CN117968897B - Piezoelectric sensor control method, circuit and piezoelectric sensing system - Google Patents

Abstract

The application relates to a piezoelectric sensor control method, a circuit and a piezoelectric sensing system, which immediately control a comparator to stop enabling when a force removing event is detected, so that the output voltage of a piezoelectric sensor cannot trigger a pressure event, thereby avoiding false triggering of the pressure event due to rebound voltage, improving the accuracy of pressure monitoring of the piezoelectric sensor, ensuring that rebound voltage is quickly and accurately reduced when the piezoelectric sensor removes force, and improving the accuracy of pressure monitoring of the piezoelectric sensor.

Description

Piezoelectric sensor control method, circuit and piezoelectric sensing system

Technical Field

The present application relates to the field of piezoelectric sensor control technology, and in particular to a piezoelectric sensor control method, circuit and piezoelectric sensing system.

Background Art

A piezoelectric sensor is a sensor that converts mechanical pressure into electrical signals. It uses the characteristics of piezoelectric materials. When external force is applied to its surface, the internal charge distribution changes, thereby generating voltage. Piezoelectric sensors convert physical quantities into electrical signals, and the processing of electrical signals requires chips. Therefore, in practical applications, piezoelectric sensors are usually combined with piezoelectric sensor control circuits to enhance the function and measurement accuracy of the sensor, so that it can better meet the needs of different industries.

Figure 1 is a schematic diagram of the state change of a piezoelectric sensor in the related art. Referring to Figure 1, a piezoelectric sensor is generally a parallel plate capacitor structure, with uniform positive and negative charges in the medium. In the absence of external force, the overall electrical neutrality is present. When the sensor is subjected to force, the geometric centers of the positive and negative charges are misaligned, thereby presenting induced charges on the two plates. The greater the force, the greater the degree of misalignment of the geometric centers of the positive and negative charges, and the greater the amount of charge on the plates. If the sensor is subjected to pressure in the opposite direction, charges are generated in the same way as above, but the charge signs corresponding to each plate will change according to the direction of the force. When the internal charge of the piezoelectric sensor changes, a voltage will be output, and the piezoelectric sensor control circuit determines whether a pressure event has occurred based on the output voltage.

However, piezoelectric sensors generally have charge leakage, which can cause the piezoelectric sensor to generate rebound voltage during the force removal process, which may cause the piezoelectric sensor control circuit to incorrectly determine that a pressure event has occurred, affecting the measurement accuracy of the piezoelectric sensor.

At present, in the related technology, there is no effective solution to the problem that piezoelectric sensors are prone to false triggering when the force is removed.

Summary of the invention

Based on this, it is necessary to provide a piezoelectric sensor control method, circuit and piezoelectric sensing system that can avoid false triggering of the piezoelectric sensor when the force is removed to address the above technical problems.

In a first aspect, the present application provides a piezoelectric sensor control method. The method comprises:

Monitoring whether a force removal event occurs in the piezoelectric sensor, wherein the force removal event indicates that the pressure on the piezoelectric sensor gradually decreases;

In response to the force removal event, a comparator connected to the piezoelectric sensor is controlled to stop being enabled, so that the output voltage of the piezoelectric sensor cannot trigger a pressure event.

In one embodiment, the piezoelectric sensor control method further includes:

After maintaining a preset time, the comparator is enabled again, wherein the preset time is not less than the discharge time of the residual charge that can trigger the pressure event.

In one embodiment, monitoring whether a force removal event occurs in the piezoelectric sensor includes:

When it is monitored that the voltage output by the piezoelectric sensor decreases to the first threshold voltage, it is determined that a force removal event occurs in the piezoelectric sensor, wherein the first threshold voltage does not exceed the first voltage output by the piezoelectric sensor at the moment of the force removal event, and the first threshold voltage and the first voltage are both positive voltages.

