Touch determination device

Abstract

To achieve highly accurate touch determination with a simple configuration.SOLUTION: The presence or absence of a touch on a region where sensor electrodes are disposed is determined (step 70) by combining a first determination process (steps 54 to 60) in which the presence or absence of a touch on the region where the sensor electrodes are disposed is determined by repeatedly detecting the capacitance of a sensor electrode disposed on a steering wheel (step 50) and comparing the difference between the maximum and minimum values of the amplitude of the capacitance difference over time with a first threshold value, the difference being obtained by repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value (step 52), and a second determination process (steps 62 to 68) in which the presence or absence of a touch on the region where the sensor electrodes are disposed is determined by comparing the maximum absolute value of the amplitude of the capacitance difference over time with a second threshold value.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a touch determination device. [Background technology]

[0002] Patent document 1 describes a technology that improves the accuracy of contact detection by changing the threshold value according to the results of detecting the ambient temperature of the handle by a temperature detection unit in a configuration in which a contact state is determined when the output of the contact sensor is equal to or greater than a threshold value, and a non-contact state is determined when the output of the contact sensor is smaller than a predetermined threshold value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-87883 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 requires a temperature detection unit that detects the temperature around the steering wheel, which results in a complicated device configuration.

[0005] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a touch determination device that can achieve highly accurate touch determination with a simple configuration. [Means for solving the problem]

[0006] The touch determination device according to the first aspect includes a determination unit that determines whether or not a touch has occurred in an area where a sensor electrode is arranged on an operating member of a moving body, based on the amplitude of a noise component superimposed on a capacitance detection value of the sensor electrode.

[0007] In the second aspect, in the first aspect, the judgment unit repeatedly detects the capacitance of the sensor electrode and repeatedly calculates the difference between the previous capacitance detection value and the current capacitance detection value, and compares the difference between the maximum and minimum values ​​of the amplitude of the difference over time with a first threshold value to perform a first judgment process to determine whether or not there is a touch on the area where the sensor electrode is located.

[0008] In the third aspect, in the first aspect, the judgment unit performs a second judgment process to determine whether or not there is a touch on the area where the sensor electrode is disposed by repeatedly detecting the capacitance of the sensor electrode and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, and comparing the maximum value of the absolute value of the amplitude of the difference over time, which is obtained by repeating the detection, with a second threshold value.

[0009] In the fourth aspect, in the first aspect, the judgment unit determines whether or not the area where the sensor electrode is disposed has been touched by combining a first judgment process in which the judgment unit repeatedly detects the capacitance of the sensor electrode and repeatedly calculates the difference between the previous capacitance detection value and the current capacitance detection value, thereby comparing the difference between the maximum and minimum values ​​of the amplitude of the difference over time with a first threshold value, and a second judgment process in which the judgment unit determines whether or not the area where the sensor electrode is disposed has been touched by comparing the maximum absolute value of the amplitude of the difference over time with a second threshold value.

[0010] The fifth aspect is the fourth aspect, wherein the judgment unit judges that there is a touch to the area where the sensor electrode is disposed if the judgment results of the first judgment process and the second judgment process both indicate that there is a touch, judges that there is no touch to the area where the sensor electrode is disposed if the judgment results of the first judgment process and the second judgment process both indicate that there is no touch, and maintains the previous judgment result if the judgment result of the first judgment process and the judgment result of the second judgment process differ.

[0011] In the sixth aspect, in the fourth aspect, the judgment unit judges that there is a touch to the area where the sensor electrode is disposed if the judgment results of the first judgment process and the second judgment process both indicate that there is a touch, and otherwise judges that there is no touch to the area where the sensor electrode is disposed.

[0012] In the seventh aspect, in the fourth aspect, if the judgment results of the first judgment process and the second judgment process are both no touch, the judgment unit judges that there is no touch to the area where the sensor electrode is disposed, and in any other cases, judges that there is a touch to the area where the sensor electrode is disposed.

[0013] In an eighth aspect, in any of the fifth to seventh aspects, the determination unit always determines that the region in which the sensor electrodes are provided has been touched when the determination result of the first determination process indicates that a touch has occurred.

[0014] In a ninth aspect, in any of the fifth to seventh aspects, the determination unit always determines that the area in which the sensor electrodes are provided has not been touched when the determination result of the first determination process is that there has been no touch.

