Dual-mode resonant sensor and closed-loop control method thereof

Abstract

The application provides a dual-mode resonant sensor, and relates to the technical field of sensors, which comprises a single resonator, the two sides of the resonant beam of which are provided with a first pair of differential detection electrodes, a second pair of differential detection electrodes and a pair of driving electrodes; the first pair of differential detection electrodes is symmetrically arranged on the two sides of the middle part of the resonant beam and is used for detecting a first-order modal vibration signal of the single resonator; the second pair of differential detection electrodes is symmetrically arranged on the two ends of one side of the resonant beam and is used for detecting a second-order modal vibration signal of the single resonator; the pair of driving electrodes is arranged on the two ends of the other side of the resonant beam and is used for applying an alternating driving signal to the resonant beam; a closed-loop control circuit is connected with the first pair of differential detection electrodes through a pair of first input terminals, connected with the second pair of differential detection electrodes through a pair of second input terminals and connected with the pair of driving electrodes through an output terminal, and is used for feeding back and adjusting the alternating driving signal according to the first-order modal vibration signal and / or the second-order modal vibration signal. The application also provides a closed-loop control method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, more particularly, to a dual-mode resonant sensor and a closed-loop control method thereof. BACKGROUND

[0002] Resonant sensors are high-performance sensors based on the principle of resonance. Their core advantages lie in high precision, high sensitivity, strong anti-interference ability, and low power consumption. Such sensors detect changes in external physical quantities such as pressure, acceleration, density, etc. by detecting changes in resonance frequency. The output signal is a periodic frequency signal, which is convenient for computer connection and long-distance transmission. At the same time, the sensor system adopts a closed-loop structure, with the output automatically tracking the input to ensure the stability of the measurement results. Due to the small vibration energy of the resonator, the system has extremely low power consumption, high sensitivity and resolution, making it exhibit excellent anti-interference ability in complex environments. In addition, resonant MEMS sensors are small in size, light in weight, and compact in structure, easy to integrate into small-sized devices, suitable for application requirements in various scenarios. These advantages make them widely used in industrial automation, automotive electronics, medical devices, environmental monitoring, etc. and become an important development direction in the field of sensor technology.

[0003] Resonant sensors are widely used in various fields due to their high precision and high sensitivity, but their performance is easily affected by temperature changes, leading to measurement errors. Temperature changes can cause changes in material properties and deformation of mechanical structures, affecting the stability of the resonance frequency. For example, when the environmental temperature rises, the thermal expansion of the material will cause the resonator structure to deform, thereby changing its natural frequency and causing the output signal to drift. In addition, the mismatch between the thermal expansion coefficients of the packaging material and the sensitive element also produces thermal stress, further interfering with the accuracy of the sensor.

[0004] To solve these problems, various compensation methods have been proposed in the prior art. Among them, multi-resonator integration is an effective means. By integrating multiple resonators in the sensor, the difference in their response to temperature changes can be used to design a differential structure to offset the frequency drift caused by temperature. For example, Lu Y, et al. Measurement, 2024, 224:113946, uses a double-tongue resonator structure, and the frequency shift generated by the two under temperature change cancels each other out, thereby realizing decoupling of the measured quantity and temperature. However, this method increases the size of the MEMS device, and a complex design process is required to achieve sensitivity matching. Another method is multi-sensor integration, which integrates temperature sensors and resonant sensors on the same chip to monitor temperature changes in real time and dynamically adjust the resonant frequency. For example, Xiang C, et al. Micromachines, 2020, 11(11):1022, uses a thermistor and a resonator to work together, and through a closed-loop feedback system, the frequency drift caused by temperature is compensated in real time to ensure that the sensor maintains high precision in the full temperature range. However, this method also increases the size and power consumption of the device, and due to the positional differences between multiple devices, thermal hysteresis may occur. There are also methods of in-situ temperature compensation for sensors through the amplitude of the resonator, such as the technical invention "Temperature Self-Compensating Resonant Pressure Sensor Control Circuit and Implementation Method" (CN114646412A), which uses a circuit to provide a constant excitation to the resonator. Since the amplitude of the resonator changes with temperature, in-situ temperature compensation is achieved by detecting the amplitude of the resonator. This method is simple and easy to implement, but the detection and transmission of the amplitude signal are susceptible to external interference, which affects the stability of the sensor. In addition, there are also methods of directly controlling temperature to eliminate temperature interference, such as SALVIA J C, et al. Journal of Microelectromechanical Systems, 2010, 19(1):192-201, which integrates a micro-heater to maintain the operating temperature of the resonator at a constant level. This method significantly increases the complexity and power consumption of the system, and is only suitable for low-temperature environments.

