Data acquisition circuit, data acquisition method and data acquisition system

Abstract

The invention discloses a data acquisition circuit, a data acquisition method and a data acquisition system. The data acquisition circuit is used for acquiring electric signals in the piezoresistive sensor, the piezoresistive sensor comprises piezoresistive units arranged in a matrix mode, and the data acquisition circuit comprises a power supply module used for providing power; the reference voltage module is connected with the power supply module and forms reference voltage based on electric power; one end of the switch module is connected with the reference voltage module, the other end of the switch module is connected with the input end of the piezoresistive sensor, and piezoresistive units in the same row or column are selected from the piezoresistive sensor to form an acquisition path; and the crosstalk suppression module is connected with the output end of the piezoresistive sensor, and the crosstalk suppression module is connected with the reference voltage module and receives the reference voltage, so that the reference voltage is loaded at the two ends of the non-acquisition path, and isopotential is formed to suppress electric signals generated in the non-acquisition path. According to the technical scheme, crosstalk generated by the non-gated piezoresistive units can be effectively reduced, and the accuracy of a detection result is improved.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a data acquisition circuit, a data acquisition method and a data acquisition system. Background Art

[0002] In recent years, with the rapid development of intelligent robots, wearable devices and human-computer interaction technology, tactile sensors have become particularly important as key components for achieving natural perception and interaction. Among them, piezoresistive array sensors based on specific flexible materials (such as conductive polymers, carbon nanotubes, graphene, etc.) have attracted great attention from many scholars and experts at home and abroad due to their unique performance. This type of sensor can detect pressure or deformation through the change in resistivity of the material when it is subjected to force, and output an electrical signal proportional to the force applied. It is widely used in many fields such as robot tactile perception, health monitoring, industrial automation, etc.

[0003] Although the traditional row and column scanning method has been widely used in practical applications due to its simplified circuit design, this method has obvious limitations: when reading the pressure information at a certain position, the unselected piezoresistive unit will cause crosstalk to the working unit, which seriously affects the measurement accuracy and reduces the accuracy of the detection results. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a data acquisition circuit which can effectively reduce the crosstalk generated by the unselected piezoresistive units and improve the accuracy of the detection results.

[0005] The present application provides a data acquisition circuit, which is used to collect electrical signals from a piezoresistive sensor, wherein the piezoresistive sensor includes piezoresistive units arranged in a matrix, and the data acquisition circuit includes:

[0006] A power module, the power module is used to provide power;

[0007] a reference voltage module, the reference voltage module being connected to the power module, and the reference voltage module forming a reference voltage based on the power of the power module;

[0008] A switch module, one end of which is connected to the reference voltage module, and the other end of which is used to connect to the input end of the piezoresistive sensor, and to select piezoresistive units in the same row or column in the piezoresistive sensor to form a collection path;

[0009] A crosstalk suppression module, wherein the crosstalk suppression module is connected to the output end of the piezoresistive sensor, the crosstalk suppression module is connected to the reference voltage module, and receives the reference voltage to load the reference voltage at both ends of the non-collection path to form an equipotential to suppress the generation of electrical signals in the non-collection path.

[0010] In one aspect, the reference voltage module includes: a first voltage-dividing resistor, a second voltage-dividing resistor, a first operational amplifier, a first transistor, and a second transistor;

[0011] The first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, one end of the first voltage-dividing resistor facing away from the second voltage-dividing resistor is connected to the power supply module, the non-inverting input end of the first operational amplifier is connected to the line between the first voltage-dividing resistor and the second voltage-dividing resistor, the collector of the first transistor is connected to the power supply module, the emitter of the first transistor is connected to the collector of the second transistor, the emitter of the second transistor is grounded, the base of the first transistor and the base of the second transistor are both connected to the output end of the first operational amplifier, the emitter of the first transistor and the collector of the second transistor are connected to the output line, and the inverting input end of the first operational amplifier is connected to the output line.

[0012] In one aspect, the first transistor is an NPN transistor, and the second transistor is a PNP transistor.