In one embodiment, monitoring whether a force withdrawal event occurs in the piezoelectric sensor further includes:

When it is monitored that the voltage output by the piezoelectric sensor increases to a second threshold voltage, it is determined that a force removal event occurs in the piezoelectric sensor, wherein the second threshold voltage is not less than a second voltage corresponding to the piezoelectric sensor at the moment of the force removal event, and the second threshold voltage and the second voltage are both negative voltages.

In one embodiment, monitoring whether a force withdrawal event occurs in the piezoelectric sensor further includes:

When it is monitored that the output voltage of the piezoelectric sensor switches from the first voltage region to the second voltage region, or the output voltage of the piezoelectric sensor switches from the third voltage region to the second voltage region, it is determined that a force withdrawal event occurs in the piezoelectric sensor; wherein the voltage in the first voltage region is not less than a first threshold voltage, the voltage in the second voltage region is greater than the second threshold voltage and less than the first threshold voltage, and the voltage in the third voltage region is not greater than the second threshold voltage.

In one embodiment, monitoring whether a force withdrawal event occurs in the piezoelectric sensor further includes:

When it is monitored that the piezoelectric sensor changes from the first state code to the second state code, or the piezoelectric sensor changes from the third state code to the second state code, it is determined that a force withdrawal event occurs in the piezoelectric sensor; wherein the first state code is a logical code representing that the output voltage of the piezoelectric sensor is within the first voltage range, the second state code is a logical code representing that the output voltage of the piezoelectric sensor is within the second voltage range, and the third state code is a logical code representing that the output voltage of the piezoelectric sensor is within the third voltage range.

In a second aspect, an embodiment of the present application provides a piezoelectric sensor control circuit, including:

A comparison module, used to monitor whether a force removal event occurs in the piezoelectric sensor, and output a monitoring result, wherein the force removal event indicates that the pressure on the piezoelectric sensor is gradually reduced;

The logic module is connected to the comparison module and is configured to shield the monitoring result of the comparison module in response to the force withdrawal event.

In one embodiment, the comparison module includes: a first comparator; the input end of the first comparator is connected to the output end of the piezoelectric sensor, the output end of the first comparator is connected to the input end of the logic module, and the enable end of the first comparator is connected to the output end of the logic module; the first comparator is used to compare the magnitude relationship between the voltage output by the piezoelectric sensor and the first threshold voltage.

In one embodiment, the comparison module also includes: a second comparator; the input end of the second comparator is connected to the output end of the piezoelectric sensor, the output end of the second comparator is connected to the input end of the logic module, and the enable end of the second comparator is connected to the output end of the logic module; the second comparator is used to compare the magnitude relationship between the voltage output by the piezoelectric sensor and the second threshold voltage.

In a third aspect, an embodiment of the present application further provides a piezoelectric sensing system, comprising: a piezoelectric sensor and a piezoelectric sensor control circuit as described in any one of the second aspects above; wherein the piezoelectric sensor is connected to the piezoelectric sensor control circuit.

In a fourth aspect, an embodiment of the present application further provides an electronic cigarette, comprising: a main body, on which a piezoelectric sensor and a piezoelectric sensor control circuit as described in any one of the second aspects are arranged, and the piezoelectric sensor is connected to the piezoelectric sensor control circuit.

The above-mentioned piezoelectric sensor control method, circuit and piezoelectric sensing system, when detecting a force removal event, immediately control the comparator to stop enabling, so that the output voltage of the piezoelectric sensor cannot trigger a pressure event, thereby avoiding false triggering of a pressure event due to a rebound voltage, improving the accuracy of pressure monitoring of the piezoelectric sensor, and ensuring that the rebound voltage is quickly and accurately reduced when the piezoelectric sensor removes force, thereby improving the accuracy of pressure monitoring of the piezoelectric sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a piezoelectric sensor;

FIG2 is an equivalent circuit diagram of a single-ended piezoelectric sensor;

FIG3 is a schematic diagram of a response curve of a single-ended piezoelectric sensor;

FIG4 is a schematic flow chart of a piezoelectric sensor control method in one embodiment;

FIG5 is a schematic diagram showing the principle of a piezoelectric sensor control method in one embodiment;

FIG6 is a schematic diagram showing the principle of logic state encoding of a piezoelectric sensor in one embodiment;

FIG7 is a schematic diagram of the structure of a piezoelectric sensor control circuit in one embodiment;

FIG8 is an equivalent circuit diagram of a two-terminal piezoelectric sensor;

FIG9 is a schematic diagram of the structure of a piezoelectric sensor control circuit in another embodiment;

FIG. 10 is a schematic diagram of the structure of a piezoelectric sensing system in one embodiment.

