Control circuit, control method and vehicle steering wheel

Abstract

The invention relates to a control circuit, a control method and a vehicle steering wheel. The control circuit comprises a capacitance detection module and a switch module, and the capacitance detection module sends a first enable signal and a second enable signal to the switch module in a first stage, so that a heating wire can enter a heating state in the first stage. And the capacitance detection module sends a first driving signal and a second driving signal to the switch module in the second stage, so that the heating wire can be used as a shielding electrode. According to the control circuit provided by the embodiment of the invention, the heating wire is multiplexed into the heating device and the shielding device in a time division manner, so that a shielding electrode does not need to be additionally arranged in the vehicle steering wheel connected with the control circuit, and the pin connection number between the control circuit and the vehicle steering wheel can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control circuit, in particular to a control circuit, a control method and a vehicle steering wheel. BACKGROUND

[0002] With the rapid development of circuit technology, a hand-off detection (HOD) technology applied in a vehicle steering wheel has appeared. The vehicle steering wheel applying the HOD technology usually adopts a three-layer cushion structure including an induction layer provided with an induction electrode, a shielding layer provided with a shielding electrode and a heating layer provided with a heating wire.

[0003] The vehicle steering wheel with the three-layer cushion structure has a large number of pin connections with a circuit board, which is not conducive to improving the integration of the control circuit connected with the vehicle steering wheel. SUMMARY

[0004] Therefore, it is necessary to provide a control circuit, a control method and a vehicle steering wheel capable of reducing the number of pin connections with the vehicle steering wheel.

[0005] In a first aspect, an embodiment of the present application provides a control circuit, which comprises:

[0006] a capacitance detection module and a switch module; the switch module is connected with the capacitance detection module, the heating wire and a heating power supply respectively; the capacitance detection module is further connected with an induction module;

[0007] the capacitance detection module is configured to send a first enable signal and a second enable signal to the switch module in a first stage respectively;

[0008] the switch module is configured to work under the action of the first enable signal and the second enable signal in the first stage, so that the heating power supply heats the heating wire, so that the heating wire enters a heating state;

[0009] the capacitance detection module is further configured to send a first drive signal and a second drive signal to the switch module in a second stage respectively;

[0010] the switch module is further configured to transmit the first drive signal to the heating wire in the second stage, so that the heating wire serves as a shielding electrode;

[0011] the switch module is further configured to transmit the second drive signal to the induction module in the second stage, so that the induction module transmits a current signal to the capacitance detection module;

[0012] the capacitance detection module is further configured to output a capacitance signal based on the current signal, and the capacitance signal is used to determine whether a user touches the vehicle steering wheel.

[0013] In one exemplary embodiment, the switch module comprises a first switch unit and a second switch unit;

[0014] The first end of the first switch unit is connected with the first end of the capacitance detection module, the second end of the first switch unit is connected with the first end of the heating wire, and the third end of the first switch unit is connected with the heating power supply; the first end of the second switch unit is connected with the second end of the capacitance detection module, the second end of the second switch unit is connected with the ground, and the third end of the second switch unit is connected with the third end of the capacitance detection module and the second end of the heating wire respectively;

[0015] The first switch unit is used for being turned on under the action of the first enable signal.

[0016] The second switch unit is used for being turned on under the action of the first enable signal and the second enable signal.

[0017] In one exemplary embodiment, the first switch unit and the second switch unit respectively comprise analog devices capable of controlling switch states.

[0018] In one exemplary embodiment, the first switch unit comprises a P-type MOS tube, and the second switch unit comprises an N-type MOS tube.

[0019] In one exemplary embodiment, the capacitance detection module comprises a signal generation unit, a first driving unit, a second driving unit and a detection unit; and the inductive module comprises an inductive electrode.

[0020] The signal generation unit is connected with the first end of the first driving unit and the first end of the second driving unit respectively; the second end of the first driving unit is connected with the third end of the first driving unit and the switch module respectively; the second end of the second driving unit is connected with the third end of the second driving unit and the first end of the inductive electrode respectively, and the target end of the second driving unit is connected with the detection unit.

[0021] The signal generation unit is used for generating a first voltage signal in a second stage; and the first voltage signal is transmitted to the first driving unit and the second driving unit respectively.

[0022] The first driving unit is used for generating a first driving signal based on the first voltage signal in the second stage, and the first driving signal is transmitted to the switch module.

[0023] The second driving unit is used for generating a second driving signal based on the first voltage signal in the second stage, and the second driving signal is transmitted to the inductive electrode; the second driving unit receives a current signal from the inductive electrode; and the current signal is transmitted to the detection unit.

[0024] The detection unit is used for outputting a capacitance signal based on the current signal in the second stage.

[0025] In an example embodiment, the capacitance detection module comprises a signal generation unit, a first driving unit, M second driving units, and a detection unit; the sensing module comprises M sensing electrodes, M being an integer greater than 1;

[0026] The signal generation unit is connected with the first ends of the first driving unit and the first ends of the M second driving units respectively; the second ends of the first driving unit are connected with the third ends of the first driving unit and the switch module respectively; the second ends of the i-th second driving unit are connected with the third ends of the i-th second driving unit and the first ends of the i-th sensing electrode respectively, and the target ends of the M second driving units are connected with the detection unit respectively; i = 1, …, M;

[0027] The signal generation unit is configured to generate a first voltage signal in a second phase; and transmit the first voltage signal to the first driving unit and the M second driving units respectively;

[0028] The first driving unit is configured to generate a first driving signal based on the first voltage signal in the second phase, and transmit the first driving signal to the switch module;

[0029] Each second driving unit is configured to generate a second driving signal based on the first voltage signal in the second phase, transmit the second driving signal to the corresponding sensing electrode, receive a current signal from the corresponding sensing electrode, and transmit the current signal to the detection unit;

[0030] The detection unit is configured to output a capacitance signal based on the current signal.

[0031] In an example embodiment, the signal waveform of the first driving signal is the same as the signal waveform of the second driving signal.

[0032] In an example embodiment, the heating power supply is a 10V-14V power supply.