[0013] In one aspect, the switch module includes a plurality of switch channels connected in parallel, the switch channels are used to control the on and off of the piezoresistive units in the same row or column, the switch channels include a single-pole double-throw switch, a first input end of the single-pole double-throw switch is connected to the reference voltage module, and a second input end of the single-pole double-throw switch is grounded;

[0014] The switch channel further includes a voltage follower, wherein a non-inverting input end of the voltage follower is connected to an output end of the single-pole double-throw switch, and an output end of the voltage follower is connected to the piezoresistive unit in the same row or column.

[0015] In one aspect, the crosstalk suppression module includes a plurality of suppression channels, one suppression channel corresponds to one switch channel to connect piezoresistive units in the same row or column, the suppression channel includes a second operational amplifier and a digital potentiometer, the non-inverting input terminal of the second operational amplifier is connected to the reference voltage module, the inverting input terminal of the second operational amplifier is connected to the piezoresistive unit, one end of the digital potentiometer is connected to the inverting input terminal of the second operational amplifier, and the other end of the digital potentiometer is connected to the output terminal of the second operational amplifier.

[0016] In one aspect, the digital potentiometer includes an adjustable resistor, one end of the adjustable resistor is connected to the inverting input end of the second operational amplifier, and a resistance adjustment end of the adjustable resistor is connected to the output end of the second operational amplifier.

[0017] In one aspect, the data acquisition circuit includes a controller, the controller includes a control port, the control port is connected to the switch module and the crosstalk suppression module respectively, and provides control signals to the switch module and the crosstalk suppression module respectively to control the startup of the switch module and the crosstalk suppression module;

[0018] The controller further comprises an analog-to-digital conversion port, which is connected to the output end of the crosstalk suppression module to receive collected data and perform analog-to-digital conversion on the collected data.

[0019] In one aspect, the data acquisition circuit further includes a data communicator, the data communicator is integrated with the controller, and the data communicator is used to transmit the collected data externally;

[0020] The data communicator is also connected to the power module, the data communication module provides power to the power module, and the power module is used to convert the power into power adapted to the reference voltage module, the switch module and the crosstalk suppression module.

[0021] In order to solve the above problem, the present application also provides a data acquisition method, which is applied to the data acquisition circuit as described above, and the data acquisition method includes:

[0022] Controlling the power supply module to provide power to the reference voltage module, and causing the reference voltage module to form a reference voltage based on the power;

[0023] Control the switch module to select piezoresistive units in the same row or column in the piezoresistive sensor to form a collection path;

[0024] A reference voltage is provided to the crosstalk suppression module so that the reference voltage is loaded on both ends of the non-collection path to form an equal potential to suppress the generation of electrical signals in the non-collection path.

[0025] In order to solve the above problems, the present application also provides a data acquisition system, which includes an analysis terminal and a data acquisition circuit as described above, wherein the data acquisition circuit transmits the acquired data to the analysis terminal, and the analysis terminal analyzes the acquired data.

[0026] The beneficial effects of the present invention are embodied in that the reference voltage provided by the reference voltage module is loaded to the input end of the piezoresistive sensor through the switch module. At the same time, the reference voltage can also be loaded to the output end of the piezoresistive sensor through the crosstalk suppression module. When performing data acquisition, the piezoresistive units in the same row or column are selected by the switch module to form an acquisition path, and data is collected on the acquisition path, while the piezoresistive units in other rows or columns that are not selected form a non-acquisition path, and the reference voltage is loaded at both ends of the non-acquisition path. The potentials at both ends of the non-acquisition path are equal to form an equipotential. Due to the equal potential, no current will flow in the non-acquisition path, which will reduce the generation of electrical signals. Thereby, the crosstalk generated by the unselected piezoresistive units can be effectively reduced, and the accuracy of the detection results can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0028] Figure 1 It is a schematic diagram of the overall structure of the data acquisition circuit in this application;

[0029] Figure 2 This is a circuit diagram of the reference voltage module in this application;

[0030] Figure 3 This is a circuit diagram of the switch module and the crosstalk suppression module in this application;

[0031] Figure 4 This is a schematic diagram of the process steps of the data collection method in this application;

[0032] Figure 5 Schematic diagram of the cyclic collection process steps of the data collection method in this application.