DETAILED DESCRIPTION

In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

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

It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

When used herein, the singular forms "a", "an", and "said/the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include/comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and/or" used in this specification includes any and all combinations of the relevant listed items.

Figure 2 is a schematic diagram of the equivalent circuit of a single-ended piezoelectric sensor. As shown in Figure 2, MEMS represents a piezoelectric sensor, which can be equivalent to a charge source q, a capacitor Cp and a resistor Rp connected in parallel, Vout represents the output voltage of the piezoelectric sensor, and Vref represents the reference voltage of the piezoelectric sensor. When the plate is under pressure, the charge source q generates charge and stores it in the capacitor Cp, forming a voltage difference of Vout-Vref=q/Cp. However, due to the existence of the resistor Rp, the charge on the capacitor Cp will slowly leak through Rp, resulting in a decrease in the amount of charge on the capacitor Cp, thereby reducing the value of Vout-Vref, until Vout=Vref, the charge is 0.

FIG3 is a schematic diagram of the response curve of a single-ended piezoelectric sensor. As shown in FIG3, when reverse pressure is applied to the piezoelectric sensor (for example, force is applied to the lower plate of FIG1), charge is generated on the plate to form a voltage; as the force increases, the amount of charge increases, and the output voltage Vout also increases. When the force just changes from increasing to maintaining unchanged, the output voltage Vout reaches a peak value. Subsequently, due to the aforementioned charge leakage, the output voltage Vout slowly decreases. If the "force removal process" occurs before the charge is completely leaked, a charge with an opposite sign will be generated inside the piezoelectric sensor to offset the charge generated in the "force application process", which is manifested as a steep force removal edge and a rebound voltage on the output voltage. The rebound voltage is the voltage formed on the capacitor Cp by the residual charge after the charge generated by the "force removal process" is offset by the charge remaining after leakage at the "start of the force removal process". As this residual charge slowly leaks, the rebound voltage will gradually return to the baseline potential (the schematic diagram is shown as 0 potential for convenience). Similarly, when positive pressure is applied to the sensor (for example, force is applied to the upper plate in Figure 1), the sensor will still go through the four processes mentioned above: the voltage reaches a peak as the force increases, the charge leaks when the force remains stable, causing the voltage to decrease, a rebound voltage occurs when the force is removed, and the rebound voltage slowly recovers.

Under normal circumstances (without considering the rebound voltage), a pressure event refers to the output voltage of the piezoelectric sensor being no less than the voltage threshold. Whether it is judging a forward pressure event or a reverse pressure event, it is only necessary to detect whether the output voltage is greater than the voltage threshold. If so, it is determined that a pressure event has occurred. It should be noted that the voltage threshold judgment here refers to comparing the voltage amplitude, regardless of the direction. As for the direction of force application, it can be determined by comparing the output voltage with the baseline voltage. However, if the amplitude of the rebound voltage generated during the withdrawal process exceeds the judgment threshold of the pressure event, it is mistakenly believed that a pressure event has occurred. In other words, the rebound voltage may trigger a false judgment, causing the piezoelectric sensor control circuit to "mistakenly believe" that pressure has occurred. For example, industrial equipment is mistakenly turned on, medical equipment is falsely reported, and electronic cigarettes are mistakenly ignited, which will cause inconvenience and even safety hazards.

Based on the above analysis, in one embodiment, a piezoelectric sensor control method is provided. FIG4 is a flow chart of the piezoelectric sensor control method of this embodiment. As shown in FIG4 , the flow chart includes the following steps:

Step S401 , monitoring whether a force removal event occurs in the piezoelectric sensor, wherein the force removal event indicates that the pressure on the piezoelectric sensor gradually decreases.

