MEMS capacitive acceleration sensor state self-checking circuit and method

Abstract

The invention provides an MEMS capacitive acceleration sensor state self-checking circuit and method. Belongs to the field of acceleration sensor state self-detection. The circuit comprises an MEMS capacitive acceleration sensor, a current detection circuit and an MCU judgment circuit, the MCU judgment circuit is used for judging whether a voltage difference value between the two ends of a resistor R1 in the current detection circuit is within a first preset range or not, and taking a first judgment result as sensor state self-checking information and outputting the sensor state self-checking information; and judging whether the frequency value of the carrier signal in the MEMS capacitive acceleration sensor is within a second preset range or not, and taking a second judgment result as another sensor state self-checking information and outputting the information. State self-checking information of two types of sensors can be monitored at the same time, and the working states of the sensors are monitored more comprehensively.

Description

Technical Field

[0001] The present application relates to the field of acceleration sensor state self-test, and in particular, to a MEMS capacitive acceleration sensor state self-test circuit and method. Background Art

[0002] In the prior art, the state self-check of the MEMS capacitive acceleration sensor is a current monitoring method, which monitors the state of the sensor by connecting a resistor in series at the power input end of the sensor and using a comparator or other methods to monitor the voltage on one side of the series resistor.

[0003] The above sensor fault status self-check method can only monitor the sensor input current, and the fault points that can be monitored are limited. Although the change in the detection current can effectively determine that the sensor is faulty, the current remains unchanged after some faults occur. Therefore, it is not enough to rely solely on the current change as the basis for judgment, and there is a risk of missed judgment. Summary of the invention

[0004] The purpose of the present application is to provide a MEMS capacitive acceleration sensor state self-check circuit and method, which can continuously provide more comprehensive sensor working state information.

[0005] This application is implemented as follows:

[0006] In a first aspect, the present application provides a MEMS capacitive acceleration sensor state self-check circuit, comprising:

[0007] MEMS capacitive acceleration sensor, current detection circuit and MCU judgment circuit;

[0008] The MEMS capacitive acceleration sensor is connected to the current detection circuit and the MCU judgment circuit respectively, and the current detection circuit is connected to the MCU judgment circuit;

[0009] The MCU judgment circuit is used to simultaneously:

[0010] Determine whether the voltage difference across the resistor R1 in the current detection circuit is within a first preset range, and output the first determination result as a sensor state self-test information;

[0011] It is determined whether the frequency value of the carrier signal in the MEMS capacitive acceleration sensor is within a second preset range, and the second determination result is output as another sensor state self-test information.

[0012] Based on the first aspect, the current detection circuit is used to convert the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1, and directly transmit them to the ADC1 port and ADC2 port of the MCU judgment circuit.

[0013] Based on the first aspect, the A and B ends of the resistor R1 in the current detection circuit are respectively connected to the ADC1 and ADC2 ports of the MCU judgment circuit, and the B end of the resistor R1 is also connected to the VDD port of the MEMS capacitive acceleration sensor, and is grounded through the capacitor C1 and the VSS port of the MEMS capacitive acceleration sensor.

[0014] Based on the first aspect, the MEMS capacitive acceleration sensor is used to output a carrier signal containing a frequency to the MCU judgment circuit.

[0015] Based on the first aspect, the MEMS capacitive acceleration sensor is connected to the T port of the MCU judgment circuit via the CA port.

[0016] Based on the first aspect, the MCU judgment circuit converts the signals received by the ADC1 port and the ADC2 port into digital signals and subtracts the digital signals to obtain the first sensor status self-test information, and reads the carrier signal frequency received by the T port to obtain the second sensor status self-test information; and outputs the first sensor status self-test information and the second sensor status self-test information through the OUT port.

[0017] In a second aspect, the present application provides a MEMS capacitive acceleration sensor state self-check method, comprising the following steps:

[0018] S1: The current detection circuit converts the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1;

[0019] S2: directly transmits the DC voltage signals A and B across the resistor R1 to the ADC1 and ADC2 ports of the MCU judgment circuit;

[0020] S3: The MCU judgment circuit converts the input voltage signals of the ADC1 and ADC2 ports into digital signals;

[0021] S4: The MCU judgment circuit subtracts the digital signals converted by the ADC1 and ADC2 ports to obtain a sensor status self-test information;

[0022] S5: The MEMS capacitive acceleration sensor generates a carrier signal through the CA port and directly inputs it into the T port of the MCU judgment circuit;

[0023] S6: The MCU judgment circuit counts the frequency of the input carrier signal to obtain another sensor status self-test information output;

[0024] S7: The MCU judgment circuit simultaneously outputs two types of sensor status self-test information through the OUT port.

