JP2021079767A - Contact detection device - Google Patents

Abstract

To detect a contact state to an operation body.SOLUTION: An operation detection device 30 is configured such that a first electrode 36, an insulating sheet 40, and a second electrode 38 are disposed on a steering wheel 12 and that the first electrode 36 and the second electrode 38 are connected to a contact detection circuit 42 or a pressure-sensitive detection circuit 44. A determination unit 50 determines via the contact detection circuit 42 whether an operator is in touch with the steering wheel 12, determines via the pressure-sensitive detection circuit 44 whether the operator applies pressure to the steering wheel 12 and determines whether the operator is gripping the steering wheel. As a result, the operation detection device 30 can appropriately detect a contact state of the operator to the steering wheel 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a contact detection device.

The proximity / contact sensor of Patent Document 1 includes a sensor unit in which an intermediate layer made of an elastic body is laminated and arranged between a first detection unit and a second detection unit. In the first detection unit, the sheet-shaped upper electrode layer and the lower electrode layer, each of which has a square checkerboard pattern, are laminated so that the squares do not overlap each other in a plan view and are in an insulated state. In this proximity / contact sensor, the second detection unit is ground-connected by the switching unit to perform proximity measurement of the user by the first detection unit, and the first detection unit is ground-connected by the switching unit by the second detection unit. The user's contact or pressure is measured.

International Publication No. 2014/08024

By the way, in a vehicle equipped with an automatic driving system, it is possible to drive in a manual driving mode operated by the driver and in an automatic driving mode not performed by the driver. In such a vehicle, it is required to detect various contact states such as whether or not the driver's hand is touching the steering wheel and whether or not the driver's hand is holding the steering wheel while the driver can operate the vehicle. To.

However, in the steering wheel, the rim portion gripped by the driver has an elliptical cross section, and the way the steering wheel is touched (held) differs depending on the driver. Therefore, there is a problem that it is difficult to detect a state in which the driver is touching the steering wheel because the contact area of the driver with the steering wheel is different and the output of the contact sensor is also different.

The present invention has been made in view of the above facts, and an object of the present invention is to provide a contact detection device capable of detecting a contact state with an operating body.

Each of the contact detection devices according to the first aspect of the present invention has a sheet shape, and has a first electrode provided on the outer peripheral portion of the operating body operated by the operator and an insulating property inside the first electrode. A second electrode provided via the sheet body, a first detecting means for detecting an electric signal corresponding to a change in capacitance generated in the first electrode when the operator is brought close to the operating body, and an operation. The operation is performed from the detection results of the second detection means for detecting the electric signal according to the distance between the first electrode and the second electrode, which changes when the operating body is pressurized by a person, and the detection result of the first detection means. It is determined whether or not the person has touched the operating body, and it is determined from the detection result of the second detecting means whether or not the operator has pressurized the operating body, and the first detecting means and the second detecting means and the second are used. It includes a determination means capable of determining from each detection result of the detection means that the operator is in operably contacting the operating body and outputting each of the determination results.

In the first aspect, the contact detection device of the second aspect switches the first electrode and the second electrode into a state of being connected to the first detection means and a state of being connected to the second detection means. The means and a control means which controls the switching means and controls the detection by the 1st detection means and the detection by the 2nd detection means are included.

In the contact detection device of the third aspect, when the first electrode and the second electrode are connected to the first detection means in the first or second aspect, the first detection means is the second electrode. Is set to the same potential as the first electrode, and the electric signal output from the first electrode is detected.

In the contact detection device of the fourth aspect, when the first electrode and the second electrode are connected to the second detection means in any one of the first to third aspects, the second detection means is used. The electric signal output from the second electrode is detected with the first electrode as the ground side.

In the contact detection device of the fifth aspect, in any one of the first to fourth aspects, the first detecting means detects the proximity of the operator to the operating body, and the second detecting means detects the proximity of the operator to the operating body. When the pressurization on the operating body is detected, the determination means determines that the operator is in operable contact with the operating body.