Step S402 , in response to a force removal event, controlling a comparator connected to the piezoelectric sensor to stop being enabled, so that the output voltage of the piezoelectric sensor cannot trigger a pressure event.

The force removal event is reflected in the gradual reduction of the pressure on the piezoelectric sensor. Controlling the comparator to stop enabling means using a comparator with an enable terminal to control the piezoelectric sensor, and enabling the comparator through the enable terminal of the comparator. When the comparator stops enabling, the output of the comparator will be set to a voltage region that cannot trigger a pressure event. At this time, any voltage output by the piezoelectric sensor cannot trigger a pressure event. That is, during the force removal process, it is ensured that the output voltage of the piezoelectric sensor will not mistakenly trigger a pressure event.

In the above steps S401 to S402, considering that the rebound voltage occurs following the force removal event, when the force removal event is detected, the comparator is immediately controlled to stop enabling, so that the output voltage of the piezoelectric sensor cannot trigger a pressure event, thereby avoiding false triggering of a pressure event due to the rebound voltage, improving the accuracy of pressure monitoring of the piezoelectric sensor, and ensuring that the rebound voltage is quickly and accurately reduced when the piezoelectric sensor removes force, thereby improving the accuracy of pressure monitoring of the piezoelectric sensor.

In one embodiment, the piezoelectric sensor control method further includes: after maintaining a preset time, restoring the enabling of the comparator, wherein the preset time is not less than the discharge time of the residual charge that can trigger the pressure event.

Among them, the residual charge refers to the charge generated when the force is removed, which can trigger the pressure event after offsetting the remaining charge after the leakage, that is, the residual charge that can trigger the pressure event after the force is removed. When the force removal event occurs, the comparator is immediately controlled to stop enabling so that the output voltage of the piezoelectric sensor cannot trigger the pressure event, thereby avoiding the false triggering of the pressure event. Since stopping the comparator will affect the normal operation of the piezoelectric sensor, it is necessary to restore the comparator after the preset time, so that when the rebound voltage cannot trigger the pressure event and the rebound voltage does not exist, the piezoelectric sensor can output voltage normally to maintain the normal working state of the piezoelectric sensor.

In this embodiment, by promptly restoring the comparator enable after the preset time, the piezoelectric sensor can output voltage normally, maintain the normal working state of the piezoelectric sensor, and improve the working stability and output accuracy of the piezoelectric sensor.

In one embodiment, monitoring whether a force removal event occurs in a piezoelectric sensor includes: when it is monitored that the voltage output by the piezoelectric sensor decreases to a first threshold voltage, determining that a force removal event occurs in the piezoelectric sensor, wherein the first threshold voltage does not exceed the first voltage output by the piezoelectric sensor at the moment the force removal event occurs, and the preset voltage and the first voltage are both positive voltages.

As shown in FIG5 , a first threshold voltage V ₁ is set, wherein the magnitude of V ₁ may be the same as the preset voltage of the voltage when the piezoelectric sensor detects a pressure event, and does not exceed the first voltage. As shown in FIG5 , the first voltage is the maximum value of the positive voltage output by the piezoelectric sensor. When the voltage output by the piezoelectric sensor decreases to the first threshold voltage, it can be determined that the piezoelectric sensor has withdrawn its force.

In this embodiment, the force removal process of the piezoelectric sensor is monitored by comparing the forward voltage value, which improves the accuracy of the force removal process monitoring and ensures that the force removal process of the piezoelectric sensor can be quickly monitored.

In one embodiment, monitoring whether a force withdrawal event occurs in the piezoelectric sensor also includes: when it is monitored that the voltage output by the piezoelectric sensor increases to a second threshold voltage, determining that a force withdrawal event occurs in the piezoelectric sensor, wherein the second threshold voltage is not less than a second voltage corresponding to the piezoelectric sensor at the moment the force withdrawal event occurs, and the second threshold voltage and the second voltage are both negative voltages.

