Touch pressure switch based on capacitive sensor and vehicle
Through the touch pressure switch based on capacitive sensors, the upper and lower electrode plates and microcontrollers are used to detect capacitance changes, solving the problems of easy wear and false triggering of traditional touch switches, achieving high-precision, low-cost and reliable key detection.
Patent Information
- Application Number
- CN202422324692.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-09-23
AI Technical Summary
Traditional mechanical touch switches are prone to wear and costly. Although the electronic Hall sensor is highly accurate, it increases the development cost. There is a problem of error triggering of existing electronic touch switches.
The touch pressure switch based on a capacitive sensor is adopted, and the capacitive sensor composed of the upper and lower electrode plates is combined with the AD sampling unit and the microcontroller to achieve accurate detection of the buttons. The output circuit outputs the switching signal through the transistor and the capacitor resistor network, and the vehicle controller triggers the corresponding function.
Improve detection accuracy, reduce costs, and detect button operation through capacitance change, reduce false triggering, and improve safety, reliability and stability.
Smart Images
Figure CN223285818U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of touch switches, and in particular to a touch pressure switch based on a capacitive sensor and a vehicle. Background Art
[0002] With the development of new energy vehicles and smart cars, as well as the electronicization of traditional mechanical switch control systems, touch switches are increasingly being used in vehicles. Touch switches are popular due to their aesthetic design and ease of operation. However, traditional mechanical touch switches are susceptible to wear and tear, which can lead to mechanical failures and other problems. Currently, electronic touch switches are typically implemented using Hall effect sensors. While Hall effect sensors offer high precision, they can increase the cost of touch switch development. Therefore, a high-precision, low-cost touch switch design is needed. Utility Model Content
[0003] The present invention aims to solve the technical problems in the related art at least to a certain extent. To this end, the first object of the present invention is to provide a touch pressure switch based on a capacitive sensor, which has the advantages of high detection accuracy and low cost.
[0004] A second object of the present invention is to provide a vehicle.
[0005] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions:
[0006] A capacitive sensor-based touch pressure switch, comprising:
[0007] Multiple buttons, signal processing circuits and multiple groups of output circuits, each button is a capacitive sensor composed of an upper electrode plate and a lower electrode plate; the signal processing circuit includes an AD sampling unit and a single-chip microcomputer, the upper electrode plate and the lower electrode plate of each button are respectively connected to the input end corresponding to the AD sampling unit, the output end of the AD sampling unit corresponding to each button is connected to the single-chip microcomputer, and the single-chip microcomputer is also respectively connected to the output circuit corresponding to each button.
[0008] Preferably, each output circuit has the same structure, and the output circuit includes first to third resistors, a first capacitor, a second capacitor, and a transistor.
[0009] Preferably, one end of the first resistor is connected to the single-chip microcomputer, the other end of the first resistor is connected to the base of the transistor, the base of the transistor is also grounded through the second resistor and the first capacitor, the emitter of the transistor is grounded, the collector of the transistor is connected to one end of the third resistor, and the other end of the third resistor is grounded through the second capacitor; wherein, after the collector of the transistor is connected to the third resistor, it outputs a switching signal triggered by pressing the corresponding button.
[0010] Preferably, the other end of the third resistor is also connected to the vehicle controller, and the vehicle controller is used to trigger a corresponding button function after detecting the switch signal.
[0011] Preferably, the model of the single chip microcomputer is Attiny1616.
[0012] Preferably, the touch pressure switch further comprises a power conversion module connected to the signal processing circuit and an external power supply respectively, and the power conversion module is used for voltage conversion so as to supply power to the signal processing circuit.
[0013] Preferably, the input end of the power conversion module is connected to a transient voltage suppressor.
[0014] Preferably, the touch pressure switch further includes a power-on detection circuit connected to the single-chip microcomputer for power-on detection of the single-chip microcomputer.
[0015] Preferably, the power-on detection circuit includes fourth to sixth resistors and a third capacitor; one end of the fourth resistor is connected to the external power supply and grounded through the third capacitor, the other end of the fourth resistor is grounded through the sixth resistor and connected to the microcontroller through the fifth resistor.
[0016] To achieve the above-mentioned object, a second aspect of the present invention provides a vehicle, comprising the above-mentioned touch pressure switch based on the capacitive sensor.