In the contact detection device of the sixth aspect, in any one of the first to fifth aspects, the detection by the first detection means and the detection by the second detection means are alternately executed.

In the contact detection device of the seventh aspect, in any one of the first to sixth aspects, it is determined from the detection result of the first detection means that the operator is touching the operating body. From the detection result of the second detection means, it is determined whether or not the operator pressurizes the operating body.

In the contact detection device of the first aspect, the first electrode and the second electrode, each of which is in the shape of a sheet, are provided on the outer peripheral portion of the operating body operated by the operator via the insulating sheet body. The two electrodes are inside the first electrode. The first detecting means detects an electric signal corresponding to a change in capacitance generated in the first electrode when the operator is brought close to the operating body, and the second detecting means pressurizes the operating body by the operator. The electric signal corresponding to the distance between the first electrode and the second electrode, which changes by doing so, is detected.

The determination means determines whether or not the operator is touching the operating body from the detection result of the first detecting means, and determines whether or not the operator is pressurizing the operating body from the detection result of the second detecting means. .. Further, the determining means determines whether or not the operator is in contact with the operating body so that the operating body can be operated from the detection results of the first detecting means and the second detecting means.

Here, since the first detection unit and the second detection unit use the first electrode and the second electrode, respectively, the configuration for contact detection of the operating body can be simplified. Further, the determination means determines the determination result according to the detection result of the first detection means, the determination result according to the detection result of the second detection means, and the determination according to the detection result of the first detection means and the second detection means. Since the result can be output, the operation state of the operator with respect to the operating body can be detected accurately.

In the contact detection device of the second aspect, the switching means switches the first electrode and the second electrode between the state of being connected to the first detection means and the state of being connected to the second detection means. Further, since the control means controls the switching means to control the detection using the first detection means and the detection using the second detection means, each of the first detection means and the second detection means is used. It is possible to smoothly detect the contact state.

In the contact detection device of the third aspect, when the first electrode and the second electrode are connected to the first detection means, the first detection means sets the second electrode at the same potential as the first electrode and starts from the first electrode. Detects the output electrical signal. Therefore, since the first electrode can be shielded by the second electrode, the parasitic capacitance generated in the first electrode can be suppressed, and the detection accuracy of the first detection means can be improved.

In the contact detection device of the fourth aspect, when the first electrode and the second electrode are connected to the second detection means, the second detection means grounds the first electrode and outputs an electric signal from the second electrode. To detect. Therefore, the capacitance generated between the first electrode and the operator can be suppressed, and the detection accuracy of the second detection means can be improved.

In the contact detection device of the fifth aspect, the first detecting means detects the proximity of the operator to the operating body, and the second detecting means detects the pressurization of the operating body of the operator, whereby the operator Determines that the operating body is in operable contact. Therefore, it is possible to determine the contact state of the operator with the operating body, which is not included in the determination result according to the detection result of the first detection means and the determination result according to the detection result of the second detection means.

In the contact detection device of the sixth aspect, the detection by the first detection means and the detection by the second detection means are alternately executed, so that the operator changes the contact state, the pressurization state, and the gripping state with the operating body. Can be determined.

In the contact detection device of the seventh aspect, it is determined from the detection result of the first detection means that the operator is touching the operating body, and the operator adds the operating body from the detection result of the second detecting means. Since it is determined whether or not the pressure is applied, it is possible to effectively determine the operating state using the first detecting means and the second detecting means.

It is a schematic block diagram which shows the operation detection apparatus which concerns on this embodiment. It is a front view which shows the steering apparatus which concerns on this embodiment. It is a flow chart which shows the determination process in the operation detection apparatus which concerns on this embodiment. It is a flow chart which shows the determination process which concerns on the modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The steering device 10 according to the present embodiment includes an operating body and a steering wheel 12 as a steering body. FIG. 1 shows a main part of the steering wheel 12 in a cross-sectional view along the radial direction, and FIG. 2 shows a main part of the steering device 10 in a front view. In the drawings, the front side of the vehicle is indicated by an arrow FR, the right side of the vehicle width is indicated by an arrow RH, and the upper side is indicated by an arrow UP.

