 above the spoke portion 40 to be detected well by the gripping sensor 50.

[0033] The occupant may grasp the top of the rim portion 30 (upper rim portion 32). Since the distance from the electrode 51 to the top of the rim portion 30 exceeds the detectable distance, it is difficult for the gripping sensor 50 to detect the gripping motion of the top of the rim portion 30. Such a gripping motion can be detected by a torque sensor provided on the steering shaft 11.

[0034] Figure 5 is a schematic diagram showing the main components of the torque sensor 60. As shown in Figure 5, the torque sensor 60 has a pinion 61 integrally mounted with the steering shaft 11 and a sleeve 62 arranged around the pinion 61. A coil 63 is wound around the sleeve 62 and a window 62a is opened in it. As the steering shaft 11 rotates, the projection of the pinion 61 moves closer to or away from the coil 63 through the window 62a, causing a change in magnetic flux density. By reading this change in magnetic flux density, the operating direction and operating torque of the steering wheel 10 can be detected.

[0035] When the weight F of the driver's hand acts on the top of the steering wheel 10, the steering shaft 11 is pushed downward, and the pinion 61 moves downward relative to the sleeve 62. This changes the positional relationship between the projection of the pinion 61 and the coil 63 of the sleeve 62, and changes the magnetic flux density. It is then determined whether the change in magnetic flux density is greater than or equal to a predetermined threshold α1, and if it is greater than or equal to the threshold α1, it is determined that the weight of the driver's hand is acting on the top of the steering wheel 10, that is, that the top is being gripped. As a result, the torque sensor 60 can detect the gripping motion of the top of the steering wheel 10.

[0036] The occupant may also grip the bottom (lower rim portion 31) of the steering wheel 10. In this case, the weight of the hand acts on the bottom of the steering wheel 10, changing the relative position of the pinion 61 with respect to the sleeve 62, and similarly to the above, the magnetic flux density around the coil 63 changes. Therefore, by determining whether the change in magnetic flux density is above a predetermined threshold α2, the torque sensor 60 can detect the gripping motion of the bottom of the steering wheel 10.

[0037] Incidentally, when the occupant grips the top of the steering wheel 10, the downward load acting on the steering wheel 10 is greater than the downward load acting when gripping the bottom, and the change in magnetic flux density is also greater. Therefore, the threshold value α1 may be set to a value larger than the threshold value α2. However, in the present embodiment, since the distance from the electrode 51 to the bottom of the steering wheel 10 is within the detectable distance, the gripping operation at the bottom can be detected by the gripping sensor 50. Therefore, it is not necessary to detect the gripping operation at the bottom of the steering wheel 10 with the torque sensor 60.

[0038] FIG. 6 is a block diagram showing the control configuration of the steering apparatus 100 according to the present embodiment. As shown in FIG. 6, the steering apparatus 100 includes a gripping sensor 50, a torque sensor 60, a controller 70, a notification device 75, and an automatic driving system 76. The notification device 75 is a device for notifying the occupant of a gripping request for the steering wheel 10, and is composed of a speaker and a monitor.

[0039] Signals from the gripping sensor 50 (detection circuit 52) and the torque sensor 60 are input to the controller 70. The controller 70 includes a computer having a CPU, a ROM, a RAM, and other peripheral circuits. The controller 70 has functions as a determination unit 71 and an output unit 72.

[0040] The determination unit 71 determines whether or not the capacitance C detected via the detection circuit 52 is equal to or greater than a predetermined threshold value Ca. When the capacitance C is equal to or greater than the threshold value Ca (C≧Ca), the determination unit 71 determines that the steering wheel 10 is gripped. On the other hand, when the capacitance C is less than the threshold value Ca (C<Ca), the determination unit 71 determines that the steering wheel 10 is not gripped. When C≧Ca, the determination unit 71 identifies which of the plurality of electrode portions 511 to 513 the signal from which the capacitance C is determined to be equal to or greater than the threshold value Ca. Thereby, the gripping regions AR1 to AR3 (FIG. 4A) of the steering wheel 10 can be identified.

