Touch type door handle control circuit based on capacitive sensor and strain gauge

Abstract

The utility model discloses a touch type door handle control circuit based on a capacitance sensor and a strain gauge, which comprises an MCU (Microprogrammed Control Unit), an AD (Analog to Digital) acquisition module, a capacitance acquisition module and a strain gauge composite capacitance acquisition metal pole piece, the MCU is connected with the strain gauge composite capacitance collection metal pole piece through the AD collection module and the capacitance collection module, the capacitance collection module can collect the capacitance value of the strain gauge composite capacitance collection metal pole piece and output the capacitance value to the MCU, and the AD collection module can collect the voltage division AD value of the strain gauge composite capacitance collection metal pole piece and output the voltage division AD value to the MCU. Therefore, the MCU controls the touch type door handle according to the capacitance change value and the strain value caused by the external conductor, mistaken touch can be reduced, and the circuit is simple in overall composition structure and easy to implement.

Description

Technical Field

[0001] This utility model relates to the field of vehicle control technology, specifically to a touch-sensitive door handle control circuit. Background Technology

[0002] With the development of new energy vehicles, physical keys are becoming increasingly marginalized, and the unlocking and closing methods of car doors have been transformed into external switches. Touch switches do not rely on mechanical structures, have a long service life and waterproof performance, and are widely used in the automotive field.

[0003] Chinese Patent No. CN 222107924 U discloses a touch-sensitive switch circuit, comprising: a touch-sensitive switch chip, wherein the third pin of the touch-sensitive switch chip is connected to a touch button, and its first pin is connected to an external driven element through a first signal driving unit and to another external driven element through a second signal driving unit; in response to pressing the touch button, the first signal driving unit and the second signal driving unit are controlled to execute a first action command to put the two driven elements into a working state; in response to not pressing the touch button, the first signal driving unit and the second signal driving unit are controlled to execute a second action command to put the two driven elements into an initial state, thereby realizing the control of the touch switch.

[0004] However, existing touch control circuits have complex overall structures, are not easy to implement in hardware, and are susceptible to false triggering due to rain or high-pressure water jets, resulting in low circuit reliability.

[0005] Therefore, providing a touch-sensitive door handle control circuit that is simple in structure, easy to implement, and reduces accidental touches has become an urgent problem to be solved in this field. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a touch-type door handle control circuit based on a capacitive sensor and strain gauge that has a simple structure, is easy to implement, and reduces accidental touches.

[0007] To achieve the above objectives, this utility model provides a touch-sensitive door handle control circuit based on a capacitive sensor and strain gauge, comprising an MCU, an AD acquisition module, a capacitance acquisition module, and a strain gauge composite capacitance acquisition metal electrode. The strain gauge composite capacitance acquisition metal electrode and an external conductor form a parallel-plate capacitor. The MCU is connected to the strain gauge composite capacitance acquisition metal electrode through both the AD acquisition module and the capacitance acquisition module. The capacitance acquisition module can acquire the capacitance value of the strain gauge composite capacitance acquisition metal electrode and output it to the MCU. The AD acquisition module can acquire the voltage divider AD value of the strain gauge composite capacitance acquisition metal electrode and output it to the MCU.

[0008] Furthermore, the strain gauge composite capacitor acquisition metal electrode integrated strain gauge includes a metal strain gauge, which is composed of several parallel metal grids.

[0009] Furthermore, the AD acquisition module includes an AD acquisition enable pin, one end of which is connected to the MCU, and the other end is connected to the first end of the first resistor. The second end of the first resistor is connected to the base of the first switch. The emitter of the first switch is connected to the metal electrode of the strain gauge composite capacitor acquisition plate, and the collector is connected to the power supply.

[0010] Furthermore, the AD acquisition module also includes an AD acquisition pin, one end of which is connected to the MCU, and the other end is connected to the first end of the second resistor. The second end of the second resistor is connected to the first end of the fourth resistor and the first end of the third resistor, respectively. The second end of the fourth resistor is grounded, and the second end of the third resistor is connected to the emitter of the second switch. The base of the second switch is connected to the first resistor and the base of the first switch, respectively. The collector of the second switch is connected to the metal electrode of the strain gauge composite capacitor acquisition plate.

