Method for measuring voltage values of target sensor elements in a pressure sensor array

Abstract

The application discloses a kind of measurement methods of target sensing unit voltage value in pressure sensor array, solve the problem of false imaging in non-pressure area caused by crosstalk current when existing pressure sensor array is pressed in multiple points.The method comprises the following steps: S1, initial unshielded measurement is carried out, and the first voltage value flowing through the sampling resistor is obtained;S2, using crosstalk elimination circuit, first step single-column shielding measurement is carried out, and the second voltage value flowing through the sampling resistor is obtained;S3, using crosstalk elimination circuit, second step single-column shielding measurement is carried out, and the third voltage value flowing through the sampling resistor is obtained;S4, using crosstalk elimination circuit, third step single-column shielding measurement is carried out, and the fourth voltage value flowing through the sampling resistor is obtained;S5, compensation calculation is carried out according to the voltage value collected in S1-S4, and the voltage value of target sensing unit is obtained.

Description

Technical Field

[0001] This invention belongs to the field of flexible sensor and electronic signal acquisition and data processing technology. Specifically, it relates to a method for measuring the voltage value of a target sensing unit in a pressure sensor array. Background Technology

[0002] Pressure sensor arrays, as core pressure sensing components, have wide applications in human-computer interaction, tactile perception in bionic robots, and high-precision multi-point mechanical monitoring. Among them, piezoresistive pressure sensor arrays are favored due to their relatively simple structure and ease of large-area fabrication. However, in actual working conditions with multiple points under pressure, piezoresistive flexible sensor arrays inevitably face serious crosstalk problems. Since the sensing units in the array are connected via pressure-sensitive material layers or shared row-column orthogonal electrodes, when pressure is applied to multiple points simultaneously, current will form crosstalk current conduction paths through non-target sensing units. This causes unpressed nodes to output false low-resistance signals, resulting in abnormal sampling voltages in the data acquisition system. Ultimately, this leads to incorrect pressure areas in the generated pressure distribution heatmap, reducing the accuracy of multi-point force data reproduction.

[0003] To eliminate crosstalk current within the array, researchers both domestically and internationally have achieved relevant literature results: In terms of physical structural isolation, Zhu et al. (Zhu ZY, Jin ML, Wang SX, et al. A flexible crosstalk-free piezoresistive pressure sensor array based on interdigital-electrode for high-precision pressure mapping[C]. In: Proc. of the 2023 China AutomationCongress (CAC). IEEE, 2023: 643-647.) proposed a scheme in which a unidirectional conducting diode is connected in series at the intersection node of each row and column electrode, utilizing the reverse cutoff characteristic of the diode to cut off the conduction path of the crosstalk current. Regarding voltage feedback methods, Zhang et al. (Zhang XY, Wang RP, Xie Y, et al. Design of sensorarray data acquisition system based on equipotential method[C]. In: Proc. of the 5th World Conference on Mechanical Engineering and Intelligent Manufacturing (WCMEIM). IEEE, 2022: 93-96.) proposed an improved voltage feedback circuit scheme. By feeding back the actual voltage across the sampling resistor to the unselected column line in real time at the hardware level, the potential across the parasitic loop is made equal using the principle of equipotentiality, thereby eliminating crosstalk current paths at the circuit level. Kim et al. (Kim JS, Kwon DY, Choi B D. High-accuracy, compact scanning method and circuit for resistive sensor arrays[J]. Sensors, 2016, 16(2): 155.) proposed a row driving circuit scheme to address the problem of complex hardware circuit structure in the zero-potential shielding method. This scheme enables the system to achieve high-precision driving of each row by using only a single operational amplifier as a buffer amplification, and controls the maximum measurement error to within 0.1%.Regarding backend algorithm repair, Wang Xiaodong et al. (Wang Xiaodong, Chen Junpeng, Pei Zeguang. Crosstalk solution for fabric pressure sensor array based on U-Net convolutional neural network [J]. Journal of Textile Research, 2024, 45(07): 86-93.) proposed a pressure data imaging result repair scheme based on U-Net convolutional neural network. By inputting the pressure image affected by crosstalk into a deep learning model for training, the erroneous imaging result of the pressure image is repaired from the software algorithm level. However, the pure software anti-crosstalk scheme has the defect of relying on the high computing power hardware platform of the host computer, and it is difficult to realize real-time crosstalk compensation calculation on the resource-constrained embedded microprocessor front end. Summary of the Invention

[0004] Technical problem: The present invention aims to solve the problem of crosstalk current in existing pressure sensor arrays causing erroneous imaging in non-pressurized areas when multiple pressure points are subjected to pressure.