[0017] The utility model has at least the following technical effects:
[0018] The present invention provides a capacitive sensor-based touch pressure switch, comprising multiple buttons, a signal processing circuit, and multiple output circuits. Each button is a capacitive sensor composed of an upper electrode plate and a lower electrode plate. The signal processing circuit includes an AD sampling unit and a single-chip microcomputer. The upper and lower electrode plates of each button are respectively connected to the input terminals of the AD sampling unit. The output terminals of the AD sampling unit corresponding to each button are respectively connected to the single-chip microcomputer. The single-chip microcomputer is also respectively connected to the output circuits corresponding to each button. When a button is pressed, the distance between the upper and lower electrode plates changes, causing a change in capacitance. The AD sampling unit samples the voltage change caused by the capacitance change. The single-chip microcomputer outputs a control signal to the output circuit of the corresponding button based on the voltage change, thereby outputting a switch signal. The vehicle controller detects the switch signal and triggers the corresponding button function accordingly. Thus, the present invention effectively solves the problem of false triggering of the touch pressure switch. By sensing the operation of the human hand through the capacitive switch, the capacitive switch samples the capacitance change of different channels, thereby realizing the output function of the corresponding button. This further enables reliable key detection and improves safety and reliability.
[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a structural block diagram of a touch pressure switch based on a capacitive sensor according to an embodiment of the present invention.
[0021] Figure 2 This is a schematic diagram of a single chip microcomputer according to an embodiment of the present utility model.
[0022] Figure 3 A schematic diagram of multiple buttons.
[0023] Figure 4 This is a schematic structural diagram of the output circuit of an embodiment of the present utility model.
[0024] Figure 5 This is a schematic diagram of the switch signal output of an embodiment of the present utility model.
[0025] Figure 6 This is a schematic diagram of the output circuit corresponding to the hazard switch key of an embodiment of the present utility model.
[0026] Figure 7 This is a structural diagram of a power conversion module according to an embodiment of the present utility model.
[0027] Figure 8 This is a structural diagram of a power-on detection circuit according to an embodiment of the present utility model. DETAILED DESCRIPTION
[0028] The present embodiment is described in detail below. Examples of the embodiment are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.
[0029] The capacitive sensor-based touch pressure switch and the vehicle according to the present embodiment will be described below with reference to the accompanying drawings.
[0030] Figure 1 FIG is a structural block diagram of a touch pressure switch based on a capacitive sensor according to an embodiment of the present invention. Figure 1 As shown, the capacitive sensor-based touch pressure switch includes a plurality of buttons 10 , a signal processing circuit 20 and a plurality of output circuits 30 , wherein one button 10 corresponds to one group of output circuits 30 .
[0031] In this embodiment, each button 10 is a capacitive sensor composed of an upper electrode plate and a lower electrode plate. A signal processing circuit 20 includes an analog-to-digital (ADC) sampling unit 21 and a single-chip microcomputer 22. The upper and lower electrode plates of each button 10 are connected to the corresponding inputs of the AD sampling unit 21. The outputs of the AD sampling unit 21 corresponding to each button 10 are connected to the single-chip microcomputer 22. The single-chip microcomputer 22 is also connected to the output circuit 30 corresponding to each button 10.
[0032] The model of the single chip microcomputer 22 is Attiny1616. Figure 2 This is a schematic diagram of a single chip microcomputer according to an embodiment of the present utility model. Figure 2 As shown, Attiny1616 includes multiple IO (input and output) ports, such as PB0, PB1, PA4, PA5 and PA6 ports. Figure 3 is a schematic diagram of multiple buttons. Figure 3 As shown, the button 10 includes a hazard switch CS1 button, a driving mode CS2 button, and an automatic parking button CS3. Of course, it can also include other function buttons, which are not specifically limited here. For example, the automatic parking button CS3 may include an upper electrode plate and a lower electrode plate. The upper electrode plate and the lower electrode plate constitute a capacitive sensor, which is arranged on a flexible circuit board and is responsible for collecting key signals. When the automatic parking button CS3 is pressed, the AD sampling unit 21 collects the voltage change caused by the capacitance change, and then inputs the voltage change after analog-to-digital conversion to an IO port of the Attiny1616, such as the PB0 port. After internal calculation, the Attiny1616 can output a high-level signal to the output circuit 30 corresponding to the automatic parking button CS3 through the PA4 port to output a switch signal. After the vehicle controller detects the switch signal, it triggers the automatic parking function.
[0033] It should be noted that the structures of the output circuits 30 in this embodiment are the same. Figure 4 This is a schematic structural diagram of the output circuit of an embodiment of the present utility model. Figure 5 This is a schematic diagram of the switch signal output of an embodiment of the present utility model. Figure 4 and Figure 5 As shown, the output circuit 30 includes first to third resistors R1 to R3 , a first capacitor C1 and a second capacitor C2 , and a transistor Q1 .
