Multi-sensor signal acquisition device and method for battery system

Abstract

The invention provides a multi-sensor signal acquisition device and method for a battery system. The device comprises a microcontroller, an analog front-end chip, a multiplexer, a multi-channel signal acquisition module and a plurality of sensors, the multi-path signal acquisition module is used for acquiring output signals of a plurality of sensors based on partial voltage acquisition, constant voltage driving, threshold comparison, current sampling, filtering and amplification; output signals of the plurality of sensors are selectively sent to the analog front-end chip through the multiplexer, the analog front-end chip processes the output signals of the sensors and then sends the output signals to the microcontroller, and the microcontroller controls the multiplexer to switch and select the output signals of the plurality of sensors; according to the device, acquisition circuits of various sensor signals monitored by a related battery system can be integrated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery management, and particularly relates to a multi-sensor signal acquisition device and method for a battery system. BACKGROUND

[0002] In current battery systems (such as lithium battery packs and energy storage systems), more and more key parameters such as battery voltage, battery temperature, pressure, gas concentration, and firelight signal need to be monitored in real time to improve system safety and operating performance. However, the multiple monitoring data in the current battery system are collected by using dispersed sensors, which leads to high power consumption, complex wiring, low system integration, and cannot meet the needs of battery-powered, low-power, and volume-limited application scenarios.

[0003] In addition, the voltage division method is generally used in the pressure sensor resistance measurement scheme in the existing battery system, which has obvious defects: since the resistance of the pressure sensor is affected by the double variables of the applied voltage and the pressure, and the system power supply has power supply noise, the transmission line has parasitic capacitance, parasitic inductance and other problems, which leads to poor stability and insufficient accuracy of the measurement results, especially in the case of sensor long-distance wiring or complex working conditions. Some studies use operational amplifiers to form an inverting amplifier circuit to collect the resistance change of the pressure sensor. Although this scheme improves the sensitivity to a certain extent, it is still susceptible to high-frequency noise interference in practical application, and the dynamic response performance is limited, and the stability and measurement range adaptability are insufficient. Patent CN102901549A discloses a driving, signal conditioning and acquisition device for a strain resistance pressure sensor, which comprises a high-precision constant voltage source, a preamplifier, an analog-to-digital conversion module, a microcontroller and a wireless communication module; wherein the high-precision constant voltage source is used to drive the strain resistance sensor, and a 10V constant voltage source is formed by a reference voltage source chip REF102, a PNP transistor switch 2N2905 and a current limiting resistor R1; wherein the No. 2 pin of the reference voltage source chip REF102 is connected with the base of the PNP transistor switch 2N2905, and also connected with the positive terminal of the 12V DC power supply through the current limiting resistor R1; the No. 4 pin of the reference voltage source chip REF102 is grounded; the emitter of the PNP transistor switch 2N2905 is connected with the positive terminal of the 12V DC power supply, and the collector is connected with the No. 6 pin of the reference voltage source chip REF102 to serve as the output end of the driving circuit together, and is connected with the positive and negative terminals of the power supply of the strain resistance pressure sensor respectively; the preamplifier adopts a signal conditioning method of amplifying the differential signal output by the strain resistance sensor, which is composed of AD620 chip, AD705 chip, feedback resistor RF, resistor R2 and resistor R3. In this scheme, the reference voltage source chip REF102, the PNP transistor switch 2N2905 and the current limiting resistor R1 form a 10V constant voltage source, which can provide stable excitation for the pressure sensor, but cannot realize the integration of multiple sensors and cannot be applied to the acquisition of multiple sensor signals in the battery system. SUMMARY

[0004] The application provides a multi-sensor signal acquisition device and method for a battery system, which can improve the system integration of multi-sensor signal acquisition in the battery system.

[0005] A multi-sensor signal acquisition device for a battery system, comprising a microcontroller, an analog front-end chip, a multiplexer, a multi-channel signal acquisition module and a plurality of sensors; the multi-channel signal acquisition module, the battery system and the plurality of sensors are connected in cooperation, the multiplexer is connected with the multi-channel signal acquisition module, the multiplexer is also connected with the analog front-end chip, and the microcontroller is connected with the analog front-end chip and the multiplexer; The multi-channel signal acquisition module acquires the output signals of the plurality of sensors based on voltage division acquisition, constant voltage driving, threshold comparison, current sampling, filtering and amplification; the output signals of the plurality of sensors are selected and sent to the analog front-end chip through the multiplexer, the analog front-end chip sends the output signals of the sensors to the microcontroller after processing, and the microcontroller controls the multiplexer to switch and select the output signals of the plurality of sensors.