As shown in FIG. 2, the steering wheel 12 is formed in a substantially annular shape, and the steering wheel 12 is a seat (driver's seat) in which a driver (occupant) as an operator who drives a vehicle (steering target) is seated. ) Is located on the front side of the vehicle.

The steering wheel 12 is composed of an annular rim portion 14 as a grip portion, a boss portion 16 provided at a central portion, and a stay portion 18. The steering wheel 12 is provided with a metal core, which forms the skeleton of the steering wheel 12. The core metal is composed of the rim core metal portion 20 of the rim portion 14 (see FIG. 2), the boss core metal portion of the boss portion 16, and the stay core metal portion of the stay portion 18, and the rim core metal portion 20 is a circle. It is formed in a ring shape. In the steering wheel 12, the rim core metal portion 20 and the boss core metal portion are connected by the stay core metal portion, and the rim portion 14, the boss portion 16, and the stay portion 18 are integrated.

The steering device 10 includes a steering shaft (not shown), and the steering shaft is rotatably supported by the vehicle body with the axis direction being substantially the vehicle front-rear direction on the front side of the vehicle in the driver's seat. In the steering wheel 12, the boss core metal portion of the boss portion 16 is fixed to the rear end of the steering shaft of the vehicle, and the steering wheel 12 is supported by the steering shaft and can rotate integrally with the steering shaft.

Therefore, when the steering wheel 12 is rotated, the steering shaft is rotated and the vehicle is steered. At this time, in the steering device 10, the rotation angle of the steering shaft is detected by a sensor (not shown), and an actuator (not shown) is operated according to the rotation angle of the steering shaft to steer the steering wheel. Note that FIG. 2 shows the steering wheel 12 at the rotational position (straight steering position) when the vehicle is traveling straight.

As shown in FIG. 1, the rim portion 14 of the steering wheel 12 has a substantially elliptical (or substantially circular) cross section in the radial direction of the steering wheel 12, and the base 22 is arranged in the rim portion 14. ing. A resin material such as urethane as an insulating material is used for the base 22, and the base 22 is formed so that the outer circumference of the steering wheel 12 radial cross section is substantially circular (may be substantially elliptical).

The rim core metal portion 20 is housed in the substrate 22 by insert molding, and the rim core metal portion 20 is covered with the substrate 22. Further, a decorative portion 24 as a contact portion is arranged on the outer peripheral portion of the substrate 22. The decorative portion 24 has an insulating property, and the decorative portion 24 is made of leather, resin, or the like. The entire circumference of the base 22 in the radial cross section of the steering wheel 12 and the entire circumference (entire area) in the 12-circumferential direction of the steering wheel are covered with the decorative portion 24.

On the other hand, the vehicle according to the present embodiment is provided with an automatic driving system (not shown), and the vehicle travels in a manual driving mode in which the vehicle is driven according to the driving operation of the driver and without the driver. The automatic operation mode is set. The automatic driving system switches between the manual driving mode and the automatic driving mode, and by switching to the automatic driving mode, the vehicle is driven without the operation of the driver.

The steering device 10 provided in this vehicle includes an operation detection device 30 as a contact detection device according to the present embodiment. The operation detection device 30 detects the contact state of the driver with the steering wheel 12. Note that FIG. 1 shows a schematic configuration of the operation detection device 30 in a block diagram.

The operation detection device 30 includes an electrode unit 32 and a controller 34. The electrode portion 32 is provided with a first electrode 36, a second electrode 38, and an insulating sheet 40 as an elastic sheet body, and the first electrode 36 and the second electrode 38 are each in the form of a sheet. ing. In the electrode portion 32, the first electrode 36 and the second electrode 38 are overlapped with each other via the insulating sheet 40, and in the electrode portion 32, the first electrode 36, the insulating sheet 40 and the second electrode 38 are layered. It is formed in the form of arranged sheets.