[0025] In a third aspect, the present application provides an electronic device, including:

[0026] A memory for storing one or more programs;

[0027] processor;

[0028] When one or more programs are executed by a processor, the above method is implemented.

[0029] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which implements the above method when executed by a processor.

[0030] Compared with the prior art, the present invention has at least the following advantages or beneficial effects:

[0031] The present application provides a MEMS capacitive acceleration sensor state self-test circuit and method, in which a resistor R1 is connected in series in the input power circuit of the MEMS capacitive acceleration sensor, and the voltage across the resistor R1 is collected and the difference between them is calculated to obtain the MEMS capacitive acceleration sensor state self-test information. This voltage difference reflects the change in the current of the sensor when it is working, and as one of the self-test information, it indirectly reflects the working state of the sensor. At the same time, the frequency value of the carrier signal is also counted as another self-test information. The carrier signal is a signal generated when the sensor is working, and its frequency is related to the working state of the sensor. By counting this frequency value, the working state of the sensor can be further understood. If the frequency value belongs to the normal working frequency range, it means that the working frequency of the sensor is normal, and if the frequency value belongs to the fault frequency range, it means that the working frequency of the sensor is abnormal. By simultaneously monitoring the above two types of self-test information, the working state of the sensor can be more comprehensively understood, which helps to timely discover problems with the sensor and improve the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A circuit schematic diagram of a MEMS capacitive acceleration sensor state self-test circuit for this application;

[0034] Figure 2 A flowchart of a self-checking method for a MEMS capacitive acceleration sensor state is provided for this application;

[0035] Figure 3 This is a structural block diagram of an electronic device for this application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0038] Example

[0039] After long-term research and practice, the applicant found that the state self-check of the MEMS capacitive acceleration sensor in the prior art is a current monitoring method, which monitors the state of the sensor by connecting a resistor in series at the input end of the sensor power supply and using a comparator or other method to monitor the voltage on one side of the resistor. Although this self-check method is simple, it has the following defects: the coverage detection area is low, the acceleration sensor cannot be fully monitored, and there is a risk of missed judgment.

[0040] In view of this, the present application provides a MEMS capacitive acceleration sensor state self-detection circuit, which can comprehensively monitor the working state of the MEMS capacitive acceleration sensor.

[0041] Please refer to Figure 1 , Figure 1 The invention is a circuit schematic diagram of a self-checking circuit. The MEMS capacitive acceleration sensor state self-checking circuit includes a MEMS capacitive acceleration sensor, a current detection circuit and an MCU judgment circuit.

[0042] MEMS capacitive accelerometer: A sensor made using microelectronics technology that measures acceleration based on the principle of capacitance. When the sensor is subjected to acceleration, its internal capacitance value changes, and this change can be converted into an electrical signal output to measure acceleration.

[0043] Current detection circuit: A circuit used to monitor the working current of a MEMS capacitive accelerometer. A MEMS capacitive accelerometer consumes a certain amount of current when it is working, and the magnitude of this current can reflect the working status of the sensor. By detecting this current, the working status of the sensor can be indirectly understood.

[0044] MCU judgment circuit (microcontroller unit): capable of performing various functions by executing preset codes. In the self-test method of the present application, the MCU judgment circuit can receive and process signals from the current detection circuit. It also has an analog-to-digital function (converting analog signals into digital signals for processing), a counter function (for counting or measuring time, etc.), and a function for judging the level voltage and input voltage frequency. These functions enable the MCU judgment circuit to process electrical signals from the current detection circuit and electrical signals from the MEMS capacitive acceleration sensor, and to judge the working state of the sensor based on these two electrical signals.

[0045] The MEMS capacitive acceleration sensor is connected to the current detection circuit and the MCU judgment circuit respectively, and the current detection circuit is connected to the MCU judgment circuit;

[0046] Through such a connection, the MCU judgment circuit can receive the electrical signal from the MEMS capacitive acceleration sensor and the electrical signal from the current detection circuit.

[0047] The MCU judgment circuit is used to simultaneously:

[0048] Determine whether the voltage difference across the resistor R1 in the current detection circuit is within a first preset range, and output the first determination result as a sensor state self-test information;

[0049] It is determined whether the frequency value of the carrier signal in the MEMS capacitive acceleration sensor is within a second preset range, and the second determination result is output as another sensor state self-test information.

