Sensor module for pressure measurement and vibration feedback and its pressure measurement method

Abstract

The present invention discloses a sensor module for pressure measurement and vibration feedback and a pressure measurement method thereof. The sensor module includes a piezoelectric ceramic sheet and an FPC board. In the sensor module of the present invention, four piezoresistive inks are arranged on the FPC board to form resistors, and the piezoelectric ceramic sheet is arranged at the gap of the FPC board. The whole module structure is a thin structure, reducing the volume. The pressure measurement method of the present invention: when the piezoelectric ceramic sheet is deformed by force, two of the piezoresistive inks are deformed to increase the magnitude of the resistance. By calculating the voltage difference, voltage V S1 - voltage V S2 , and then through F = aV + b, the magnitude of the pressure received by the piezoelectric ceramic sheet is measured. The sensor module of the present invention combines the low-voltage part of the pressure sensor and the high-voltage part driven by the piezoelectric ceramic on one FPC. By adding a voltage of 100V to 300V to the driving voltage ports VH1 and VH2 of the piezoelectric ceramic sheet, the driving feedback of the piezoelectric ceramic sheet can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of tactile feedback, and specifically to a sensor module for pressure measurement and vibration feedback and a pressure measurement method thereof. Background Art

[0002] Tactile feedback technology is a current popular technology, and among them, pressure measurement technology and vibration feedback technology are the core parts of this tactile feedback technology.

[0003] I. The pressure measurement technology in tactile feedback applications is divided into two categories:

[0004] The first category utilizes the piezoelectric effect of piezoelectric ceramics: mechanical deformation generates an alternating voltage, and the magnitude of the deformation is determined by measuring the magnitude of this voltage.

[0005] The second category utilizes a strain gauge or piezoresistive ink to form a Wheatstone bridge, and uses deformation to change the resistance value of one or more of the resistors. By measuring the tiny voltage change of the Wheatstone bridge, the amount of deformation is calculated.

[0006] Among them, the first category has obvious defects: only when the deformation speed is relatively fast, the piezoelectric effect is obvious; when the pressure remains unchanged, the output voltage of the piezoelectric ceramic is zero. Therefore, it is impossible to accurately measure the situation where the pressure change is small or the pressure is poorly maintained.

[0007] The second category can overcome the defects of the first category: the second category can measure the situation of small pressure changes and constant pressure, such as the electronic scale commonly used by people in daily life is a typical application of this type.

[0008] II. Vibration feedback technology is also divided into two categories:

[0009] The first category is a linear motor: utilizing the electromagnetic effect, driving a magnetic substance such as an iron block in the Z-axis direction, X-axis, or Y-axis of the linear motor for rapid start and stop, generating a specific vibration, thereby realizing vibration feedback.

[0010] The second category is piezoelectric ceramics: applying a relatively high voltage, such as a voltage of 60 to 300V, across the two poles of the piezoelectric ceramic to generate mechanical energy for the piezoelectric ceramic, thereby realizing vibration feedback.

[0011] The linear motor requires a large volume to generate a sufficient amount of mechanical vibration, and requires a longer running time and vibration cycle compared to piezoelectric ceramics, and also requires more electrical energy. Therefore, it is difficult to make products driven by linear motors thin and light.

[0012] In addition, piezoelectric ceramics have more advantages in terms of lightness and thinness in terms of volume and are also more power-saving. However, piezoelectric ceramics require a higher voltage, so a dedicated circuit is required for management. Summary of the Invention

[0013] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a sensor module for pressure measurement and vibration feedback and its pressure measurement method. The purpose of designing this sensor module is to measure through the pressure change or no pressure on the piezoelectric ceramic sheet to achieve vibration feedback.