As shown in FIG. 2, the electrode portion 32 is arranged on the rim portion 14 of the steering wheel 12, and the electrode portion 32 is arranged on the rim portion 14 in the steering wheel 12 circumferential direction. In the present embodiment, the electrode portions 32 are continuously provided over the entire area in the 12-circumferential direction of the steering wheel. The electrode portion 32 may be provided in a predetermined angle range on the steering wheel 12.

As shown in FIG. 1, the electrode portion 32 is arranged between the base 22 and the decorative portion 24 in the rim portion 14, and the electrode portion 32 has the second electrode 38 on the base 22 side and the base. It covers the outer circumference of 22 over almost the entire circumference. As a result, the electrode portion 32 is arranged on the outer peripheral portion of the substrate 22 with the second electrode 38 on the inner peripheral side (internal electrode) and the first electrode 36 on the outer peripheral side (outer electrode) in the rim portion 14, and the electrode portion 32 is added. It is covered with a decorative portion 24.

The controller 34 is provided with a contact detection circuit 42 as a first detection means constituting the detection means, a pressure sensitive detection circuit 44 as a second detection means constituting the detection means, and a switching unit 46 as a switching means. There is. Further, the controller 34 is formed with a control unit 48 as a control means and a determination unit 50 as a determination means.

The controller 34 operates by electric power supplied from a power source (vehicle battery) (not shown). Further, the controller 34 is provided with a microcomputer (not shown) to which a CPU, ROM, RAM, etc. are connected by a bus. In the controller 34, the functions of the control unit 48 and the determination unit 50 are realized by the CPU executing the program stored in the ROM, and the control unit 48 performs the contact detection circuit 42, the pressure sensitive detection circuit 44, and the switching unit 46. Control the operation of.

As a result, in the operation detection device 30, proximity detection (contact detection) using the electrode portion 32 (first electrode 36 and second electrode 38) by the contact detection circuit 42 and the electrode portion 32 by the pressure sensitive detection circuit 44 are used. The pressure detection (pressure sensitive detection) that has been performed is executed.

Each of the first electrode 36 and the second electrode 38 of the electrode portion 32 is connected to the switching portion 46 of the controller 34. Further, the switching unit 46 is connected to each of the contact detection circuit 42 and the pressure sensitive detection circuit 44. The switching unit 46 is controlled by the control unit 48, and has a state in which each of the first electrode 36 and the second electrode 38 is connected to the contact detection circuit 42 (a state shown by a two-dot chain line in FIG. 1) and a pressure-sensitive detection circuit. It switches to the state of being connected to 44 (the state shown by the solid line in FIG. 1). The first electrode 36 and the second electrode 38 are connected to the contact detection circuit 42 or the pressure sensitive detection circuit 44 by the switching unit 46.

In the electrode portion 32, when the driver grips (grasps) the steering wheel 12 (rim portion 14) and makes contact with the decorative portion 24, the driver's hand approaches the first electrode 36 and the first The capacitance Cs of the electrode 36 changes. In the controller 34, the first electrode 36 and the second electrode 38 are electrically connected to the contact detection circuit 42, so that whether or not the driver is touching the steering wheel 12 is detected by the self-capacity method. The contact detection circuit 42 detects the capacitance Cs (or an electric signal corresponding to the capacitance Cs) of the first electrode 36, and the driver's hand approaches the steering wheel 12 from the detected capacitance Cs. It is possible to determine whether or not (whether or not it is in contact with the decorative portion 24).

The first electrode 36 is connected to the contact detection circuit 42, and the second electrode 38 is connected to the contact detection circuit 42. In the contact detection circuit 42, a predetermined current (constant current, pulse may be used) is supplied to the first electrode 36 and the second electrode 38 by being operated, and the first electrode 36 and the second electrode 38 have the same potential. .. After that, the contact detection circuit 42 detects an electric signal (current value or voltage value) output from the first electrode 36 according to the capacitance Cs generated in the first electrode 36.