[0033] In a second aspect, the embodiments of the present application provide a control method, which is applied to the control circuit as described in any one of the first aspects of the present application, and the method comprises:

[0034] In a first phase, a first enable signal and a second enable signal are respectively sent to the switch module;

[0035] In the first phase, the heating power supply heats the heating wire under the action of the first enable signal and the second enable signal, so that the heating wire enters a heating state;

[0036] In a second phase, a first driving signal and a second driving signal are respectively sent to the switch module;

[0037] In the second phase, the first driving signal is transmitted to the heating wire, so that the heating wire serves as a shielding electrode;

[0038] transmitting the second driving signal to the sensing module in the second stage, so that the sensing module transmits a current signal to the capacitance detection module;

[0039] outputting a capacitance signal based on the current signal, the capacitance signal being used to determine whether the user touches the steering wheel.

[0040] In an exemplary embodiment, the method further comprises:

[0041] determining that a capacitance change corresponding to the capacitance signal is less than or equal to a capacitance threshold for a maintenance time;

[0042] generating an alarm signal when the maintenance time is greater than or equal to a time threshold.

[0043] In a third aspect, the embodiments of the present application provide a vehicle steering wheel, which comprises the control circuit according to any one of the first aspect of the present application, a vehicle steering wheel pad, and a judgment circuit; the vehicle steering wheel pad comprises a sensing module and a heating wire.

[0044] The control circuit is connected to the judgment circuit.

[0045] The heating wire is used to be in a heating state in the first stage.

[0046] The heating wire is also used as a shielding electrode in the second stage.

[0047] The judgment circuit is used to determine whether the user touches the vehicle steering wheel based on the capacitance signal.

[0048] The control circuit comprises a capacitance detection module and a switching module; the capacitance detection module sends a first enabling signal and a second enabling signal to the switching module in the first stage, so that the heating wire can enter a heating state in the first stage; and the capacitance detection module sends a first driving signal and a second driving signal to the switching module in the second stage, so that the heating wire can be used as a shielding electrode. It can be seen that the heating wire can not only be used as a heater in the first stage, but also be used as a shielding electrode in the second stage, that is, the heating wire can be used for different purposes in different stages, and the heating wire is time-multiplexed as a heating device and a shielding device. Therefore, the vehicle steering wheel connected to the control circuit does not need to be additionally provided with a shielding electrode, so that the number of pin connections between the control circuit and the vehicle steering wheel is reduced, and the integration of the control circuit connected to the vehicle steering wheel is improved. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0050] Figure 1 A schematic structural view of a vehicle steering wheel according to an embodiment of the present application is shown in FIG. 1.

[0051] Figure 2 A schematic structural view of a control circuit according to an embodiment of the present application is shown in FIG. 2.

[0052] Figure 3 A schematic structural view of another control circuit according to an embodiment of the present application is shown in FIG. 3.

[0053] Figure 4 A schematic structural view of still another control circuit according to an embodiment of the present application is shown in FIG. 4.

[0054] Figure 5 A schematic structural view of still another control circuit according to an embodiment of the present application is shown in FIG. 5.

[0055] Figure 6 A flowchart of a control method according to an embodiment of the present application is shown in FIG. 6.

[0056] Figure 7 A schematic structural view of a vehicle steering wheel according to an embodiment of the present application is shown in FIG. 7.

[0057] Figure 8 A schematic structural view of another vehicle steering wheel according to an embodiment of the present application is shown in FIG. 8. DETAILED DESCRIPTION

[0058] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The embodiments of the present application are shown in the accompanying drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided for the purpose of making the disclosure of the present application more thorough and comprehensive.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0060] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first switching unit may be referred to as a second switching unit, and similarly, a second switching unit may be referred to as a first switching unit. Both the first switching unit and the second switching unit are switching units, but they are not the same switching unit.

[0061] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0062] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0063] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0064] As described in the background section, HOD technology applied to vehicle steering wheels has already emerged. For example... Figure 1 As shown, vehicle steering wheels employing HOD technology typically utilize a three-layer pad structure, comprising a sensing layer 102 with sensing electrodes, a shielding layer 104 with shielding electrodes, and a heating layer 106 with heating wires. The sensing layer 102 is the outermost layer, the shielding layer 104 is located between the sensing layer 102 and the heating layer 106, and the heating layer 106 is the innermost layer. This three-layer pad structure results in a large number of pin connections between the vehicle steering wheel and the circuit board, thus hindering the improvement of the integration density of the connected control circuitry.

[0065] Based on the above technical problems, it is found through research that by multiplexing the heating wire in the vehicle steering wheel, the heating wire can not only play a heating role but also act as a shielding electrode, so that the vehicle steering wheel can be changed from a three-layer cushion structure to a two-layer cushion structure with a simpler structure, thereby reducing the number of pin connections between the circuit board carrying the control circuit and the heating wire. Based on this, it is necessary to provide a control circuit that can ensure that the heating wire can heat up at the appropriate time and can act as a shielding electrode together with the sensing electrode to achieve capacitive detection at the appropriate time, so as to cooperate with the normal operation of the vehicle steering wheel.

[0066] The above is the core idea of the present application. The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0067] As shown in FIG. 1, a control circuit 20 of an embodiment includes: Figure 2

[0068] a capacitive detection module 202 and a switching module 204; the switching module 204 is connected with the capacitive detection module 202, the heating wire and the heating power supply respectively; the capacitive detection module 202 is further connected with a sensing module.

[0069] The capacitive detection module 202 is configured to send a first enable signal and a second enable signal to the switching module 204 in a first stage.

[0070] The switching module 204 is configured to work under the action of the first enable signal and the second enable signal in the first stage, so that the heating power supply heats the heating wire, so that the heating wire enters a heating state.

[0071] The capacitive detection module 202 is further configured to send a first drive signal and a second drive signal to the switching module 204 in a second stage.

[0072] The switching module 204 is further configured to transmit the first drive signal to the heating wire in the second stage, so that the heating wire acts as a shielding electrode.

[0073] The switching module 204 is further configured to transmit the second drive signal to the sensing module in the second stage, so that the sensing module transmits a current signal to the capacitive detection module 202.

[0074] The capacitive detection module 202 is further configured to output a capacitive signal based on the current signal, and the capacitive signal is used to determine whether a user touches the vehicle steering wheel.

[0075] ​The capacitance detection module 202 is configured to detect the capacitance change on the sensing module to determine whether a touch event occurs on the sensing module. In the case that the sensing module and the shielding electrode are located in the steering wheel of the vehicle, the touch event can be that a user's hand is placed on the steering wheel of the vehicle.

[0076] In the case that the capacitance detection module 202 switches from the first stage to the second stage, the capacitance detection module 202 switches from sending the first and second enable signals to the switching module 204 to sending the first and second driving signals to the switching module 204. Conversely, switching from the second stage to the first stage is the same, and thus will not be described here.