[0050] Specifically, in this embodiment, a resistor R1 is connected in series in the input power circuit of the MEMS capacitive acceleration sensor. The voltage across the resistor R1 is collected and the difference between them is calculated to obtain the self-test information of the MEMS capacitive acceleration sensor state. This voltage difference reflects the change of the current when the sensor is working, and as one of the self-test information, it indirectly reflects the working state of the sensor. The MCU judgment circuit will first focus on a specific resistor R1 in the current detection circuit. This resistor R1 is used as a part of the current detection. When the current passes through, it will generate a certain voltage difference at both ends. The MCU judgment circuit will measure this voltage difference and compare it with a preset range (i.e., the first preset range). This range is determined according to the specifications of the resistor, the design of the circuit, and the desired current detection accuracy, and is not specifically limited here. According to the judgment result of the above voltage difference, the MCU judgment circuit will generate a first judgment result. This result is reflected by high and low levels, which is used to indicate whether the current detection circuit is in a normal state. This first judgment result is output as a sensor state self-test information. This kind of sensor state self-test information will be recorded for further analysis or processing. If the voltage difference falls within the first preset range, it means that the current detection circuit is working normally without significant faults or abnormalities.

[0051] In addition to the above-mentioned voltage difference information, the present application also counts the frequency value of the carrier signal as another self-test information. The carrier signal is a signal generated when the sensor is working, and its frequency is related to the working state of the sensor. By counting this frequency value, the working state of the sensor can be further understood. The MCU judgment circuit measures the frequency value of the carrier signal and compares it with another preset range (i.e., the second preset range). This range is determined based on the specifications of the sensor, the expected acceleration range, and the required detection accuracy, and is not specifically limited here. If the frequency value of the carrier signal falls within the second preset range, it means that the acceleration sensor is working normally without significant faults or abnormalities. Based on the judgment result of the above-mentioned carrier signal frequency value, the MCU judgment circuit generates a second judgment result. This result is also reflected by high and low levels to indicate whether the acceleration sensor is in a normal state. This second judgment result is also output as a sensor state self-test information for further analysis or processing.

[0052] The self-test circuit of the present application simultaneously monitors the above two types of self-test information, namely, the voltage difference across the resistor R1 and the frequency value of the carrier signal. This can provide a more comprehensive understanding of the working state of the sensor and improve the accuracy of detection. Since two types of self-test information are monitored simultaneously, this method can more comprehensively monitor the working state of the sensor. This helps to promptly detect problems with the sensor and improve reliability and stability.

[0053] In summary, the present embodiment comprehensively monitors the working state of the MEMS capacitive acceleration sensor by collecting the voltage difference across the resistor R1 and counting the frequency value of the carrier signal. This method can monitor two types of self-test states at the same time, thereby improving the accuracy and comprehensiveness of the detection.

[0054] Based on the first aspect, the current detection circuit is used to convert the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1, and directly transmit them to the ADC1 port and ADC2 port of the MCU judgment circuit.

[0055] Specifically, the main function of the current detection circuit is to convert the current consumed by the MEMS capacitive accelerometer into a signal form that can be directly measured or processed. This conversion is achieved through a resistor R1. When the MEMS capacitive accelerometer is working, it consumes a certain current. When this current flows through the resistor R1, a voltage drop will be generated at both ends of R1. Due to the voltage drop generated by the current on the resistor R1, two voltage signals will appear at the A and B ends of the resistor R1 respectively. These two voltage signals are direct current (DC) signals, and their voltage values ​​do not change with time. The two DC voltage signals A and B are directly transmitted to the ADC1 port and ADC2 port of the MCU judgment circuit. The ADC1 port and the ADC2 port can convert the analog voltage signal into a digital signal for further processing and judgment by the MCU judgment circuit.

[0056] Based on the first aspect, the A and B ends of the resistor R1 in the current detection circuit are respectively connected to the ADC1 and ADC2 ports of the MCU judgment circuit, and the B end of the resistor R1 is also connected to the VDD port of the MEMS capacitive acceleration sensor, and is grounded through the capacitor C1 and the VSS port of the MEMS capacitive acceleration sensor.

[0057] Specifically, when the MEMS capacitive accelerometer is working, it consumes a certain amount of current from the power supply (through VDD and VSS). When this current flows through resistor R1, a voltage drop will be generated on resistor R1. Since the A and B ends of resistor R1 are respectively connected to the ADC1 and ADC2 ports of the MCU, the MCU can measure the voltage difference between the two ports to calculate the current flowing through resistor R1. The specific calculation method includes: the resistance value of resistor R1 is known, and then the voltage drop across the resistor R1 is measured. According to Ohm's law (V=IR), the current flowing through resistor R1 can be calculated. Capacitor C1 is connected to the VSS port and ground (GND) of the MEMS capacitive accelerometer. VSS is the negative power supply or ground terminal of the sensor. Capacitor C1 plays a role of decoupling or filtering here, which helps to stabilize the power supply voltage of the sensor and reduce the impact of power supply fluctuations on sensor performance.