[0033] In the accompanying drawings, 100, power module; 200, reference voltage module; 300, switch module; 400, crosstalk suppression module; 500, controller; 600, data communicator; 700, piezoresistive array; 800, analysis terminal;

[0034] VCC, power supply voltage; R1, first voltage-dividing resistor; R2, second voltage-dividing resistor; U1, first operational amplifier; U2, second operational amplifier; T1, first transistor; T2, second transistor; 210, output line; 311, single-pole double-throw switch; 312, voltage follower; 410, digital potentiometer; 510, control port; 520, analog-to-digital conversion port; R3, piezoresistive unit; R4, adjustable resistor; Ro, on-resistance. DETAILED DESCRIPTION

[0035] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0036] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0037] like Figure 1 As shown, the data acquisition circuit is used to collect electrical signals in the piezoresistive sensor, and the piezoresistive sensor includes piezoresistive units R3 arranged in a matrix to form a piezoresistive array 700. Since the piezoresistive units R3 are distributed in a matrix, there can be multiple piezoresistive units R3 in the same row or the same column. A piezoresistive unit R3 is an independent detection unit, which can independently feedback the pressure changes. The data acquisition circuit includes: a power supply module 100, a reference voltage module 200, a switch module 300 and a crosstalk suppression module 400. The data acquisition circuit of the present application can be used to collect data to determine whether the piezoresistive sensor can operate normally, and can also be used to scan and detect the pressure applied to the piezoresistive unit R3.

[0038] The power module 100 is used to provide power. By configuring the power module 100 , the data acquisition circuit can operate normally and data acquisition can be completed smoothly.

[0039] The reference voltage module 200 is connected to the power module 100 , and forms a reference voltage based on the power of the power module 100 ; the reference voltage is a standard voltage, and a stable standard can be formed through the setting of the reference voltage module 200 to reduce fluctuations in the standard.

[0040] One end of the switch module 300 is connected to the reference voltage module 200, and the other end of the switch module 300 is used to connect to the input end of the piezoresistive sensor, and selects the piezoresistive unit R3 in the same row or column in the piezoresistive sensor to form an acquisition path; in the present application, the acquisition scanning process can be carried out in a row-by-row scanning manner or a column-by-column scanning manner. In the row-by-row scanning manner, the switch module 300 can control the on and off of the piezoresistive unit R3 of each row respectively, and in the column-by-column scanning manner, the switch module 300 can control the on and off of the piezoresistive unit R3 of each column respectively.

[0041] The crosstalk suppression module 400 is connected to the output end of the piezoresistive sensor. The crosstalk suppression module 400 is connected to the reference voltage module 200 and receives a reference voltage to load the reference voltage at both ends of the non-collection path. Since the voltages at both ends are equal, no potential difference is generated, thereby forming an equipotential, and the equipotential is used to suppress the generation of electrical signals in the non-collection path.

[0042] In this embodiment, the reference voltage provided by the reference voltage module 200 is loaded to the input end of the piezoresistive sensor through the switch module 300. At the same time, the reference voltage can also be loaded to the output end of the piezoresistive sensor through the crosstalk suppression module 400. When performing data acquisition, the piezoresistive unit R3 in the same row or column is selected by the switch module 300 to form an acquisition path, and data is collected on the acquisition path, while the piezoresistive units R3 in other rows or columns that are not selected form a non-acquisition path, and the reference voltage is loaded at both ends of the non-acquisition path. The potentials at both ends of the non-acquisition path are equal, forming an equipotential. Due to the equal potential, no current will flow in the non-acquisition path, which will reduce the generation of electrical signals. Thereby, the crosstalk generated by the unselected piezoresistive unit R3 can be effectively reduced, and the accuracy of the detection results can be improved.

[0043] In addition, the technical solution of the present application can effectively improve the communication rate by reducing signal crosstalk. For some high-density piezoresistive arrays, it can also effectively improve the efficiency of data acquisition, save detection time, make the detection process faster, and make the detection response faster.

[0044] In one embodiment, the reference voltage module 200 can form a reference voltage whose magnitude remains basically unchanged. In order to maintain the stability of the reference voltage, the reference voltage module 200 in the present application includes: a first voltage-dividing resistor R1, a second voltage-dividing resistor R2, a first operational amplifier U1, a first transistor T1 and a second transistor T2; generally, the first voltage-dividing resistor R1 is larger than the second voltage-dividing resistor R2.