[0015] In a tenth aspect, in any of the fifth to seventh aspects, the determination unit always determines that the region in which the sensor electrodes are provided has been touched when the determination result of the second determination process indicates that a touch has occurred.

[0016] In an eleventh aspect, in any of the fifth to seventh aspects, the determination unit always determines that the area in which the sensor electrodes are provided has not been touched when the determination result of the second determination process is that there has been no touch. [Effects of the Invention]

[0017] Generally, a noise component whose amplitude varies oscillately is superimposed on the capacitance detection value of the sensor electrode. As shown in FIG. 1, the amplitude of this noise component is relatively larger when the area where the sensor electrode is disposed is touched than when the area where the sensor electrode is not touched, regardless of the ambient temperature, etc. This is thought to be because when the area where the sensor electrode is disposed is touched, vibration components such as the human heartbeat are added to the noise component. In the first aspect, the above phenomenon is utilized to determine whether or not the area where the sensor electrode is disposed is touched based on the amplitude of the noise component superimposed on the capacitance detection value of the sensor electrode. This makes it possible to achieve high-precision touch determination with a simple configuration.

[0018] In the second aspect, the difference between the maximum and minimum amplitude values ​​in the time change of the capacitance detection value difference is compared with a first threshold value to determine whether or not the area where the sensor electrodes are located has been touched, thereby making it possible to determine whether or not the area where the sensor electrodes are located has been touched through simple processing.

[0019] In the third aspect, the presence or absence of a touch on the area where the sensor electrodes are arranged is determined by comparing the maximum absolute value of the amplitude of the time change in the difference in capacitance detection values ​​with a second threshold value, so that the presence or absence of a touch on the area where the sensor electrodes are arranged can be determined by simple processing.

[0020] In the fourth aspect, the first determination process and the second determination process are combined to determine whether or not the area where the sensor electrodes are disposed has been touched. This allows for improved accuracy in touch determination by combining simple determination processes.

[0021] In the fifth aspect, if the determination results of the first determination process and the second determination process both indicate a touch, it is determined that there is a touch, if the determination results of the first determination process and the second determination process both indicate a no-touch, it is determined that there is no touch, and if the determination results of the first determination process and the second determination process differ, the previous determination result is maintained. This makes it possible to improve the accuracy of touch determination by combining simple determination processes.

[0022] In the sixth aspect, if the determination results of both the first determination process and the second determination process indicate a touch, it is determined that there is a touch, and otherwise it is determined that there is no touch. This allows for improved accuracy in touch determination through a combination of simple determination processes.

[0023] In the seventh aspect, if the determination results of both the first determination process and the second determination process are no touch, it is determined that there is no touch, and otherwise it is determined that there is a touch. This makes it possible to improve the accuracy of touch determination by combining simple determination processes.

[0024] In the eighth aspect, if the determination result of the first determination process indicates that a touch has occurred, the determination result is given priority and the touch is always determined to have occurred. This makes it possible to give priority to the first determination process when it determines that a touch has occurred in the area where the sensor electrodes are disposed.

[0025] In the ninth aspect, if the determination result of the first determination process is no touch, the determination result is given priority and it is always determined that there is no touch. This makes it possible to give priority to the case where the first determination process determines that there is no touch on the area where the sensor electrodes are disposed.

[0026] In the tenth aspect, if the determination result of the second determination process indicates that a touch has occurred, the determination result is given priority and the touch is always determined to have occurred. This makes it possible to give priority to the second determination process when it determines that a touch has occurred in the area where the sensor electrodes are disposed.

[0027] In the eleventh aspect, if the determination result of the second determination process is no touch, the determination result is given priority and it is always determined that there is no touch. This makes it possible to give priority to the case where the second determination process determines that there is no touch on the area where the sensor electrodes are disposed. [Brief explanation of the drawings]

[0028] [Figure 1] 10 is a diagram showing an example of a change over time in noise components superimposed on the capacitance detection value of the sensor electrode; [Figure 2] FIG. 2 is a front view of the steering wheel according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the rim portion as viewed in the circumferential direction of the steering wheel. [Figure 4] FIG. 2 is a functional block diagram of a steering ECU. [Figure 5] 10 is a flowchart illustrating an example of a touch determination process. [Figure 6] FIG. 10 is an explanatory diagram for explaining a touch determination that combines the first determination process and the second determination process. DETAILED DESCRIPTION OF THE INVENTION

[0029] An example of an embodiment of the present disclosure will be described in detail below with reference to the drawings. Fig. 2 shows a vehicle steering wheel 12 as an example of an operating member of a moving body according to this embodiment. The steering wheel 12 is disposed on the front side of a seat (driver's seat) in which a user (driver) who drives the vehicle sits. In Figs. 2 and 3, the front side of the vehicle is indicated by an arrow FR, the upper side of the vehicle is indicated by an arrow UP, and the right side in the vehicle width direction is indicated by an arrow HR. The radial direction of the steering wheel 12 is indicated by an arrow R, and the circumferential direction of the steering wheel 12 is indicated by an arrow L.