[0005] Technical solution: To solve the above technical problems, the present invention adopts the following technical solution: A method for measuring the voltage value of a target sensing unit in a pressure sensor array, wherein the top and bottom electrodes are distributed on both sides of a pressure-sensitive layer in an orthogonal row-column pattern, and the intersections between the electrodes and the pressure-sensitive layer together constitute an independent sensing unit; each row and column line of the top and bottom electrodes is connected through the pressure-sensitive layer, and each row and column line is equipped with a switch; all row lines are directly connected to a driving voltage via switches, and all column lines are connected to a sampling resistor R via analog switches. s After connection, ground; divide the pressure sensor array into m networks according to the column lines, each network includes 4 column lines, and there are m-1 column lines between two adjacent column lines in each network; use one sensing unit as the target sensing unit; The method includes the following steps: S1 performs an initial unshielded measurement to obtain the flow through the sampling resistor R. s First voltage value V un ; S2 utilizes a crosstalk cancellation circuit to perform the first step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The second voltage value V S1 ; S3 utilizes a crosstalk cancellation circuit to perform a second-step single-column shielded measurement, obtaining the flow rate through the sampling resistor R. s The third voltage value V S2 ; S4 utilizes a crosstalk cancellation circuit to perform the third step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The fourth voltage valueV S3 ; S5 performs compensation calculations based on the voltage values ​​collected in S1 to S4 to obtain the voltage value of the target sensing unit.

[0006] As a preferred example, S1 specifically includes: when scanning the target sensing unit, not driving all other through electrodes belonging to the same network as the target sensing unit to the reference voltage, and measuring the current flowing through the sampling resistor R. s First voltage value V un .

[0007] As a preferred example, S2 specifically includes: driving only the unselected first column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The second voltage value V S1 .

[0008] As a preferred example, S3 specifically includes: driving only the unselected second pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The third voltage value V S2 .

[0009] As a preferred example, S4 specifically includes: driving only the unselected third pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The fourth voltage value V S3 .

[0010] As a preferred example, the same crosstalk cancellation circuit is used in S2, S3 and S4.

[0011] As a preferred embodiment, the crosstalk cancellation circuit includes two analog switches and an operational amplifier; one end of each of the two analog switches is connected to the other end, and the other end is connected to the output and negative input of the operational amplifier, respectively; the positive input of the operational amplifier is connected to... V adc ,in V adc Sampling resistor R s Voltage at both ends.

[0012] As a preferred example, the step of driving to the reference voltage via the crosstalk cancellation circuit includes: [the step of] driving the reference voltage in the crosstalk cancellation circuit to the reference voltage. V refAfter being selected by a multiplex analog switch, it is connected to the unselected column electrode that needs crosstalk cancellation.

[0013] As a preferred example, S5 specifically includes: calculating the voltage value of the target sensing unit according to equation (1). V c : Equation (1).

[0014] As a preferred example, the reference voltage is the sampling resistor R. s The analog-to-digital converters at both ends sample the voltage.

[0015] Beneficial effects: Existing piezoresistive sensors are prone to crosstalk currents under multi-point pressure. Compared with existing anti-crosstalk technologies, this invention has the following beneficial effects: 1. Eliminate the incorrect display results of unpressed areas: Through the four-step measurement in steps S1-S4 and the compensation calculation in step S5, the interference of direct crosstalk current is eliminated, thereby eliminating the phenomenon of unpressed areas being incorrectly displayed as pressurized states in the pressure distribution heat map, and significantly improving the restoration accuracy of multi-point force data.

[0016] 2. Saves hardware resources: Since the method of this invention only needs to drive one unselected column to the reference voltage during each shielding measurement, the crosstalk cancellation circuit of the data acquisition system uses fewer operational amplifiers compared to the traditional voltage feedback method, which significantly reduces the complexity of the hardware system. Attached Figure Description