[0005] Micro-mechanical resonators are the core structure of resonant MEMS sensors. Micro-mechanical resonators generally have multiple modes, and different modes have different sensitivities to environmental parameter changes. If multiple modes of the micro-mechanical resonator are used for simultaneous sensing, i.e. multi-mode sensing, the measured physical quantity and temperature changes can be well decoupled, in-situ temperature measurement and compensation can be achieved, and the device size can be further reduced, the system complexity and production cost can be reduced, and the stability of the sensor can be improved. SUMMARY

[0006] Therefore, the application provides a dual-mode resonant sensor and a closed-loop control method thereof.

[0007] One aspect of the application provides a dual-mode resonant sensor and a closed-loop control method thereof, comprising: a single resonator, two sides of a resonant beam of which are provided with a first pair of differential detection electrodes, a second pair of differential detection electrodes and a pair of driving electrodes; the first pair of differential detection electrodes are symmetrically arranged on both sides of the middle part of the resonant beam, and are used for detecting a first-order modal vibration signal of the single resonator; the second pair of differential detection electrodes are symmetrically arranged on both ends of one side of the resonant beam, and are used for detecting a second-order modal vibration signal of the single resonator; the pair of driving electrodes are arranged on both ends of the other side of the resonant beam, and are opposite to the second pair of differential detection electrodes, and the pair of driving electrodes are used for applying an alternating current driving signal to the resonant beam; a closed-loop control circuit, which is connected to the first pair of differential detection electrodes through a pair of first input terminals, is connected to the second pair of differential detection electrodes through a pair of second input terminals, and is connected to the pair of driving electrodes through an output terminal, and is used for feedback adjusting the alternating current driving signal according to the first-order modal vibration signal and / or the second-order modal vibration signal.

[0008] According to an embodiment of the application, the closed-loop control circuit comprises: an adder, which is used for adding a first feedback driving signal generated according to the first-order modal vibration signal and a second feedback driving signal generated according to the second-order modal vibration signal when the first-order modal vibration signal and the second-order modal vibration signal are detected simultaneously; and the closed-loop control circuit adjusts the alternating current driving signal based on the sum of the first feedback driving signal and the second feedback driving signal.

[0009] According to an embodiment of the application, the closed-loop control circuit comprises: a first-order modal closed-loop control circuit, which comprises a first transimpedance amplification sub-circuit, a second transimpedance amplification sub-circuit, a first differential amplification sub-circuit, a first phase shift amplification sub-circuit and a first control sub-circuit; the first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit are used for amplifying the first-order modal vibration signal detected by the first pair of differential detection electrodes; the first differential amplification sub-circuit is used for calculating a first differential signal of signals amplified by the first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit; the first phase shift amplification sub-circuit is used for adjusting the phase of the first differential signal; and the first control sub-circuit is used for generating a first feedback driving signal based on the first differential signal after phase adjustment, so as to realize feedback adjustment of the alternating current driving signal.

[0010] According to an embodiment of the present application, the closed-loop control circuit comprises: a second-order modal closed-loop control circuit comprising a third transimpedance amplification sub-circuit, a fourth transimpedance amplification sub-circuit, a second differential amplification sub-circuit, a second phase-shift amplification sub-circuit, and a second control sub-circuit; the third transimpedance amplification sub-circuit and the fourth transimpedance amplification sub-circuit are configured to amplify the second-order modal vibration signal detected by the second differential detection electrode pair; the second differential amplification sub-circuit is configured to calculate a second differential signal of the second-order modal vibration signal detected by the second differential detection electrode pair; the second phase-shift amplification sub-circuit is configured to adjust the phase of the second differential signal; and the second control sub-circuit is configured to generate a second feedback driving signal based on the second differential signal after phase adjustment, so as to realize feedback adjustment of the alternating current driving signal.