[0058] Based on the first aspect, the MEMS capacitive acceleration sensor is used to output a carrier signal containing a frequency to the MCU judgment circuit.

[0059] Specifically, the carrier signal containing the frequency is transmitted to the MCU judgment circuit. The MCU judgment circuit receives the carrier signal output by the sensor and analyzes or measures its frequency. By measuring the frequency of the signal, the MCU can infer the value of acceleration to monitor the status of the sensor.

[0060] Based on the first aspect, the MEMS capacitive acceleration sensor is connected to the T port of the MCU judgment circuit via the CA port.

[0061] Specifically, CA port: used to output the signal detected by the sensor. T port: This is a specific port on the MCU judgment circuit, used to receive the signal of the MEMS capacitive acceleration sensor. Through such a connection, the MCU judgment circuit can receive and process the signal from the MEMS capacitive acceleration sensor.

[0062] Based on the first aspect, the MCU judgment circuit converts the signals received by the ADC1 port and the ADC2 port into digital signals and subtracts the digital signals to obtain the first sensor status self-test information, and reads the carrier signal frequency received by the T port to obtain the second sensor status self-test information; and outputs the first sensor status self-test information and the second sensor status self-test information through the OUT port.

[0063] Specifically, the MCU judgment circuit has two analog-to-digital converter (ADC) ports, ADC1 and ADC2. These two ports receive analog signals from the MEMS capacitive acceleration sensor. The MCU judgment circuit converts these analog signals into digital signals for subsequent digital processing. After converting the analog signals of the ADC1 and ADC2 ports into digital signals, the MCU judgment circuit performs a subtraction operation on the two digital signals. The difference obtained is used as the first sensor state self-test information. In addition to the ADC1 and ADC2 ports, the MCU judgment circuit also has a T port for receiving a carrier signal. The carrier signal is usually a high-frequency signal used to carry or modulate other information. The MCU judgment circuit reads the frequency of the carrier signal received by the T port and uses this frequency value as the second sensor state self-test information. The MCU judgment circuit integrates the two self-test information obtained above (the first sensor state self-test information and the second sensor state self-test information). Then, it outputs these self-test information through the OUT port.

[0064] The following is a description of the MEMS capacitive acceleration sensor state self-checking method provided by the present invention. The MEMS capacitive acceleration sensor state self-checking method described below and the MEMS capacitive acceleration sensor state self-checking circuit described above can correspond to each other.

[0065] Please refer to Figure 2 , Figure 2 The flowchart of the self-test method is as follows:

[0066] S1: The current detection circuit converts the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1;

[0067] Specifically, when the MEMS capacitive acceleration sensor is working, it consumes a certain current, and this current changes with the change of acceleration. The current detection circuit uses resistor R1 to convert the current consumed by the sensor into a voltage signal across the resistor R1. Due to the change of current, the voltage across the resistor R1 will also change accordingly.

[0068] S2: directly transmits the DC voltage signals A and B across the resistor R1 to the ADC1 and ADC2 ports of the MCU judgment circuit;

[0069] Specifically, the DC voltage signals A and B are directly transmitted to the ADC1 and ADC2 ports of the MCU judgment circuit.

[0070] S3: The MCU judgment circuit converts the input voltage signals of the ADC1 and ADC2 ports into digital signals;

[0071] Specifically, when voltage signals A and B arrive at ADC1 and ADC2 ports, they are converted into digital signals. The converted digital signals represent the discrete values ​​of the original analog voltage signals. These digital signals can be further processed by the MCU judgment circuit.

[0072] S4: The MCU judgment circuit subtracts the digital signals converted by the ADC1 and ADC2 ports to obtain a sensor status self-test information;

[0073] Specifically, the MCU judgment circuit performs a subtraction operation on the two digital signals converted by the ADC1 and ADC2 ports, that is, calculates their difference. This difference represents the difference between the two voltage signals and reflects the working status of the sensor. Through the calculated difference, the MCU can extract a kind of self-test information about the sensor status. This information is used to determine whether the sensor is working properly, whether there is a fault or drift, etc.

[0074] S5: The MEMS capacitive acceleration sensor generates a carrier signal through the CA port and directly inputs it into the T port of the MCU judgment circuit;

[0075] Specifically, the MEMS capacitive accelerometer senses the change of acceleration through its internal capacitance structure and converts this change into a carrier signal. The carrier signal is a modulated signal that contains the acceleration information measured by the sensor. The carrier signal is directly input from the CA port to the T port of the MCU judgment circuit.