[0014] To solve the above technical problems, the present invention is achieved through the following solutions: The sensor module for pressure measurement and vibration feedback of the present invention includes:

[0015] A piezoelectric ceramic sheet, on its front side, there is a circular copper surface serving as an electrode and electrode metal contacts provided inside the inner circle of the circular copper surface. Among them, the circular copper surface is adhered with a first conductive double-sided adhesive, and the electrode metal contacts are adhered with a second conductive double-sided adhesive;

[0016] An FPC board, having a connected hollow part and a circular part. The hollow part and the circular part form a structure with a gap after being bent at the connection part. The piezoelectric ceramic sheet is arranged in this gap. The front side of the circular part is adhesively fixed to the back side of the piezoelectric ceramic sheet, and the front sides of the hollow part and the piezoelectric ceramic sheet are adhesively fixed through the first conductive double-sided adhesive and the second conductive double-sided adhesive;

[0017] Four piezoresistive inks are printed on the front side of the circular part. These four piezoresistive inks can form resistors and are distributed on the midlines of each side of a rectangle. These four piezoresistive inks form a Wheatstone bridge circuit;

[0018] The hollow part, on the side where it is adhesively fixed to the piezoelectric ceramic sheet, there is a circuit connected to the four piezoresistive inks, and a first contact electrode and a second contact electrode are provided in this circuit. The first conductive double-sided adhesive and the first contact electrode are bonded to form an electrically conductive structure, and the second conductive double-sided adhesive and the second contact electrode are bonded to form an electrically conductive structure;

[0019] A buffer sheet is adhered to the back side of the piezoelectric ceramic sheet. There are multiple buffer sheets, and these multiple buffer sheets are divided into two equal parts. These two parts of buffer sheets are symmetrically arranged at the edge of the piezoelectric ceramic sheet and are respectively close to two opposite piezoresistive inks and far from the other two piezoresistive inks.

[0020] Further, the buffer sheet is a bent rubber thin sheet with double-sided adhesive or a bent silicone thin sheet with double-sided adhesive.

[0021] Further, the four piezoresistive inks are, in clockwise order, resistor R1, resistor R3, resistor R4, and resistor R2. Among them, resistor R1 and resistor R4 are respectively close to the two parts of the buffer sheets.

[0022] Further, one end of the hollowed-out portion is provided with an FPC connector, and the FPC connector is provided with six electrical contacts, which are a VS electrical contact, an S1 electrical contact, an S2 electrical contact, a GND electrical contact, a VH1 electrical contact, and a VH2 electrical contact respectively;

[0023] Among them, the VS electrical contact is a power supply end, which is respectively connected to one end of the resistor R1 and one end of the resistor R3;

[0024] The S1 electrical contact is respectively connected to the other end of the resistor R1 and one end of the resistor R2, and the other end of the resistor R2 is grounded;

[0025] The S2 electrical contact is respectively connected to the other end of the resistor R3 and one end of the resistor R4, and the other end of the resistor R4 is grounded;

[0026] The GND electrical contact is the ground loop of the four resistors;

[0027] The VH1 electrical contact is connected to the first contact electrode;

[0028] The VH2 electrical contact is connected to the second contact electrode.

[0029] A pressure measurement method for a sensor module. When the sensor module is not under pressure, the voltage difference between the S1 electrical contact and the S2 electrical contact is zero;

[0030] When the center of the sensor module is pressed, due to the deformation of the back surface of the piezoelectric ceramic sheet, the four piezoresistive inks are deformed;

[0031] Among them, the deformation of the resistor R1 and the resistor R4 due to the action of the buffer sheet is small, and their resistance value changes little;

[0032] The resistor R2 and the resistor R3 are bent and deformed greatly following the deformation of the piezoelectric ceramic sheet, and their resistance values increase;

[0033] Thus, the voltage V = voltage V S1 - voltage V S2 , the voltage V increases from small to large. Among them, the voltage V S1 is the voltage at the circuit node between the resistor R1 and the resistor R2, and the voltage V S2 is the voltage at the circuit node between the resistor R3 and the resistor R4;

[0034] Furthermore, within the elastic deformation range of the piezoelectric ceramic sheet, the pressure F on the piezoelectric ceramic sheet is proportional to the voltage V;

[0035] By applying a plurality of preset standard pressures on the piezoelectric ceramic sheet to calibrate the piezoelectric ceramic sheet, through the following linear equation:

[0036] F = aV + b, calculate the coefficient a and coefficient b of the linear equation;

[0037] Obtain the coefficient a and coefficient b of the equation, and then deduce the pressure value of the piezoelectric ceramic sheet within the range of the applied pressure.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] 1. The sensor module of the present invention forms resistors by setting four piezoresistive inks on the FPC board, and a piezoelectric ceramic sheet is arranged at the gap of the FPC board. The whole module structure is a thin structure, reducing the volume.