[0017] Figure 1 This is the equivalent circuit diagram of the 32×32 piezoresistive pressure sensor array used in this embodiment of the invention; Figure 2 This is a schematic diagram of crosstalk current path classification according to an embodiment of the present invention, wherein the yellow solid line represents possible direct crosstalk current and the blue dashed line represents possible indirect crosstalk current; Figure 3 This is a circuit diagram of the crosstalk cancellation circuit in an embodiment of the present invention; Figure 4 These are comparison images of pressure data imaging effects using the method of the present invention and existing methods, wherein (a) is a pressure data imaging image using the existing method and (b) is a pressure data imaging image using the method of the present invention. Figure 5 This is a graph showing the resistance measurement error results using the method of this invention and existing methods. Detailed Implementation

[0018] The technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0019] The pressure sensor array used in the measurement method of this invention typically employs a three-layer composite structure. It includes a top electrode, a bottom electrode, and a pressure-sensitive layer. The top and bottom electrodes are distributed in a row-column orthogonal pattern on both sides of the pressure-sensitive layer, and the intersections between the electrodes and the pressure-sensitive layer together form independent sensing units. In the top and bottom electrodes, each row line and each column line is connected through the pressure-sensitive layer, and each row line and each column line is equipped with a switch. All row lines are connected to the driving voltage V through the switches. cc All column lines are connected to the sampling resistor R via an analog switch (e.g., switch ADG708). s Grounding is required after connection.

[0020] In this embodiment of the invention, the pressure sensor array is divided into m networks based on the column lines. Each network includes 4 column lines, and there are m-1 column lines between any two adjacent column lines in each network. A sensing unit is designated as the target sensing unit. The target sensing unit is a single sensing unit composed of the currently selected row line, column line, and pressure-sensitive layer in the data acquisition system. For example, such as... Figure 1 As shown, a 32×32 flexible pressure sensor array is constructed. The array is divided into eight networks based on the column lines. Each network comprises four column lines, with seven column lines between any two adjacent column lines within each network. Column lines 1, 9, 17, and 25 belong to the same network. Row lines refer to the row electrodes of the pressure sensor array, and column lines refer to the column electrodes. Resistor R... i，j Refers to the first i The first row electrode, the first j The resistance corresponding to the sensing unit composed of individual electrodes and a pressure-sensitive layer. V cc This is the driving voltage; R s This is the sampling resistor.

[0021] The method includes the following steps: S1 performs an initial unshielded measurement to obtain the flow through the sampling resistor R. s First voltage value V un .

[0022] S1 specifically includes: when scanning the target sensing unit, not driving all other pass electrodes belonging to the same network as the target sensing unit to the reference voltage, and measuring the current flowing through the sampling resistor R. s First voltage value V un .

[0023] In S1, all pass electrodes are not connected to the crosstalk cancellation circuit, that is, all pass electrodes are not shielded.

[0024] S2 utilizes a crosstalk cancellation circuit to perform the first step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The second voltage value V S1 .

[0025] S2 specifically includes: driving only the unselected first column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The second voltage value V S1 The reference voltage is the sampling resistor R. s The analog-to-digital converter samples the voltage at both ends. By driving the unselected gate column to this reference voltage, the voltage across the sensing unit in the unselected gate column is made close to the same potential, thereby blocking the path of crosstalk current flowing through the unselected gate column to the sampling resistor.

[0026] S3 utilizes a crosstalk cancellation circuit to perform a second-step single-column shielded measurement, obtaining the flow rate through the sampling resistor R. s The third voltage value V S2 .

[0027] S3 specifically includes: driving only the unselected second pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The third voltage value V S2 The reference voltage is the sampling resistor R. s The analog-to-digital converters at both ends sample the voltage.

[0028] S4 utilizes a crosstalk cancellation circuit to perform the third step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The fourth voltage value V S3 .

[0029] S4 specifically includes: driving only the unselected third pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The fourth voltage value V S3 The reference voltage is the sampling resistor R. s The analog-to-digital converters at both ends sample the voltage.

[0030] S5 performs compensation calculations based on the voltage values ​​collected in S1 to S4 to obtain the voltage value of the target sensing unit.

[0031] S5 specifically includes: calculating the voltage value of the target sensing unit according to equation (1). V c : Equation (1).

[0032] Step S5 uses equation (1) to eliminate the voltage drop caused by the direct crosstalk current flowing through the sampling resistor, while retaining the influence of the indirect crosstalk current, so that the voltage sampling value of the unpressurized sensing unit is close to zero or negative.