On the other hand, in the electrode portion 32, when the driver grips the steering wheel 12 (rim portion 14), the first electrode 36 is pressurized via the decorative portion 24. As a result, in the electrode portion 32, the insulating sheet 40 is elastically deformed to change the distance between the first electrode 36 and the second electrode 38, and the electrical resistance between the first electrode 36 and the second electrode 38 is increased. As it changes, the capacitance Cp between the first electrode 36 and the second electrode 38 changes.

In the pressure-sensitive detection circuit 44, by connecting the first electrode 36 and the second electrode 38, one of the first electrode 36 and the second electrode 38 is in a connected state and the other is in a grounded state, and the pressure-sensitive detection circuit 44 Brings the first electrode 36 to the ground (connected to GND). In the pressure-sensitive detection circuit 44, a predetermined current (or a pulse may be used) is supplied to the second electrode 38 by being operated, and charges corresponding to the capacitance Cp of the first electrode 36 and the second electrode 38 are accumulated. Let me. After that, the pressure-sensitive detection circuit 44 detects an electric signal (response signal, current value or voltage value) output from the second electrode 38. As a result, the pressure-sensitive detection circuit 44 detects the capacitance Cp between the first electrode 36 and the second electrode 38.

The detection results (for example, current value, voltage value may be used) of each of the contact detection circuit 42 and the pressure sensitive detection circuit 44 are input to the determination unit 50. The determination unit 50 determines whether the driver's hand is touching the steering wheel 12 based on whether or not the current value detected by the contact detection circuit 42 is equal to or higher than a predetermined value (value corresponding to a preset threshold value Csth). Determine if it is in contact. The threshold value Csth in the present embodiment is set corresponding to the capacitance Cs when the driver holds the steering wheel 12 with at least one hand, and the threshold value Csth is set according to the capacitance Cs when the driver holds the steering wheel 12 with one hand. It is set to a value at which it can be determined whether or not the player holds the twelve.

Further, in the determination unit 50, the capacitance Cs (current value corresponding to the capacitance Cs) detected by the pressure-sensitive detection circuit 44 is equal to or higher than a predetermined value (value corresponding to a preset threshold value Cps). Judge whether or not. The output of the pressure-sensitive detection circuit 44 (current value, voltage value, or response signal according to the capacitance Cp) changes according to the strength and area of the driver gripping the steering wheel 12. From this, the threshold value Cps is set to the capacitance (value corresponding to the capacitance) corresponding to the pressurization in the state where the driver holds the steering wheel 12 with at least one hand. As a result, the determination unit 50 determines from the output of the pressure-sensitive detection circuit 44 whether or not the same pressure as when the driver holds the steering wheel 12 with at least one hand is applied.

Further, the determination unit 50 determines whether or not the steering wheel 12 is held in a rotationally operable state by at least one hand of the driver based on the detection results of the contact detection circuit 42 and the pressure sensitive detection circuit 44. From the determination result obtained from the output of the contact detection circuit 42 and the determination result obtained from the output of the pressure sensitive detection circuit 44, the determination unit 50 determines whether or not the driver can operate the steering wheel 12 with at least one hand. judge.

In the operation detection device 30, the determination result of the determination unit 50 is output to the automatic driving system in response to a request from the automatic driving system provided in the vehicle.

The process executed by the operation detection device 30 will be described below.
In the present embodiment, the operation detection device 30 determines whether the driver's hand is in contact with the steering wheel 12, the driver pressurizes the steering wheel 12, and the driver is operably holding the steering wheel. Judge (whether you are holding it). FIG. 3 is a flow chart showing a contact state determination process as an operation state determination process executed by the controller 34 of the operation detection device 30.

The operation detection device 30 operates when the power supply is started by turning on an ignition switch (not shown) of the vehicle, and stops when the vehicle travel ends and the power supply is stopped. The contact state determination process shown in FIG. 3 is executed at predetermined time intervals while the operation detection device 30 is operating. The contact state determination process may be executed in response to a request from an external device such as an automatic operation system that requests the output of the determination result.