[0006] Further, the microcontroller is connected with the multiplexer through an anti-interference driving circuit, the microcontroller, the analog front-end chip, the anti-interference driving circuit and the multiplexer are powered by an external power supply, and the anti-interference circuit is used to realize stable output of the channel selection signal of the microcontroller.

[0007] Further, the plurality of sensors comprise a temperature sensor, a light sensor, a pressure sensor and a gas sensor, the battery system converts the battery voltage into a working voltage through a DC / DC conversion circuit to supply power for the plurality of sensors and the multi-channel signal acquisition module.

[0008] Further, the multi-channel signal acquisition module comprises a voltage acquisition channel, a temperature acquisition voltage division module, a light detection voltage division threshold comparison module, a pressure detection constant voltage driving module, a pressure detection current sampling module, a gas detection voltage division module, a gas detection filtering module and an amplification module; the multiplexer comprises a first acquisition port, a second acquisition port, a third acquisition port and a fourth acquisition port; The voltage acquisition channel is connected with two poles of the battery system, and is used for acquiring the battery voltage of the battery system and sending to the first acquisition port; the output signal of the temperature sensor is acquired by voltage division through the temperature acquisition voltage division module, and is sent to the fourth acquisition port by multiplexing the voltage acquisition channel; the firelight detection voltage division threshold comparison module and the temperature acquisition module multiplex the fourth acquisition port, and monitor the output signal of the temperature sensor acquired by the fourth acquisition port when no firelight appears in the environment; when the firelight sensor detects firelight, the output signal of the firelight sensor is acquired by voltage division and voltage threshold comparison through the firelight detection voltage division threshold comparison module, and the corresponding channel is turned on to send the output signal of the firelight sensor to the fourth acquisition port; the output signal of the gas sensor is acquired by voltage division through the gas detection voltage division module and is sent to the third acquisition port after being filtered by the gas detection filtering module; the battery voltage is provided with constant excitation for the pressure sensor through dynamic voltage adjustment and current limiting of the pressure detection constant voltage driving module, and the output signal of the pressure sensor is sampled and sent to the amplification module for amplification after being sampled by the pressure detection current sampling module and then sent to the second acquisition port.

[0009] Further, the temperature acquisition voltage division module forms a voltage division detection loop based on a first voltage division resistor module and the battery system, the mapping voltage output by the temperature sensor is acquired by voltage division through the first voltage division resistor module, and a pressure difference is formed with the battery voltage of the battery system, and the pressure difference is used to calculate temperature information.

[0010] Further, the firelight detection voltage division threshold comparison module forms a voltage division network based on a second voltage division resistor module and the firelight sensor, the output signal of the firelight sensor is acquired by the second voltage division resistor module, and voltage threshold comparison is performed through a current limiting resistor and a transistor, and the output signal of the firelight sensor is sent to the fourth acquisition port according to the comparison result by turning on the corresponding channel.

[0011] Further, the gas detection voltage division module forms a potential voltage division network of the gas sensor based on a third voltage division resistor module, the gas detection filtering module is an RC filtering network, and the output signal of the gas sensor is acquired by voltage division through the third voltage division resistor module and then sent to the RC filtering network for filtering, and then sent to the third acquisition port after filtering.

[0012] Further, the pressure detection constant voltage driving module partially multiplexes the third partial pressure resistance module in the gas detection partial pressure module to drive the pressure sensor with constant voltage, and dynamically adjusts the voltage across the pressure sensor through the joint action of the operational amplifier, the current limiting resistor and the field effect transistor; the output signal of the pressure sensor is sampled by the current limiting detection resistor in the pressure detection current sampling module to form a sampling current signal and sent to the amplification module, which amplifies and filters the sampling current signal based on two-stage amplification and active filter network and then sends it to the second collection port.

[0013] Further, the multi-channel signal collection module further comprises a filter module composed of multiple capacitors, which is connected with the first collection port, the second collection port, the third collection port and the fourth collection port of the multiplexer.

[0014] A multi-sensor signal collection method for a battery system applied to the above device, comprising: The multi-channel signal collection module collects the output signals of multiple sensors based on partial pressure collection, constant voltage driving, threshold comparison, current collection, filtering and amplification; The microcontroller generates a channel selection signal and sends it to the multiplexer, which selects the output signal of the corresponding sensor to send to the analog front-end chip according to the channel selection signal, and the analog front-end chip processes the output signal of the sensor and sends it to the microcontroller.