As shown in FIG5 , a second threshold voltage V ₂ is set, wherein the magnitude of V ₂ may be the same as the preset voltage of the voltage when the piezoelectric sensor detects a pressure event, and does not exceed the second voltage. As shown in FIG5 , the second voltage is the minimum value of the negative voltage output by the piezoelectric sensor. When the voltage output by the piezoelectric sensor increases to the first threshold voltage, it can be determined that the piezoelectric sensor has withdrawn its force.

In this embodiment, the force removal process of the piezoelectric sensor is monitored by comparing the reverse voltage value, which improves the accuracy of the force removal process monitoring and ensures that the force removal process of the piezoelectric sensor can be quickly monitored.

In one embodiment, monitoring whether a force removal event occurs in the piezoelectric sensor also includes: when it is monitored that the output voltage of the piezoelectric sensor switches from the first voltage region to the second voltage region, or the output voltage of the piezoelectric sensor switches from the third voltage region to the second voltage region, determining that a force removal event occurs in the piezoelectric sensor; wherein the voltage in the first voltage region is not less than a first threshold voltage, the voltage in the second voltage region is greater than the second threshold voltage and less than the first threshold voltage, and the voltage in the third voltage region does not exceed the second threshold voltage.

Among them, FIG5 shows a schematic diagram of the principle of the piezoelectric sensor control method. Please refer to FIG5. V1 represents the first threshold voltage, which is used to detect a positive pressure event; V2 represents the second threshold voltage, which is used to detect a reverse pressure event; the first threshold voltage V1 and the second threshold voltage V2 have equal amplitudes and opposite directions. The first threshold voltage V1 and the part above it are defined as region C, and the second threshold voltage V2 and the part below it are defined as region A, where region C is the first voltage region and region A is the third voltage region. The part between the first threshold voltage V1 and the second threshold voltage V2 is defined as region B, and region B is the second voltage region. When it is detected that the output voltage of the piezoelectric sensor shows a switch from the first voltage region (region C) to the second voltage region (region B), or from the third voltage region (region A) to the second voltage region (region B), it can be considered that a force withdrawal event has occurred. For example, for a positive pressure event, the process of Vout exceeding V1 is considered to have applied force, and the process of Vout changing from greater than V1 to less than V1 is considered to have withdrawn force. Similarly, the reverse pressure event can also be judged by the process of Vout crossing V2 to determine whether force is applied or withdrawn.

To further reveal the effect of the piezoelectric sensor control method, please continue to refer to Figure 5. By real-time monitoring the transition of the output voltage of the piezoelectric sensor between regions A, B, and C. When a transition from region A to region B occurs, the comparator is quickly controlled to stop enabling so that the output voltage of the piezoelectric sensor cannot trigger a pressure event, and maintains a preset time, and then automatically restores the comparator. Similarly, when a transition from region C to region B occurs, the comparator is quickly controlled to stop enabling so that the output voltage of the piezoelectric sensor cannot trigger a pressure event, and maintains a preset time, and then automatically restores the comparator.

In this embodiment, on the one hand, when the force withdrawal action occurs, the comparator is promptly controlled to stop enabling, and the stopping of enabling lasts for a period of time. Therefore, during this period of time, the output of the comparator is set to the second voltage area, that is, the output voltage of the piezoelectric sensor will not have an effect on the triggering of the pressure event, and the false triggering of the pressure event caused by the rebound voltage will not occur. On the other hand, thanks to the detection mechanism of the three areas of the proposed method, the comparator will not stop enabling during the time when the piezoelectric sensor responds to the force application process, and will only stop enabling when the piezoelectric sensor senses the force withdrawal action, so it will not affect the normal working function of the piezoelectric sensor.