[0033] The method of this invention proposes a four-step scanning approach: First, an initial measurement is performed without applying any unselected column shielding; then, the three unselected columns belonging to the same network as the target sensing unit are driven individually to a reference voltage, and three single-column shielding measurements are performed respectively. The microcontroller performs compensation calculations based on the four acquired voltage values, effectively offsetting the error caused by the direct crosstalk current flowing through the sampling resistor. This method eliminates the voltage error caused by the direct crosstalk current, obtains the compensated voltage value of the target sensing unit, and then calculates the voltage value. This method eliminates the erroneous display results of unpressurized areas caused by crosstalk current, and can more accurately restore the true pressure distribution.

[0034] As an example, columns 1, 9, 17, and 25 are in the same network. S1 performs an initial unshielded measurement to obtain the flow through the sampling resistor R. s The first voltage value; S2 uses the crosstalk cancellation circuit to perform single-column shielding measurement on column line 9; S3 uses the crosstalk cancellation circuit to perform single-column shielding measurement on column line 17; S4 uses the crosstalk cancellation circuit to perform single-column shielding measurement on column line 25.

[0035] Preferably, the same crosstalk cancellation circuit is used in steps S2, S3, and S4. In this way, only a single crosstalk cancellation circuit is used in the entire measurement method, greatly saving hardware resources.

[0036] Preferred, such as Figure 3 As shown, the crosstalk cancellation circuit includes two analog switches and an operational amplifier; one end of the two analog switches is connected to each other, and the other end is connected to the output terminal and the negative input terminal of the operational amplifier, respectively; the positive input terminal of the operational amplifier is connected to... V adc ,in V adc Sampling resistor R s Voltage at both ends.

[0037] Description of external connections: During operation, the positive input terminal of the operational amplifier in the crosstalk cancellation circuit is connected to the sampling resistor R. s voltage to ground V adcOne end of each of the two analog switches is connected to the unselected column electrode that needs to be crosstalk-cancelled.

[0038] Driven to a reference voltage via a crosstalk cancellation circuit, including: the reference voltage in the crosstalk cancellation circuit... V ref After being selected by a multiplex analog switch, it is connected to the unselected column electrode that needs crosstalk cancellation.

[0039] by Figure 1 The structure shown, with columns 1, 9, 17, and 25 forming the same network, is used as an example to illustrate the principle of this technical solution. In the measurement method of this invention: (1) First measurement (initially unshielded): The microcontroller controls the multiplexer to select the target row and column. i (Here, the list is incomplete) i (For example, if =1), columns belonging to the same network will not be included. i+ 8. Column i+ 16. Column i+ 24 is driven to the reference voltage. At this time, current flows through the sampling resistor R. s current I un = I real + I i+8 + I i+16 + I i+24 + I i+8,i+16 + I i+8,i+24 + I i+16,i+24 The system reads the voltage across the sampling resistor. V un In the formula, I real For the flow through the gated sensing unit resistor R i,i The actual signal current; I i+8 , I i+16 , I i+24 They are respectively the flow through the column i +8, Column i +16, Column i +24 direct crosstalk current; I i+8,i+16 , I i+8,i+24 , I i+16,i+24 They are respectively the flow through the column i +8 sum column i+16, Column i +8 sum column i +24, Column i +16 sum column i +24 indirect crosstalk current.

[0040] (2) Second measurement (first step single column masking): only the first unselected column (column) within the same network is masked. i +8) Driven to the reference voltage by the crosstalk cancellation circuit, the direct crosstalk current brought by this column is cut off. At this time, the current flowing through the sampling resistor... I Si+8 = I real + I i+16 + I i+24 + I i+16,i+24 The system reads the voltage across the sampling resistor. V S1 .

[0041] (3) Third measurement (second step single column shielding): reset column i +8, only select the second ungated column (column) within the same network. i +16) Driven separately to the reference voltage, the current flowing through the sampling resistor I Si+16 = I real + I i+8 + I i+24 + I i+8,i+24 The system reads the voltage across the sampling resistor. V S2 .

[0042] (4) Fourth measurement (third step single column shielding): Reset column i +16, only the third ungated column (column) within the same network will be selected. i +24) Driven separately to the reference voltage, the current flowing through the sampling resistor I Si+24 = I real + I i+8 + I i+16 + I i+8,i+16 The system reads the voltage across the sampling resistor. V S3 .

