Piezoelectric combined feedback enhanced sensing system

Abstract

The invention discloses a piezoelectric combined feedback enhanced sensing system, relates to the field of measurement, and aims to solve the problem of low sensitivity of an existing piezoelectric ceramic sensor. The piezoelectric ceramic sensor is used for sensing external pressure or vibration to generate an initial alternating current signal and sending the initial alternating current signal to the energy collection unit; the processor is also used for receiving the adjusted AC signal, converting the AC signal into pressure or vibration, generating an AC signal according to the converted pressure or vibration, superposing the AC signal with the initial AC signal to obtain an enhanced AC signal, and outputting the enhanced AC signal; the energy collection unit is used for rectifying the received initial alternating-current electric signal into a direct-current electric signal and sending the direct-current electric signal to the feedback path unit; and the feedback path unit is used for converting the direct-current electric signal into an alternating-current electric signal, carrying out signal characteristic adjustment on the alternating-current electric signal, obtaining the adjusted alternating-current electric signal and transmitting the adjusted alternating-current electric signal to the piezoelectric ceramic sensor. The sensitivity of the piezoelectric ceramic sensor is improved.

Description

Technical Field

[0001] The invention relates to the field of measurement, and belongs to a sensor signal enhancement system. Background Art

[0002] Existing piezoelectric ceramic sensors are used to measure various physical quantities and their changes, such as acceleration, pressure, and vibration. However, the output signal of the piezoelectric ceramic sensor is relatively weak, and an amplification processing device is required to amplify the signal. However, the amplification processing device requires an external power supply or battery to work. Therefore, when a measuring device that integrates a piezoelectric ceramic sensor, an amplification processing device, and an external power supply or a battery is used for a long time, the piezoelectric ceramic sensor itself has low sensitivity due to limitations such as short battery life and complex maintenance. Summary of the invention

[0003] The purpose of the present invention is to solve the problem of low sensitivity of existing piezoelectric ceramic sensors and propose a piezoelectric combined feedback enhanced sensing system.

[0004] A piezoelectric combined feedback enhanced sensing system, the sensing system comprising a piezoelectric ceramic sensor, an energy collection unit and a feedback path unit;

[0005] The piezoelectric ceramic sensor is used to sense external pressure or vibration to generate an initial AC signal and send it to the energy collection unit; it is also used to receive the regulated AC signal and convert it into pressure or vibration, generate an AC signal according to the converted pressure or vibration, and superimpose it with the initial AC signal to obtain an enhanced AC signal for output;

[0006] An energy collection unit, used for rectifying the received initial alternating current signal into a direct current signal, and sending the signal to the feedback path unit;

[0007] The feedback path unit is used to convert a direct current signal into an alternating current signal, and adjust the signal characteristics of the alternating current signal to obtain the adjusted alternating current signal and transmit it to the piezoelectric ceramic sensor.

[0008] Preferably, the piezoelectric ceramic sensor comprises a piezoelectric sensing unit, a piezoelectric feedback unit, a piezoelectric collection unit and two insulating layers;

[0009] The piezoelectric sensing unit, the piezoelectric feedback unit and the piezoelectric collecting unit are stacked together in sequence from top to bottom, and an insulating layer is set between the piezoelectric sensing unit and the piezoelectric feedback unit, and an insulating layer is set between the piezoelectric feedback unit and the piezoelectric collecting unit;

[0010] The piezoelectric sensing unit, the piezoelectric feedback unit and the piezoelectric collection unit simultaneously sense external pressure or vibration and generate an initial alternating current signal, and the piezoelectric collection unit sends the initial alternating current signal to the energy collection unit;

[0011] A piezoelectric feedback unit, which receives the regulated AC signal and converts it into pressure or vibration, and transmits it to the piezoelectric sensing unit;

[0012] The piezoelectric sensing unit is used to generate an alternating current signal according to the converted pressure or vibration, and to output the enhanced alternating current signal by superimposing it with the initial alternating current signal.

[0013] Preferably, both insulating layers are made of polyimide film.

[0014] Preferably, the energy collection unit comprises an energy collector and an energy storage capacitor;

[0015] An energy collector is used to rectify the received initial AC signal into a DC signal and transmit it to the energy storage capacitor;

[0016] The energy storage capacitor is used to store a DC signal and send the stored DC signal to the feedback path unit.

[0017] Preferably, the energy harvester model is LTC3588.