In one embodiment, logical coding can be used to determine a force withdrawal event, by logically coding the above-mentioned three voltage regions to obtain three state codes, and judging whether a force withdrawal event has occurred based on the conversion process between the three state codes. Exemplarily, FIG6 shows a schematic diagram of the state code conversion process. As shown in FIG6, the logical states corresponding to the three voltage regions A, B, and C are respectively encoded, wherein voltage region A corresponds to the third state code 00, region B corresponds to the second state code 01, and region C corresponds to the first state code 10. When it is monitored that the piezoelectric sensor is converted from the third state code 00 to the second state code 01, or the piezoelectric sensor is converted from the first state code 10 to the second state code 01, it is determined that a force withdrawal event has occurred in the piezoelectric sensor;

Among them, when the conversion from area A to area B occurs, the comparator is controlled to stop enabling, so that the output of the comparator is set to the voltage area B, and the comparator is automatically restored to enable after maintaining a preset time. Similarly, when the conversion from area C to area B occurs, the comparator is controlled to stop enabling, so that the output of the comparator is set to the voltage area B, and the comparator is automatically restored to enable after maintaining a preset time.

In this embodiment, the three voltage regions of the piezoelectric sensor are represented by logic state codes, which facilitates monitoring of voltage region conversion of the piezoelectric sensor, thereby improving the accuracy of monitoring the force withdrawal event.

It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the present application also provides a piezoelectric sensor control circuit configured to implement the piezoelectric sensor control method involved above. The implementation scheme for solving the problem provided by the circuit is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more piezoelectric sensor control circuit embodiments provided below can refer to the limitations of the piezoelectric sensor control method above, and will not be repeated here.

In one embodiment, as shown in FIG. 7 , a piezoelectric sensor control circuit is provided, including: a comparison module 71 and a logic module 72, wherein:

A comparison module 71 is used to monitor whether a force removal event occurs in the piezoelectric sensor and output a monitoring result, wherein the force removal event indicates that the pressure on the piezoelectric sensor is gradually reduced;

The logic module 72 is connected to the comparison module 71 and is configured to shield the monitoring result of the comparison module in response to the force withdrawal event.

Among them, the comparison module 71 monitors whether the piezoelectric sensor has a force withdrawal event by comparing the magnitude relationship between the output voltage of the piezoelectric sensor and the first threshold voltage and/or the second threshold voltage, and outputs the monitoring result. The logic module 72 controls the enabling of the comparison module 71 according to the monitoring result. When a force withdrawal event occurs, the logic module 72 controls the comparison module 71 to stop enabling so that the output voltage of the piezoelectric sensor cannot trigger a pressure event; after the comparison module 71 stops enabling for a period of time, the logic module 72 controls the comparison module 71 to resume enabling to control the normal output voltage of the piezoelectric sensor so that the piezoelectric sensor can work normally. Specifically, Circuits in Figure 7 is used to indicate the above-mentioned piezoelectric sensor control circuit.

The piezoelectric sensor control circuit of this embodiment can, on the one hand, post-process the output voltage of the piezoelectric sensor to meet the actual application requirements. On the other hand, when the piezoelectric sensor control circuit is executing the piezoelectric sensor control method, it immediately controls the comparator to stop enabling when the force withdrawal event is detected, so that the output voltage of the piezoelectric sensor cannot trigger the pressure event, thereby avoiding the false triggering of the pressure event due to the rebound voltage, improving the accuracy of the pressure monitoring of the piezoelectric sensor, ensuring that the rebound voltage is quickly and accurately reduced when the piezoelectric sensor is withdrawn, and improving the accuracy of the pressure monitoring of the piezoelectric sensor.

The piezoelectric sensor control circuit provided in the above embodiment can be configured to control a single-ended piezoelectric sensor. In practical applications, a piezoelectric sensor with differential output at both ends may also appear. For this situation, it is only necessary to change the circuit structure in Figure 7 into a circuit for processing differential signals. In one embodiment, Figure 8 shows an equivalent circuit diagram of a double-ended piezoelectric sensor. Accordingly, Figure 9 provides a structural schematic diagram of another piezoelectric sensor control circuit. As shown in Figure 9, unlike the comparison module 71 in Figure 7 that processes the voltage signal output by the piezoelectric sensor, the comparison module 71 in Figure 9 is used to process the differential signal outputted from both ends of the piezoelectric sensor. In addition, the control module 72, including the comparison unit 721 and the logic unit 722, are the same in principle and structure as the control module 72, the comparison unit 721 and the logic unit 722 described in the above embodiment, and will not be repeated here.