[0030] As shown in FIG. 2, the steering wheel 12 includes an annular rim portion 14 serving as a grip portion, a boss portion 16 provided in the center, and stay portions 18. The steering wheel 12 is provided with a metal core. The core is made up of a rim core portion 20 (see FIG. 3) of the rim portion 14, a boss core portion (not shown) of the boss portion, and a stay core portion (not shown) of the stay portions 18, and the rim core portion 20 is formed in an annular (ring-like) shape. In the steering wheel 12, the rim core portion 20 and the boss core portion are connected via the stay core portion, and the core forms a skeleton, integrating the rim portion 14, boss portion 16, and stay portions 18.

[0031] The vehicle is provided with a steering shaft (not shown), which is axially aligned along the longitudinal direction of the vehicle and rotatably supported by the vehicle body. The steering wheel 12 is supported by the steering shaft, with the boss core portion of the boss portion 16 fixed to the rear end of the steering shaft, and is rotatable integrally with the steering shaft. Therefore, when the steering wheel 12 is rotated, the steering shaft is rotated and the vehicle is steered.

[0032] 3, the rim portion 14 has a generally circular (or generally elliptical) cross section in the radial direction of the steering wheel 12, and a base body 22 formed in a circular ring shape from a resin material such as urethane as an insulating material is disposed within the rim portion 14. The rim portion 14 has a rim core metal portion 20 housed within the base body 22 by insert molding, and the rim core metal portion 20 is covered by the base body 22.

[0033] Additionally, a decorative portion 24 serving as a contact portion is disposed on the outer periphery of the base body 22, and the entire circumference of the base body 22 in the radial cross section of the steering wheel 12 and the entire circumference (entire area) of the steering wheel 12 are covered with the decorative portion 24. A resin material such as urethane is used as an insulating material for the decorative portion 24, and the rim portion 14 of the steering wheel 12 is decorated with the decorative portion 24. The decorative portion 24 may be made of leather such as tanned leather.

[0034] A touch sensor 28 including a sensor electrode 32 is embedded between the base 22 and the decorative portion 24 in the rim portion 14 of the steering wheel 12. The sensor electrode 32 is formed in a generally strip-like shape from a sheet-like or film-like conductive material. The touch sensor 28 may include a shield electrode formed in a generally strip-like shape from an insulating material, similar to the sensor electrode 32, with the sensor electrode 32 disposed on one side of the strip-like insulating material and the shield electrode disposed on the other side. The sensor electrode 32 (as well as the shield electrode) of the touch sensor 28 may be formed from a conductive cloth in which a conductive material such as a metal is attached to the surface of a stretchable fabric woven with warp and weft threads.

[0035] According to the present disclosure, since the accuracy of touch determination can be ensured even if the shield electrode is omitted, it is also possible to reduce the cost of the steering wheel 12 by omitting the shield electrode.

[0036] 2, the touch sensors 28 (sensor electrodes 32) have their longitudinal direction aligned with the circumferential direction of the steering wheel 12, and are arranged in the rim portion 14 in a range that extends approximately halfway around the circumferential direction of the steering wheel 12. Also, as shown in FIG. 3, the touch sensors 28 are wrapped around approximately the entire outer periphery of the base 22, with each sensor electrode 32 positioned radially outward from the rim portion 14 and its width direction aligned with the circumferential direction of the rim portion 14.

[0037] As a result, the touch sensor 28 is wrapped around the outer peripheral surface of the base body 22 over substantially the entire circumference of the steering wheel 12 and the rim portion 14, and is covered by the decorative portion 24. Furthermore, when the steering wheel 12 is in the straight-ahead steering position (the position shown in FIG. 2), one of the two touch sensors 28 is located on the right side of the vehicle and the other is located on the left side of the vehicle, and they are electrically separated.