In the first step 100 of this flowchart, contact detection using the contact detection circuit 42 is performed. In contact detection, the first electrode 36 and the second electrode 38 are connected to the contact detection circuit 42 by the switching unit 46. In the contact detection circuit 42, the capacitance Cs is detected by detecting the electric signal output from the first electrode 36 after setting the first electrode 36 and the second electrode 38 to the same potential.

In the next step 102, it is determined whether or not the contact with the steering wheel 12 is detected, and it is determined whether or not the detected capacitance Cs is equal to or greater than the threshold value Csth.

Here, when the driver's hand is not in contact with the steering wheel 12 and the capacitance Cs is less than the threshold value Csth (Cs <Csth), a negative determination is made in step 102 and the process proceeds to step 104. In this step 104, it is determined that the driver's hand is not in contact with the steering wheel 12 (non-contact determination). After that, the process proceeds to step 116.

On the other hand, if the capacitance Cs is equal to or greater than the threshold value Csth (Cs ≧ Csth), an affirmative determination is made in step 102, and the process proceeds to step 106. In step 106, it is determined that the driver's hand is in contact with the steering wheel 12 (contact determination).

In the next step 108, pressure-sensitive detection using the pressure-sensitive detection circuit 44 is performed. In pressure-sensitive detection, the first electrode 36 and the second electrode 38 are connected to the pressure-sensitive detection circuit 44 by the switching unit 46. In the pressure-sensitive detection circuit 44, the pressure applied to the first electrode 36 is detected by using the self-capacity method, and in the pressure-sensitive detection circuit 44, the first electrode 36 is grounded (connected to GND). Further, the pressure-sensitive detection circuit 44 detects an electric signal output from the second electrode 38 after supplying a predetermined current to the second electrode 38, and the pressure-sensitive detection circuit 44 detects the first electrode 36 and the first electrode 38. Capacitance Cp is detected by detecting an electric signal corresponding to the distance between the two electrodes 38.

In the next step 110, it is determined whether or not the pressurization on the steering wheel 12 is detected, and it is determined whether or not the detected capacitance Cp is equal to or greater than the threshold value Cpt.

Here, when the driver does not pressurize the steering wheel 12 and the capacitance Cp is less than the threshold value Cps (Cp <Cps), a negative determination is made in step 110 and the process proceeds to step 112. In this step 112, it is determined that the driver's hand is not pressurizing the steering wheel 12 (non-pressure sensitive determination). After that, the process proceeds to step 116.

On the other hand, if the capacitance Cp is equal to or greater than the threshold value Cps (Cp ≧ Cps), a positive determination is made in step 110 and the process proceeds to step 114. In step 114, it is determined that the steering wheel 12 is pressurized by the driver's hand (pressure sensitive determination).

In the next step 116, the driver determines whether or not the steering wheel 12 is gripped so that the steering wheel 12 can be operated. In the present embodiment, it is determined that the driver is holding the steering wheel 12 by at least the driver holding the steering wheel 12 with one hand.

Here, it is determined that the driver's hand is not in contact with the steering wheel 12 (non-contact determination), or it is determined that the driver's hand is not pressurizing the steering wheel 12 (non-pressure sensitive determination). If so, a negative determination is made in step 116, and the process proceeds to step 118. In this step 118, it is determined that the driver does not operably grip the steering wheel 12 (non-grasping determination).

On the other hand, it is determined that the driver's hand is in contact with the steering wheel 12 (contact determination), and it is determined that the driver's hand is pressurizing the steering wheel 12 (pressure sensitive determination). If so, affirmative determination is made in step 116, and the process proceeds to step 120. In this step 120, it is determined that the driver is operably gripping the steering wheel 12 (grasping determination).

After that, in step 122, it is confirmed whether or not the output of the determination result is requested from the automatic driving system or the like. At this time, if the output of the determination result is requested, an affirmative determination is made in step 122, the process proceeds to step 124, and the requested determination result is output to the request source.