[0015] Further, the multiple sensors include a temperature sensor, a firelight sensor, a pressure sensor and a gas sensor.

[0016] The multi-channel signal collection module collects the output signals of multiple sensors based on partial pressure collection, constant voltage driving, threshold comparison, current collection, filtering and amplification, comprising: The voltage collection channel in the multi-channel signal collection module collects the battery voltage across the battery system and sends it to the first collection port, and the output signal of the temperature sensor is collected by the temperature collection module in the multi-channel signal collection module after partial pressure collection and then sent to the multiplexer; The firelight detection partial pressure threshold comparison module in the multi-channel signal collection module collects the output signal of the firelight sensor and compares the voltage threshold when the firelight sensor detects firelight, and turns on the corresponding channel to send the output signal of the firelight sensor to the multiplexer; The gas detection partial pressure module in the multi-channel signal collection module collects the output signal of the gas sensor after partial pressure collection, and sends it to the multiplexer after filtering by the detection filter module in the multi-channel signal collection module; The battery voltage of the battery system is provided with constant excitation by the dynamic voltage regulation and current limiting of the pressure detection constant voltage driving module in the multi-channel signal acquisition module, and the output signal of the pressure sensor is sampled by the pressure detection current sampling module in the multi-channel signal acquisition module, sent to the amplification module for amplification, and then sent to the multiplexer.

[0017] Further, the multiplexer comprises a first acquisition port, a second acquisition port, a third acquisition port and a fourth acquisition port, and the microcontroller controls the first acquisition port, the second acquisition port, the third acquisition port and the fourth acquisition port to be sequentially turned on in a polling manner. The microcontroller generates a first channel selection signal for gating battery voltage acquisition and sends the first channel selection signal to the multiplexer, the multiplexer selects the first acquisition port according to the first channel selection signal to send the battery voltage of the battery system to the analog front-end chip, and the analog front-end chip processes the battery voltage and then sends the battery voltage to the microcontroller. The microcontroller generates a second channel selection signal for gating temperature acquisition and sends the second channel selection signal to the multiplexer, the multiplexer selects the fourth acquisition port according to the second channel selection signal to send the output signal of the temperature sensor to the analog front-end chip, the analog front-end chip processes the output signal of the temperature sensor and then sends the output signal of the temperature sensor to the microcontroller, and when fire light appears in the environment, the output signal of the fire light sensor is sent to the analog front-end chip through the fourth acquisition port, the analog front-end chip processes the output signal of the fire light sensor and then sends the output signal of the fire light sensor to the microcontroller. The microcontroller generates a third channel selection signal for gating gas acquisition and sends the third channel selection signal to the multiplexer, the multiplexer selects the third acquisition port according to the third channel selection signal to send the output signal of the gas sensor to the analog front-end chip, and the analog front-end chip processes the output signal of the gas sensor and then sends the output signal of the gas sensor to the microcontroller. The microcontroller generates a fourth channel selection signal for gating pressure acquisition and sends the fourth channel selection signal to the multiplexer, the multiplexer selects the second acquisition port according to the fourth channel selection signal to send the output signal of the pressure sensor to the analog front-end chip, and the analog front-end chip processes the output signal of the gas sensor and then sends the output signal of the gas sensor to the microcontroller.

[0018] The multi-sensor signal acquisition device and method for the battery system have at least the following beneficial effects: (1) The acquisition circuits of various sensor signals related to the battery system monitoring are integrated, the channels and modules are multiplexed, the wiring is simplified, the integration degree of the device is improved, the power consumption is reduced, and the application scenarios with low power consumption and limited volume of the battery system monitoring are met. (2) Adopting layered power supply architecture, the microcontroller, analog front-end chip, anti-interference driving circuit and multiplexer are powered by external power supply, and the battery system converts the battery voltage into working voltage through DC / DC conversion circuit, thereby powering multiple sensors and the multi-channel signal acquisition module. The design retains the flexibility of external power supply while enabling the battery to independently power specific modules, thereby reducing redundancy, improving system reliability, and simplifying internal power management structure; (3) The constant voltage driving module ensures that the voltage across the pressure sensor is fixed, so that the working point of the pressure sensor remains stable even if the supply voltage or system load changes, thereby keeping the resistance value corresponding to the same pressure consistent, eliminating the nonlinear measurement error caused by changes in applied voltage, significantly improving the measurement stability and repeatability, ensuring that the pressure sensor works under stable voltage conditions, and eliminating the voltage-dependent error in the traditional voltage division measurement architecture; (4) It has excellent anti-wire parasitic interference ability and is suitable for long-distance wiring environment. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The structure schematic diagram of one embodiment of the multi-sensor signal acquisition device for the battery system provided by the application.