[0077] Optionally, the capacitance detection module 202 can include a capacitance detection chip.

[0078] Optionally, the sensing module can include at least one sensing electrode. The sensing electrode is configured to sense the touch of an external human hand through its ground capacitance. When the human hand touches the sensing electrode, the ground capacitance of the sensing electrode will change.

[0079] The heating wire is configured to heat the steering wheel of the vehicle after entering the heating state. By increasing the temperature of the steering wheel of the vehicle, the comfort of the user's hand placed on the steering wheel of the vehicle can be improved.

[0080] The shielding electrode served by the heating wire is configured to isolate the electric field interference of the external environment on the sensing electrode in the sensing module, so that the ground capacitance of the sensing electrode can only change when the touch event acts on the sensing electrode.

[0081] The sensing module and the heating wire are located in the steering wheel pad of the steering wheel of the vehicle, and further, the sensing module can be located in the sensing layer of the steering wheel pad, and the heating wire can be located in the multiplexing layer of the steering wheel pad.

[0082] The steering wheel pad is connected to the control circuit 20 provided in the embodiment by a pin.

[0083] Optionally, the sensing module is located on the side of the heating wire away from the center of the steering wheel pad, that is, the circumference where the sensing module is located is located on the outside of the circumference where the heating wire is located, and correspondingly, the sensing layer is located on the outside of the multiplexing layer.

[0084] Optionally, in the steering wheel pad, an insulating layer can be arranged between the sensing module and the heating wire, and the insulating layer is configured to isolate the sensing module and the heating wire to avoid short circuit between the sensing module and the heating wire.

[0085] The first stage and the second stage belong to different stages of the operating cycle of the control circuit 20. Optionally, one operating cycle may include one first stage and one second stage; or one operating cycle may include multiple first stages and multiple second stages, with the first stage and the second stage alternating.

[0086] Optionally, the duration of the first phase can be the same as or different from that of the second phase.

[0087] Optionally, the duration of the first stage and the duration of the second stage can be determined by the temperature of the environment around the vehicle's steering wheel, the driving speed of the vehicle using the steering wheel, or other factors.

[0088] Optionally, when the ambient temperature of the vehicle's steering wheel is less than or equal to a temperature threshold, the duration of the first stage can be longer than the duration of the second stage; conversely, when the ambient temperature of the vehicle's steering wheel is greater than the temperature threshold, the duration of the first stage can be shorter than or equal to the duration of the second stage. Therefore, when it is necessary to increase the temperature of the vehicle's steering wheel to improve user comfort, the heating stage has a longer duration, which can better improve the temperature of the vehicle's steering wheel.

[0089] Optionally, when the vehicle's speed is greater than or equal to a speed threshold, the duration of the second stage can be longer than that of the first stage, and the duration of the second stage is positively correlated with the driving speed. Therefore, in driving scenarios with higher speeds and a certain degree of danger, the longer duration of the capacitance detection stage results in higher HOD detection accuracy to ensure the safety of the vehicle and the user.

[0090] The current signal refers to the signal fed back from the sensing module to the capacitance detection module 202 under the action of the second driving signal and the touch event.

[0091] In a straightforward manner, the capacitance signal corresponds to the amount of capacitance change caused by a touch event acting on the sensing module.

[0092] It is easy to understand that since the heating wire enters a heating state in the first stage and acts as a shielding electrode in the second stage, the first stage can be called the heating stage and the second stage can be called the capacitance detection stage.

[0093] It should be noted that the first stage and the second stage do not overlap each other, that is, the first stage and the second stage will not conflict with each other in time, so as to avoid the case that the heating wire is still in a heating state when the control circuit 20 switches from the first stage to the second stage, that is, the case that the heating wire is still in a heating state when switching from the heating stage to the capacitance detection stage, which causes capacitance interference to the capacitance detection process of the induction module. It can be seen that ensuring that the first stage and the second stage will not conflict with each other in time can ensure that the heating effect of the heating wire and the shielding effect will not conflict with each other by ensuring disturbance-free switching of different stages.

[0094] The above control circuit includes a capacitance detection module and a switching module. The capacitance detection module sends a first enable signal and a second enable signal to the switching module in the first stage, so that the heating wire can enter a heating state in the first stage. The capacitance detection module sends a first drive signal and a second drive signal to the switching module in the second stage, so that the heating wire can be used as a shielding electrode. It can be seen that the heating wire can not only play a heating role in the first stage but also play a shielding role in the second stage, that is, the heating wire can play different roles in different stages. The heating wire is time-multiplexed as a heating device and a shielding device. Based on this, the vehicle steering wheel connected with the control circuit does not need to additionally set a shielding electrode, so that the number of pin connections between the control circuit and the vehicle steering wheel is reduced, and the integration of the control circuit for connecting with the vehicle steering wheel is improved.

[0095] It should be noted that in the embodiment, since the heating wire can be used as a shielding electrode in the second stage, in the vehicle steering wheel pad connected with the control circuit 20 provided in the embodiment, a shielding electrode does not need to be additionally set, that is, only the induction module and the heating wire need to be set in the vehicle steering wheel pad to simultaneously realize the heating effect and the capacitance detection effect. Based on this, compared with the traditional vehicle steering wheel pad which needs to simultaneously set an induction electrode, a shielding electrode and a heating wire, in the vehicle steering wheel pad connected with the control circuit 20 provided in the embodiment, the number of pins and related wire harnesses of the shielding electrode can be reduced, so that the structure of the vehicle steering wheel pad is simplified and the manufacturing cost is reduced.

[0096] It should be noted that in the embodiment, the heating wire can be reused, and simultaneously serves as the heating device and the shielding device of the control circuit 20. The control circuit 20 can realize the switching of the first stage and the second stage through the cooperation of the capacitance detection module 202 and the switching module 204, that is, realize the time-sharing reuse mechanism of the heating wire, so that the heating wire can enter the heating state to improve the temperature of the vehicle steering wheel, and at the same time, the heating wire can serve as a shielding electrode in the vehicle steering wheel to improve the capacitance detection accuracy together with the inductive module. That is, through the time-sharing reuse of the heating wire, the embodiment can balance the heating efficiency and the capacitance detection accuracy.