In one embodiment, the comparison module 71 includes: a first comparator 711; the input end of the first comparator 711 is connected to the output end of the piezoelectric sensor, the output end of the first comparator 711 is connected to the input end of the logic module 72, and the enable end of the first comparator 711 is connected to the output end of the logic module 72; the first comparator 711 is used to compare the voltage output by the piezoelectric sensor with the first threshold voltage.

In one embodiment, the comparison module 71 also includes: a second comparator 712; the input end of the second comparator 712 is connected to the output end of the piezoelectric sensor, the output end of the second comparator 712 is connected to the input end of the logic module 72, and the enable end of the second comparator 712 is connected to the output end of the logic module 72; the second comparator 712 is used to compare the voltage output by the piezoelectric sensor with the second threshold voltage.

As shown in FIG7 , the comparison module 71 includes a first comparator 711 and a second comparator 712. The first comparator 711 is used to monitor the positive pressure event of the piezoelectric sensor. When the voltage output by the piezoelectric sensor exceeds the first threshold voltage, the first comparator 711 outputs a square wave signal. The width of the square wave signal is consistent with the time width from ta to tb shown in FIG5 . In response to the falling edge of the square wave signal, the logic module 72 controls the comparison module 71 to stop enabling. The second comparator 712 is used to monitor the reverse pressure event of the piezoelectric sensor. When the voltage output by the piezoelectric sensor is lower than the second threshold voltage, the second comparator 712 outputs a square wave signal. The width of the square wave signal is consistent with the time width from tc to td shown in FIG5 . In response to the falling edge of the square wave signal, the logic module 72 controls the comparison module 71 to stop enabling.

The embodiment of the present application also provides a piezoelectric sensing system, as shown in FIG10, the system includes: a piezoelectric sensor 101 and a piezoelectric sensor control circuit 102 of any one of the above embodiments; wherein the piezoelectric sensor 101 is connected to the piezoelectric sensor control circuit 102. The piezoelectric sensor control circuit can reduce the rebound voltage and periodically control the comparator to stop enabling to suppress the baseline voltage from rising, avoid false triggering of pressure events, and thus improve the reliability of the piezoelectric sensing system. The piezoelectric sensing system can be widely used in various fields, including but not limited to: industrial automation, piezoelectric sensors can be used to measure the execution force of robot terminal actuators to ensure that they can operate accurately; medical equipment, piezoelectric sensors can be used to measure physiological parameters such as blood pressure, respiratory rate and heart rate; in the automotive industry, piezoelectric sensors can be used to measure the weight and pressure distribution of vehicles, provide data support for vehicle design, and monitor systems such as airbags and brakes; air quality detection, piezoelectric sensors can be used to measure the pressure and humidity in the air, thereby helping to detect harmful gases in the air; in construction engineering, piezoelectric sensors can be used to monitor the structural safety and stability of buildings, as well as measure the vibration of structures such as bridges and tunnels; in consumer electronics, such as e-cigarettes, piezoelectric sensors can be used to detect smoking or blowing actions, thereby triggering the function switch of the e-cigarette.

In one embodiment, an electronic cigarette is provided, including a main body, which is equipped with a piezoelectric sensor, and the main body is also equipped with the piezoelectric sensor control circuit described above, or is integrated with a chip including the piezoelectric sensor control circuit described above, or is equipped with the piezoelectric sensing system described above. Optionally, the main body also includes a PCB mainboard, and the piezoelectric sensor is arranged on the PCB mainboard.