[0020] Figure 2 The structure schematic diagram of one embodiment of the anti-interference driving circuit in the multi-sensor signal acquisition device for the battery system provided by the application.

[0021] Figure 3 The structure schematic diagram of another embodiment of the multi-sensor signal acquisition device for the battery system provided by the application.

[0022] Figure 4 The structure schematic diagram of one embodiment of the multi-channel signal acquisition module in the multi-sensor signal acquisition device for the battery system provided by the application.

[0023] Figure 5 The flowchart of one embodiment of the multi-sensor signal acquisition method for the battery system provided by the application. DETAILED DESCRIPTION

[0024] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the drawings in the specification and specific embodiments.

[0025] REFERENCE Figure 1In some embodiments, a multi-sensor signal acquisition device for a battery system is provided, comprising a microcontroller 1, an analog front-end chip 2, a multiplexer 3, a multi-channel signal acquisition module 4, and a plurality of sensors; the multi-channel signal acquisition module 4, the battery system, and the plurality of sensors are connected in cooperation, the multiplexer 3 is connected with the multi-channel signal acquisition module 4, the multiplexer 3 is also connected with the analog front-end chip 2, and the microcontroller 1 is connected with the analog front-end chip 2 and the multiplexer 3; The multi-channel signal acquisition module 4 acquires the output signals of the plurality of sensors based on voltage division acquisition, constant voltage driving, threshold comparison, current sampling, filtering, and amplification; the output signals of the plurality of sensors are sent to the analog front-end chip 2 through the multiplexer 3, the analog front-end chip 2 sends the output signals of the sensors to the microcontroller 1 after processing, and the microcontroller 1 controls the multiplexer 3 to switch and select the output signals of the plurality of sensors.

[0026] Reference Figure 2 The microcontroller 1 communicates with the analog front-end chip 2 through an I2C interface to realize the acquisition and digitization of analog signals. Meanwhile, the microcontroller 1 controls the enable signal ENB and the channel selection signal ports HC_C1 and HC_C2 of the multiplexer through the enable port GPIO_EN, the gating port GPIO_C1, and the gating port GPIO_C2 pin to realize the dynamic switching acquisition of the output signals of the plurality of sensors.

[0027] Further, in some embodiments, the microcontroller 1 is connected with the multiplexer 3 through an anti-interference driving circuit 5 to realize the stable output of the channel selection signal of the microcontroller, as shown in Figure 2 The anti-interference driving circuit 5 comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a first MOS tube Q1, and a second MOS tube Q2; the source levels of the first MOS tube Q1 and the second MOS tube Q2 are grounded, the two ends of the first resistor R1 are respectively connected with the gating port GPIO_C2 of the microcontroller 1 and the gate of the first MOS tube Q1, the drain of the first MOS tube Q1 is connected with one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected with the channel selection signal port HC_C2 of the multiplexer 3, the two ends of the second resistor R2 are respectively connected with the gating port GPIO_C1 of the microcontroller 1 and the gate of the second MOS tube Q2, the drain of the second MOS tube Q2 is connected with one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected with the channel selection signal port HC_C1 of the multiplexer 3, one end of the third resistor R3 is connected with the pull-up power supply Vcc and the V CCThe other end of the port is connected with the drain of the first MOS transistor Q1; one end of the fifth resistor R5 is connected with the pull-up power supply Vcc and the V CC The other end of the port is connected with the drain of the second MOS transistor Q2.