[0045] The first voltage-dividing resistor R1 and the second voltage-dividing resistor R2 are connected in series, and the end of the first voltage-dividing resistor R1 facing away from the second voltage-dividing resistor R2 is connected to the power module 100. The non-inverting input end of the first operational amplifier U1 is connected to the line between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. The collector of the first transistor T1 is connected to the power module 100. The emitter of the first transistor T1 is connected to the collector of the second transistor T2. The emitter of the second transistor T2 is grounded. The base of the first transistor T1 and the base of the second transistor T2 are both connected to the output end of the first operational amplifier U1. The emitter of the first transistor T1 and the collector of the second transistor T2 are connected to the output line 210. The inverting input end of the first operational amplifier U1 is connected to the output line 210.

[0046] After the power provided by the power module 100 passes through the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, the voltage is respectively divided by the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, thereby forming a required input voltage between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. For example, the power provided by the power module 100 is 5V, and after passing through the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, an input voltage of 3.3V is formed.

[0047] When the voltage provided by the output line 210 is lower than the reference voltage, the output voltage is fed back to the inverting input terminal of the first operational amplifier U1. At this time, the input voltage is greater than the output voltage, that is, the voltage at the non-inverting input terminal is greater than the voltage at the inverting input terminal. The output terminal of the operational amplifier is 3.3V, the first transistor T1 is turned on, and the second transistor T2 is turned off. The first transistor T1 obtains power from the power module 100, thereby raising the voltage of the output line 210.

[0048] When the voltage provided by the output circuit 210 is higher than the reference voltage, the output voltage is fed back to the inverting input terminal of the first operational amplifier U1. At this time, the input voltage is less than the output voltage, that is, the voltage at the non-inverting input terminal is less than the voltage at the inverting input terminal. The output terminal of the operational amplifier is 0V, and the first transistor T1 is turned off, and the second transistor T2 is turned on. The output circuit 210 discharges power to the ground terminal through the second transistor T2, thereby lowering the voltage of the output circuit 210.

[0049] It can be seen from this that when the voltage of the output line 210 of the reference voltage module 200 fluctuates, the first transistor T1 or the second transistor T2 can be controlled to conduct to calibrate and keep the reference voltage basically unchanged.

[0050] In one embodiment, in order to ensure that the first transistor T1 and the second transistor T2 can respond to different signals, the first transistor T1 can be an NPN transistor and the second transistor T2 can be a PNP transistor. The first transistor T1 and the second transistor T2 are of different types. When the output end of the first operational amplifier U1 is 3.3V, the base of the NPN transistor receives 3.3V, that is, the base of the NPN transistor receives a high level, the collector and emitter of the NPN transistor are turned on, and the collector and emitter of the PNP transistor are turned off.

[0051] When the output end of the first operational amplifier U1 is 0V, the base of the NPN transistor receives 0V, that is, the base of the NPN transistor receives a low level, the collector and emitter of the NPN transistor are cut off, and the collector and emitter of the PNP transistor are turned on.

[0052] In one embodiment, the switch module 300 includes a plurality of switch channels connected in parallel, and the switch channels are used to control the on and off of the piezoresistive units R3 in the same row or column, and the switch channels include a single-pole double-throw switch 311, and the single-pole double-throw switch 311 has two input terminals and one output terminal. By controlling the conduction between the input terminal and the output terminal of the single-pole double-throw switch 311, electrical signals of different magnitudes can be provided to the piezoresistive unit R3. The first input terminal of the single-pole double-throw switch 311 is connected to the reference voltage module 200, and the second input terminal of the single-pole double-throw switch 311 is grounded; in the single-pole double-throw switch 311, when the first input terminal is connected to the output terminal, the reference voltage is provided to the piezoresistive unit R3; when the second input terminal is connected to the output terminal, the ground voltage, i.e., 0V voltage, is provided to the piezoresistive unit R3.

[0053] For example, when data collection is required for the piezoresistive unit R3 in a row or column, the second input terminal and the output terminal of the single-pole double-throw switch 311 corresponding to the row or column are connected, and the input terminal of the piezoresistive unit R3 in the row or column is 0V voltage, while the output terminal of the piezoresistive unit R3 in the same row or column is a reference voltage of 3.3V. The voltages at the two ends are not equal, and current flows in the piezoresistive unit R3, so it can be scanned and detected.