[0038] The left and right touch sensors 28 (left and right sensor electrodes 32) are each connected to a steering ECU 30 built into the boss portion 16 of the steering wheel 12. The left and right touch sensors 28 (sensor electrodes 32) have the same associated circuit configuration and the same processing such as touch determination / determination by the touch sensor ECU 30, and the following describes the configuration corresponding to one touch sensor 28.

[0039] Although not shown, the steering ECU 30 includes a CPU (Central Processing Unit), memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory), non-volatile storage such as a HDD (Hard Disk Drive) and an SSD (Solid State Drive), a communication I / F (Interface) unit, and an input / output I / F unit, which are communicatively connected to each other via a bus. A touch sensor 28 is connected to the input / output I / F unit via an A / D converter. In this embodiment, the steering ECU 30 is an example of a touch determination device according to the present disclosure.

[0040] A touch determination program is stored in the ROM or storage of the steering ECU 30. The touch determination program is read from the ROM or storage and loaded into memory, and the touch determination program loaded into memory is executed by the CPU, causing the steering ECU 30 to function as the capacitance detection unit 34, the difference calculation and accumulation unit 36, and the determination unit 38 shown in FIG.

[0041] For example, the capacitance detection unit 34 connects the sensor electrode 32 to a constant current source to charge the sensor electrode 32, and then acquires a detection signal of a voltage level corresponding to the capacitance value C of the sensor electrode 32 from the sensor electrode 32 via an A / D converter (not shown), and calculates the capacitance value C of the sensor electrode 32. This process is repeated at predetermined time intervals for each of the left and right sensor electrodes 32. An example of the predetermined time is 100 ms.

[0042] The difference calculation storage unit 36 ​​calculates the difference between the capacitance value C detected by the capacitance detection unit 34 in the previous cycle and the capacitance value C detected by the capacitance detection unit 34 in the current cycle, and stores the calculated difference in a memory or the like.

[0043] The determination unit 38 determines whether or not the area where the sensor electrode 32 is provided has been touched, based on the amplitude of the noise component superimposed on the capacitance value C of the sensor electrode 32. More specifically, the determination unit 38 performs a first determination process to determine whether or not the area where the sensor electrode 32 is provided has been touched, by comparing the difference between the maximum and minimum amplitude values ​​in the time change of the difference in the capacitance value C accumulated and stored in a memory or the like by the difference calculation and storage unit 36 ​​with a first threshold value. The determination unit 38 also performs a second determination process to determine whether or not the area where the sensor electrode 32 is provided has been touched, by comparing the maximum absolute value of the amplitude in the time change of the difference in the capacitance value C with a second threshold value. The determination unit 38 then determines whether or not the area where the sensor electrode 32 is provided has been touched by combining the first and second determination processes.

[0044] Next, as an operation of this embodiment, a touch determination process executed by the steering ECU 30 while the vehicle ignition switch is on will be described with reference to Fig. 5. In step 50 of the touch determination process, the capacitance detection unit 34 detects and acquires the capacitance value C of the sensor electrode 32.

[0045] In step 52, the difference calculation and accumulation unit 36 ​​calculates the difference ΔC between the capacitance value C acquired in step 50 (the capacitance value C acquired in the current cycle) and the capacitance value C acquired in the previous cycle (for example, the capacitance value C acquired 100 ms ago). Then, the calculated capacitance difference ΔC is accumulated and stored in a memory or the like.

[0046] In the next steps 54 to 60, a first determination process is performed. That is, in step 54, the determination unit 38 extracts the maximum and minimum values ​​of the difference ΔC from the time change of the difference ΔC in the capacitance value over a predetermined time (e.g., 1 second) stored in a memory or the like. Then, the determination unit 38 calculates the difference between the maximum and minimum values ​​of the amplitude of the difference ΔC.

[0047] In step 56, the determination unit 38 determines whether the difference between the maximum and minimum amplitudes of the difference ΔC calculated in step 54 is greater than a predetermined first threshold TH1. If the determination in step 56 is positive, the process proceeds to step 58. Then, in step 58, the determination unit 38 determines that "touch has occurred" in the first determination process. On the other hand, if the determination in step 56 is negative, the process proceeds to step 60. Then, in step 60, the determination unit 38 determines that "touch has not occurred" in the first determination process.