In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims (10)

1. A piezoelectric sensor control method, characterized by comprising: Monitoring whether a force removal event occurs in the piezoelectric sensor, wherein the force removal event indicates that the pressure on the piezoelectric sensor gradually decreases; In response to the force removal event, controlling a comparator connected to the piezoelectric sensor to stop being enabled, so that an output voltage of the piezoelectric sensor cannot trigger a pressure event; After maintaining a preset time, the comparator is enabled again, wherein the preset time is not less than the discharge time of the residual charge that can trigger the pressure event. 2. The piezoelectric sensor control method according to claim 1, wherein monitoring whether a force withdrawal event occurs in the piezoelectric sensor comprises: When it is monitored that the voltage output by the piezoelectric sensor decreases to a first threshold voltage, it is determined that a force removal event occurs in the piezoelectric sensor, wherein the first threshold voltage does not exceed the first voltage output by the piezoelectric sensor at the moment of the force removal event, and the first threshold voltage and the first voltage are both positive voltages. 3. The piezoelectric sensor control method according to claim 1, wherein monitoring whether a force withdrawal event occurs in the piezoelectric sensor comprises: When it is monitored that the voltage output by the piezoelectric sensor increases to a second threshold voltage, it is determined that a force removal event occurs in the piezoelectric sensor, wherein the second threshold voltage is not less than a second voltage corresponding to the piezoelectric sensor at the moment of the force removal event, and the second threshold voltage and the second voltage are both negative voltages. 4. The piezoelectric sensor control method according to claim 1, wherein monitoring whether the piezoelectric sensor has a force withdrawal event further comprises: When it is monitored that the output voltage of the piezoelectric sensor switches from the first voltage region to the second voltage region, or the output voltage of the piezoelectric sensor switches from the third voltage region to the second voltage region, it is determined that a force withdrawal event occurs in the piezoelectric sensor; wherein the voltage in the first voltage region is not less than a first threshold voltage, the voltage in the second voltage region is greater than the second threshold voltage and less than the first threshold voltage, and the voltage in the third voltage region is not greater than the second threshold voltage. 5. The piezoelectric sensor control method according to claim 4, wherein monitoring whether the piezoelectric sensor has a force withdrawal event further comprises: When it is monitored that the piezoelectric sensor changes from the first state code to the second state code, or the piezoelectric sensor changes from the third state code to the second state code, it is determined that a force withdrawal event occurs in the piezoelectric sensor; wherein the first state code is a logical code for the first voltage region, the second state code is a logical code for the second voltage region, and the third state code is a logical code for the third voltage region. 6. A piezoelectric sensor control circuit, comprising: A comparison module, used to monitor whether a force removal event occurs in the piezoelectric sensor, and output a monitoring result, wherein the force removal event indicates that the pressure on the piezoelectric sensor is gradually reduced; A logic module is connected to the comparison module and is configured to shield the monitoring result of the comparison module in response to the force withdrawal event; wherein, when the force withdrawal event occurs, the logic module controls the comparison module to stop being enabled, and after the comparison module stops being enabled for a period of time, the logic module controls the comparison module to resume being enabled. 7. The piezoelectric sensor control circuit according to claim 6 is characterized in that the comparison module includes: a first comparator; the input end of the first comparator is connected to the output end of the piezoelectric sensor, the output end of the first comparator is connected to the input end of the logic module, and the enable end of the first comparator is connected to the output end of the logic module; the first comparator is used to compare the voltage output by the piezoelectric sensor with the first threshold voltage. 8. The piezoelectric sensor control circuit according to claim 6 is characterized in that the comparison module includes: a second comparator; the input end of the second comparator is connected to the output end of the piezoelectric sensor, the output end of the second comparator is connected to the input end of the logic module, and the enable end of the second comparator is connected to the output end of the logic module; the second comparator is used to compare the voltage output by the piezoelectric sensor with the second threshold voltage. 9. A piezoelectric sensing system, comprising: a piezoelectric sensor and a piezoelectric sensor control circuit according to any one of claims 6 to 8; wherein the piezoelectric sensor is connected to the piezoelectric sensor control circuit. 10. An electronic cigarette, characterized in that it comprises: a main body, on which a piezoelectric sensor and a piezoelectric sensor control circuit according to any one of claims 6 to 8 are arranged, and the piezoelectric sensor is connected to the piezoelectric sensor control circuit.