[0011] According to an embodiment of the present application, the closed-loop control circuit is an automatic gain control-based closed-loop control circuit or a phase-locked loop-based closed-loop control circuit.

[0012] According to an embodiment of the present application, the feedback driving signal for feedback adjustment of the alternating current driving signal is applied to one or both of the driving electrode pairs.

[0013] Another aspect of the present application provides a closed-loop control method applied to the dual-mode resonant sensor of the first aspect, comprising: detecting a first-order modal vibration signal of a single resonator based on a first differential detection electrode pair arranged in the middle of a resonant beam of the single resonator, and / or detecting a second-order modal vibration signal of the single resonator based on a second differential detection electrode pair arranged at both ends of one side of the resonant beam; and feedback adjusting an alternating current driving signal of the single resonator according to the first-order modal vibration signal and / or the second-order modal vibration signal.

[0014] According to an embodiment of the present application, the feedback adjustment of the alternating current driving signal of the single resonator according to the first-order modal vibration signal and / or the second-order modal vibration signal comprises: when the first-order modal vibration signal and the second-order modal vibration signal are detected simultaneously, adding a first feedback driving signal generated according to the first-order modal vibration signal and a second feedback driving signal generated according to the second-order modal vibration signal; and adjusting the alternating current driving signal based on the sum of the first feedback driving signal and the second feedback driving signal.

[0015] According to an embodiment of the present application, when detecting the first-order modal vibration signal, the feedback adjustment of the alternating current driving signal of the single resonator according to the first-order modal vibration signal and / or the second-order modal vibration signal comprises: amplifying the first-order modal vibration signal detected by the first differential detection electrode pair and calculating a first differential signal of the first-order modal vibration signal; adjusting the phase of the first differential signal, generating a first feedback driving signal based on the first differential signal after adjusting the phase, and realizing feedback adjustment of the alternating current driving signal.

[0016] According to an embodiment of the present application, when detecting the second-order modal vibration signal, the feedback adjustment of the alternating current driving signal of the single resonator according to the first-order modal vibration signal and / or the second-order modal vibration signal comprises: amplifying the second-order modal vibration signal detected by the second differential detection electrode pair and calculating a second differential signal of the amplified second-order modal vibration signal; adjusting the phase of the second differential signal, generating a second feedback driving signal based on the second differential signal after adjusting the phase, and realizing feedback adjustment of the alternating current driving signal.

[0017] According to an embodiment of the present application, by means of double differential detection based on modal symmetry, double modal closed loop and synchronous real-time reading of double modal frequency are realized. Since different modal frequencies have different sensitivities to environmental parameter changes, the double modal sensor realized by the present application can well decouple the measured physical quantity and temperature changes, realize in-situ temperature measurement and compensation or multi-parameter measurement. Since only one resonator is needed, the device size, design complexity, production cost, etc. of the sensor of the present application can be greatly reduced. At the same time, the present application is essentially still a double-frequency sensor, retaining the advantages of frequency output, ensuring the stability and reliability of the sensor. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and other objects, features and advantages of the present application will become more apparent from the following description of embodiments of the present application, taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A resonator schematic diagram of a double modal resonant sensor according to an embodiment of the present application is schematically shown;

[0020] Figure 2 A first-order modal closed loop control subcircuit schematic diagram according to an embodiment of the present application is schematically shown;

[0021] Figure 3 A second-order modal closed loop control subcircuit schematic diagram according to an embodiment of the present application is schematically shown;

[0022] Figure 4 A resonator double modal closed loop control circuit schematic diagram according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0023] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0025] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0026] This application addresses the problems of existing temperature compensation techniques for resonant sensors by designing a sensor and its phase closed-loop circuit. Utilizing the multimodal characteristics of micromechanical resonators, it achieves decoupling between the measured quantity and temperature through single-resonator multimodal sensing, and even enables multi-parameter measurement. Since the proposed method requires only a single resonator, the sensor's device size, design complexity, and production cost can be significantly reduced.

[0027] This application provides a dual-mode resonant sensor comprising a single resonator and a closed-loop control circuit. The single resonator has three pairs of electrodes on both sides.