[0097] At the same time, since the different functions of the heating wire are switched in the control circuit 20, the user outside the vehicle steering wheel cannot perceive that the heating wire does not heat in the second stage. Alternatively, in order to further ensure that the user can perceive that the heating wire provides heat to the vehicle steering wheel to improve the comfort of the human hand, the duration of the first stage can be set to be greater than the duration of the second stage.

[0098] In an exemplary embodiment, as shown in Figure 3 The switching module 204 includes a first switching unit 2042 and a second switching unit 2044.

[0099] The first end of the first switching unit 2042 is connected with the first end of the capacitance detection module 202, the second end of the first switching unit 2042 is connected with the first end of the heating wire, and the third end of the first switching unit 2042 is connected with the heating power supply; the first end of the second switching unit 2044 is connected with the second end of the capacitance detection module 202, the second end of the second switching unit 2044 is connected with the ground, and the third end of the second switching unit 2044 is connected with the third end of the capacitance detection module 202 and the second end of the heating wire, respectively.

[0100] The first switching unit 2042 is configured to be turned on under the action of the first enable signal.

[0101] The second switching unit 2044 is configured to be turned on under the action of the first enable signal and the second enable signal.

[0102] In an exemplary embodiment, the first switching unit 2042 and the second switching unit 2044 each include an analog device capable of controlling the switching state.

[0103] The analog device capable of controlling the switching state refers to a device that can be controlled to be in the on state or the off state by an external control signal.

[0104] Optionally, the analog device that can control the switch state can include a Metal-Oxide-Semiconductor (MOS), a Bipolar Junction Transistor (BJT), a relay or other analog device.

[0105] In an exemplary embodiment, the first switch unit 2042 includes a P-type MOS tube, and the second switch unit 2044 includes an N-type MOS tube.

[0106] In the case where the first switch unit 2042 includes a P-type MOS tube, the first end of the first switch unit 2042 is the gate of the P-type MOS tube, the second end of the first switch unit 2042 is the source of the P-type MOS tube, and the third end of the first switch unit 2042 is the drain of the P-type MOS tube.

[0107] In the case where the second switch unit 2044 includes an N-type MOS tube, the first end of the second switch unit 2044 is the gate of the N-type MOS tube, the second end of the second switch unit 2044 is the source of the N-type MOS tube, and the third end of the second switch unit 2044 is the drain of the N-type MOS tube.

[0108] As can be easily understood, under the action of the first enable signal, the first switch unit 2042 is turned on, and under the action of the first enable signal, the second switch unit 2044 is turned on. When the first end of the second switch unit 2044 receives the second enable signal and the third end of the second switch unit 2044 receives the heating power signal, the second switch unit 2044 can be turned on, and thus, the second switch unit 2044 is turned on under the action of the first enable signal and the second enable signal.

[0109] Optionally, in addition to the P-type MOS tube, the first switch unit 2042 can also include a P-type transistor, a P-type BJT or other switch device. Similarly, in addition to the N-type MOS tube, the second switch unit 2044 can also include an N-type transistor, an N-type BJT or other switch device.

[0110] In an exemplary embodiment, the signal waveform of the first drive signal is the same as the signal waveform of the second drive signal.

[0111] In the case where the signal waveform of the first drive signal is the same as the signal waveform of the second drive signal, the voltage value of the first drive signal transmitted to the heating wire as the shielding electrode is the same as the voltage value of the second drive signal transmitted to the sensing module.

[0112] In the embodiment, by ensuring that the signal waveform of the first driving signal is the same as the signal waveform of the second driving signal, and at this time, since the heating wire is used as the shielding electrode, at this time, the voltage dynamic consistency between the sensing electrode and the shielding electrode can be ensured, so as to ensure that the coupling capacitance between the sensing electrode and the shielding electrode does not affect the touch data detection accuracy of the capacitance detection module, that is, the accuracy of the capacitance signal detected by the capacitance detection module can be improved.

[0113] In one exemplary embodiment, as shown in Figure 3 The capacitance detection module 202 includes a signal generation unit 2022, a first driving unit 2024, a second driving unit 2026, and a detection unit 2028; and the sensing module includes a sensing electrode.

[0114] The signal generation unit 2022 is connected to the first end of the first driving unit 2024 and the first end of the second driving unit 2026 respectively; the second end of the first driving unit 2024 is connected to the third end of the first driving unit 2024 and the switch module 204 respectively; the second end of the second driving unit 2026 is connected to the third end of the second driving unit 2026 and the first end of the sensing electrode respectively, and the target end of the second driving unit 2026 is connected to the detection unit 2028.

[0115] The signal generation unit 2022 is configured to generate a first voltage signal in the second stage; and transmit the first voltage signal to the first driving unit 2024 and the second driving unit 2026 respectively.

[0116] The first driving unit 2024 is configured to generate a first driving signal based on the first voltage signal in the second stage, and transmit the first driving signal to the switch module 204.

[0117] The second driving unit 2026 is configured to generate a second driving signal based on the first voltage signal in the second stage, and transmit the second driving signal to the sensing electrode; receive a current signal from the sensing electrode; and transmit the current signal to the detection unit 2028.

[0118] The detection unit 2028 is configured to output a capacitance signal based on the current signal in the second stage.

[0119] The signal generation unit 2022 can be a digital-to-analog converter (DAC).

[0120] Optionally, the first driving unit 2024 can include a first operational amplifier A1.

[0121] In the case that the first driving unit 2024 comprises the first operational amplifier A1, the first end of the first driving unit 2024 is the non-inverting input terminal of the first operational amplifier A1, the second end of the first driving unit 2024 is the output terminal of the first operational amplifier A1, and the third end of the first driving unit 2024 is the inverting input terminal.

[0122] Optionally, the second driving unit 2026 can comprise the second operational amplifier A2.

[0123] In the case that the second driving unit 2026 comprises the second operational amplifier A2, the first end of the second driving unit 2026 is the non-inverting input terminal of the second operational amplifier A2, the second end of the second driving unit 2026 is the output terminal of the second operational amplifier A2, and the third end of the second driving unit 2026 is the inverting input terminal.

[0124] Optionally, the first voltage signal can be a sinusoidal voltage signal. The frequency and the time of the first voltage signal correspond to the frequency and the time of the first driving signal (or the second driving signal) respectively.

[0125] The current signal from the sensing electrode refers to the signal fed back to the detection unit 2028 through the second driving unit 2026 under the action of the second driving signal and the touch event.