[0048] In the next steps 62 to 68, a second determination process is performed. That is, in step 62, the determination unit 38 calculates the maximum absolute value of the amplitude of the difference ΔC from the change over time of the difference ΔC in the capacitance value over a predetermined time (for example, 1 second) that is stored in a memory or the like. In addition, in step 64, the determination unit 38 determines whether the maximum absolute value of the amplitude of the difference ΔC calculated in step 62 is greater than a predetermined second threshold value TH2.

[0049] If the determination in step 64 is positive, the process proceeds to step 66. Then, in step 66, the determination unit 38 determines that "touched" in the second determination process. On the other hand, if the determination in step 64 is negative, the process proceeds to step 68. Then, in step 68, the determination unit 38 determines that "not touched" in the second determination process.

[0050] In step 70, the determination unit 38 performs a touch determination by combining the determination result of the first determination process and the determination result of the second determination process. As shown in Fig. 6, there are 15 different patterns of touch determination by combining the determination result of the first determination process and the determination result of the second determination process, and the touch determination is performed using one of the following patterns A to O.

[0051] Pattern A: If both the first and second judgment processes judge that there is a touch, then there is a touch. If both judge that there is no touch, then there is no touch. Otherwise, the previous value is maintained. Pattern B: If both the first and second judgment processes determine that there is a touch, then there is a touch. Otherwise, there is no touch. Pattern C: If both the first and second judgment processes determine that there is no touch, then it is determined that there is no touch; otherwise, it is determined that there is a touch. Pattern D: Based on Pattern A, if the first determination process determines that there is a touch, it is always determined that there is a touch (the first determination process determines that there is a touch). Pattern E: Based on Pattern B, if the first determination process determines that there is a touch, it is always determined that there is a touch (the first determination process determines that there is a touch). Pattern F: Based on Pattern C, if the first determination process determines that there is a touch, it is always determined that there is a touch (priority is given to the first determination process's determination that there is a touch). Pattern G: Based on Pattern A, if the first determination process determines that there is no touch, it is always determined that there is no touch (the first determination process determines that there is no touch). Pattern H: Based on Pattern B, if the first determination process determines that there is no touch, it is always determined that there is no touch (priority is given to the no-touch determination of the first determination process). Pattern I: Based on Pattern C, if the first determination process determines that there is no touch, it is always determined that there is no touch (the first determination process determines that there is no touch). Pattern J: Based on Pattern A, if the second determination process determines that there is a touch, it is always determined that there is a touch (the second determination process determines that there is a touch). Pattern K: Based on Pattern B, if the second determination process determines that there is a touch, it is always determined that there is a touch (the second determination process determines that there is a touch). Pattern L: Based on Pattern C, if the second determination process determines that there is a touch, it is always determined that there is a touch (the second determination process determines that there is a touch). Pattern M: Based on Pattern A, if the second determination process determines that there is no touch, it is always determined that there is no touch (the second determination process determines that there is no touch). Pattern N: Based on Pattern B, if the second determination process determines that there is no touch, it is always determined that there is no touch (the second determination process determines that there is no touch). Pattern O: Based on Pattern C, if the second determination process determines that there is no touch, it is always determined that there is no touch (the second determination process determines that there is no touch).

[0052] After making the touch determination in step 70, in the next step 72, the determination unit 38 outputs the touch determination result, and the process returns to step 50. The above touch determination process makes it possible to improve the accuracy of the touch determination with a simple configuration that does not require a temperature sensor or the like.

[0053] As described above, in this embodiment, the determination unit 38 determines whether or not a touch has been made on the area where the sensor electrode 32 is disposed, based on the amplitude of the noise component superimposed on the capacitance detection value of the sensor electrode 32 disposed on the vehicle steering wheel 12. This makes it possible to achieve highly accurate touch determination with a simple configuration.

[0054] In this embodiment, the determination unit 38 performs a first determination process to determine whether or not the area where the sensor electrode 32 is provided has been touched by repeatedly detecting the capacitance of the sensor electrode 32 and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, and comparing the difference between the maximum and minimum values ​​of the amplitude of the capacitance difference over time, which is obtained by comparing the difference with a first threshold TH1. This allows the determination of whether or not the area where the sensor electrode 32 is provided has been touched by a simple process.

[0055] In this embodiment, the determination unit 38 performs a second determination process to determine whether or not the area where the sensor electrode 32 is provided has been touched by repeatedly detecting the capacitance of the sensor electrode 32 and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, and comparing the maximum value of the absolute value of the amplitude of the capacitance difference over time, which is obtained by repeating this detection, with a second threshold value TH2. This allows the determination of whether or not the area where the sensor electrode 32 is provided has been touched by a simple process.