[0034] One end of a first resistor R1 is connected to port PA4 of the microcontroller 22. The other end of the first resistor R1 is connected to the base of a transistor Q1, which is also grounded via a second resistor R2 and a first capacitor C1. The emitter of the transistor Q1 is grounded. The collector of the transistor Q1 is connected to one end of a third resistor R3, the other end of which is grounded via a second capacitor C2. After the collector of the transistor Q1 is connected to the third resistor R3, it outputs a switch signal triggered by pressing a corresponding key. The other end of the third resistor R3 is also connected to a vehicle controller, which is configured to trigger the corresponding key function upon detecting the switch signal.
[0035] For example, the PA4 port of the MCU 22 corresponds to the automatic parking button CS3, and the PA5 port of the MCU 22 corresponds to the driving mode CS2 button. Taking the driving mode CS2 button as an example, assuming that the user touches the driving mode CS2 button, the distance between the upper and lower electrode plates decreases, and the capacitance formed by the upper and lower electrode plates increases. According to the set program, each button 10 has a corresponding touch pressure signal. When the voltage change caused by the change in capacitance does not reach the touch pressure signal, the touch driving mode CS2 button function is not responded to. When the user presses the driving mode CS2 button, the AD sampling unit 21 inputs the collected voltage change into the MCU 22. When the MCU 22 determines that the voltage change reaches the press signal or press threshold, it outputs a high level through the PA5 port. After being driven by the corresponding transistor Q2, it outputs the corresponding switch signal through the resistor R9. After the vehicle controller detects this switch signal, it triggers the driving mode function.
[0036] Figure 6 This is a schematic diagram of the output circuit corresponding to the hazard switch key of an embodiment of the present invention. It should be noted that the control port of the microcontroller 22 corresponding to the hazard switch key CS1 is port PA6. The key triggering principle of the hazard switch key CS1 is the same as that of other keys and will not be described in detail here.
[0037] Specifically, the signal processing circuit 20 and the multiple output circuits 30 in this embodiment are both provided on an FR4 (grade of organic substrate material used to manufacture circuit boards) circuit board. The FR4 circuit board is primarily responsible for touch signal processing. When the user presses the button 10 firmly, the distance between the upper and lower electrode plates of the flexible circuit board will change accordingly, thereby generating a touch pressure signal. The touch pressure signal is sampled and transmitted to the microcontroller 22. The microcontroller 22 determines and controls the corresponding function IO port to output a high level, so that Figure 4 The transistor in is turned on, and the corresponding function is triggered normally after the transistor is turned on.
[0038] As you can understand, the upper and lower electrode plates are used to detect touch pressure signals. If a hand is not pressing, the touch pressure switch will not respond. Only when both the touch signal quantity and the touch pressure signal exceed the pressing threshold will the switch signal be output. This effectively prevents the problem of false triggering of the touch pressure switch.
[0039] Furthermore, for functional safety considerations, a protective electrode can be added between the buttons 10 to avoid gear position recognition errors caused by interference.
[0040] Furthermore, both the upper electrode plate and the lower electrode plate can be connected to a spare line to achieve a redundant design. Specifically, both the upper electrode plate and the lower electrode plate are connected to two lines for signal input, and the two signals are ANDed. Both the upper and lower electrode plates can be used individually for touch pressure detection. After the touch pressure switch is pressed, if a single signal line of an electrode plate is disconnected, there is still a line to ensure signal input. Therefore, by adding two signal inputs to each capacitive sensor and ANDing the two signals, normal input can be achieved when any signal is normal, thereby improving the stability of the product.
[0041] The touch pressure switch further includes a power conversion module connected to the signal processing circuit 20 and an external power source, respectively. The power conversion module is used for voltage conversion to supply power to the signal processing circuit 20 .
[0042] Figure 7 This is a schematic diagram of the structure of the power conversion module of the embodiment of the utility model. Figure 7 As shown, the power conversion module is a TPL820F50-89TR chip, which is connected to the external power supply B+. The external power supply B+ voltage is 12V. Due to the presence of clutter interference, it needs to be filtered through a filter circuit and then input into the power conversion module. After the power conversion module converts the voltage to 5V, it powers the microcontroller 22.
[0043] In order to filter out clutter interference signals, this embodiment further connects a transient voltage suppressor D2 to the input end of the power conversion module. The transient voltage suppressor D2 can realize a clamping function, thereby effectively filtering out clutter interference signals.
[0044] The touch pressure switch further includes a power-on detection circuit connected to the single-chip microcomputer 22 for power-on detection of the single-chip microcomputer 22 .