[0028] like Figure 1 As shown, the resonant beam of the single resonator 1 is provided with a first differential detection electrode pair (2-2 and 2-5), a second differential detection electrode pair (2-4 and 2-6), and a driving electrode pair (2-1 and 2-3) on both sides.

[0029] The driving electrode pairs (2-1 and 2-3) are located at both ends on the other side of the resonant beam, opposite to the second differential detection electrode pair. The driving electrode pairs are used to apply AC driving signals to the resonant beam.

[0030] The first differential detection electrode pair (2-2 and 2-5) is symmetrically arranged on both sides of the middle part of the resonant beam. It is used to detect the first-order mode vibration signal of the single resonator 1 when the resonator is in the first-order mode vibration. Through differential detection, the first-order mode vibration signal of the resonator can be differentially amplified, the signal-to-noise ratio can be improved, and common-mode interference signals can be filtered out.

[0031] The second differential detection electrode pair (2-4 and 2-6) is symmetrically arranged at both ends of one side of the resonant beam, and is used to detect the second-order modal vibration signal of the single resonator 1 when the resonator is in the second-order modal vibration. Through differential detection, the second-order modal vibration signal of the resonator can be differentially amplified to improve the signal-to-noise ratio and filter out the first-order modal and other common-mode interference.

[0032] The closed-loop control circuit is connected to the first differential detection electrode pair (2-2 and 2-5) through a pair of first input terminals, connected to the second differential detection electrode pair (2-4 and 2-6) through a pair of second input terminals, and connected to the driving electrode pair through an output terminal, and is used to feedback adjust the alternating current driving signal according to the first-order modal vibration signal and / or the second-order modal vibration signal.

[0033] Specifically, the resonator can work in a closed-loop stable vibration state through a closed-loop control circuit based on automatic gain control (AGC) or a phase-locked loop. Taking the closed-loop circuit based on automatic gain control (AGC) as an example, the first-order or second-order modal closed-loop control circuit structure of the resonator is as shown in Figure 2 or Figure 3 , which includes a transimpedance amplification link, a differential amplification link, a phase shift amplification link and an automatic gain control (AGC) link. Through differential detection and closed-loop feedback, the resonator can maintain stable vibration and frequency real-time reading of the first-order or second-order modal.

[0034] As shown in Figure 2 , the closed-loop control circuit includes a first-order modal closed-loop control circuit, which includes a first transimpedance amplification sub-circuit (corresponding to one transimpedance amplification link in Figure 2 ), a second transimpedance amplification sub-circuit (corresponding to another transimpedance amplification link in Figure 2 ), a first differential amplification sub-circuit (corresponding to a differential amplification link in Figure 2 ), a first phase shift amplification sub-circuit (corresponding to a phase shift amplification link in Figure 2 ), and a first control sub-circuit (corresponding to an AGC control link in Figure 2 ). Among them,

[0035] The first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit are connected with two electrodes in the first differential detection electrode pair (2-2 and 2-5) through the first input end respectively, for amplifying the first-order modal vibration signal detected by the first differential detection electrode pair (2-2 and 2-5). The first differential amplification sub-circuit is used for calculating the first differential signal of the signals amplified by the first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit; the first phase shift amplification sub-circuit is used for adjusting the phase of the first differential signal; and the first control sub-circuit is used for generating the first feedback driving signal based on the first differential signal after the phase adjustment, and feedback adjusting the alternating current driving signal based on the first feedback driving signal.

[0036] As shown in Figure 3 , the closed-loop control circuit includes a second-order modal closed-loop control circuit, which includes a third transimpedance amplification sub-circuit (corresponding to one transimpedance amplification link in Figure 3 ), a fourth transimpedance amplification sub-circuit (corresponding to another transimpedance amplification link in Figure 3 ), a second differential amplification sub-circuit (corresponding to a differential amplification link in Figure 3 ), a second phase shift amplification sub-circuit (corresponding to a phase shift amplification link in Figure 3 ), and a second control sub-circuit (corresponding to an AGC control link in Figure 3 ).