[0041] When C < Ca, the determination unit 71 further determines whether the steering wheel 10 is gripped based on the signal from the torque sensor 60. Specifically, it determines whether the output value (change in magnetic flux density) α of the torque sensor 60 is equal to or greater than a predetermined threshold value α1. When the output value α is equal to or greater than the threshold value α1 (α ≧ α1), the determination unit 71 determines that the steering wheel 10 is gripped (for example, the top of the steering wheel 10 is gripped). On the other hand, when the output value α is less than the threshold value α1 (α < α1), the determination unit 71 determines that the steering wheel 10 is not gripped. The determination unit 71 may determine whether the steering wheel 10 is gripped (for example, the bottom of the steering wheel 10 is gripped) by determining the magnitude relationship between the output value α of the torque sensor 60 and a predetermined threshold value α2 (< α1).

[0042] The output unit 72 outputs the determination result by the determination unit 71 to the notification device 75 and the automatic driving system 76. In addition to this, the output unit 72 communicates with the automatic driving system 76 to determine whether a grip request for the steering wheel 10 is output from the automatic driving system 76. When a grip request is output from the automatic driving system 76, a signal is output to the notification device 75 to notify the occupant to grip the steering wheel 10.

[0043] The automatic driving system 76 determines, for example, whether it is necessary to switch the driving mode from the automatic driving mode to the manual driving mode based on the situation around the vehicle 1 and the situation of the vehicle itself while the vehicle 1 is traveling in the automatic driving mode. When it is determined that it is necessary to switch from the automatic driving mode to the manual driving mode (for example, when changing the automatic driving level from level 3 to level 2), the automatic driving system 76 outputs a grip request for the steering wheel 10.

[0044] Figure 7 is a flowchart showing an example of processing performed by the CPU of the controller 70 according to a pre-stored program. The processing shown in this flowchart is started, for example, when the vehicle 1 is driving in automatic driving mode and the automatic driving system 76 outputs a request to grip the steering wheel 10, that is, when the notification device 75 notifies the driver of a request to grip the steering wheel 10, and is repeated at predetermined intervals. Regardless of whether or not a grip request is output, the processing shown in the flowchart may also be started when the power switch of the vehicle 1 is turned on.

[0045] First, in step S1, the controller 70 reads signals from the gripping sensor 50 (detection circuit 52) ​​and the torque sensor 60. Next, in step S2, the controller 70 determines whether the capacitance C detected by the gripping sensor 50 is greater than or equal to the threshold Ca. If the determination in step S2 is negative, the process proceeds to step S3; if it is positive, the process proceeds to step S4.

[0046] In step S3, the controller 70 determines whether the torque output value α detected by the torque sensor 60 is greater than or equal to the threshold α1. If the result in step S3 is positive, the process proceeds to step S4; otherwise, the process proceeds to step S5. In step S4, a grip signal indicating that the steering wheel 10 has been gripped is output to the notification device 75 and the automatic driving system 76. This stops the notification of the request to grip the steering wheel 10.

[0047] Meanwhile, in step S5, a non-gripping signal indicating that the steering wheel 10 is not being gripped is output to the notification device 75 and the automated driving system 76. The notification device 75 continues to notify of the gripping request as long as the non-gripping signal is output. If the gripping signal is not output despite the notification device 75 notifying of the gripping request for a predetermined time (i.e., the occupant does not grip the steering wheel 10), the automated driving system 76 performs a predetermined action of the vehicle 1 (e.g., a stop action).

[0048] The operation of the steering device 100 according to this embodiment can be summarized as follows. When driving in automatic driving mode, if it becomes necessary to switch to manual driving mode, the notification device 75 notifies the driver of a request to grip the steering wheel 10. As a result, the occupant (driver) grips the steering wheel 10. The distance from the electrode 51 to the lower rim portion 31 and the vertical rim portion 331, the distance to the vicinity of the connection portion 33a where the spoke portion 40 and the rim portion 30 intersect, and the distance from the upper vertical rim portion 332A to the lower upper vertical rim portion 332A are all less than or equal to the detectable distance of the grip sensor 50. Therefore, when the occupant grips these parts, the gripping action is detected by the grip sensor 50.