[0126] In the case that the first driving unit 2024 comprises the first operational amplifier A1 and the second driving unit 2026 comprises the second operational amplifier A2, the signal generation unit 2022 is connected to the non-inverting input terminal of the first operational amplifier A1 and the non-inverting input terminal of the second operational amplifier A2 respectively; the output terminal of the first operational amplifier A1 is connected to the inverting input terminal of the first operational amplifier A1 and the switch module 204 respectively; the output terminal of the second operational amplifier A2 is connected to the inverting input terminal of the second operational amplifier A2 and the sensing electrode respectively, and the target terminal of the second operational amplifier A2 is connected to the detection unit 2028.

[0127] The target terminal of the second operational amplifier A2 can be any one of the output terminal (i.e. the second end of the second driving unit 2026), the positive power supply terminal and the ground terminal of the second operational amplifier A2.

[0128] As can be easily understood, in the second stage, the first driving signal output by the output terminal of the first operational amplifier A1 is transmitted to the switch module 204, and the switch module 204 transmits the first driving signal to the second end of the heating wire, so it can be understood that the output terminal of the first operational amplifier A1 is connected to the second end of the heating wire through the switch module 204.

[0129] In the embodiment, in the case that the induction module includes one induction electrode, the capacitance detection module includes a signal generation unit, a first driving unit, a second driving unit and a detection unit, so that in the second stage, the driving capability for the heating wire as the shielding electrode and the induction electrode can be respectively improved by the first driving unit and the second driving unit, so as to improve the accuracy of the capacitance signal detected by the capacitance detection module.

[0130] In one exemplary embodiment, as shown in Figure 3 In the case that the induction module includes one induction electrode, the detection unit 2028 includes a current-voltage converter I2V, an analog-to-digital converter ADC and a data processor DSP.

[0131] The current-voltage converter I2V is connected with the target end of the second driving unit 2026 and the first end of the analog-to-digital converter ADC respectively; the second end of the analog-to-digital converter ADC is connected with the data processor DSP, and the data processor DSP is connected with the judgment circuit.

[0132] The current-voltage converter I2V is configured to convert the current signal into a second voltage signal.

[0133] The analog-to-digital converter ADC is configured to perform analog-to-digital conversion on the second voltage signal to obtain a digital voltage signal.

[0134] The data processor DSP is configured to process the digital voltage signal to obtain a capacitance signal.

[0135] The current-voltage converter I2V can be a transimpedance amplifier (Current-to-Voltage, I2V).

[0136] The analog-to-digital converter ADC is an Analog-to-Digital Converter, abbreviated as ADC.

[0137] The data processor DSP refers to a Digital Signal Processor (DSP).

[0138] In one exemplary embodiment, as shown in Figure 4 The capacitance detection module 202 includes a signal generation unit 2022, a first driving unit 2024, M second driving units 2026 (2026-1, 2026-2, …) and a detection unit 2028; the induction module includes M induction electrodes, and M is an integer greater than 1.

[0139] The signal generation unit 2022 is connected to the first end of the first driving unit 2024 and the first ends of the M second driving units 2026 respectively; the second end of the first driving unit 2024 is connected to the third end of the first driving unit 2024 and the switch module 204 respectively; the second end of the i-th second driving unit 2026 is connected to the third end of the i-th second driving unit 2026 and the first end of the i-th sensing electrode respectively; the target ends of the M second driving units 2026 are connected to the detection unit 2028 respectively; i=1,…,M.

[0140] The signal generation unit 2022 is used to generate a first voltage signal in the second stage; and transmit the first voltage signal to the first driving unit 2024 and M second driving units 2026 respectively.

[0141] The first driving unit 2024 is used to generate a first driving signal based on a first voltage signal in the second stage and to send the first driving signal to the switching module 204.

[0142] Each second driving unit 2026 is used to generate a second driving signal based on the first voltage signal in the second stage, transmit the second driving signal to the corresponding sensing electrode, receive the current signal from the corresponding sensing electrode, and transmit the current signal to the detection unit 2028.

[0143] The detection unit 2028 is used to output a capacitance signal based on the current signal.

[0144] When M is greater than 1, multiple sensing electrodes can be distributed at different angular positions on the vehicle steering wheel. For example, when M=3, the vehicle steering wheel is equipped with 3 sensing electrodes, which are evenly distributed along the circumference of the vehicle steering wheel. Each sensing electrode corresponds to a 120° position. For example, the 3 sensing electrodes can correspond to 0°~120°, 120°~240°, and 240°~360° positions respectively to achieve full circumferential coverage.

[0145] Optionally, the second operational amplifier A2 in different second drive units 2026 can be different operational amplifiers. For example... Figure 4 As shown, the first operational amplifier A2-1 included in the second driving unit 2026-1 may be a different operational amplifier from the second operational amplifier A2-2 included in the second driving unit 2026-2.

[0146] In this embodiment, when the sensing module includes multiple sensing electrodes, the second driving unit and the sensing electrodes correspond one-to-one, and only one detection unit needs to be set in the capacitance detection module of the detection circuit to realize the detection of multiple sensing electrodes. Thus, the applicability and flexibility of the detection circuit to vehicle steering wheels with different numbers of sensing electrodes are improved.

[0147] In an example embodiment, as shown in Figure 4 The detection unit 2028 includes a data selector MUX, a current-voltage converter I2V, an analog-digital converter ADC, and a data processor DSP.

[0148] The data selector MUX is connected to the target end of each first driving unit 2024 and the first end of the current-voltage converter I2V, respectively. The two ends of the analog-digital converter ADC are connected to the second end of the current-voltage converter I2V and the data processor DSP, respectively. The data processor DSP is connected to the judgment circuit.

[0149] The data selector MUX is configured to transmit the current signal from the corresponding sensing electrode to the current-voltage converter I2V based on a first preset timing.

[0150] The current-voltage converter I2V is configured to convert the current signal into a second voltage signal.

[0151] The analog-digital converter ADC is configured to perform analog-digital conversion on the second voltage signal to obtain a digital voltage signal.

[0152] The data processor DSP is configured to process the digital voltage signal to obtain a capacitance signal.

[0153] The data selector MUX is an abbreviation of Multiplexer.

[0154] The first preset timing can be artificially preset to achieve the timing of detecting the plurality of sensing electrodes in time.

[0155] In the example embodiment, when the sensing module includes a plurality of sensing electrodes, the detection unit includes a data selector, a current-voltage converter, an analog-digital converter, and a data processor. Therefore, the data selector can transmit the current signal from the corresponding sensing electrode to the current-voltage converter based on the preset timing, achieving the detection of the plurality of sensing electrodes in time. Based on this, the accuracy of the capacitance signal detected by the capacitance detection module can be improved, and the detection precision of the capacitance detection module can also be improved.