[0045] Figure 8 FIG. 1 is a schematic diagram of the structure of the power-on detection circuit of an embodiment of the present utility model. Figure 8 As shown, the power-on detection circuit includes fourth to sixth resistors R4 to R6 and a third capacitor C3. One end of the fourth resistor R4 is connected to the external power supply and grounded via the third capacitor C3. The other end of the fourth resistor R4 is grounded via the sixth resistor R6 and connected to the PC0 port of the microcontroller 22 via the fifth resistor R5.
[0046] In this embodiment, when the system is powered on, a power-on detection may be performed through the PC0 port of the single-chip microcomputer 22 .
[0047] In summary, the present invention provides a touch pressure switch based on a capacitive sensor, which includes multiple buttons, a signal processing circuit, and multiple output circuits. Each button is a capacitive sensor composed of an upper electrode plate and a lower electrode plate. The signal processing circuit includes an AD sampling unit and a single-chip microcomputer. The upper electrode plate and the lower electrode plate of each button are respectively connected to the input end corresponding to the AD sampling unit. The output end of the AD sampling unit corresponding to each button is connected to the single-chip microcomputer. The single-chip microcomputer is also connected to the output circuit corresponding to each button. When a button is pressed, the distance between the upper electrode plate and the lower electrode plate changes, and the capacitance changes accordingly. The AD sampling unit will collect the voltage change caused by the capacitance change. The single-chip microcomputer outputs a control signal to the output circuit of the corresponding button based on the voltage change, thereby outputting a switch signal so that the vehicle controller detects the switch signal and triggers the corresponding button function accordingly. Therefore, the present invention can effectively solve the problem of false triggering of the touch pressure switch. It senses the operation of the human hand through the capacitive switch, collects the capacitance changes of different channels, and thus realizes the output function of the corresponding button, thereby realizing reliable key detection and improving safety and reliability.
[0048] Furthermore, the present invention also provides a vehicle, which includes the above-mentioned touch pressure switch based on the capacitive sensor.
[0049] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.
[0050] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. After reading the above description, various modifications and alternatives to the present invention will be readily apparent to those skilled in the art. Therefore, the scope of protection of the present invention shall be defined by the appended claims.
Claims
1. A touch pressure switch based on a capacitive sensor, characterized in that: include: Multiple buttons, signal processing circuits and multiple groups of output circuits, each button is a capacitive sensor composed of an upper electrode plate and a lower electrode plate; the signal processing circuit includes an AD sampling unit and a single-chip microcomputer, the upper electrode plate and the lower electrode plate of each button are respectively connected to the input end corresponding to the AD sampling unit, the output end of the AD sampling unit corresponding to each button is connected to the single-chip microcomputer, and the single-chip microcomputer is also respectively connected to the output circuit corresponding to each button.
2. The capacitive sensor-based touch pressure switch according to claim 1, wherein: Each output circuit has the same structure, and includes first to third resistors, a first capacitor, a second capacitor, and a transistor.
3. The capacitive sensor-based touch pressure switch according to claim 2, wherein: One end of the first resistor is connected to the single-chip microcomputer, the other end of the first resistor is connected to the base of the transistor, the base of the transistor is also grounded through the second resistor and the first capacitor, the emitter of the transistor is grounded, the collector of the transistor is connected to one end of the third resistor, and the other end of the third resistor is grounded through the second capacitor; wherein, after the collector of the transistor is connected to the third resistor, it outputs a switching signal triggered by pressing the corresponding key.
4. The capacitive sensor-based touch pressure switch according to claim 3, wherein: The other end of the third resistor is also connected to the vehicle controller, and the vehicle controller is used to trigger the corresponding button function after detecting the switch signal.
5. The capacitive sensor-based touch pressure switch according to claim 1, wherein: The model of the single chip microcomputer is Attiny1616.
6. The capacitive sensor-based touch pressure switch according to claim 1, wherein: It also includes a power conversion module, which is connected to the signal processing circuit and an external power supply respectively. The power conversion module is used for voltage conversion to supply power to the signal processing circuit.
7. The capacitive sensor-based touch pressure switch according to claim 6, wherein: The input end of the power conversion module is connected to a transient voltage suppressor.
8. The capacitive sensor-based touch pressure switch according to claim 1, wherein: It also includes a power-on detection circuit connected to the single-chip microcomputer and used for power-on detection of the single-chip microcomputer.
9. The capacitive sensor-based touch pressure switch according to claim 8, wherein: The power-on detection circuit includes fourth to sixth resistors and a third capacitor; one end of the fourth resistor is connected to an external power supply and grounded through the third capacitor, the other end of the fourth resistor is grounded through the sixth resistor and connected to the microcontroller through the fifth resistor.
10. A vehicle, characterized in that: The invention comprises a touch pressure switch based on a capacitive sensor as claimed in any one of claims 1 to 9.