[0049] On the other hand, the distance from the electrode 51 to the upper upper vertical rim portion 332B of the upper vertical rim portion 332 exceeds the detectable area. Therefore, if the upper upper vertical rim portion 332B is grasped, it is difficult for the grasping sensor 50 to detect the grasping action. However, the upper upper vertical rim portion 332B rises at a predetermined angle θ3 (for example, 60 degrees or more) with respect to the horizontal line. For this reason, when grasping the upper upper vertical rim portion 332B, the occupant must grasp it against the weight of their own hand, which is burdensome for the occupant. Thus, by configuring the upper upper vertical rim portion 332B (undetectable rim portion 30X) to be difficult for the occupant to grasp, the time the occupant spends grasping the upper upper vertical rim portion 332B is shortened, and the frequency of grasping the upper upper vertical rim portion 332B is also reduced. As a result, the occupant will grip the rim portion 30 within the area detectable by the gripping sensor 50, and the gripping action of the rim portion 30 can be detected effectively.

[0050] When an occupant grips the top of the steering wheel 10, the output value α of the torque sensor 60 exceeds the threshold α1. Therefore, even if the top of the steering wheel 10, which cannot be detected by the grip sensor 50, is gripped, the gripping motion can be reliably detected by the torque sensor 60. Even if the grip sensor 50 malfunctions, the gripping motion of the rim portion 30 can be detected based on the output value of the torque sensor 60.

[0051] This embodiment can produce the following effects and benefits. (1) The steering device 100 includes a steering wheel 10, i.e., a hub portion 20 connected to a steering shaft 11, a rim portion 30 that extends around the hub portion 20 over the entire circumference in the circumferential direction centered on the hub portion 20 and is gripped by the occupant, and spoke portions 40 that extend from the hub portion 20 in the left-right direction and connect the hub portion 20 and the rim portion 30, and a non-contact gripping sensor 50 provided on the spoke portions 40 to detect the occupant's gripping motion of the rim portion 30 (Figures 2, 3). The rim portion 30 has an upper rim portion 32 and a lower rim portion 31 that extend substantially horizontally above and below the hub portion 20, respectively, and a pair of left and right vertical rim portions 33 that connect the left-right ends of the upper rim portion 32 and the lower rim portion 31 (Figure 2). The distance from the hub portion 20 to the upper rim portion 32 is longer than the distance from the hub portion 20 to the lower rim portion 31 (Figure 2). The vertical rim portion 33 has a lower vertical rim portion 331 below the spoke portion 40 and an upper vertical rim portion 332 above the spoke portion 40 (Figure 3). In the neutral state when the steering wheel 10 is not steered, the upper vertical rim portion 332 extends substantially vertically from the spoke portion 40 to the upper rim portion 32, and the angle θ3 of the upper vertical rim portion 332 with respect to the horizontal line is greater than or equal to a predetermined angle (at least 45 degrees).

[0052] In this embodiment, the distance from the hub portion 20 to the upper rim portion 32 is increased, that is, the upper vertical rim portion 332 is made longer than the lower vertical rim portion 331, and the upper vertical rim portion 332 is extended vertically at a predetermined angle θ3 or more relative to the horizontal line. As a result, the gripping area of ​​the upper vertical rim portion 332 is expanded, but gripping the upper vertical rim portion 332 (especially the upper part of the upper vertical rim portion 332) against the weight of the hand is burdensome for the occupant. As a result, the occupant will support the lower part of their hand with the spoke portion 40 and grip the upper vertical rim portion 332, and the actual gripping area of ​​the steering wheel will be near the spoke portion 40. This makes it possible to accurately detect the gripping operation of the steering wheel 10 by the gripping sensor 50 placed on the spoke portion 40. As a result, costs can be reduced without increasing the number of sensors or the contact area for detecting the gripping state.

[0053] (2) The grip sensor 50 is a capacitive type grip sensor 50 having electrodes 51 positioned on the spoke portion 40 to detect when an occupant is in contact with or close to the rim portion 30. This makes it possible to construct the grip sensor 50 at low cost. Furthermore, as described above, by providing the upper vertical rim portion 332 at an angle θ3 or more with respect to the horizontal line, the occupant's hand when gripping the steering wheel 10 is positioned near the spoke portion 40, and the distance from the grip sensor 50 to the occupant's hand gripping the steering wheel 10 becomes less than or equal to a predetermined detectable distance. As a result, the grip sensor 50 can reliably detect the gripping action of the rim portion 30.

[0054] (3) The electrode 51 has a central electrode portion 511 that extends substantially vertically, a lower electrode portion 512 that extends downward and inward in the left-right direction from the lower end of the central electrode portion 511, and an upper electrode portion 513 that extends upward and inward in the left-right direction from the upper end of the central electrode portion 511 (Figure 4A). This expands the electrode 51 in the vertical direction, and the detection area of ​​the gripping action by the gripping sensor 50 installed on the spoke portion 40 can be expanded.