As a result, in the automatic driving system, it can be confirmed that the driver is in contact with the steering wheel 12 while driving in the automatic driving mode, but is not gripping (not gripping) more than necessary. Further, when switching from the automatic driving mode to the manual driving mode, the automatic driving system can confirm whether or not the driver is operably gripping the steering wheel 12.

As described above, when the operation detection device 30 detects the driver's contact with the steering wheel 12, the driver's pressurization of the steering wheel 12 is detected, and the driver's contact with the steering wheel 12 is detected. At the same time, while the driver's pressurization on the steering wheel 12 is detected, the contact detection and the pressure sensitive detection are alternately repeated. Further, the operation detection device 30 continues to detect the driver's contact with the steering wheel 12 at least while the driver's contact with the steering wheel 12 is not detected. As a result, the operation detection device 30 can efficiently detect the operation state by the driver, and can effectively detect the contact state of the steering wheel 12 by the driver.

Further, in the operation detection device 30, contact detection is performed using the first electrode 36 and the second electrode 38 and the contact detection circuit 42, and the first electrode 36 and the second electrode 38 and the pressure sensitive detection circuit 44 are used. Detects the pressure sensitivity. This makes it possible to simplify the configuration of the electrodes provided on the steering wheel 12 for detecting the driver's contact with the steering wheel 12 and detecting the pressure sensitivity.

Further, in addition to the contact detection and the pressure sensitive detection, the operation detection device 30 can perform grip detection using these detection results and output these detection results (determination results), so that the driver's steering wheel 12 contacts. The state can be accurately determined and output.

Further, in the operation detection device 30, the switching unit 46 switches the connection destination of the first electrode 36 and the second electrode 38 between the contact detection circuit 42 and the pressure sensitive detection circuit 44. Therefore, the driver's contact detection and pressure sensitivity detection with respect to the steering wheel 12 can be smoothly performed with a simple configuration.

Further, in the contact detection circuit 42, when the electric signal corresponding to the capacitance Cs output from the first electrode 36 is detected, the first electrode 36 and the second electrode 38 have the same potential. Therefore, in the contact detection circuit 42, the rim core metal portion 20 side of the rim portion 14 can be shielded by the second electrode 38. As a result, in contact detection, the parasitic capacitance between the first electrode 36, the second electrode 38, the rim core metal portion 20, etc. can be suppressed, and the driver's hand close to the first electrode 36 and the first electrode 36 can be suppressed. Capacitance Cs between and can be detected accurately.

Further, in the pressure sensitive detection circuit 44, the first electrode 36, which is the driver side, is grounded with respect to the second electrode 38. As a result, in pressure-sensitive detection, the capacitance (parasitic capacitance, etc.) generated between the driver and each of the first electrode 36 and the second electrode can be suppressed, and the second electrode 38 and the first electrode 36 can be combined with each other. The capacitance Cp between them can be detected accurately.

In the present embodiment described above, the pressure-sensitive detection is performed by performing the contact detection and performing the contact determination in the contact state determination process. However, the contact detection may be performed by performing the pressure-sensitive detection in the contact state determination process and performing the pressure-sensitive determination in the pressure-sensitive detection.

Further, in the contact state determination process, the contact detection and the pressure sensitive detection may be alternately performed. FIG. 4 shows a flow diagram of a contact state determination process in which contact detection and pressure sensitive detection are alternately performed as a modification. In addition, in FIG. 4, the same process as in FIG. 3 is assigned the same step number as in FIG.

In the flowchart of FIG. 4, contact detection is executed in step 100. At this time, if a negative determination is made in step 102 and a non-contact determination is made in step 104, the process proceeds to step 108 to execute pressure sensitive detection. As a result, regardless of the determination results of contact detection and pressure sensitive detection, contact detection and pressure sensitive detection can be performed alternately, and the driver's contact state (grip state) with respect to the steering wheel 12 can be accurately changed. Can be detected (judged).