[0054] When the first input and output ends of the corresponding single-pole double-throw switches 311 in other rows or columns are connected, the input and output ends of the remaining piezoresistive units R3 are both reference voltages, and the voltages at both ends are equal. No current flows in the remaining piezoresistive units R3, and no electrical signals are generated, thereby reducing interference to the detection circuit.

[0055] The switch channel also includes a voltage follower 312, the in-phase input end of the voltage follower 312 is connected to the output end of the single-pole double-throw switch 311, and the output end of the voltage follower 312 is connected to the piezoresistive unit R3 in the same row or column. Since the single-pole double-throw switch 311 has a certain on-resistance Ro, its existence will cause the measured value to be too small. By adding the voltage follower 312, due to its "virtual short" characteristic, the input impedance is approximately infinite, thereby reducing the influence of the on-resistance Ro of the single-pole double-throw switch 311 on the measurement, and at the same time improving the load capacity. The voltage follower 312 is also an operational amplifier. Since the operational amplifier has a certain drift voltage that will also affect the measurement, a precision operational amplifier with a low drift voltage is generally selected to reduce errors.

[0056] In one embodiment, the crosstalk suppression module 400 includes a plurality of suppression channels, one suppression channel corresponds to a switch channel to connect the piezoresistive unit R3 in the same row or column, the suppression channel includes a second operational amplifier U2 and a digital potentiometer 410, the non-inverting input terminal of the second operational amplifier U2 is connected to the reference voltage module 200, the inverting input terminal of the second operational amplifier U2 is connected to the piezoresistive unit R3, one end of the digital potentiometer 410 is connected to the inverting input terminal of the second operational amplifier U2, and the other end of the digital potentiometer 410 is connected to the output terminal of the second operational amplifier U2.

[0057] It can be seen that the switch module 300 is located at the input end of the piezoresistive sensor, and the crosstalk suppression module 400 is located at the output end of the piezoresistive sensor. And for example, for each row of the piezoresistive unit R3, a single-pole double-throw switch 311 is provided at the input end, and a second operational amplifier U2 is provided at the output end, so that row-by-row scanning data acquisition is performed. In another structure, for each column of the piezoresistive unit R3, a single-pole double-throw switch 311 is provided at the input end, and a second operational amplifier U2 is provided at the output end, so that column-by-column scanning data acquisition is performed.

[0058] In addition, the crosstalk suppression module 400 may be a programmable gain amplifier.

[0059] In one embodiment, the digital potentiometer 410 includes an adjustable resistor R4, one end of which is connected to the inverting input end of the second operational amplifier U2, and the resistance adjustment end of the adjustable resistor R4 is connected to the output end of the second operational amplifier U2. The adjustable resistor R4 can adjust the amplification factor as needed.

[0060] Specifically, the resistance of the piezoresistive unit R3 is defined as R ij , the resistance of the adjustable resistor R4 is R f , then the adjustable multiple of the second operational amplifier U2 is 1+R f / R ij The resistance value of the adjustable resistor R4 is generally between 1-10KΩ, and the adjustable range of the adjustable resistor R4 is relatively large, which can make the adjustment of the amplification factor more flexible.

[0061] In one embodiment, the data acquisition circuit includes a controller 500, which can be a single chip microcomputer or other controller 500 components, such as a programmable control chip or a microprocessor. The controller 500 includes a control port 510, which is connected to the switch module 300 and the crosstalk suppression module 400 respectively. The controller 500 provides control signals to the switch module 300 and the crosstalk suppression module 400 respectively through the control port 510 to control the start-up of the switch module 300 and the crosstalk suppression module 400; the controller 500 controls the switch module 300 and the crosstalk suppression module 400 relatively independently.

[0062] For example, a plurality of switch channels are provided in the switch module 300, and the control of the single-pole double-throw switch 311 in each switch channel is also separate. For the piezoresistive unit R3 that needs to detect and collect data, the control port 510 sends a control signal to the corresponding single-pole double-throw switch 311, and the second input terminal and the output terminal of the single-pole double-throw switch 311 are turned on. For the piezoresistive unit R3 that does not need to collect data, the control port 510 controls the first input terminal and the output terminal of the single-pole double-throw switch 311 to be turned on.