[0011] Furthermore, the capacitance acquisition module includes a capacitance acquisition enable pin, one end of which is connected to the MCU and the other end is connected to the base of the third switch. The collector of the third switch is connected to the strain gauge composite capacitance acquisition metal electrode, and the emitter is connected to the first terminal of the first capacitor. The second terminal of the first capacitor is grounded.

[0012] Furthermore, the capacitance acquisition module also includes a capacitance acquisition pin. One end of the capacitance acquisition pin is connected to the MCU, and the other end is connected to the first end of the fifth resistor. The second end of the fifth resistor is connected to the collector of the fourth switch. The emitter of the fourth switch is connected to the strain gauge composite capacitance acquisition metal electrode, and the base is connected to the capacitance acquisition enable pin and the base of the third switch, respectively.

[0013] This utility model provides a touch-sensitive door handle control circuit based on a capacitive sensor and strain gauge. The strain gauge composite capacitor acquisition metal electrode is a metal strain gauge, which also forms a parallel plate capacitor with an external conductor. This allows the AD acquisition module and the capacitance acquisition module to respectively acquire the voltage division AD value and capacitance value of the strain gauge composite capacitor acquisition metal electrode and output them to the MCU. The MCU can then control the touch-sensitive door handle based on the capacitance change and strain value caused by the external conductor. This reduces accidental touches, and the overall circuit structure is simple and easy to implement. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1A system block diagram of the touch-sensitive door handle control circuit based on a capacitive sensor and strain gauge provided by this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of the strain gauge composite capacitor collecting metal electrode in this utility model;

[0017] Figure 3 The circuit diagram of the touch-sensitive door handle control based on a capacitive sensor and strain gauge provided by this utility model. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0019] See Figure 1 The diagram shows an example of a touch-sensitive door handle control circuit based on a capacitive sensor and strain gauge provided by this utility model.

[0020] As shown in the figure, the touch door handle control circuit based on a capacitive sensor and strain gauge in this example mainly includes MCU 1, AD acquisition module 2, capacitive acquisition module 3, and strain gauge composite capacitive acquisition metal electrode 4.

[0021] The strain gauge composite capacitor acquisition metal electrode 4 and the external conductor form a parallel plate capacitor. The MCU 1 is connected to the strain gauge composite capacitor acquisition metal electrode 4 through the AD acquisition module 2 and the capacitance acquisition module 3 respectively. The capacitance acquisition module 3 can acquire the capacitance value of the strain gauge composite capacitor acquisition metal electrode 4 and output it to the MCU 1. The AD acquisition module 2 can acquire the voltage divider AD value of the strain gauge composite capacitor acquisition metal electrode 4 and output it to the MCU 1. The MCU 1 can control the touch door handle according to the capacitance value and strain value caused by the external conductor, which can effectively reduce accidental touch. Moreover, the overall circuit structure is simple and easy to implement.

[0022] Combination Figure 2 The strain gauge composite capacitor acquisition metal electrode 4 includes a metal strain gauge 41, which is composed of several parallel metal grids 42. In this way, the metal grids 42 can act as strain gauges, and their resistance changes when pressed by an external conductor. At the same time, the metal grids 42 can form an equipotential conductor plane through electrical connection, so that the plane range formed by the metal grids 42 forms one pole of a parallel plate capacitor, thereby enabling the metal grids 42 to cooperate with the external conductor to form a parallel plate capacitor.

[0023] The strain gauge composite capacitor acquisition metal electrode 4 thus constitutes an integrated strain gauge and parallel plate capacitor. It can generate a change in resistance when pressed by an external conductor, and a change in capacitance when the external conductor approaches, so that the AD acquisition module 2 and the capacitance acquisition module 3 can respectively acquire the voltage division AD value and capacitance value of the strain gauge composite capacitor acquisition metal electrode 4.

[0024] Combination Figure 1 and Figure 3 In conjunction with this, the AD acquisition module 2 includes an AD acquisition enable pin. One end of the AD acquisition enable pin is connected to the MCU 1, and the other end is connected to the first end of the first resistor R1. The second end of the first resistor R1 is connected to the base of the first switch Q1. The emitter of the first switch Q1 is connected to the strain gauge composite capacitor acquisition metal electrode 4, and the collector is connected to the power supply 12V.