[0018] Preferably, the feedback path unit comprises an oscillator, an LC matching network and a filter;

[0019] An oscillator, used to convert a DC signal into an AC signal and transmit it to an LC matching network;

[0020] The LC matching network is used to adjust the phase and amplitude of the AC signal, and the adjusted AC signal is transmitted to the filter;

[0021] The filter is used to filter the regulated AC signal, and obtain the filtered AC signal to transmit to the piezoelectric ceramic sensor.

[0022] The beneficial effects of the present invention are:

[0023] The present invention utilizes piezoelectric ceramic sensors to collect weak environmental mechanical vibration or pressure change energy, and amplifies the sensing response to the environmental vibration or pressure through the electrical feedback mechanism of the energy collection unit and the feedback path unit, that is, amplifies the piezoelectric effect of the piezoelectric ceramic sensor, thereby enhancing the sensitivity and responsiveness of the piezoelectric ceramic component.

[0024] The feedback path unit of the present invention has the ability to adjust the gain, and can adjust the signal amplification effect according to changes in the external environment. Under strong vibration or pressure conditions, the gain of the feedback loop can be adjusted to ensure stable operation under changing environmental conditions.

[0025] The present invention can generate stronger electrical signals by amplifying the piezoelectric effect through a combination of electrical feedback and piezoelectric feedback without an external power supply, thus eliminating the need for frequent battery replacement, greatly extending the service life of the device and reducing long-term operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the principle diagram of the piezoelectric combined feedback enhanced sensing system;

[0027] Figure 2 is a structural diagram of a piezoelectric ceramic component;

[0028] Figure 3 This is the schematic diagram of the piezoelectric ceramic component;

[0029] Figure 4 This is the vibration response and load sensitivity diagram of the piezoelectric combined feedback enhanced energy output system. In the figure, Figure 4 (a) is the vibration response diagram of the piezoelectric combined feedback enhanced sensing system. Figure 4 (b) is the load sensitivity diagram of the piezoelectric combined feedback enhanced sensing system;

[0030] FIG. 5 is a packaging diagram of a piezoelectric ceramic component, wherein FIG. 5( a ) is a packaging example diagram of a piezoelectric ceramic component, and FIG. 5( b ) is a longitudinal cross-sectional diagram of FIG. 5( a );

[0031] Figure 6 This is the specific schematic diagram of the piezoelectric combined feedback enhanced sensing system. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0035] Example:

[0036] Combination Figures 1 to 6 This embodiment describes a piezoelectric combined feedback enhanced sensing system, wherein the sensing system comprises a piezoelectric ceramic sensor 1, an energy collection unit 2 and a feedback path unit 3;

[0037] The piezoelectric ceramic sensor 1 is used to sense external pressure or vibration to generate an initial AC signal, which is sent to the energy collection unit 2; it is also used to receive the regulated AC signal and convert it into pressure or vibration, generate an AC signal according to the converted pressure or vibration, and superimpose it with the initial AC signal to obtain an enhanced AC signal for output;

[0038] The energy collection unit 2 is used to rectify the received initial AC signal into a DC signal and send it to the feedback path unit 2;

[0039] The feedback path unit 3 is used to convert a direct current signal into an alternating current signal, and adjust the signal characteristics of the alternating current signal to obtain the adjusted alternating current signal and transmit it to the piezoelectric ceramic sensor 1 .

[0040] Specifically, when the piezoelectric ceramic sensor 1 receives external vibration or load, the piezoelectric ceramic sensor 1 collects energy and gives it back to the piezoelectric ceramic sensor 1 through electrical feedback, thereby improving the electrical response and piezoelectric sensitivity. The electrical response and sensitivity of this embodiment are compared with those of the piezoelectric ceramic sensor 1 without feedback structure, and the effect is as follows: Figure 4 shown.

[0041] The piezoelectric ceramic sensor 1 is further defined as comprising:

[0042] The piezoelectric ceramic component sensor 1 includes a piezoelectric sensing unit 1-1, a piezoelectric feedback unit 1-2, a piezoelectric collection unit 1-3 and two insulating layers 1-4;

[0043] The piezoelectric sensing unit 1-1, the piezoelectric feedback unit 1-2 and the piezoelectric collection unit 1-3 simultaneously sense external pressure or vibration and generate an initial alternating current signal, which is then sent by the piezoelectric collection unit 1-3 to the energy collection unit 2;

[0044] The piezoelectric feedback unit 1-2 is used to receive the regulated AC signal, convert it into pressure or vibration, and transmit it to the piezoelectric sensing unit 1-1;

[0045] The piezoelectric sensing unit 1-1 is used to generate an alternating current signal according to the converted pressure or vibration, and to superimpose the signal with the initial alternating current signal to obtain an enhanced alternating current signal for output.