[0156] In an example embodiment, the heating power supply is a 10V-14V power supply.

[0157] In an example embodiment, the heating power supply is a 12V power supply.

[0158] In an example embodiment, as shown in Figure 3As shown, the capacitance detection module 202 further comprises a first enabling unit 20210 and a second enabling unit 20212; the first enabling unit 20210 is connected with the first end of the first switch unit 2042, and the second enabling unit 20212 is connected with the first end of the second switch unit 2044.

[0159] The first enabling unit 20210 is configured to send a first enabling signal to the first end of the first switch unit 2042 in the first stage.

[0160] The second enabling unit 20212 is configured to send a second enabling signal to the first end of the second switch unit 2044 in the first stage.

[0161] In an exemplary embodiment, as shown, Figure 5 The control circuit 20 further comprises:

[0162] a first isolation module 502 and a second isolation module 504; two ends of the first isolation module 502 are respectively connected with the first end of the capacitance detection module 202 and the first end of the first switch unit 2042; two ends of the second isolation module 504 are respectively connected with the second end of the capacitance detection module 202 and the first end of the second switch unit 2044.

[0163] The first isolation module 502 is configured to isolate a third voltage signal transmitted from the heating wire to the capacitance detection module 202; the voltage value of the third voltage signal is greater than or equal to a first voltage threshold.

[0164] The second isolation module 504 is configured to isolate a fourth voltage signal transmitted from the inductive module to the capacitance detection module 202; the voltage value of the fourth voltage signal is greater than or equal to a second voltage threshold.

[0165] The third voltage signal refers to a high-voltage signal from the heating wire.

[0166] The fourth voltage signal refers to a high-voltage signal from the inductive module.

[0167] Optionally, the first voltage threshold and the second voltage threshold can be 16V, 32V or other voltage thresholds, respectively.

[0168] In an exemplary embodiment, the first isolation module 502 comprises a first resistor R1 and a first capacitor C1.

[0169] The first capacitor C1 is connected in parallel with the first resistor R1.

[0170] The capacitance value of the first capacitor C1 is greater than the capacitance value of the shielding electrode.

[0171] In an exemplary embodiment, a ratio between a capacitance value of the first capacitor C1 and a capacitance value of the shielding electrode is greater than or equal to 10.

[0172] The first resistor R1 is used to isolate the third voltage signal transmitted by the heating wire to the capacitance detection module 202, and the first capacitor C1 is used to effectively reduce the impedance influence of the first resistor R1, so as to ensure that the first isolation module 502 can isolate the high-voltage signal from the shielding electrode while ensuring that the control circuit has high signal transmission efficiency. The second isolation module 504, the second resistor R2 and the second capacitor C2 in the following are the same, and thus will not be described hereinafter.

[0173] The first resistor R1 is connected to the output terminal of the first operational amplifier A1 and the second end of the heating wire, respectively.

[0174] In an exemplary embodiment, the second isolation module 504 includes the second resistor R2 and the second capacitor C2.

[0175] The second capacitor C2 is connected in parallel with the second resistor R2.

[0176] The capacitance value of the second capacitor C2 is greater than the capacitance value of the sensing electrode in the sensing module.

[0177] In an exemplary embodiment, a ratio between a capacitance value of the second capacitor C2 and a capacitance value of the sensing electrode in the sensing module is greater than or equal to 10.

[0178] The second resistor R2 is connected to the output terminal of the second operational amplifier A2 and the first end of the sensing module, respectively.

[0179] As can be easily understood, in the case that the high-voltage signal is transmitted to the capacitance detection module 202, the capacitance detection module 202 can be damaged, and thus the accuracy of the detection result of the capacitance signal cannot be guaranteed. Therefore, by arranging the first isolation module 502 and the second isolation module 504 in the control circuit 20, the safety and reliability of the capacitance detection module 202 in the high-voltage application scenario can be ensured, and thus the accuracy and reliability of the capacitance signal detected by the capacitance detection module 202 can be ensured.

[0180] The application process of the control circuit 20 will be described below in combination with a detailed embodiment. For example, the sensing module includes one sensing electrode, as shown in FIG. 2, and the specific process is as follows. Figure 3

[0181] The control circuit 20 includes the capacitance detection module 202 and the switch module 204. The control circuit 20 is connected with a vehicle steering wheel pad, and the vehicle steering wheel pad includes a sensing electrode and a heating wire.

[0182] ​The capacitance detection module 202 comprises a first enable signal, a second enable unit 20212, a signal generation unit 2022, a first driving unit 2024, a second driving unit 2026, and a detection unit 2028, wherein the detection unit 2028 comprises a current-voltage converter I2V, an analog-to-digital converter ADC, and a data processor DSP; the switch module 204 comprises a first switch unit 2042 and a second switch unit 2044.

[0183] The signal generation unit 2022 is connected with the first end of the first driving unit 2024 and the first end of the second driving unit 2026 respectively; the second end of the first driving unit 2024 is connected with the third end of the first driving unit 2024, the third end of the second switch unit 2044, and the second end of the heating wire in the vehicle steering wheel pad; the second end of the second driving unit 2026 is connected with the third end of the second driving unit 2026 and the first end of the sensing electrode in the vehicle steering wheel pad respectively, and the target end of the second driving unit 2026 is connected with the current-voltage converter I2V.

[0184] The first end of the first switch unit 2042 is connected with the first enable unit 20210, the second end of the first switch unit 2042 is connected with the first end of the heating wire, and the third end of the first switch unit 2042 is connected with the heating power supply; the first end of the second switch unit 2044 is connected with the second enable unit 20212, and the second end of the second switch unit 2044 is connected with the ground.

[0185] The current-voltage converter I2V is connected with the target end of the second driving unit 2026 and the first end of the analog-to-digital converter ADC respectively; the second end of the analog-to-digital converter ADC is connected with the data processor DSP, and the data processor DSP is connected with the judgment circuit.

[0186] (1) Application process in the first stage

[0187] In the first stage, the first enable unit 20210 sends the first enable signal to the first end of the first switch unit 2042, and at the same time, the second enable unit 20212 sends the second enable signal to the first end of the second switch unit 2044; the first switch unit 2042 is turned on under the action of the first enable signal, and at the same time, the second switch unit 2044 is turned on under the action of the first enable signal and the second enable signal, so that the heating power supply heats the heating wire, so that the heating wire enters the heating state.