[0025] Furthermore, the AD acquisition module also includes an AD acquisition pin. One end of the AD acquisition pin is connected to MCU 1, and the other end is connected to the first end of the second resistor R2. The second end of the second resistor R2 is connected to the first end of the fourth resistor R4 and the first end of the third resistor R3, respectively. The second end of the fourth resistor R4 is grounded. The second end of the third resistor R3 is connected to the emitter of the second switch Q2. The base of the second switch Q2 is connected to the base of the first resistor R1 and the first switch Q1, respectively. The collector of the second switch Q2 is connected to the strain gauge composite capacitor acquisition metal electrode 4.

[0026] The AD acquisition module 2 thus constitutes the strain gauge AD acquisition circuit of the strain gauge composite capacitor acquisition metal electrode 4. The MCU 1 enables the AD acquisition enable pin, which can turn on the AD acquisition module 2, so that the AD acquisition module 2 and the strain gauge composite capacitor acquisition metal electrode 4 form a voltage divider circuit, which converts the resistance change caused by the external conductor into a voltage change, thereby acquiring the voltage divider AD value of the strain gauge composite capacitor acquisition metal electrode 4, and outputting it to the MCU 1 through the AD acquisition pin.

[0027] Furthermore, MCU 1 calculates the stress on metal electrode 4 based on the voltage divider AD value of the strain gauge composite capacitor acquisition metal electrode 4. Here, MCU 1's calculation of the stress on metal electrode 4 based on the voltage divider AD value is a conventional technique in this field and will not be elaborated here.

[0028] As an example, MCU 1 calculates the resistance change of the strain gauge composite capacitor acquisition metal electrode 4 based on the voltage divider AD value, and can deduce the stress condition of the strain gauge composite capacitor acquisition metal electrode 4 by combining the material stress coefficient, elastic modulus and cross-sectional area of ​​the strain gauge composite capacitor acquisition metal electrode 4.

[0029] Combination Figure 1 and Figure 3Furthermore, to reduce accidental touches, this circuit also includes a capacitance acquisition module 3. The capacitance acquisition module 3 includes a capacitance acquisition enable pin. One end of the capacitance acquisition enable pin is connected to the MCU 1, and the other end is connected to the base of the third switch Q3. The collector of the third switch Q3 is connected to the strain gauge composite capacitor acquisition metal electrode 4, and the emitter is connected to the first end of the first capacitor C1. The second end of the first capacitor C1 is grounded.

[0030] Meanwhile, the capacitance acquisition module 3 also includes a capacitance acquisition pin. One end of the capacitance acquisition pin is connected to the MCU 1, and the other end is connected to the first end of the fifth resistor R5. The second end of the fifth resistor R5 is connected to the collector of the fourth switch Q4. The emitter of the fourth switch Q4 is connected to the strain gauge composite capacitance acquisition metal electrode 4, and the base is connected to the capacitance acquisition enable pin and the base of the third switch Q3, respectively.

[0031] The capacitance acquisition module 3 thus constitutes the capacitance acquisition circuit of the strain gauge composite capacitance acquisition metal electrode 4. The MCU 1 enables the capacitance acquisition enable pin, which can turn on the capacitance acquisition module 3. The strain gauge composite capacitance acquisition metal electrode 4 is one of the poles of the parallel plate capacitor formed with the external conductor. When the external conductor approaches the strain gauge composite capacitance acquisition metal electrode 4, the capacitance acquisition module 3 will acquire the change in capacitance value of the parallel plate capacitor and output it to the MCU 1 through the capacitance acquisition pin.

[0032] In this way, AD acquisition module 2 and capacitance acquisition module 3 can cooperate to form strain gauge AD acquisition circuit and capacitance acquisition circuit, respectively acquiring the voltage divider AD value and capacitance value of strain gauge composite capacitor acquisition metal electrode 4, and outputting them to MCU 1, so that MCU 1 can control the touch door handle together based on the voltage divider AD value and capacitance value, thereby reducing the accidental touch caused by controlling the touch door handle based on a single parameter.

[0033] Here, the control of the touch door handle by MCU 1 is a conventional technique in this field, and will not be elaborated here.

[0034] The following example illustrates the working process of this utility model in a specific application. It should be noted that the content described here is only a specific application example of this solution and does not constitute a limitation on this solution.

[0035] As an example, the AD acquisition module 2 and the capacitor acquisition module 3 are time-division multiplexed during the acquisition period. When the AD acquisition enable pin is enabled and the AD acquisition module 2 is turned on, the capacitor acquisition module 3 is turned off, so that this circuit constitutes a strain gauge AD acquisition circuit and acquires the voltage division AD value of the strain gauge composite capacitor acquisition metal electrode 4.