[0037] The third transimpedance amplification sub-circuit and the fourth transimpedance amplification sub-circuit are used for amplifying the second-order modal vibration signal detected by the second differential detection electrode pair (2-4 and 2-6); the second differential amplification sub-circuit is used for calculating the second differential signal of the second-order modal vibration signal detected by the second differential detection electrode pair (2-4 and 2-6); the second phase shift amplification sub-circuit is used for adjusting the phase of the second differential signal; and the second control sub-circuit is used for generating the second feedback driving signal based on the second differential signal after the phase adjustment, and feedback adjusting the alternating current driving signal based on the second feedback driving signal.

[0038] On the basis of the above-mentioned closed-loop structure, the closed-loop control circuit structure of the dual-mode resonant sensor proposed in the present application is shown in Figure 4 . Due to the symmetry and anti-symmetry characteristics of the first-order and second-order modes of the resonator, through the differential detection of the detection electrodes 2-2 and 2-5, the second-order modal vibration signal of the resonator is filtered out as a common-mode signal, only the first-order modal vibration signal of the resonator is reserved, which ensures the stable closed loop and real-time frequency reading of the first-order mode; through the differential detection of the detection electrodes 2-4 and 2-6, the first-order modal vibration signal of the resonator is filtered out, and the second-order modal vibration signal is differentially amplified, which improves the signal-to-noise ratio of the second-order modal vibration signal and ensures the stable closed loop and frequency reading of the second-order mode.

[0039] As shown in Figure 4As shown, when the first-order modal vibration signal and the second-order modal vibration signal are detected simultaneously, the closed-loop control circuit includes an adder. The adder is used to add the first feedback driving signal generated according to the first-order modal vibration signal and the second feedback driving signal generated according to the second-order modal vibration signal when the first-order modal vibration signal and the second-order modal vibration signal are detected simultaneously; the closed-loop control circuit adjusts the alternating current driving signal based on the sum of the first feedback driving signal and the second feedback driving signal. The two-way closed-loop feedback driving signals are added through the adder and then applied to the driving electrode 2-1, thereby maintaining the stability of the dual-mode closed-loop vibration.

[0040] Through the proposed dual-mode resonant sensor and the closed-loop system thereof, the first-order modal frequency and the second-order modal frequency of the resonator can be synchronously and real-timely read out, and dual-mode sensing and multi-parameter decoupling measurement are achieved.

[0041] In the embodiments of the present application, when multiple modes of the resonator are excited simultaneously, the vibration signals detected by the single detection electrode are superimposed with multiple modal vibration signals and high-order components thereof, and a complex signal processing method is required to decouple the modal vibration signals. However, through the differential detection method based on modal symmetry proposed in the embodiments of the present application, the dual-mode vibration signals can be easily decoupled, and the signals in the modal closed-loop control circuit are single, pure and stable.

[0042] In the embodiments of the present application, the feedback driving signals of the two-way closed loop can be added through the adder and then applied to one driving electrode, or can be applied to two driving electrodes separately.

[0043] In the embodiments of the present application, the proposed dual-mode resonant sensor and the closed-loop control method thereof are not limited to the first-order and second-order modes of the resonator, and can also achieve simultaneous closed-loop and sensing of the second-order and third-order modes.

[0044] The closed-loop control of a single mode can be an automatic gain control (AGC) based closed-loop control, or a phase-locked loop based closed-loop control circuit, etc.

[0045] According to the dual-mode resonant sensor provided in the embodiments of the present application, the core sensitive structure is a single resonator 1, and the resonator has three pairs of electrodes on both sides. Due to the symmetry and anti-symmetry characteristics of the resonator modes, the dual-mode vibration signals can be easily decoupled through the double differential detection of the detection electrodes 2-2 and 2-5 and 2-4 and 2-6, and the stable closed loop and real-time frequency readout of the dual modes are ensured.

[0046] According to the dual-mode resonant sensor as shown in Figures 1-4 The present application further provides a closed-loop control method, including S1-S2.

[0047] S1, detecting a first order modal vibration signal of the single resonator 1 based on a first pair of differential detection electrodes (2-2 and 2-5) disposed at the middle of the resonant beam of the single resonator 1, and / or detecting a second order modal vibration signal of the single resonator 1 based on a second pair of differential detection electrodes (2-4 and 2-6) disposed at both ends of the resonant beam.

[0048] S2, adjusting the AC driving signal of the single resonator 1 according to the first order modal vibration signal and / or the second order modal vibration signal.