[0040] 2. In the pressure measurement method of the sensor module of the present invention, when the piezoelectric ceramic sheet is deformed by force, two of the piezoresistive inks are deformed to increase the resistance value. By calculating the voltage difference, voltage V S1 - Voltage V S2 , and then through F = aV + b, measure the magnitude of the pressure received by the piezoelectric ceramic sheet.

[0041] 3. The structure of the sensor module of the present invention isolates the pressure test of the pressure sensor and the high-voltage drive of the piezoelectric ceramic sheet, and then combines the low-voltage part of the pressure sensor and the high-voltage part of the piezoelectric ceramic drive on one FPC.

[0042] 4. By adding a voltage of 100V to 300V to the drive voltage ports VH1 and VH2 of the piezoelectric ceramic sheet, the drive feedback of the piezoelectric ceramic sheet can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is an exploded view of the sensor module of the present invention.

[0044] Figure 2 is a front structural view of the FPC board of the present invention.

[0045] Figure 3 is a back structural view of the FPC board of the present invention.

[0046] Figure 4 is a structural view after the circular part of the FPC board of the present invention is bonded to the back of the piezoelectric ceramic sheet.

[0047] Figure 5 is a Wheatstone bridge circuit diagram of the present invention.

[0048] Figure 6 is a circuit diagram of the low voltage of the pressure sensing module of the present invention and the high-voltage part of the piezoelectric ceramic sheet.

[0049] Figure 7 This is the circuit structure diagram of the hollowed-out part of the present invention.

[0050] Figure 8 This is the three-dimensional view of the visible bottom surface of the sensor module of the present invention.

[0051] Figure 9 This is the three-dimensional view of the visible front surface of the sensor module of the present invention.

[0052] Figure 10 This is the structure diagram of the piezoelectric ceramic sheet of the present invention.

[0053] Figure 11 This is the schematic diagram of the linear fitting of voltage and pressure of the present invention.

[0054] Reference signs in the drawings: piezoelectric ceramic sheet 1, FPC board 2, buffer sheet 3, piezoresistive ink 4, low-voltage wire Figure 5 , high-voltage wire Figure 6 , first conductive double-sided adhesive 7, second conductive double-sided adhesive 8, pressing sheet 9, annular copper surface 11, electrode metal contact 12, hollowed-out part 21, circular part 22, first contact electrode 211, second contact electrode 212. Detailed implementation manners

[0055] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention. Obviously, the described embodiments of the present invention are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0056] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0057] Embodiment 1: The specific structure of the present invention is as follows:

[0058] Please refer to the attached Figures 1 - 11 , the sensor module for pressure measurement and vibration feedback of the present invention includes:

[0059] A piezoelectric ceramic sheet 1, on the front surface of which there is a layer of annular copper surface 11 serving as an electrode and an electrode metal contact 12 provided inside the inner circle of the annular copper surface 11. Among them, the annular copper surface 11 is adhered with a first conductive double-sided adhesive 7, and the electrode metal contact 12 is adhered with a second conductive double-sided adhesive 8;

[0060] The FPC board 2 has a connected hollow portion 21 and a circular portion 22. The hollow portion 21 and the circular portion 22 form a structure with a gap after being bent at the connection portion. The piezoelectric ceramic sheet 1 is disposed in this gap. The front surface of the circular portion 22 is adhesively fixed to the back surface of the piezoelectric ceramic sheet 1. The front surfaces of the hollow portion 21 and the piezoelectric ceramic sheet 1 are adhesively fixed through a first conductive double-sided tape 7 and a second conductive double-sided tape 8;

[0061] Four piezoresistive inks 4 are printed on the front surface of the circular portion 22. These four piezoresistive inks 4 can form a resistance and are distributed on the midlines of the four sides of a rectangle. These four piezoresistive inks 4 form a Wheatstone bridge circuit;