[0043] (5) Calculation of compensation results: The system's main control microprocessor uses the formula The voltage value of the target sensing unit is obtained. V S1 = I Si+8 *R s , V S2 = I Si+16 *R s , V S3 = I Si+24 *R s , V un = I un *R s , V real = I real *R s , V i+8,i+16 = I i+8,i+16 *R s , V i+8,i+24 = I i+8,i+24 *R s , V i+16,i+24 = I i+16,i+24 *R s Substituting into the above formula, we get . V i+8,i+16 , V i+8,i+24 , V i+16,i+24 They are respectively I i+8,i+16 , I i+8,i+24 , I i+16,i+24 The voltage drop generated by the current flowing through the sampling resistor. Therefore, it can be seen that the voltage drop caused by the direct crosstalk current flowing through the sampling resistor has been eliminated, and the remaining interference term is the voltage drop caused by the indirect crosstalk current flowing through the sampling resistor. At this time, the crosstalk current will cause the ADC sampling voltage value of the pressure-sensitive unit to be lower than the true value. For example, when the first row and first column sensor unit is under pressure, the crosstalk current will cause the voltage value measured by the data acquisition system to be lower than its true voltage value; when the first row and first column sensor unit is not under pressure, the crosstalk current will cause the measured voltage value to be close to zero or negative. Therefore, in the pressure data imaging results, the unpressurized area will not be incorrectly displayed as a high-pressure area.

[0044] The erroneous signal value is caused by crosstalk current flowing through the sampling resistor. This is due to the selected sensing unit. R 1,1 And when the remaining columns of the same network are not connected to the reference voltage, the possible crosstalk current paths are as follows: Figure 2 As shown. Figure 2 In the diagram, the yellow-marked resistors connect the currently selected and unselected columns, while the blue-marked resistors connect different unselected columns. Crosstalk currents are classified based on the type of resistor they flow through: crosstalk currents that flow only through the resistors of the sensing units in the same row as the target sensing unit and the yellow-marked resistors are called direct crosstalk currents (e.g., ...). Figure 2 (As shown by the solid yellow line in the middle); crosstalk current flowing through the resistor of a sensing unit in the same row as the target sensing unit, and simultaneously flowing through the resistors marked in yellow and blue, is called indirect crosstalk current (e.g., Figure 2 (As shown by the blue dashed line).

[0045] Without any crosstalk cancellation, crosstalk current will cause the calculated voltage value of the target sensing unit to be less than the actual voltage value; according to the formula... It can be seen that the final calculation result of the method of the present invention V c Less than V real ,in V real The voltage value is the actual voltage value of the sampling resistor. The method of this invention ultimately yields a calculated voltage value for the target sensing unit that is greater than the actual voltage value. Therefore, the method of this invention can eliminate erroneous display results in unpressurized areas.

[0046] The following resistance measurement error experiment demonstrates that the technical solution of this invention has excellent performance.

[0047] The experimental platform uses a 3×4 resistor matrix constructed with standard resistors. The test conditions are set as follows: the standard resistance value of the target node (second row, second column) is gradually adjusted from 10 Ω to 6800 Ω, while maintaining the resistance of the remaining standard resistors at 2200 Ω. The resistance value of the target node is measured using both the method of this invention and an existing method for disabling crosstalk cancellation. (Resistance measurement error...) R error Calculated from equation (2): Equation (2) In the formula, R calc This is the measured value of the standard resistor. R real This is the actual resistance value of the standard resistor.

[0048] Experimental test data such as Figure 5 As shown. Experimental results show that: (1) In existing methods for disabling crosstalk cancellation procedures, the measured resistance value is significantly smaller than its actual resistance value. R calc Less than R real This causes the calculated voltage value to be greater than the actual voltage value. Consequently, in pressure data imaging results, unpressed areas are incorrectly displayed as pressurized areas.

[0049] (2) When using the measurement method of the present invention, the measured resistance value is higher than its actual resistance value. R calc Greater than R real This results in the calculated voltage value being less than the actual voltage value. As the actual resistance value gradually increases, the effective signal current flowing through the target node decreases, leading to a relative increase in the proportion of crosstalk current in the total current flowing through the sampling resistor. Consequently, the measurement error of this invention shows a certain increasing trend. However, the measurement method of this invention can ensure that the voltage sampling value of the unpressurized sensing unit is close to zero or negative, so that it will not be incorrectly displayed as a pressurized state in the pressure data imaging results due to interference from crosstalk current. In addition, the measurement method of this invention only needs to drive at most one unselected column to the reference voltage in each measurement step, thus reducing the complexity of the hardware circuit.