[0188] (2) Application process in the second stage

[0189] In the switching from the first stage to the second stage, the first enabling signal stops sending the first enabling signal and the second enabling signal stops sending the second enabling signal, the signal generating unit 2022 in the capacitance detection module 202 generates a first voltage signal and transmits the first voltage signal to the first driving unit 2024 and the second driving unit 2026 respectively; the first driving unit 2024 generates a first driving signal based on the first voltage signal and transmits the first driving signal to the second end of the first driving unit 2024; the second driving unit 2026 generates a second driving signal based on the first voltage signal and transmits the second driving signal to the sensing electrode; receives a current signal from the sensing electrode and transmits the current signal to the current-voltage converter I2V;

[0190] The current-voltage converter I2V converts the current signal into a second voltage signal, the analog-to-digital converter ADC performs analog-to-digital conversion on the second voltage signal to obtain a digital voltage signal, and the data processor DSP processes the digital voltage signal to obtain a capacitance signal. In this way, the data processor DSP sends the capacitance signal to the judgment circuit to enable the judgment circuit to determine whether the user touches the vehicle steering wheel based on the capacitance signal.

[0191] In the embodiment, after the operation of determining whether the user touches the vehicle steering wheel is completed, the second stage can be switched back to the first stage to heat the heating wire, that is, the first stage and the second stage are switched to realize the cyclic execution of the two different stages, so as to ensure that the heating wire can play a heating role in the heating stage and a shielding role in the capacitance detection stage. Obviously, the control circuit with the specific connection relationship provided in the embodiment can enable the heating wire in the vehicle steering wheel electronics to realize different roles based on a higher integration.

[0192] It can be understood that the control circuit 20 can also adopt other forms, and is not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of reducing the number of pin connections between the vehicle steering wheel.

[0193] Based on the same inventive concept, the embodiment of the present application also provides a control method. The control method is applied to any one of the control circuits 20 in the above embodiments, as shown in the control method, the above method comprises steps 602-612: Figure 6

[0194] 602, in the first stage, the first enabling signal and the second enabling signal are respectively sent to the switch module 204.

[0195] 604, in the first stage, work under the action of the first enabling signal and the second enabling signal, so that the heating power supplies heat to the heating wire, so that the heating wire enters the heating state.

[0196] ​606. The first driving signal and the second driving signal are respectively transmitted to the switch module 204 in the second stage.

[0197] 608. The first driving signal is transmitted to the heating wire in the second stage, so that the heating wire serves as a shielding electrode.

[0198] 610. The second driving signal is transmitted to the induction module in the second stage, so that the induction module transmits a current signal to the capacitance detection module 202.

[0199] 612. A capacitance signal is output based on the current signal, and the capacitance signal is used to determine whether the user touches the vehicle steering wheel.

[0200] In an exemplary embodiment, the above method further comprises:

[0201] determining that the capacitance change corresponding to the capacitance signal is less than or equal to a capacitance threshold for a maintenance time.

[0202] generating an alarm signal when the maintenance time is greater than or equal to a time threshold.

[0203] The time threshold can be 3 seconds, 5 seconds, 6 seconds, or other lengths of time.

[0204] Optionally, the time threshold can be negatively correlated with the driving speed of the vehicle to which the vehicle steering wheel is applied, so that in a certain dangerous driving scenario with a high driving speed, the HOD detection accuracy is higher at this time due to the shorter time threshold, thereby ensuring the safety of the vehicle and the user.

[0205] Optionally, the alarm signal can be presented in the form of voice broadcast, i.e., the alarm signal is broadcasted through language to alert the user to place his hand on the vehicle steering wheel to ensure driving safety.

[0206] It should be noted that the implementation scheme for solving the problem provided by the control method is similar to the implementation scheme described above for the control circuit 20, so the specific limitations in one or more control method embodiments described above can refer to the limitations of the control circuit 20 described above, and will not be described here.

[0207] Based on the same inventive concept, the embodiments of the present application also provide a vehicle steering wheel, as shown in Figure 7 The vehicle steering wheel 70 includes any one of the control circuit 20, the vehicle steering wheel pad 30, and the judgment circuit 40 described above, the vehicle steering wheel pad 30 includes the induction module 302 and the heating wire 304.

[0208] The control circuit 20 is connected to the judgment circuit 40.

[0209] The heating wire 304 is used for being in a heating state at the first stage.

[0210] The heating wire 304 is also used for being a shielding electrode at the second stage.

[0211] The judgment circuit 40 is used for determining whether a user touches the vehicle steering wheel based on the capacitance signal.

[0212] The induction module 302 can be located in an induction layer of the vehicle steering wheel pad 30, and the heating wire can be located in a multiplexing layer of the vehicle steering wheel pad 30.

[0213] As shown in Figure 8 In the vehicle steering wheel provided by the embodiment of the present application, the vehicle steering wheel pad 30 only needs to be provided with two layered structures of the induction layer 32 and the multiplexing layer 34, the induction module 302 is located in the induction layer 32, the heating wire 304 is located in the multiplexing layer 34, and the multiplexing layer 34 is located on the inner side of the induction layer 32.

[0214] In combination with Figure 7 and Figure 8 It can be seen that the vehicle steering wheel pad 30 provided by the embodiment of the present application is a two-layer pad structure, and only needs to be provided with M+2 pins for connecting with the control circuit 20, that is, the vehicle steering wheel pad 30 only needs to be provided with at least 3 pins for connecting with the control circuit 20, so that the number of pin connections can be reduced to improve the working stability of the vehicle steering wheel.

[0215] In an exemplary embodiment, the judgment circuit 40 is specifically used for determining a maintaining time when the capacitance change amount corresponding to the capacitance signal is less than or equal to the capacitance threshold value; and generating an alarm signal in a case where the maintaining time is greater than or equal to a time threshold value.

[0216] Optionally, the judgment circuit 40 can include a microcontroller unit (MCU).

[0217] In the embodiment, the vehicle steering wheel pad does not need to be additionally provided with a shielding electrode, so that the vehicle steering wheel pad only needs to include two layered structures of the induction layer provided with the induction module and the multiplexing layer provided with the heating wire. Therefore, compared with the traditional vehicle steering wheel, one shielding layer is saved, so that the number of pin connections between the vehicle steering wheel and the control circuit can be reduced, and the thickness of the vehicle steering wheel pad can be reduced, so that the manufacturing difficulty and manufacturing cost of the vehicle steering wheel can be reduced.