[0062] On the side of the hollow portion 21 that is adhesively fixed to the piezoelectric ceramic sheet 1, there is a circuit connected to the four piezoresistive inks 4. In this circuit, there are a first contact electrode 211 and a second contact electrode 212. The first conductive double-sided tape 7 and the first contact electrode 211 are bonded to form an electrically conductive structure. The second conductive double-sided tape 8 and the second contact electrode 212 are bonded to form an electrically conductive structure;

[0063] A buffer sheet 3 is adhered to the back surface of the piezoelectric ceramic sheet 1. There are multiple buffer sheets 3. These multiple buffer sheets 3 are divided into two equal parts. These two parts of buffer sheets 3 are symmetrically disposed at the edge of the piezoelectric ceramic sheet 1 and are respectively close to two opposite piezoresistive inks 4 and far from the other two piezoresistive inks 4.

[0064] A preferred technical solution of this embodiment: The buffer sheet 3 is a bent rubber thin sheet with double-sided adhesive or a bent silicone thin sheet with double-sided adhesive.

[0065] A preferred technical solution of this embodiment: The four piezoresistive inks 4 are, in clockwise order, a resistor R1, a resistor R3, a resistor R4, and a resistor R2. Among them, the resistor R1 and the resistor R4 are respectively close to the two parts of the buffer sheet 3.

[0066] A preferred technical solution of this embodiment: One end of the hollow portion 21 is provided with an FPC connector. This FPC connector has six electrical contacts, which are a VS electrical contact, an S1 electrical contact, an S2 electrical contact, a GND electrical contact, a VH1 electrical contact, and a VH2 electrical contact;

[0067] Among them, the VS electrical contact is a power supply end, which is respectively connected to one end of the resistor R1 and one end of the resistor R3;

[0068] The S1 electrical contact is respectively connected to the other end of the resistor R1 and one end of the resistor R2. The other end of the resistor R2 is grounded;

[0069] The S2 electrical contacts are respectively connected to the other end of the resistor R3 and one end of the resistor R4, and the other end of the resistor R4 is grounded;

[0070] The GND electrical contact is the ground loop of the four resistors;

[0071] The VH1 electrical contact is connected to the first contact electrode 211;

[0072] The VH2 electrical contact is connected to the second contact electrode 212.

[0073] Example 2:

[0074] A method for measuring the pressure of a sensor module. When the sensor module is not under pressure, the voltage difference between the S1 electrical contact and the S2 electrical contact is zero;

[0075] When the center of the sensor module is under pressure, due to the deformation of the back surface of the piezoelectric ceramic sheet 1, the four piezoresistive inks 4 are further deformed;

[0076] Among them, the deformations of the resistor R1 and the resistor R4 due to the action of the buffer sheet 3 are small, and their resistance value changes are small;

[0077] The resistor R2 and the resistor R3 are bent and deformed greatly following the deformation of the piezoelectric ceramic sheet 1, and their resistance values increase;

[0078] Thus, it can be obtained that the voltage V = voltage V S1 - voltage V S2 , the voltage V increases from small to large, where the voltage V S1 is the voltage at the circuit node between the resistor R1 and the resistor R2, and the voltage V S2 is the voltage at the circuit node between the resistor R3 and the resistor R4;

[0079] Furthermore, within the elastic deformation range of the piezoelectric ceramic sheet 1, the pressure F applied to the piezoelectric ceramic sheet 1 is proportional to the voltage V;

[0080] By applying multiple preset standard pressures to the piezoelectric ceramic sheet 1 to calibrate the piezoelectric ceramic sheet 1, through the following linear equation:

[0081] F = aV + b, calculate the coefficients a and b of this linear equation;

[0082] Obtain the coefficients a and b of the equation, and then calculate the pressure value within the pressure range borne by the piezoelectric ceramic sheet 1.

[0083] Example 3:

[0084] The following is to calibrate the sensor module based on the content of Embodiment 2:

[0085] Apply 100 grams of force and 200 grams of force on the piezoelectric ceramic sheet 1 for two-stage calibration and linear fitting process, and the voltage V can be calculated through voltage V S1 - Voltage V S2 Therefore:

[0086] Equation 1: 100 = a1V1; (b1 = 0);

[0087] Equation 2: 100 = a2V1 + b2;

[0088] Equation 3: 200 = a2V2 + b2;

[0089] Subtract Equation 2 from Equation 3 to get

[0090] Equation 4: 100 = a2(V2 - V1)

[0091] Among them, V1 is the voltage difference measured under a pressure of 100 grams of force, V1 = voltage V S1 - Voltage V S2 . Assume V1 = 2 volts.