In the present embodiment and the modified examples described above, the threshold values (capacitance) Csth and Cpt) are used one by one. However, in the contact detection and the pressure sensitive detection, a threshold value (reference value) may be set in a plurality of steps according to the contact state to be determined. For example, in the present embodiment and the modified example, the threshold value is set according to the state in which the driver holds the steering wheel 12 with one hand, but the driver holds the steering wheel 12 with one hand and holds the steering wheel 12 with both hands. Thresholds may be set for each of the states. Thereby, it can be determined whether the driver holds the steering wheel 12 with one hand or both hands.

Further, in the present embodiment and the modified example, one electrode portion 32 (first electrode 36, second electrode 38, and insulating sheet 40) is provided over the entire area in the 12-circumferential direction of the steering wheel. However, a plurality of electrode portions 32 (first electrode, second electrode, and seat body) may be used and provided in the steering wheel 12 at predetermined angle ranges. In this case, the contact state of the driver may be detected in each of the electrode portions 32, or the contact state of the driver may be detected collectively by using the plurality of electrode portions 32.

Further, in the present embodiment and the modified example, a self-capacitating method is applied in which the first electrode 36 is grounded in the pressure sensitive detection circuit 44 and the output signal of the second electrode 38 is detected. However, as the second detection means, a mutual capacitance method may be applied in which one of the first electrode and the second electrode is the transmitting side and the other is the receiving side.

Further, in the present embodiment and the modified example described above, it has been described that the contact state of the operator on the steering wheel 12 is detected. However, the operating body may be any operating body that the operator comes into contact with when operating, and the operating body may be a shift lever or the like provided in the vehicle. Further, the contact detection device can be applied to various operating bodies that the operator grips and operates, and can be used to detect the contact state of the operator with respect to the operating body.

12 ... Steering wheel, 22 ... Base, 30 ... Operation detection device (contact detection device), 32 ... Electrode, 36 ... 1st electrode, 38 ... 2nd electrode, 40 ... Insulating sheet (sheet body), 42 ... Contact detection circuit (first detection means), 44 ... Pressure sensitive detection circuit (second detection means), 46 ... Switching unit (switching means) , 48 ... Control unit (control means), 50 ... Judgment unit (determination means).

Claims (7)

Each has a sheet shape, and a first electrode provided on the outer peripheral portion of the operating body operated by the operator, and a second electrode provided inside the first electrode via an insulating sheet body.
A first detecting means for detecting an electric signal corresponding to a change in capacitance generated in the first electrode when the operator is brought close to the operating body.
A second detecting means for detecting an electric signal according to the distance between the first electrode and the second electrode, which changes when the operating body is pressurized by the operator.
From the detection result of the first detection means, it is determined whether or not the operator has touched the operating body, and from the detection result of the second detecting means, it is determined whether or not the operator has pressurized the operating body. From the detection results of the first detection means and the second detection means, it is determined that the operator is in operable contact with the operating body, and each of the determination results can be output.
Contact detection device including. A switching means for switching the first electrode and the second electrode into a state of being connected to the first detection means and a state of being connected to the second detection means.
A control means that controls the switching means to control detection by the first detection means and detection by the second detection means.
The contact detection device according to claim 1. When the first electrode and the second electrode are connected to the first detection means, the first detection means sets the second electrode at the same potential as the first electrode and outputs the second electrode from the first electrode. The contact detection device according to claim 1 or 2, which detects an electric signal. A claim that when the first electrode and the second electrode are connected to the second detection means, the second detection means detects an electric signal output from the second electrode with the first electrode as the ground side. The contact detection device according to any one of claims 1 to 3. The first detecting means detects the proximity of the operator to the operating body, and the second detecting means detects the pressurization of the operating body so that the operator can operate the operating body. The contact detection device according to any one of claims 1 to 4, wherein the determination means determines that the contact detection device is used. The contact detection device according to any one of claims 1 to 5, wherein the detection by the first detection means and the detection by the second detection means are alternately executed. From the detection result of the first detection means, it is determined that the operator is touching the operation body, and from the detection result of the second detection means, whether or not the operator pressurizes the operation body is determined. The contact detection device according to any one of claims 1 to 6.

Images