[0028] The first MOS transistor Q1 and the second MOS transistor Q2 are both N-channel MOS transistors, and are connected to the pull-up power supply Vcc through the third resistor R3 and the fifth resistor R5. The gates of the first MOS transistor Q1 and the second MOS transistor Q2 are respectively driven by control signals, so as to realize effective pull-down control of the output node. When the first MOS transistor Q1 and the second MOS transistor Q2 are turned on, the output node is quickly pulled to a low level, realizing high-speed and effective strobe signal output; when the first MOS transistor Q1 and the second MOS transistor Q2 are turned off, the output node is restored to a high level through the pull-up resistor. The fourth resistor R4, the first capacitor C1, the fifth resistor R5 and the second capacitor C2 constitute a resistance-capacitance coupling network, which is used for inhibiting level jitter caused by line parasitic parameters or driving jump, realizing stable strobe output under high-speed signal switching. The structure significantly enhances the driving capability of the GPIO control signal to the multiplexer channel, improves the system anti-interference performance and level conversion speed, and is suitable for fast and reliable strobe control of complex sensor array and long-distance wiring.

[0029] Further, the microcontroller 1, the analog front-end chip 2, the anti-interference driving circuit 5 and the multiplexer 3 are powered by an external power supply, and the battery system converts the battery voltage into a working voltage through a DC / DC conversion circuit to power the plurality of sensors and the multi-channel signal acquisition module. The design retains the flexibility of external power supply while enabling the battery to independently power specific modules, thereby reducing the redundancy of the system and improving the reliability, and simplifying the internal power management structure.

[0030] Further, referring to Figure 4 , the plurality of sensors include a temperature sensor R T , a firelight sensor R FD , a pressure sensor Rp and a gas sensor Sensor.

[0031] Referring to Figure 3 , the multi-channel signal acquisition module 4 includes a voltage acquisition channel 41, a temperature acquisition voltage division module 42, a firelight detection voltage division threshold comparison module 43, a pressure detection constant voltage driving module 44, a pressure detection current sampling module 45, a gas detection voltage division module 46, a gas detection filtering module 47 and an amplification module 48; the multiplexer includes a first acquisition port S1, a second acquisition port S2, a third acquisition port S3 and a fourth acquisition port S4; The voltage acquisition channel 41 is connected with two poles of the battery system BT, and is used for acquiring the battery voltage V BTand sent to the first acquisition port S1; the output signal of the temperature sensor is acquired by the temperature acquisition voltage division module, and sent to the fourth acquisition port S4 through the multiplexing voltage acquisition channel 41; the voltage acquisition channel 41 is connected with the first acquisition port S1 and the fourth acquisition port S4, the firelight detection voltage division threshold comparison module 43 is multiplexed with the fourth acquisition port S4 of the temperature acquisition module 42, and the output signal of the temperature sensor is acquired by the fourth acquisition port S4 when there is no firelight in the environment; when the firelight sensor RFD detects the firelight, the output signal of the firelight sensor RFD is sent to the fourth acquisition port S4 through the firelight detection voltage division threshold comparison module 43 for voltage division acquisition and voltage threshold comparison; the output signal of the gas sensor Sensor is acquired by the gas detection voltage division module 46 and sent to the third acquisition port S3 after being filtered by the gas detection filtering module 47; the battery voltage is dynamically voltage-regulated and current-limited by the pressure detection constant voltage driving module 44 to provide constant excitation for the pressure sensor RP, and the output signal of the pressure sensor RP is sampled by the pressure detection current sampling module 45 and sent to the second acquisition port S2 after being amplified by the amplification module 48.

[0032] Further, the temperature acquisition voltage division module 42 forms a voltage division detection loop based on a first voltage division resistor module and a battery system, and the mapping voltage output by the temperature sensor RT is acquired by the first voltage division resistor module, and a pressure difference is formed with the battery voltage of the battery system, and the pressure difference is used to calculate temperature information.

[0033] Further, the firelight detection voltage division threshold comparison module 43 forms a voltage division network based on a second voltage division resistor module and the firelight sensor R FD , and the output signal of the firelight sensor is acquired by the second voltage division resistor module, and a voltage threshold comparison is performed through a current-limiting resistor and a transistor, and the output signal of the firelight sensor is sent to the fourth acquisition port according to the comparison result.

[0034] Further, the gas detection voltage division module 46 forms a potential voltage division network of the gas sensor based on a third voltage division resistor module, and the gas detection filtering module 47 is an RC filtering network, and the output signal of the gas sensor is acquired by the third voltage division resistor module and sent to the RC filtering network for filtering after being acquired by the third voltage division resistor module, and then sent to the third acquisition port S3.