[0092] V2 is the voltage difference measured under a pressure of 200 grams of force, V2 = voltage V S1 - Voltage V S2 . Assume V2 = 3 volts.

[0093] Then, from Equation 1, a1 = 50 can be calculated, and from Equation 4, a2 = 100 can be calculated. Substitute into Equation 2 to get b2 = -100. That is, when the force is from 0 to 100 grams, use F = 50V to calculate the pressure; when the force is from 100 grams to 200 grams, use F = 100V - 100 to calculate the pressure. If higher precision is required, more intervals can be added.

[0094] Embodiment 4:

[0095] As Figure 1 shown, the sensor module of the present invention further includes a pressing sheet 9, the pressing sheet 9 is fixedly adhered to the center of the hollow portion 21, and the pressing sheet 9 is located at the center of each resistor.

[0096] Embodiment 5:

[0097] As Figures 6 - 7 shown, Figure 6 is the low-voltage and high-voltage partial circuit diagram of the pressure sensing module of the present invention. Figure 7 is the circuit structure diagram of the hollow portion of the present invention.

[0098] Figure 6 In, the dotted line part without an arrow is the low-voltage wire of the sensor module of the present invention Figure 5, the two dotted lines with arrows are the high-voltage wires of the positive and negative electrodes of the piezoelectric ceramic sheet 1 of the present invention Figure 6 . It can be seen from the figure that the pressure test of the sensor module and the high-voltage drive of the piezoelectric ceramic sheet are isolated, and then the low part of the sensor module and the high-voltage part driven by the piezoelectric ceramic sheet are combined on a single FPC.

[0099] Such as Figure 7 shown, by applying a voltage of 100V to 300V to the drive voltage ports VH1 and VH2 of the piezoelectric ceramic sheet 1, the drive feedback of the piezoelectric ceramic can be achieved.

[0100] In summary, the sensor module of the present invention forms resistors by setting four piezoresistive inks on the FPC board, and a piezoelectric ceramic sheet is set at the gap of the FPC board. The entire module structure is a thin structure, reducing the volume. For the pressure measurement method of the sensor module of the present invention, when the piezoelectric ceramic sheet is deformed by force, two of the piezoresistive inks are deformed to increase the resistance value. By calculating the voltage difference, voltage V S1 - voltage V S2 , and then through F = aV + b, the magnitude of the pressure received by the piezoelectric ceramic sheet is measured. The structure of the sensor module of the present invention isolates the pressure test of the pressure sensor and the high-voltage drive of the piezoelectric ceramic sheet, and then combines the low-voltage part of the pressure sensor and the high-voltage part driven by the piezoelectric ceramic on a single FPC. By applying a voltage of 100V to 300V to the drive voltage ports VH1 and VH2 of the piezoelectric ceramic sheet, the drive feedback of the piezoelectric ceramic sheet can be achieved.