[0055] (4) The steering device 100 further includes a switch 45 operated by the occupant (Figure 3). The switch 45 is installed in an area surrounded by the upper electrode portion 513, the central electrode portion 511, and the lower electrode portion 512 (Figure 4A). As a result, the switch 45 is located near the area where the occupant grips the steering wheel 10 (area AR20 in Figure 2), making it easy to operate the switch.

[0056] (5) The steering device 100 further includes a torque sensor 60 that detects a gravity-direction load acting on the steering shaft 11, and a determination unit 71 that determines whether or not the rim portion 30 is being gripped based on signals from the grip sensor 50 and the torque sensor 60 (Figure 6). This allows the gripping operation of the top of the steering wheel 10, even when the distance from the grip sensor 50 exceeds the detectable range, to be reliably detected using the torque sensor 60. The torque sensor 60 can also detect gripping operations of the rim portion 30 other than the top and bottom. Therefore, if the grip sensor 50 fails, the torque sensor 60 can be used in place of the grip sensor 50 to detect gripping operations.

[0057] In the above embodiment, the vertical rim portion 33 is made to extend in a substantially vertical direction, making it difficult to grip the upper part of the vertical rim portion 33, so that the occupant's hand is positioned near the gripping sensor 50. However, the diameter of the vertical rim portion 33 may be changed so that the occupant's hand is positioned near the gripping sensor 50. That is, as shown in Figure 3, the upper vertical rim portion 332 has a lower upper vertical rim portion 332A whose distance from the spoke portion 40 is less than or equal to the detectable distance, and an upper upper vertical rim portion 332B whose distance from the spoke portion 40 exceeds the detectable distance. The diameter or thickness of the upper upper vertical rim portion 332B may be made smaller than the diameter or thickness of the lower upper vertical rim portion 332A. An upper vertical rim portion 332 with a small diameter or thin thickness is difficult to grip. Therefore, the occupants will avoid gripping the upper vertical rim portion 332B, which has a small diameter or thin thickness, and the gripping motion of the rim portion 30 can be easily detected by the gripping sensor 50 located on the spoke portion 40.

[0058] In the above embodiment, the rim portion 30 is composed of an upper rim portion 32 (upper lateral rim portion) and a lower rim portion 31 (lower lateral rim portion) that extend substantially horizontally above and below the hub portion 20, respectively, and a pair of left and right vertical rim portions 33 that connect the left and right ends of the upper rim portion 32 and the lower rim portion 31. More specifically, the distance from the hub portion 20 to the upper rim portion 32 is longer than the distance from the hub portion 20 to the lower rim portion 31, and the vertical rim portion 33 has a lower vertical rim portion 331 (first vertical rim portion) below the spoke portion 40 and an upper vertical rim portion 332 (second vertical rim portion) above the spoke portion 40. However, in the neutral state where the steering wheel 10 is not steered, the rim portion can be configured in any way as long as it extends substantially vertically from the spoke portion 40 to the upper lateral rim portion and the angle of the second vertical rim portion with respect to the horizontal line is greater than or equal to a predetermined angle.

[0059] In the above embodiment, a capacitive gripping sensor 50 (sensor unit) is installed on the spoke 40 to detect the gripping motion of the rim 30 by the rider, but the sensor unit may be installed on the hub 20. Furthermore, the sensor unit is not limited to a capacitive gripping sensor 50; other non-contact type sensor units can also be used. In the above embodiment, the electrode 51 is composed of a central electrode unit 511, a lower electrode unit 512, and an upper electrode unit 513, but the shape of the electrode is not limited to those described above.

[0060] In the above embodiment, the distance from the gripping sensor 50 to the lower upper vertical rim portion 332A is set to be less than or equal to the detectable distance of the gripping sensor 50. However, the distance to a part of the lower upper vertical rim portion 332A may also be set to be less than or equal to the detectable distance. In this case, for example, when an occupant grips the upper vertical rim portion 332 with the lower end of their hand in contact with the spoke portion 40, the position of the sensor portion and the configuration of the second vertical rim portion should be set so that the distance to the portion gripped by the occupant is less than or equal to the detectable distance.