[0218] It should be noted that the implementation scheme for solving the problem provided by the vehicle steering wheel is similar to the implementation scheme described above for the control circuit, so the specific limitations in one or more vehicle steering wheel embodiments provided above can refer to the limitations of the control circuit in the above text, and will not be described here.

[0219] In the description of the specification, the description referring to the terms "some embodiments", "other embodiments", etc. means that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the above-described terms in various places in the specification are not necessarily all referring to the same embodiment or example.

[0220] Any of the technical features of the above-described embodiments can be combined with each other, and for the sake of brevity, not all possible combinations are described in the above description, however, any combination of the technical features is to be considered as within the scope of the present application.

[0221] The above-described embodiments are merely illustrative of several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A control circuit, characterized in that, The control circuit includes: The system includes a capacitance detection module and a switch module; the switch module is connected to the capacitance detection module, the heating wire, and the heating power supply; the capacitance detection module is also connected to a sensing module. The capacitance detection module is used to send a first enable signal and a second enable signal to the switch module respectively in the first stage; The switching module is used to operate in the first stage under the action of the first enable signal and the second enable signal, so that the heating power supply heats the heating wire, so that the heating wire enters the heating state; The capacitance detection module is also used to send a first driving signal and a second driving signal to the switching module in the second stage. The switching module is further configured to transmit the first driving signal to the heating wire in the second stage, so that the heating wire acts as a shielding electrode; The switching module is also used to transmit the second driving signal to the sensing module in the second stage, so that the sensing module transmits a current signal to the capacitance detection module. The capacitance detection module is also used to output a capacitance signal based on the current signal, and the capacitance signal is used to determine whether the user touches the vehicle steering wheel.

2. The control circuit according to claim 1, characterized in that, The switching module includes a first switching unit and a second switching unit; The first end of the first switching unit is connected to the first end of the capacitance detection module, the second end of the first switching unit is connected to the first end of the heating wire, and the third end of the first switching unit is connected to the heating power supply; the first end of the second switching unit is connected to the second end of the capacitance detection module, the second end of the second switching unit is connected to ground, and the third end of the second switching unit is connected to both the third end of the capacitance detection module and the second end of the heating wire. The first switching unit is used to be turned on under the action of the first enable signal; The second switching unit is used to be turned on under the action of the first enable signal and the second enable signal.

3. The control circuit according to claim 2, characterized in that, The first switching unit and the second switching unit each include an analog device that can control the switching state.

4. The control circuit according to claim 3, characterized in that, The first switching unit includes a P-type MOSFET, and the second switching unit includes an N-type MOSFET.

5. The control circuit according to claim 1, characterized in that, The capacitance detection module includes a signal generation unit, a first driving unit, a second driving unit, and a detection unit; the sensing module includes sensing electrodes. The signal generation unit is connected to the first end of the first driving unit and the first end of the second driving unit respectively; the second end of the first driving unit is connected to the third end of the first driving unit and the switching module respectively; the second end of the second driving unit is connected to the third end of the second driving unit and the first end of the sensing electrode respectively; and the target end of the second driving unit is connected to the detection unit. The signal generation unit is used to generate a first voltage signal in the second stage; and to transmit the first voltage signal to the first driving unit and the second driving unit respectively. The first driving unit is configured to generate the first driving signal based on the first voltage signal in the second stage, and to send the first driving signal to the switching module; The second driving unit is configured to generate the second driving signal based on the first voltage signal in the second stage, and transmit the second driving signal to the sensing electrode; Receive current signals from the sensing electrodes; The current signal is transmitted to the detection unit; The detection unit is used to output the capacitance signal based on the current signal in the second stage.

6. The control circuit according to claim 1, characterized in that, The capacitance detection module includes a signal generation unit, a first driving unit, M second driving units, and a detection unit; the sensing module includes M sensing electrodes, where M is an integer greater than 1. The signal generation unit is connected to the first end of the first driving unit and the first ends of the M second driving units respectively; the second end of the first driving unit is connected to the third end of the first driving unit and the switching module respectively; the second end of the i-th second driving unit is connected to the third end of the i-th second driving unit and the first end of the i-th sensing electrode respectively; the target ends of the M second driving units are connected to the detection unit respectively; i=1,...,M; The signal generation unit is used to generate a first voltage signal in the second stage; and to transmit the first voltage signal to the first driving unit and M second driving units respectively. The first driving unit is configured to generate the first driving signal based on the first voltage signal in the second stage, and to send the first driving signal to the switching module; Each of the second driving units is configured to generate a second driving signal based on the first voltage signal in the second stage, and transmit the second driving signal to the corresponding sensing electrode; Receive current signals from the corresponding sensing electrodes; The current signal is transmitted to the detection unit; The detection unit is used to output the capacitance signal based on the current signal.

7. The control circuit according to claim 1, characterized in that, The waveform of the first driving signal is the same as the waveform of the second driving signal.

8. A control method, characterized in that, The method is applied to the control circuit as described in claim 1, and the method includes: In the first stage, a first enable signal and a second enable signal are sent to the switch module respectively; In the first stage, the heating power supply operates under the action of the first enable signal and the second enable signal, so that the heating wire heats the heating wire and puts the heating wire into a heating state. In the second stage, a first drive signal and a second drive signal are sent to the switch module respectively; In the second stage, the first driving signal is transmitted to the heating wire so that the heating wire acts as a shielding electrode; In the second stage, the second driving signal is transmitted to the sensing module, so that the sensing module transmits a current signal to the capacitance detection module; A capacitance signal is output based on the current signal, and the capacitance signal is used to determine whether the user touches the vehicle steering wheel.

9. The method according to claim 8, characterized in that, The method further includes: Determine the duration during which the capacitance change corresponding to the capacitance signal is less than or equal to the capacitance threshold. An alarm signal is generated if the duration is greater than or equal to the time threshold.

10. A vehicle steering wheel, characterized in that, The vehicle steering wheel includes the control circuit, the vehicle steering wheel mat, and the judgment circuit as described in claim 1; the vehicle steering wheel mat includes a sensing module and a heating wire; The control circuit is connected to the judgment circuit; The heating wire is used to be in a heating state during the first stage; The heating wire is also used as a shielding electrode in the second stage; The determination circuit is used to determine whether the user touches the vehicle steering wheel based on the capacitance signal.

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