[0056] In the present embodiment, the determination unit 38 repeatedly detects the capacitance of the sensor electrode 32 and repeatedly calculates the difference between the previous capacitance detection value and the current capacitance detection value. This is obtained by comparing the difference between the maximum and minimum values ​​of the amplitude of the capacitance difference over time with a first threshold TH1 to determine whether or not the area where the sensor electrode 32 is located has been touched. The determination unit 38 also compares the maximum absolute value of the amplitude of the capacitance difference over time with a second threshold TH2 to determine whether or not the area where the sensor electrode 32 is located has been touched. This combination of simple determination processes improves the accuracy of touch determination.

[0057] Furthermore, in this embodiment, if the determination results of the first determination process and the second determination process both indicate a touch, the determination unit 38 determines that the area where the sensor electrodes 32 are located has been touched, if the determination results of the first determination process and the second determination process both indicate that a touch has not been made, the determination unit 38 determines that the area where the sensor electrodes 32 are located has not been touched, and if the determination result of the first determination process and the determination result of the second determination process differ, the previous determination result is maintained (patterns A, D, G, J, M). This makes it possible to improve the accuracy of touch determination by combining simple determination processes.

[0058] Furthermore, in this embodiment, if the determination results of both the first determination process and the second determination process indicate a touch, the determination unit 38 determines that the area where the sensor electrodes 32 are located has been touched, and otherwise determines that the area where the sensor electrodes 32 are located has not been touched (patterns B, E, H, K, and N). This makes it possible to improve the accuracy of touch determination by combining simple determination processes.

[0059] In this embodiment, when the determination results of both the first determination process and the second determination process are no touch, the determination unit 38 determines that there is no touch on the area where the sensor electrodes 32 are provided, and otherwise determines that there is a touch on the area where the sensor electrodes 32 are provided (patterns C, F, I, L, O). This makes it possible to improve the accuracy of touch determination by combining simple determination processes.

[0060] Furthermore, in this embodiment, when the determination result of the first determination process indicates that a touch has occurred, the determination unit 38 always determines that a touch has occurred on the area where the sensor electrodes 32 are provided (patterns D, E, and F). This makes it possible to prioritize a case where a touch has occurred on the area where the sensor electrodes 32 are provided in the first determination process.

[0061] Furthermore, in this embodiment, when the determination result of the first determination process is no touch, the determination unit 38 always determines that there has been no touch on the arrangement area of ​​the sensor electrode 32 (patterns G, H, I). This makes it possible to prioritize the case where there has been no touch on the arrangement area of ​​the sensor electrode 32 in the first determination process.

[0062] Furthermore, in this embodiment, when the determination result of the second determination process indicates that a touch has occurred, the determination unit 38 always determines that a touch has occurred on the area where the sensor electrodes 32 are provided (patterns J, K, and L). This makes it possible to prioritize a case in which a touch has occurred on the area where the sensor electrodes 32 are provided in the second determination process.

[0063] Furthermore, in this embodiment, when the determination result of the second determination process is no touch, the determination unit 38 always determines that there has been no touch on the arrangement area of ​​the sensor electrode 32 (patterns M, N, O). This makes it possible to prioritize the case where there has been no touch on the arrangement area of ​​the sensor electrode 32 when it is determined in the second determination process that there has been no touch.

[0064] In the above embodiment, the determination unit 38 performs the first determination process in steps 54 to 60, and then performs the second determination process in steps 62 to 68. However, the present disclosure is not limited to the determination unit 38 performing the determination processes in the above order, and the determination unit 38 may perform the first determination process after performing the second determination process.

[0065] Furthermore, in the above embodiment, a configuration in which two sensor electrodes 32 are arranged is described, but the present disclosure is not limited to this and can also be applied to a case in which three or more sensor electrodes 32 are arranged.

[0066] In the above embodiment, the first determination process and the second determination process are combined to determine whether or not a touch has occurred in the area where the sensor electrodes 32 are located. However, the present disclosure is not limited to this, and the first determination process or the second determination process may be used alone to determine whether or not a touch has occurred. Furthermore, the touch determination according to the present disclosure (e.g., a touch determination that combines the first determination process and the second determination process) may be combined with a touch determination by another method. An example of a touch determination by another method is a touch determination in which, in a configuration in which a touch determination is performed by comparing a detected value of capacitance with a reference value for touch determination, if the derivative of the detected value of capacitance is equal to or less than a threshold, the reference value for touch determination is corrected by the derivative value of capacitance.