[0061] In the above embodiment, the upper vertical rim portion 332 is composed of a lower upper vertical rim portion 332A (lower second vertical rim portion) and an upper upper vertical rim portion 332B (upper second vertical rim portion). That is, the second vertical rim portion is approximated by a pair of straight lines L2 and L3, but it may also be approximated by a single straight line or three or more straight lines. Alternatively, the second vertical rim portion may be approximated by a curve, assuming that the entire second vertical rim portion extends along a curve.

[0062] In the above embodiment, a pair of upper and lower switches 45 operated by the occupant are provided on the spoke portion 40, but the configuration of the switch portion is not limited to that described above. However, it is preferable that the switch portion be provided in an area surrounded by the electrodes 51. In the above embodiment, the torque sensor 60 is used to detect that a load in the direction of gravity is acting on the steering shaft 11, but the load in the direction of gravity may be detected using other sensor portions. Therefore, the configuration of the determination unit that determines whether or not the rim portion is being gripped based on signals from the sensor portion and other sensors is not limited to that described above.

[0063] The above description is merely an example, and the present invention is not limited by the embodiments and modifications described above, as long as the features of the present invention are not impaired. It is also possible to arbitrarily combine one or more of the above embodiments and modifications, and to combine modifications with each other. [Explanation of symbols]

[0064] 10 Steering wheel, 11 Steering shaft, 20 Hub section, 30 Rim section, 31 Lower rim section, 32 Upper rim section, 33 Vertical rim section, 40 Spoke section, 45 Switch, 50 Gripping sensor, 51 Electrode, 60 Torque sensor, 70 Controller, 71 Judgment section, 100 Steering device, 331 Lower vertical rim section, 332 Upper vertical rim section, 332A Lower upper vertical rim section, 332B Upper upper vertical rim section, 511 Central electrode section, 512 Lower electrode section, 513 Upper electrode section

Claims

1. A steering wheel having a hub portion connected to a steering shaft, a rim portion extending around the hub portion over the entire circumference in the circumferential direction centered on the hub portion and gripped by the occupant, and spoke portions extending from the hub portion in the left-right direction and connecting the hub portion and the rim portion, It comprises a non-contact sensor unit provided on the hub or spoke to detect the gripping motion of the rim by the occupant, The rim portion includes an upper lateral rim portion and a lower lateral rim portion that extend substantially horizontally above and below the hub portion, respectively, and a pair of left and right vertical rim portions that connect the left and right ends of the upper lateral rim portion and the lower lateral rim portion. The distance from the hub portion to the upper lateral rim portion is longer than the distance from the hub portion to the lower lateral rim portion. The aforementioned vertical rim portion has a first vertical rim portion below the spoke portion and a second vertical rim portion above the spoke portion. The steering device is characterized in that the second vertical rim portion extends substantially vertically from the spoke portion to the upper horizontal rim portion when the steering wheel is in a neutral state and not being steered, and the angle of the second vertical rim portion with respect to the horizontal line is greater than or equal to a predetermined angle.

2. In the steering device according to claim 1, The steering device is characterized in that the sensor unit is a capacitive sensor unit having electrodes arranged on the spokes to detect when an occupant is in contact with or close to the rim.

3. In the steering device according to claim 2, The steering device is characterized in that the electrode has a central electrode portion extending in a substantially vertical direction, a lower electrode portion extending downward and inward in the left-right direction from the lower end of the central electrode portion, and an upper electrode portion extending upward and inward in the left-right direction from the upper end of the central electrode portion.

4. In the steering device according to claim 3, It also includes a switch section operated by the crew, The steering device is characterized in that the switch portion is installed in a region surrounded by the upper electrode portion, the central electrode portion, and the lower electrode portion.

5. In the steering device according to any one of claims 1 to 4, The second vertical rim portion comprises a lower second vertical rim portion whose distance from the spoke portion is less than or equal to a predetermined distance, and an upper second vertical rim portion whose distance from the spoke portion exceeds the predetermined distance. A steering device characterized in that the diameter or thickness of the upper second vertical rim portion is smaller than the diameter or thickness of the lower second vertical rim portion.

6. In the steering device according to any one of claims 1 to 4, Another sensor unit for detecting a load in the direction of gravity acting on the steering shaft, A steering device further comprising a determination unit that determines whether or not the rim is being gripped based on signals from the sensor unit and the other sensor unit.

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