[0063] The controller 500 also includes an analog-to-digital conversion port 520, which is connected to the output end of the crosstalk suppression module 400 to receive the collected data and perform analog-to-digital conversion on the collected data. After the analog-to-digital conversion port 520 receives the collected data, the controller 500 can perform analog-to-digital conversion on the collected data to ensure that the collected data can be recognized by analysis tools such as computers.

[0064] The controller 500 can also send a control signal to the digital potentiometer 410 through the control port 510, so as to control the adjustable resistor R4 to adjust the resistance value and set it to the required amplification factor.

[0065] In one embodiment, the data acquisition circuit also includes a data communicator 600, which is integrated with the controller 500 and is used to transmit the collected data to the outside; the data communicator 600 can be a USB data transmission interface, through which the collected data can be quickly transferred to a computer, etc.

[0066] The data communicator 600 is also connected to the power module 100, and the data communication module provides power to the power module 100, and the power module 100 is used to convert the power into power to adapt the reference voltage module 200, the switch module 300 and the crosstalk suppression module 400. For example, the USB data transmission interface provides a 5V power supply, and the 5V power supply is converted into a 3.3V voltage by the power module 100. The 3.3V voltage can smoothly start the reference voltage module 200, the switch module 300 and the crosstalk suppression module 400. In addition, the data communicator 600 also has the function of transmitting power. For example, when collecting data, the power module 100 is provided with power by the data communicator 600, and when analyzing data, the data is transmitted to the outside world by the data communicator 600.

[0067] By integrating the data communicator 600 with the controller 500, the communication circuit structure is simplified and the communication rate can reach 12Mbps. The data communicator 600 can also add a wireless communication module to improve the portability of the device, such as a Bluetooth module, a WI-FI module, a Zigbee module, a LoRa module, a NB-IoT module, and other wireless communication modules. The high-speed communication protocol can be Ethernet or RS485.

[0068] In order to further illustrate the principle of the scheme of this application, the following examples are given. Figure 1 As shown, the piezoresistive units R3 are distributed in a matrix of 2 rows and 3 columns, the input ends of the piezoresistive units R3 in the same column are connected to the output ends of the voltage follower 312, and the output ends of the piezoresistive units R3 are connected to the inverting input end of the third operational amplifier.

[0069] For example, if data collection is required for the piezoresistive unit R3 in the first column on the left, the controller 500 provides a control signal to the single-pole double-throw switch 311 of the first column piezoresistive unit R3 through the control port 510, and the second input terminal and the output terminal of the single-pole double-throw switch 311 are closed and turned on, and the input terminal voltage of the first column piezoresistive unit R3 is 0V. The in-phase input terminal of the second operational amplifier U2 is the reference voltage. According to the ideal "virtual short" characteristic, the potentials of the in-phase terminal and the inverting terminal of the second operational amplifier U2 are both the reference voltage. As a result, the input terminal and the output terminal potential of the first column piezoresistive unit R3 are not equal, and current flows, so the detection of the first column piezoresistive unit R3 can be completed.

[0070] At the same time, the controller 500 provides a control signal to the single-pole double-throw switch 311 corresponding to the second column piezoresistive unit R3 and the third column piezoresistive unit R3 through the control port 510, and controls the first input terminal and the output terminal of the corresponding single-pole double-throw switch 311 to be turned on, so that the input terminal potential of the second column piezoresistive unit R3 and the third column piezoresistive unit R3 is the reference voltage. The in-phase input terminal of the second operational amplifier U2 is the reference voltage. According to the ideal "virtual short" characteristic, the potentials of the in-phase terminal and the inverting terminal of the second operational amplifier U2 are both the reference voltage. Then the potential of the output terminal of the second column piezoresistive unit R3 and the third column piezoresistive unit R3 is also the reference voltage, the potentials at both ends are equal, there is no current flowing, and no crosstalk is generated to the detection of the first column piezoresistive unit R3.

[0071] The above description is about scanning in columns, but scanning may also be performed in rows.