[0101] The above is only the preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A sensor module for pressure measurement and vibration feedback, characterized in that, Comprising: A piezoelectric ceramic sheet (1), on the front of which is covered with an annular copper surface (11) serving as an electrode and an electrode metal contact (12) provided inside the inner circle of the annular copper surface (11). Among them, the annular copper surface (11) is adhered with a first conductive double-sided adhesive (7), and the electrode metal contact (12) is adhered with a second conductive double-sided adhesive (8); An FPC board (2), having a connected hollow portion (21) and a circular portion (22). The hollow portion (21) and the circular portion (22) form a structure with a gap after being bent at the connection. The piezoelectric ceramic sheet (1) is disposed in this gap. The front of the circular portion (22) is adhesively fixed to the back of the piezoelectric ceramic sheet (1), and the front of the hollow portion (21) and the piezoelectric ceramic sheet (1) are adhesively fixed through the first conductive double-sided adhesive (7) and the second conductive double-sided adhesive (8); Four piezoresistive inks (4) are printed on the front of the circular portion (22). These four piezoresistive inks (4) can form a resistance and are distributed on the midlines of each side of a rectangle. These four piezoresistive inks (4) form a Wheatstone bridge circuit; The hollow portion (21), on the surface adhered to the piezoelectric ceramic sheet (1), is provided with a circuit connected to the four piezoresistive inks (4), and a first contact electrode (211) and a second contact electrode (212) are provided in this circuit. The first conductive double-sided adhesive (7) and the first contact electrode (211) are bonded to form an electrically conductive structure, and the second conductive double-sided adhesive (8) and the second contact electrode (212) are bonded to form an electrically conductive structure; A buffer sheet (3) is adhered to the back of the piezoelectric ceramic sheet (1). There are multiple buffer sheets (3), and these multiple buffer sheets (3) are divided into two equal parts. These two parts of buffer sheets (3) are symmetrically disposed at the edge of the piezoelectric ceramic sheet (1) and are respectively close to two opposite piezoresistive inks (4) and far from the other two piezoresistive inks (4).

2. The sensor module for pressure measurement and vibration feedback according to claim 1, wherein The buffer sheet (3) is a bent rubber thin sheet with double-sided adhesive or a bent silicone thin sheet with double-sided adhesive.

3. The sensor module for pressure measurement and vibration feedback according to claim 1, wherein The four piezoresistive inks (4) are, in a clockwise direction, a resistance R1, a resistance R3, a resistance R4, and a resistance R2 respectively. Among them, the resistance R1 and the resistance R4 are respectively close to the two parts of the buffer sheet (3).

4. The sensor module for pressure measurement and vibration feedback according to claim 3, characterized in that, One end of the hollow portion (21) is provided with an FPC connector, and this FPC connector is provided with six electrical contacts, which are a VS electrical contact, an S1 electrical contact, an S2 electrical contact, a GND electrical contact, a VH1 electrical contact, and a VH2 electrical contact respectively; Among them, the VS electrical contact is a power supply terminal, which is respectively connected to one end of the resistance R1 and one end of the resistance R3; The S1 electrical contact is respectively connected to the other end of the resistance R1 and one end of the resistance R2, and the other end of the resistance R2 is grounded; The S2 electrical contact is respectively connected to the other end of the resistance R3 and one end of the resistance R4, and the other end of the resistance R4 is grounded; The GND electrical contact is the ground loop of the four resistances; The VH1 electrical contact is connected to the first contact electrode (211); The VH2 electrical contact is connected to the second contact electrode (212).

5. A pressure measurement method for a sensor module, characterized in that, A sensor module according to any one of claims 1-4 is included.

6. The pressure measurement method according to claim 5, wherein, When the sensor module is not under pressure, the voltage difference between the S1 electrical contact and the S2 electrical contact is zero; When the center of the sensor module is under pressure, due to the deformation of the back surface of the piezoelectric ceramic sheet (1), the four piezoresistive inks (4) are deformed; Among them, the deformation of the resistor R1 and the resistor R4 due to the action of the buffer sheet (3) is small, and their resistance value changes are small; The resistor R2 and the resistor R3 are bent and deformed greatly following the deformation of the piezoelectric ceramic sheet (1), and their resistance values increase; Therefore, the voltage V = voltage V S1 - voltage V S2 , the voltage V increases from small to large, where the voltage V S1 is the voltage at the circuit node entering between the resistor R1 and the resistor R2, and the voltage V S2 is the voltage at the circuit node entering between the resistor R3 and the resistor R4; Furthermore, within the elastic deformation range of the piezoelectric ceramic sheet (1), the pressure F applied to the piezoelectric ceramic sheet (1) is proportional to the voltage V; By applying a plurality of preset standard pressures to the piezoelectric ceramic sheet (1) to calibrate the piezoelectric ceramic sheet (1), through the following linear equation: F = aV + b, calculate the coefficient a and the coefficient b of this linear equation; Obtain the coefficient a and the coefficient b of the equation, and then calculate the pressure value of the piezoelectric ceramic sheet (1) within the pressure range it bears.

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