[0035] Further, the third voltage division resistor module in the pressure detection constant voltage driving module 44 is multiplexed in the gas detection voltage division module 42 to provide constant voltage driving for the pressure sensor RP P , and the voltage at both ends of the pressure sensor RP is dynamically regulated through the cooperation of an operational amplifier, a current-limiting resistor and a field effect transistor. P ​R The output signal is sampled by the current limiting detection resistor in the pressure detection current sampling module 45 to form a sampling current signal and sent to the amplification module 48. The amplification module 48 amplifies and filters the sampling current signal based on a two-stage amplification and active filter network and then sends it to the second acquisition port S2.

[0036] Specifically, refer to Figure 3 The battery voltage VBT of the battery system BT is directly acquired by the first acquisition port S1 of the multiplexer 3. The voltage acquisition channel 41 is the connecting wire between the two terminals of the battery system BT and the first acquisition port S1 of the multiplexer 3. That is, the two terminals of the battery system BT are connected to the first acquisition port S1 of the multiplexer 3. In addition, the connecting wire between the two terminals of the battery system BT and the first acquisition port S1 of the multiplexer 3 is also connected to the fourth acquisition port S4.

[0037] Furthermore, the first voltage divider resistor module in the temperature acquisition voltage divider module 42 is the seventh resistor R7, and the temperature sensor R... T After being connected in series with the seventh resistor R7, it is connected in parallel across the battery system BT to form a voltage divider detection circuit. Temperature sensor R... T The output signal is multiplexed and sent to the fourth acquisition port S4 via the voltage acquisition channel, simplifying the measurement circuit. Temperature sensor R... T Output mapped voltage V T With the battery system BT, the battery voltage V BT The pressure difference is used to calculate the temperature information based on Ohm's law.

[0038] Furthermore, the second voltage divider resistor module in the fire detection voltage divider threshold comparison module 43 includes an eighth resistor R8. In addition, the fire detection voltage divider threshold comparison module 43 also includes a ninth resistor R9 and a third MOSFET Q3. One end of the eighth resistor R8 is connected to the fire sensor R... FD One end of the resistor R8 is connected to the fourth acquisition port S4, and the other end of the fire sensor R... FD The other end is connected to the positive terminal of the battery system BT, and one end of the ninth resistor R9 is connected to the flame sensor R. FD Between the eighth resistor R8 and the other end, it is connected to the gate of the third MOSFET Q3. The source of the third MOSFET Q3 is grounded, and the drain is connected to the fourth acquisition port S4.

[0039] Because the fire sensor corresponds to one of the most severe operating conditions in the battery safety warning range, its measurement adopts a threshold comparison-based mode. Fire sensor R FD (e.g., PT-850) has typical photoresistor characteristics: the resistance value is high in the absence of fire or light; the resistance decreases significantly when there is fire or light in the target wavelength band.

[0040] The eighth resistor R8 and the firelight sensor R FD forms a voltage divider network, the ninth resistor R9 as a current limiting resistor, and the voltage Vgs_Q3 is provided to the gate of the third MOS tube Q3 through the ninth resistor R9. When there is no flame in the battery environment, the resistance of the firelight sensor R FD is much larger than that of the eighth resistor R8, and the voltage Vgs_Q3 after the ninth resistor R9 is lower than the threshold value, the third MOS tube Q3 remains closed, the seventh resistor R7 is not short-circuited, and the fourth acquisition port S4 of the multiplexer 3 normally acquires the output signal of the temperature sensor; when a flame is generated in the battery environment, the resistance of the firelight sensor R FD drops sharply, the voltage Vgs_Q3 rises above the threshold value, the third MOS tube Q3 is turned on, the seventh resistor R7 is short-circuited, and the fourth acquisition port S4 of the multiplexer 3 detects the ground potential, thereby realizing the measurement and identification of the output signal of the firelight sensor R FD .