[0046] Specifically, the adjacent surfaces of each piezoelectric material are insulated with polyimide film, and the thickness of the interlayer is ensured to be moderate. The surfaces are coated with conductive electrode layers. The electrodes are made of highly conductive metal materials such as gold and silver, and are connected to the feedback path unit through highly conductive adhesives to ensure signal transmission stability. The insulating layer between the three piezoelectric sheets is made of polyimide film. The piezoelectric sensing unit uses a piezoelectric composite material with high sensitivity and certain flexibility, and the thickness is designed to be thin. Its design requires that it can efficiently respond to sensing signals and feedback signals to achieve signal amplification effects; the piezoelectric feedback unit is used to receive electrical feedback and generate piezoelectric feedback. It uses piezoelectric ceramic materials with good piezoelectric strain constants and is designed to be moderately thick; the piezoelectric collection unit is used to collect initial energy and provide partial mechanical support. It uses piezoelectric ceramic materials with high mechanical strength and good piezoelectric voltage constants, and is designed to be thick. The piezoelectric material component is encapsulated as a whole to meet the requirements of being able to generate sufficient electrical signals within the target pressure or vibration range, and at the same time have good fatigue resistance.

[0047] The package of the piezoelectric ceramic sensor 1 is made of glass fiber nylon. The package structure is designed as an upper and lower separation structure, the upper structure has a protruding part, and the lower structure has a groove for placing the piezoelectric sheet. This design ensures that the sensor obtains the maximum piezoelectric output signal and avoids signal attenuation caused by stress on the package structure.

[0048] The piezoelectric ceramic sensor 1 has the upper side of the first layer, the lower side of the second layer and the upper side of the third layer grounded, and the feedback part connects the lower side of the piezoelectric collection unit and the upper side of the piezoelectric feedback unit, including an energy collection unit and a feedback path unit. The energy collection unit collects and stores the electric energy generated by the positive piezoelectric effect of the piezoelectric feedback unit, and transmits it to the piezoelectric feedback unit through the feedback path unit. When the piezoelectric collection unit is subjected to pressure or vibration, the generated electric signal is transmitted to the piezoelectric feedback unit through the circuit feedback loop, enhancing its response, thereby generating piezoelectric feedback to the piezoelectric sensing unit, which is equivalent to generating an in-phase force equivalent to external excitation. This combination mechanism of piezoelectric feedback and electrical feedback can effectively amplify the signal and improve the sensing sensitivity of the system.

[0049] The electrodes of the piezoelectric sensing unit 1-1 are led out and connected to the outside, and the electrodes of the piezoelectric feedback unit 1-2 and the piezoelectric collection unit 1-3 are led out respectively and connected to the energy collection unit and the feedback path unit through interfaces.

[0050] The package of the piezoelectric ceramic sensor 1 is shown in FIG5 , which is a top-bottom separation structure, the top structure has a protruding part, and the bottom structure has a groove for placing the piezoelectric sheet. Glass fiber nylon is selected to reduce the influence of vibration damping on the response performance of the piezoelectric ceramic sheet, and achieve a balance between mechanical strength and dynamic adaptability. The piezoelectric ceramic assembly is placed in the middle. The piezoelectric sheet leads and is led out through the lead hole. After the wires are led out, the mold is filled with epoxy resin.

[0051] The materials of the two insulating layers 1-4 are limited: the two insulating layers 1-4 are both made of polyimide film.

[0052] The energy collection unit 2 is further defined as:

[0053] The energy collection unit 2 includes an energy collector 2-1 and an energy storage capacitor 2-2;

[0054] The energy collector 2-1 is used to rectify the received initial AC signal into a DC signal and transmit it to the energy storage capacitor 2-2;

[0055] The energy storage capacitor 2 - 2 is used to store a direct current signal and send the stored direct current signal to the feedback path unit 2 .

[0056] Specifically, the energy harvester 2-1 model is LTC3588.