[0049] When the dual-mode resonator sensor is used to detect the first order modal vibration signal thereof, S2 comprises S201-S202.

[0050] S201, amplifying the first order modal vibration signal detected by the first pair of differential detection electrodes (2-2 and 2-5) and calculating a first differential signal of the first order modal vibration signal.

[0051] S202, adjusting the phase of the first differential signal, generating a first feedback driving signal based on the first differential signal after the phase is adjusted, and adjusting the AC driving signal based on the first feedback driving signal.

[0052] When the dual-mode resonator sensor is used to detect the second order modal vibration signal thereof, S2 comprises S203-S204.

[0053] S203, amplifying the second order modal vibration signal detected by the second pair of differential detection electrodes (2-4 and 2-6) and calculating a second differential signal of the amplified second order modal vibration signal.

[0054] S204, adjusting the phase of the second differential signal, generating a second feedback driving signal based on the second differential signal after the phase is adjusted, and adjusting the AC driving signal based on the second feedback driving signal.

[0055] When the dual-mode resonator sensor is used to detect the first order modal vibration signal and the second order modal vibration signal simultaneously, S2 comprises S205-S206.

[0056] S205, adding the first feedback driving signal generated according to the first order modal vibration signal and the second feedback driving signal generated according to the second order modal vibration signal.

[0057] S206, adjusting the AC driving signal based on the sum of the first feedback driving signal and the second feedback driving signal.

[0058] The method can easily decouple the dual-mode vibration signals through the double differential detection of the detection electrodes 2-2 and 2-5, 2-4 and 2-6, and ensure stable closed loop and real-time frequency reading of the dual-mode.

[0059] The double-mode resonant sensor and the closed-loop control method thereof provided by the embodiments of the present application realize single-resonator double-mode sensing. Through double-differential detection based on modal symmetry, double-mode closed loop and synchronous real-time reading of double-mode frequency are realized. Since different modal frequencies have different sensitivities to environmental parameter changes, the double-mode sensing realized by the present application can well decouple the measured physical quantity and temperature changes, realizing in-situ temperature measurement and compensation or multi-parameter measurement.

[0060] Since only one resonator is needed, the device size, design complexity, production cost, etc. of the sensor of the present application can be greatly reduced. At the same time, the present application is still essentially a double-frequency sensor, retaining the advantages of frequency output and ensuring the stability and reliability of the sensor.

[0061] In addition, the proposed double-mode closed-loop circuit is simple in structure and can be completed by simply superimposing two traditional closed-loop circuits, and can be realized by ordinary analog circuits or digital circuits.

[0062] The embodiments of the present application are described above. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present application. Although each embodiment is described above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present application, and these substitutions and modifications shall fall within the scope of the present application.

Claims

1. A dual mode resonant sensor, characterized by Comprise: A single resonator, which is provided with a first pair of differential detection electrodes, a second pair of differential detection electrodes and a pair of driving electrodes on both sides of the resonant beam; The first pair of differential detection electrodes is symmetrically arranged on both sides of the middle of the resonant beam, and is used for detecting the first-order modal vibration signal of the single resonator; The second pair of differential detection electrodes is symmetrically arranged on both ends of one side of the resonant beam, and is used for detecting the second-order modal vibration signal of the single resonator; The pair of driving electrodes is arranged on both ends of the other side of the resonant beam, opposite to the second pair of differential detection electrodes, and is used for applying an alternating driving signal to the resonant beam; A closed-loop control circuit, which is connected to the first pair of differential detection electrodes through a pair of first input terminals, is connected to the second pair of differential detection electrodes through a pair of second input terminals, and is connected to the pair of driving electrodes through an output terminal, and is used for feedback adjusting the alternating driving signal according to the first-order modal vibration signal and / or the second-order modal vibration signal.

2. The dual mode resonator sensor of claim 1, wherein, The closed-loop control circuit comprises: An adder for adding a first feedback driving signal generated according to the first-order modal vibration signal and a second feedback driving signal generated according to the second-order modal vibration signal when the first-order modal vibration signal and the second-order modal vibration signal are detected at the same time; The closed-loop control circuit adjusts the alternating driving signal based on the sum of the first feedback driving signal and the second feedback driving signal.