[0072] See also Figure 4 As shown, the present application also provides a data acquisition method, which is applied to the data acquisition circuit as described above, and the data acquisition method includes:

[0073] Step S10, control the power supply module to provide power to the reference voltage module, and make the reference voltage module form a reference voltage based on the power; the power supply module 100 is used to provide power to ensure the normal operation of the data acquisition circuit and successfully complete data acquisition. By setting the reference voltage, a stable standard can be formed to reduce the fluctuation of the standard.

[0074] Step S20, controlling the switch module to select piezoresistive units in the same row or column in the piezoresistive sensor to form a collection path; the switch module can control the piezoresistive units in one row or column to be turned on, so as to facilitate data collection.

[0075] Step S30, providing a reference voltage to the crosstalk suppression module, so as to load the reference voltage on both ends of the non-collection path, forming an equal potential to suppress the generation of electrical signals in the non-collection path. Since the voltages at both ends are equal, no potential difference is generated, thereby forming an equal potential, and suppressing the generation of electrical signals in the non-collection path through the equal potential.

[0076] In this embodiment, the reference voltage is loaded to the input end of the piezoresistive sensor through the switch module 300. At the same time, the reference voltage can also be loaded to the output end of the piezoresistive sensor through the crosstalk suppression module 400. When performing data acquisition, the piezoresistive unit R3 in the same row or column is selected by the switch module 300 to form an acquisition path, and data is collected on the acquisition path, while the piezoresistive units R3 in other rows or columns that are not selected form a non-acquisition path, and the reference voltage is loaded at both ends of the non-acquisition path. The potentials at both ends of the non-acquisition path are equal, forming an equipotential. Due to the equal potential, no current will flow in the non-acquisition path, which will reduce the generation of electrical signals. Thereby, the crosstalk generated by the unselected piezoresistive unit R3 can be effectively reduced, and the accuracy of the detection results can be improved.

[0077] See also Figure 5 As shown, before step S10, step S01 is included to start scanning the piezoresistive array, which can be row-by-row scanning or column-by-column scanning.

[0078] Step S02, configure the clock and initialization settings; set the start time period and complete the initialization of some data.

[0079] Step S03, setting the gain parameter, adjusting the size of the adjustable resistor, and adjusting the amplification factor. That is, the technical solution of the present application can detect piezoresistive sensors of different specifications, and can adapt to piezoresistive sensors of different specifications by adjusting the amplification factor.

[0080] Step S04, initializing a counter, for example, starting from row 1, or starting from column 1. After the entire piezoresistive array is scanned, the next round of scanning can be repeated, and the repeated scanning still starts from the first row or the first column.

[0081] After step S30, the scanning of the first row or the first column is completed, and the determination step S40 is performed to determine whether the row counter is less than the set number. By determining whether it is less than the set number, it is detected whether the entire scanning process is completed.

[0082] Step S50: If the counter is less than the set number, it means that the scanning process is not completed. The data communicator sends the conversion data and the counter is incremented by 1.

[0083] If the counter is greater than or equal to the set number, step S04 is repeated to repeat the scanning detection process.

[0084] The present application also provides a data acquisition system, which includes an analysis terminal 800 and a data acquisition circuit as described above, wherein the data acquisition circuit transmits the collected data to the analysis terminal 800, and the analysis terminal 800 analyzes the collected data. The analysis terminal 800 can be a desktop computer, a tablet computer, or a smart phone.

[0085] The specific embodiments and beneficial effects of the data acquisition system in the present application can be found in the above-mentioned data acquisition circuit, which will not be described in detail here.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A data acquisition circuit, characterized in that: The data acquisition circuit is used to collect electrical signals from the piezoresistive sensor, the piezoresistive sensor includes piezoresistive units arranged in a matrix, and the data acquisition circuit includes: A power module, the power module is used to provide power; a reference voltage module, the reference voltage module being connected to the power module, and the reference voltage module forming a reference voltage based on the power of the power module; A switch module, one end of which is connected to the reference voltage module, and the other end of which is used to connect to the input end of the piezoresistive sensor, and to select piezoresistive units in the same row or column in the piezoresistive sensor to form a collection path; A crosstalk suppression module, wherein the crosstalk suppression module is connected to the output end of the piezoresistive sensor, the crosstalk suppression module is connected to the reference voltage module, and receives the reference voltage to load the reference voltage at both ends of the non-collection path to form an equipotential to suppress the generation of electrical signals in the non-collection path.