[0067] Furthermore, in the above embodiment, a vehicle is used as an example of a moving body, but the present disclosure is not limited thereto, and the moving body may be a ship, an airplane, etc. Furthermore, in the above embodiment, a steering wheel 12 is used as an example of an operating member, but the present disclosure is not limited thereto, and the operating member may be a shift body, etc.

[0068] Furthermore, in the above embodiment, the touch determination program is described as being pre-stored (installed) in memory or storage, but the touch determination program can also be provided in a form recorded on a non-temporary recording medium such as an HDD, SSD, or DVD. [Explanation of symbols]

[0069] 12... steering wheel, 28... touch sensor, 30... steering ECU, 32... sensor electrode, 34... capacitance detection unit, 38... determination unit

Claims

1. A touch determination device including a determination unit that determines whether or not an area where a sensor electrode is disposed on an operating member of a moving body is touched based on the amplitude of a noise component superimposed on a capacitance detection value of the sensor electrode.

2. 2. The touch determination device according to claim 1, wherein the determination unit performs a first determination process to determine whether or not a touch has occurred in the area where the sensor electrode is disposed by repeatedly detecting the capacitance of the sensor electrode and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, and comparing the difference between the maximum and minimum values ​​of the amplitude of the difference over time, obtained by repeatedly detecting the capacitance of the sensor electrode and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, with a first threshold value.

3. The touch determination device according to claim 1, wherein the determination unit performs a second determination process to determine whether or not a touch has occurred in the area where the sensor electrode is disposed by repeatedly detecting the capacitance of the sensor electrode and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, and comparing the maximum value of the absolute value of the amplitude of the difference over time, obtained by repeatedly detecting the capacitance of the sensor electrode and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, with a second threshold value.

4. 2. The touch determination device according to claim 1, wherein the determination unit determines whether or not the area where the sensor electrodes are disposed has been touched by combining: a first determination process in which the determination unit repeatedly detects the capacitance of the sensor electrodes and repeatedly calculates the difference between the previous capacitance detection value and the current capacitance detection value, thereby determining whether or not the area where the sensor electrodes are disposed has been touched by comparing the difference between the maximum and minimum values ​​of the amplitude of the difference over time, obtained by repeating detection of the capacitance of the sensor electrodes and repeatedly calculating the difference between the previous capacitance detection value and the current capacitance detection value, with a first threshold; and a second determination process in which the determination unit determines whether or not the area where the sensor electrodes are disposed has been touched by comparing the maximum absolute value of the amplitude of the difference over time, with a second threshold.

5. 5. The touch judgment device according to claim 4, wherein the judgment unit judges that there has been a touch to the area where the sensor electrodes are disposed if the judgment results of the first judgment process and the second judgment process both indicate that there has been a touch, judges that there has been no touch to the area where the sensor electrodes are disposed if the judgment results of the first judgment process and the second judgment process both indicate that there has been no touch, and maintains the previous judgment result if the judgment result of the first judgment process and the judgment result of the second judgment process differ.

6. 5. The touch determination device according to claim 4, wherein the determination unit determines that there is a touch on the area where the sensor electrodes are disposed if the determination results of the first determination process and the second determination process both indicate that there is a touch, and otherwise determines that there is no touch on the area where the sensor electrodes are disposed.

7. 5. The touch determination device according to claim 4, wherein the determination unit determines that there is no touch on the area where the sensor electrodes are disposed if the determination results of the first determination process and the second determination process are both no touch, and otherwise determines that there is a touch on the area where the sensor electrodes are disposed.

8. 8. The touch determination device according to claim 5, wherein the determination unit always determines that the area where the sensor electrodes are disposed is touched when the determination result of the first determination process indicates that a touch has occurred.

9. 8. The touch determination device according to claim 5, wherein the determination unit always determines that the area where the sensor electrodes are disposed is not touched when the determination result of the first determination process is no touch.

10. 8. The touch determination device according to claim 5, wherein the determination unit always determines that the area where the sensor electrodes are disposed is touched when the determination result of the second determination process indicates that a touch has occurred.

11. 8. The touch determination device according to claim 5, wherein the determination unit always determines that the area where the sensor electrodes are disposed is not touched when the determination result of the second determination process is no touch.

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