3. The dual mode resonant sensor of claim 1, wherein, The closed-loop control circuit comprises: A first-order modal closed-loop control circuit comprising a first transimpedance amplification sub-circuit, a second transimpedance amplification sub-circuit, a first differential amplification sub-circuit, a first phase shift amplification sub-circuit and a first control sub-circuit; The first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit are used for amplifying the first-order modal vibration signal detected by the first pair of differential detection electrodes; The first differential amplification sub-circuit is used for calculating a first differential signal of the signals amplified by the first transimpedance amplification sub-circuit and the second transimpedance amplification sub-circuit; The first phase shift amplification sub-circuit is used for adjusting the phase of the first differential signal; The first control sub-circuit is used for generating a first feedback driving signal based on the first differential signal after adjusting the phase, and feedback adjusting the alternating driving signal based on the first feedback driving signal.

4. The dual mode resonant sensor of claim 1, wherein, The closed-loop control circuit comprises: A second-order modal closed-loop control circuit comprising a third transimpedance amplification sub-circuit, a fourth transimpedance amplification sub-circuit, a second differential amplification sub-circuit, a second phase shift amplification sub-circuit and a second control sub-circuit; The third transimpedance amplification sub-circuit and the fourth transimpedance amplification sub-circuit are used for amplifying the second-order modal vibration signal detected by the second pair of differential detection electrodes; The second differential amplification sub-circuit is used for calculating a second differential signal of the signals amplified by the third transimpedance amplification sub-circuit and the fourth transimpedance amplification sub-circuit; The second phase shift amplification sub-circuit is used for adjusting the phase of the second differential signal; The second control sub-circuit is used for generating a second feedback driving signal based on the second differential signal after adjusting the phase, and feedback adjusting the alternating driving signal based on the second feedback driving signal.

5. The dual mode resonant sensor of claim 1, wherein, The closed-loop control circuit is an automatic gain control based closed-loop control circuit or a phase-locked loop based closed-loop control circuit.

6. The dual mode resonant sensor of claim 1, wherein, A feedback driving signal for feedback adjusting the alternating current driving signal is applied to one or both of the pair of driving electrodes.

7. A closed loop control method applied to the dual mode resonator sensor according to any one of claims 1 to 6, characterized in that, Comprise: Detecting a first order modal vibration signal of the single resonator based on a first pair of differential detection electrodes arranged at the middle of a resonant beam of the single resonator, and / or detecting a second order modal vibration signal of the single resonator based on a second pair of differential detection electrodes arranged at both ends of a side of the resonant beam; Feedback adjusting an alternating current driving signal of the single resonator according to the first order modal vibration signal and / or the second order modal vibration signal.

8. The closed loop control method of claim 7, wherein, The feedback adjusting an alternating current driving signal of the single resonator according to the first order modal vibration signal and / or the second order modal vibration signal comprises: When the first order modal vibration signal and the second order modal vibration signal are detected simultaneously, adding a first feedback driving signal generated according to the first order modal vibration signal and a second feedback driving signal generated according to the second order modal vibration signal; Adjusting the alternating current driving signal based on the sum of the first feedback driving signal and the second feedback driving signal.

9. The closed loop control method of claim 7, wherein, When the first order modal vibration signal is detected, the feedback adjusting an alternating current driving signal of the single resonator according to the first order modal vibration signal and / or the second order modal vibration signal comprises: Amplifying the first order modal vibration signal detected by the first pair of differential detection electrodes and calculating a first differential signal of the amplified first order modal vibration signal; Adjusting the phase of the first differential signal, generating a first feedback driving signal based on the first differential signal after adjusting the phase, and feedback adjusting the alternating current driving signal based on the first feedback driving signal.

10. The closed loop control method of claim 7, wherein, When the second order modal vibration signal is detected, the feedback adjusting an alternating current driving signal of the single resonator according to the first order modal vibration signal and / or the second order modal vibration signal comprises: Amplifying the second order modal vibration signal detected by the second pair of differential detection electrodes and calculating a second differential signal of the amplified second order modal vibration signal; Adjusting the phase of the second differential signal, generating a second feedback driving signal based on the second differential signal after adjusting the phase, and feedback adjusting the alternating current driving signal based on the second feedback driving signal.

Images