2. The data acquisition circuit according to claim 1, characterized in that: The reference voltage module includes: a first voltage-dividing resistor, a second voltage-dividing resistor, a first operational amplifier, a first transistor and a second transistor; The first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, one end of the first voltage-dividing resistor facing away from the second voltage-dividing resistor is connected to the power supply module, the non-inverting input end of the first operational amplifier is connected to the line between the first voltage-dividing resistor and the second voltage-dividing resistor, the collector of the first transistor is connected to the power supply module, the emitter of the first transistor is connected to the collector of the second transistor, the emitter of the second transistor is grounded, the base of the first transistor and the base of the second transistor are both connected to the output end of the first operational amplifier, the emitter of the first transistor and the collector of the second transistor are connected to the output line, and the inverting input end of the first operational amplifier is connected to the output line.

3. The data acquisition circuit according to claim 2, characterized in that: The first transistor is an NPN transistor, and the second transistor is a PNP transistor.

4. The data acquisition circuit according to claim 1, characterized in that: The switch module includes a plurality of switch channels connected in parallel, the switch channels are used to control the on and off of the piezoresistive units in the same row or column, the switch channels include a single-pole double-throw switch, a first input end of the single-pole double-throw switch is connected to the reference voltage module, and a second input end of the single-pole double-throw switch is grounded; The switch channel further includes a voltage follower, wherein a non-inverting input end of the voltage follower is connected to an output end of the single-pole double-throw switch, and an output end of the voltage follower is connected to the piezoresistive unit in the same row or column.

5. The data acquisition circuit according to claim 4, characterized in that: The crosstalk suppression module includes a plurality of suppression channels, one suppression channel corresponds to one switch channel to connect piezoresistive units in the same row or column, the suppression channel includes a second operational amplifier and a digital potentiometer, the non-inverting input terminal of the second operational amplifier is connected to the reference voltage module, the inverting input terminal of the second operational amplifier is connected to the piezoresistive unit, one end of the digital potentiometer is connected to the inverting input terminal of the second operational amplifier, and the other end of the digital potentiometer is connected to the output terminal of the second operational amplifier.

6. The data acquisition circuit according to claim 5, characterized in that: The digital potentiometer comprises an adjustable resistor, one end of the adjustable resistor is connected to the inverting input end of the second operational amplifier, and a resistance adjustment end of the adjustable resistor is connected to the output end of the second operational amplifier.

7. The data acquisition circuit according to any one of claims 1 to 6, characterized in that: The data acquisition circuit includes a controller, the controller includes a control port, the control port is connected to the switch module and the crosstalk suppression module respectively, and provides control signals to the switch module and the crosstalk suppression module respectively to control the start-up of the switch module and the crosstalk suppression module; The controller further comprises an analog-to-digital conversion port, which is connected to the output end of the crosstalk suppression module to receive collected data and perform analog-to-digital conversion on the collected data.

8. The data acquisition circuit according to claim 7, characterized in that: The data acquisition circuit further comprises a data communicator, which is integrated with the controller and used for transmitting the collected data externally; The data communicator is also connected to the power module, the data communication module provides power to the power module, and the power module is used to convert the power into power adapted to the reference voltage module, the switch module and the crosstalk suppression module.

9. A data collection method, characterized in that: The data acquisition method is applied to the data acquisition circuit according to any one of claims 1 to 8, and the data acquisition method comprises: Controlling the power supply module to provide power to the reference voltage module, and causing the reference voltage module to form a reference voltage based on the power; Control the switch module to select piezoresistive units in the same row or column in the piezoresistive sensor to form a collection path; A reference voltage is provided to the crosstalk suppression module so that the reference voltage is loaded on both ends of the non-collection path to form an equal potential to suppress the generation of electrical signals in the non-collection path.

10. A data acquisition system, comprising an analysis terminal and a data acquisition circuit according to any one of claims 1 to 8, wherein the data acquisition circuit transmits acquisition data to the analysis terminal, and the analysis terminal analyzes the acquisition data.

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