[0041] Further, the third voltage dividing resistor module in the gas detection voltage dividing module 46 includes the tenth resistor R 10 , the eleventh resistor R 11 and the twelfth resistor R 12 , in addition, the gas detection voltage dividing module 46 further includes the fourteenth resistor R 14 , the fifteenth resistor R 15 and the third capacitor C3, wherein the tenth resistor R 10 , the eleventh resistor R 11 and the twelfth resistor R 12 are voltage dividing resistors, the tenth resistor R 10 , the eleventh resistor R 11 and the twelfth resistor R 12 are connected in series and connected to both poles of the battery system BT, the fourteenth resistor R 14 , the fifteenth resistor R 15 and the third capacitor C3 form an RC filter network, the fourteenth resistor R 14 and the fifteenth resistor R 15 are connected in series and connected in parallel with the third capacitor C3, the first power supply interface of the gas sensor Sensor is connected between the tenth resistor R 10 and the eleventh resistor R 11 , the second power supply interface of the gas sensor Sensor is connected with the DC / DC conversion circuit, and the output end of the gas sensor Sensor is connected between the fourteenth resistor R 14 and the fifteenth resistor R 15 , the fifteenth resistor R 15The lead-out terminal between the gas sensor and the third capacitor C3 is connected to the third acquisition port S3. The output signal of the gas sensor is filtered by a filtering network to effectively remove power supply noise and high-frequency interference, ensuring the purity of the gas sensor signal. The gas sensor processing path is independent of the pressure sensor acquisition link. After filtering, the gas sensor signal is directly output to multiplexer 3, and then sent to the ADC inside the analog front-end chip 2 for sampling via the third acquisition port S3 channel of multiplexer 3. This avoids additional noise that may be introduced by the multi-stage amplification link and preserves the intrinsic response characteristics of the gas sensor.

[0042] Furthermore, the pressure detection constant pressure drive module 44 includes a tenth resistor R that is multiplexed with the third voltage divider resistor module. 10 Eleventh resistor R 11 12th resistor R 12 In addition, the pressure detection constant pressure drive module 44 also includes a thirteenth resistor R. 13 First operational amplifier U1, sixteenth resistor R 16 And the fourth MOSFET Q4, where the tenth resistor R 10 Eleventh resistor R 11 12th resistor R 12 and the thirteenth resistor R 13 All are voltage divider resistors, the tenth resistor R 10 Eleventh resistor R 11 12th resistor R 12 Multiplexed with gas detection voltage divider module 42; thirteenth resistor R 13 One end is connected to the eleventh resistor R 11 and the twelfth resistor R 12 One end is connected to the input terminal of the first operational amplifier U1, and the output terminal of the first operational amplifier U1 is connected to the sixteenth resistor R. 16 One end is connected to the sixteenth resistor R. 16 The other end is connected to the gate of the fourth MOSFET Q4, and the source of the fourth MOSFET Q4 is connected to the pressure sensor R. P The drain of the fourth MOSFET Q4 is connected to the amplifier module 45. The sixteenth resistor R... 16 The current-limiting resistor is for the constant pressure drive module 44 for pressure detection. High-precision resistor, tenth resistor R. 10 Eleventh resistor R 11 12th resistor R 12 and the thirteenth resistor R 13 Constant pressure drive with pressure sensor Rp, sixteenth resistor R 16The current limiting resistor is outputted as the first operational amplifier U1. The first operational amplifier U1 and the fourth MOS tube Q4 constitute a constant voltage source closed loop feedback structure. The feedback loop dynamically maintains the pressure sensor R P The voltage at both ends is stable. The pressure sensor Rp is a typical piezoresistor type pressure sensor, and the resistance decreases with the increase of the applied pressure.

[0043] When the piezoresistor is measured by the conventional voltage division method, the voltage applied to the pressure sensor in the voltage division structure fluctuates with the change of the external power supply voltage, load or wire pressure drop, which causes the resistance value of the pressure sensor to change with the change of the applied voltage even under the same pressure, seriously affecting the measurement consistency and accuracy. In this embodiment, the pressure detection constant voltage driving module ensures the voltage at both ends of the pressure sensor to be fixed. Even if the power supply voltage or system load changes, the working point of the pressure sensor is always stable, so that the resistance value corresponding to the same pressure remains consistent, eliminating the nonlinear measurement error caused by the change of the applied voltage, significantly improving the measurement stability and repeatability, ensuring that the pressure sensor works under stable voltage conditions, and eliminating the voltage-dependent error in the traditional voltage division measurement architecture.

[0044] The pressure detection current sampling module 45 includes the seventeenth resistor R 17 , and the seventeenth resistor R 17 is a current limiting detection resistor.

[0045] When the resistance of the pressure sensor Rp changes, the fourth MOS tube Q4 adjusts the drain voltage to absorb the excess voltage drop, ensuring that the current flowing through the fifteenth resistor R 15 and the pressure sensor Rp is approximately the same, and after the current signal is detected by the seventeenth resistor R 17 , it is sent to the signal amplification module 48.