[0057] The feedback path unit 3 is further defined as:

[0058] The feedback path unit 3 includes an oscillator 3-1, an LC matching network 3-2 and a filter 3-3;

[0059] The oscillator 3-1 is used to convert a DC signal into an AC signal and transmit it to the LC matching network 3-2;

[0060] The LC matching network 3-2 is used to adjust the phase and amplitude of the AC signal, and the adjusted AC signal is transmitted to the filter 3-3;

[0061] The filter 3 - 3 is used to filter the regulated AC signal, and obtain the filtered AC signal to transmit to the piezoelectric ceramic sensor 1 .

[0062] Specifically, the oscillator 3-1 generates an AC signal output whose frequency matches the operating frequency of the piezoelectric sensing unit. The generated AC signal is adjusted in phase and amplitude by the LC matching network, and then transmitted to the piezoelectric feedback unit through the filter to ensure that the feedback signal matches the initial signal to achieve the effect of signal optimization. At the same time, the feedback path part adopts a shielded wire design to improve the stability and anti-interference ability of the signal transmission process. After being processed by the filter, a smooth AC signal is generated.

[0063] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. Piezoelectric combined feedback enhanced sensing system, characterized in that: The sensing system comprises a piezoelectric ceramic sensor (1), an energy collection unit (2) and a feedback path unit (3); The piezoelectric ceramic sensor (1) is used to sense external pressure or vibration to generate an initial alternating current signal, which is sent to an energy collection unit (2); it is also used to receive the regulated alternating current signal and convert it into pressure or vibration, generate an alternating current signal according to the converted pressure or vibration, and superimpose it with the initial alternating current signal to obtain an enhanced alternating current signal for output; The energy collection unit (2) is used to rectify the received initial alternating current signal into a direct current signal and send it to the feedback path unit (2); The feedback path unit (3) is used to convert a direct current signal into an alternating current signal, and to adjust the signal characteristics of the alternating current signal, thereby obtaining the adjusted alternating current signal and transmitting it to the piezoelectric ceramic sensor (1).

2. The piezoelectric combined feedback enhanced sensing system according to claim 1, characterized in that: The piezoelectric ceramic sensor (1) comprises a piezoelectric sensing unit (1-1), a piezoelectric feedback unit (1-2), a piezoelectric collection unit (1-3) and two insulating layers (1-4); The piezoelectric sensing unit (1-1), the piezoelectric feedback unit (1-2) and the piezoelectric collecting unit (1-3) are stacked together in sequence from top to bottom, and an insulating layer (1-4) is provided between the piezoelectric sensing unit (1-1) and the piezoelectric feedback unit (1-2), and an insulating layer (1-4) is provided between the piezoelectric feedback unit (1-2) and the piezoelectric collecting unit (1-3); The piezoelectric sensing unit (1-1), the piezoelectric feedback unit (1-2) and the piezoelectric collection unit (1-3) simultaneously sense external pressure or vibration and generate an initial alternating current signal, and the piezoelectric collection unit (1-3) sends the initial alternating current signal to the energy collection unit (2); The piezoelectric feedback unit (1-2) is used to receive the regulated alternating current signal, convert it into pressure or vibration, and transmit it to the piezoelectric sensing unit (1-1); The piezoelectric sensing unit (1-1) is used to generate an alternating current signal according to the converted pressure or vibration, and to superimpose the signal with the initial alternating current signal to obtain an enhanced alternating current signal for output.

3. The piezoelectric combined feedback enhanced sensing system according to claim 2, characterized in that: Both insulating layers (1-4) are made of polyimide film.

4. The piezoelectric combined feedback enhanced sensing system according to claim 1, characterized in that: The energy collection unit (2) comprises an energy collector (2-1) and an energy storage capacitor (2-2); The energy collector (2-1) is used to rectify the received initial alternating current signal into a direct current signal and transmit it to the energy storage capacitor (2-2); The energy storage capacitor (2-2) is used to store a direct current signal and send the stored direct current signal to the feedback path unit (2).

5. The piezoelectric combined feedback enhanced sensing system according to claim 4, characterized in that: The energy harvester (2-1) model is LTC3588.

6. The piezoelectric combined feedback enhanced sensing system according to claim 1, characterized in that: The feedback path unit (3) includes an oscillator (3-1), an LC matching network (3-2) and a filter (3-3); An oscillator (3-1) is used to convert a direct current signal into an alternating current signal and transmit it to an LC matching network (3-2); An LC matching network (3-2) is used to adjust the phase and amplitude of the AC signal, and the adjusted AC signal is transmitted to the filter (3-3); The filter (3-3) is used to filter the regulated alternating current signal, and obtain the filtered alternating current signal to transmit to the piezoelectric ceramic sensor (1).

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