[0076] S6: The MCU judgment circuit counts the frequency of the input carrier signal to obtain another sensor status self-test information output;

[0077] Specifically, the counter or other frequency measurement unit in the MCU judgment circuit counts the frequency of the input carrier signal. This frequency information reflects a certain state or working condition of the sensor. Through the frequency information obtained by statistics, the MCU can obtain another self-test information about the sensor state. This information is related to the normal working frequency, fault frequency or other specific frequency characteristics of the sensor.

[0078] S7: The MCU judgment circuit simultaneously outputs two types of sensor status self-test information through the OUT port.

[0079] Specifically, two types of sensor status self-check information are monitored simultaneously, and the sensor working status is monitored more comprehensively.

[0080] Please refer to Figure 3 , Figure 3This is a structural block diagram of an electronic device in this embodiment. The present application also provides an electronic device, including:

[0081] Memory 2, used for storing one or more programs;

[0082] Processor 1;

[0083] When one or more programs are executed by the processor 1, the above method is implemented, such as implementing all or part of the steps in the above method. The processor 1 and the memory 2 communicate with each other through a communication interface.

[0084] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and the computer program implements the above method when executed by a processor, such as implementing all or part of the steps in the above method.

[0085] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A MEMS capacitive acceleration sensor state self-test circuit, characterized in that: include: MEMS capacitive acceleration sensor, current detection circuit and MCU judgment circuit; The MEMS capacitive acceleration sensor is connected to the current detection circuit and the MCU judgment circuit respectively, and the current detection circuit is connected to the MCU judgment circuit; The MCU judgment circuit is used to simultaneously: Determine whether the voltage difference across the resistor R1 in the current detection circuit is within a first preset range, and output the first determination result as a sensor state self-test information; It is determined whether the frequency value of the carrier signal in the MEMS capacitive acceleration sensor is within a second preset range, and the second determination result is output as another sensor state self-test information.

2. A MEMS capacitive acceleration sensor state self-checking circuit according to claim 1, characterized in that: The current detection circuit is used to convert the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1, and directly transmit them to the ADC1 port and ADC2 port of the MCU judgment circuit.

3. A MEMS capacitive acceleration sensor state self-test circuit according to claim 2, characterized in that: The A and B ends of the resistor R1 in the current detection circuit are respectively connected to the ADC1 and ADC2 ports of the MCU judgment circuit, and the B end of the resistor R1 is also connected to the VDD port of the MEMS capacitive acceleration sensor, and is grounded through the capacitor C1 and the VSS port of the MEMS capacitive acceleration sensor.

4. A MEMS capacitive acceleration sensor state self-checking circuit according to claim 3, characterized in that: The MEMS capacitive acceleration sensor is used to output a carrier signal containing a frequency to the MCU judgment circuit.

5. A MEMS capacitive acceleration sensor state self-checking circuit according to claim 4, characterized in that: The MEMS capacitive acceleration sensor is connected to the T port of the MCU judgment circuit via the CA port.

6. A MEMS capacitive acceleration sensor state self-checking circuit according to claim 5, characterized in that: The MCU judgment circuit converts the signals received by the ADC1 port and the ADC2 port into digital signals and subtracts the digital signals to obtain the first sensor state self-test information, and reads the carrier signal frequency received by the T port to obtain the second sensor state self-test information; and outputs the first sensor state self-test information and the second sensor state self-test information through the OUT port.

7. A method for self-checking the state of a MEMS capacitive acceleration sensor, characterized in that: The following steps are involved: S1: The current detection circuit converts the current consumed by the MEMS capacitive acceleration sensor into DC voltage signals A and B across the resistor R1 through the resistor R1; S2: directly transmits the DC voltage signals A and B across the resistor R1 to the ADC1 and ADC2 ports of the MCU judgment circuit; S3: The MCU judgment circuit converts the input voltage signals of the ADC1 and ADC2 ports into digital signals; S4: The MCU judgment circuit subtracts the digital signals converted by the ADC1 and ADC2 ports to obtain a sensor status self-test information; S5: The MEMS capacitive acceleration sensor generates a carrier signal through the CA port and directly inputs it into the T port of the MCU judgment circuit; S6: the MCU judgment circuit counts the frequency of the input carrier signal to obtain another sensor status self-test information output; S7: The MCU judgment circuit simultaneously outputs two types of sensor status self-test information through the OUT port.

8. An electronic device, characterized in that: include: A memory for storing one or more programs; processor; When the one or more programs are executed by the processor, the method according to claim 7 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to claim 7 is implemented.

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