[0050] The imaging results obtained by visualizing the array data after pressing a palm into a 32×32 piezoresistive pressure sensor array using a Python data visualization program (implemented through Python's pyplot module) are as follows: Figure 4 As shown. Among them, Figure 4 (a) The pressure data imaging results obtained using the existing method, i.e., disabling the crosstalk cancellation procedure; Figure 4 (b) is the imaging result of pressure data measured using the method of the present invention.

[0051] from Figure 4 (a) It can be seen that due to the interference of crosstalk current, some un-pressurized areas are incorrectly displayed as pressurized areas, thus the restoration effect of the true outline of the palm is poor. Figure 4 In (b), using the method of the present invention, the erroneous display results of the un-voltaged area caused by crosstalk current are effectively eliminated, but the voltage value of the actual stressed area is attenuated to a certain extent. (Comparison) Figure 4 (a) and Figure 4 (b) It can be seen that the method of the present invention can effectively eliminate the incorrect display results of the unvoltageed area caused by crosstalk current, but the voltage value finally calculated by the method of the present invention is less than the actual voltage value.

[0052] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for measuring the voltage value of a target sensing unit in a pressure sensor array, wherein the top and bottom electrodes are distributed on both sides of a pressure-sensitive layer in a row-column orthogonal pattern, and the intersections between the electrodes and the pressure-sensitive layer together constitute an independent sensing unit; in the top and bottom electrodes, each row line and each column line is connected through the pressure-sensitive layer, and each row line and each column line is equipped with a switch; all row lines are connected to a driving voltage via switches, and all column lines are connected to a sampling resistor R via analog switches. s Grounding after connection; Its features are, The pressure sensor array is divided into m networks according to the column lines. Each network includes 4 column lines, and there are m-1 column lines between two adjacent column lines in each network. One sensing unit is used as the target sensing unit. The method includes the following steps: S1 performs an initial unshielded measurement to obtain the flow through the sampling resistor R. s First voltage value V un ; S2 utilizes a crosstalk cancellation circuit to perform the first step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The second voltage value V S1 ; S3 utilizes a crosstalk cancellation circuit to perform a second-step single-column shielded measurement, obtaining the flow rate through the sampling resistor R. s The third voltage value V S2 ; S4 utilizes a crosstalk cancellation circuit to perform the third step of single-column shielding measurement, obtaining the flow rate through the sampling resistor R. s The fourth voltage value V S3 ; S5 performs compensation calculations based on the voltage values ​​collected in S1 to S4 to obtain the voltage value of the target sensing unit.

2. The measurement method according to claim 1, characterized in that, S1 specifically includes: when scanning the target sensing unit, not driving all other pass electrodes belonging to the same network as the target sensing unit to the reference voltage, and measuring the current flowing through the sampling resistor R. s First voltage value V un .

3. The measurement method according to claim 1, characterized in that, S2 specifically includes: driving only the unselected first column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The second voltage value V S1 .

4. The measurement method according to claim 1, characterized in that, S3 specifically includes: driving only the unselected second pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The third voltage value V S2 .

5. The measurement method according to claim 1, characterized in that, S4 specifically includes: driving only the unselected third pass column belonging to the same network as the target sensing unit to the reference voltage through the crosstalk cancellation circuit, while keeping the remaining unselected pass columns in an undriven state, and measuring the current flowing through the sampling resistor R. s The fourth voltage value V S3 .

6. The measurement method according to claim 1, characterized in that, The same crosstalk cancellation circuit is used in S2, S3 and S4.

7. The measurement method according to claim 3, 4 or 5, characterized in that, The crosstalk cancellation circuit includes two analog switches and an operational amplifier; one end of the two analog switches is connected to each other, and the other end is connected to the output terminal and the negative input terminal of the operational amplifier, respectively; the positive input terminal of the operational amplifier is connected to... V adc ,in V adc Sampling resistor R s Voltage at both ends.

8. The measurement method according to claim 7, characterized in that, The step of driving to the reference voltage through the crosstalk cancellation circuit includes: driving the reference voltage in the crosstalk cancellation circuit to the reference voltage. V ref After being selected by a multiplex analog switch, it is connected to the unselected column electrode that needs crosstalk cancellation.

9. The measurement method according to claim 1, characterized in that, Specifically, S5 includes: calculating the voltage value of the target sensing unit according to equation (1). V c : Equation (1).

10. The measurement method according to claim 2, 3, 4 or 5, characterized in that, The reference voltage is the sampling resistor R. s The analog-to-digital converters at both ends sample the voltage.

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