[0036] Furthermore, when the capacitor acquisition enable pin is enabled and the capacitor acquisition module 3 is turned on, the AD acquisition module 2 is turned off, so that this circuit constitutes a capacitor acquisition circuit and acquires the capacitance value of the strain gauge composite capacitor acquisition metal electrode 4.

[0037] At the same time, the acquisition cycle of AD acquisition module 2 and capacitance acquisition module 3 is shortened, so that AD acquisition module 2 and capacitance acquisition module 3 can acquire in parallel, and output the voltage divider AD value and capacitance value to MCU 1 for MCU 1 to control the touch door handle.

[0038] The present invention provides a touch-sensitive door handle control circuit based on a capacitive sensor and a strain gauge. The strain gauge composite capacitor acquisition metal electrode 4 is a metal strain gauge, which also forms a parallel plate capacitor with an external conductor. This allows the AD acquisition module 2 and the capacitance acquisition module 3 to acquire the voltage division AD value and capacitance value of the strain gauge composite capacitor acquisition metal electrode 4, respectively, and output them to the MCU 1. This enables the MCU 1 to control the touch-sensitive door handle according to the capacitance change and strain value caused by the external conductor, thereby reducing accidental touches. The overall circuit structure is simple and easy to implement.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A touch door handle control circuit based on a capacitive sensor plus strain gauge, characterized by, The system includes an MCU, an AD acquisition module, a capacitance acquisition module, and a strain gauge composite capacitance acquisition metal electrode. The strain gauge composite capacitance acquisition metal electrode and an external conductor form a parallel-plate capacitor. The MCU is connected to the strain gauge composite capacitance acquisition metal electrode through both the AD acquisition module and the capacitance acquisition module. The capacitance acquisition module can acquire the capacitance value of the strain gauge composite capacitance acquisition metal electrode and output it to the MCU. The AD acquisition module can acquire the voltage divider AD value of the strain gauge composite capacitance acquisition metal electrode and output it to the MCU.

2. The capacitive sensor plus strain gauge based touch handle control circuit of claim 1, wherein, The strain gauge composite capacitance acquisition metal electrode integrated strain gauge includes a metal strain gauge, which is composed of several parallel metal grids.

3. The capacitive sensor plus strain gauge based touch handle control circuit of claim 1, wherein, The AD acquisition module includes an AD acquisition enable pin. One end of the AD acquisition enable pin is connected to the MCU, and the other end is connected to the first end of the first resistor. The second end of the first resistor is connected to the base of the first switch. The emitter of the first switch is connected to the metal electrode of the strain gauge composite capacitor acquisition plate, and the collector is connected to the power supply.

4. The capacitive sensor plus strain gauge based touch handle control circuit of claim 3, wherein, The AD acquisition module also includes an AD acquisition pin. One end of the AD acquisition pin is connected to the MCU, and the other end is connected to the first end of the second resistor. The second end of the second resistor is connected to the first end of the fourth resistor and the first end of the third resistor. The second end of the fourth resistor is grounded. The second end of the third resistor is connected to the emitter of the second switch. The base of the second switch is connected to the first resistor and the base of the first switch. The collector of the second switch is connected to the metal electrode of the strain gauge composite capacitor acquisition plate.

5. The capacitive sensor plus strain gauge based touch handle control circuit of claim 4, wherein, The capacitance acquisition module includes a capacitance acquisition enable pin. One end of the capacitance acquisition enable pin is connected to the MCU, and the other end is connected to the base of the third switch. The collector of the third switch is connected to the strain gauge composite capacitor acquisition metal electrode, and the emitter is connected to the first terminal of the first capacitor. The second terminal of the first capacitor is grounded.

6. The capacitive sensor plus strain gauge based touch handle control circuit of claim 5, wherein, The capacitance acquisition module also includes a capacitance acquisition pin. One end of the capacitance acquisition pin is connected to the MCU, and the other end is connected to the first end of the fifth resistor. The second end of the fifth resistor is connected to the collector of the fourth switch. The emitter of the fourth switch is connected to the strain gauge composite capacitance acquisition metal electrode. The base is connected to the capacitance acquisition enable pin and the base of the third switch, respectively.

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