[0046] The amplification module 48 includes the eighteenth resistor R 18 , the nineteenth resistor R 19 , the twentieth resistor R 20 , the twenty-first resistor R 21 , the twenty-second resistor R 22 , the fourth capacitor C4, the second operational amplifier U2 and the third operational amplifier U3, wherein one end of the eighteenth resistor R 18 and one end of the nineteenth resistor R 19 are connected to both ends of the seventeenth resistor R 17 , and the other end of the eighteenth resistor R 18 and the other end of the nineteenth resistor R 19 are connected to the first input end and the second input end of the second operational amplifier U2, respectively, and the twenty-second resistor R 22One end of the fourth capacitor C4 is connected with the third input end of the third operational amplifier U3, and the other end is grounded.

[0047] The amplification module 48 adopts a two-stage operational amplifier (such as INA333) structure, the first-stage operational amplifier is the second operational amplifier U2 and the peripheral resistor R 18 -R 21 The second-stage operational amplifier is the third operational amplifier U3 and the twelfth resistor R 22 and the fourth capacitor C4 constitute an active filter and gain adjustment circuit, which realizes low-pass filtering and voltage stable output, further enhances the signal amplitude and suppresses high-frequency noise, thereby optimizing the signal-to-noise ratio and facilitating accurate collection of the analog front-end chip internal analog-to-digital converter (ADC) through the second collection port S2.

[0048] Further, the multi-channel signal collection module further comprises a filter module composed of a plurality of capacitors, and the filter module is connected with the first collection port S1, the second collection port S2, the third collection port S3 and the fourth collection port S4 of the multiplexer.

[0049] Specifically, the filter module comprises a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8, one end of the fifth capacitor C5 is grounded, and the other end is connected with the fourth collection port S4, one end of the sixth capacitor C6 is grounded, and the other end is connected with the third collection port S3, one end of the seventh capacitor C7 is connected with the second collection port S2, and the other end is grounded, one end of the eighth capacitor C8 is grounded, and the other end is connected with the first collection port S1.

[0050] The plurality of collection ports (S1 to S4) are respectively connected with the output signals of different sensors through the filter capacitors C5-C8, and the microprocessor realizes sharing of single high-precision ADC resource collection of the multi-channel sensor output signals by polling and gating the corresponding channel through the control end, effectively improves the system expansibility, and reduces the hardware cost.

[0051] Reference Figure 5 In some embodiments, a multi-sensor signal collection method for a battery system applied to the above device is also provided, comprising: S1, controlling the multi-channel signal collection module to collect the output signals of a plurality of sensors based on voltage division collection, constant voltage driving, threshold comparison, current collection, filtering and amplification; S2, the microcontroller generates a channel selection signal and sends it to the multiplexer, and the multiplexer selects the output signal of the corresponding sensor to send to the analog front-end chip according to the channel selection signal; the analog front-end chip processes the output signal of the sensor and then sends it to the microcontroller.

[0052] Specifically, in step S1, the plurality of sensors include a temperature sensor, a firelight sensor, a pressure sensor, and a gas sensor.

[0053] The voltage acquisition channel in the multi-channel signal acquisition module acquires the battery voltage across the battery system and sends it to the first acquisition port; the output signal of the temperature sensor is acquired by the temperature acquisition module in the multi-channel signal acquisition module after voltage division and then sent to the multiplexer.

[0054] The firelight detection voltage division threshold comparison module in the multi-channel signal acquisition module performs voltage division acquisition and voltage threshold comparison on the output signal of the firelight sensor when the firelight sensor detects firelight, and the corresponding channel is turned on to send the output signal of the firelight sensor to the multiplexer.

[0055] The gas detection voltage division module in the multi-channel signal acquisition module performs voltage division acquisition on the output signal of the gas sensor, and sends it to the multiplexer after filtering by the detection filtering module in the multi-channel signal acquisition module.

[0056] The battery voltage of the battery system is dynamically voltage-regulated and current-limited by the pressure detection constant voltage driving module in the multi-channel signal acquisition module to provide constant excitation for the pressure sensor; the output signal of the pressure sensor is sampled by the pressure detection current sampling module in the multi-channel signal acquisition module and sent to the amplification module for amplification before being sent to the multiplexer.

[0057] Further, in step S2, the multiplexer includes a first acquisition port, a second acquisition port, a third acquisition port, and a fourth acquisition port, and the microcontroller can control the first acquisition port, the second acquisition port, the third acquisition port, and the fourth acquisition port to be turned on in turn by polling.

[0058] The microcontroller generates a first channel selection signal for gating battery voltage acquisition and sends it to the multiplexer, and the multiplexer selects the first acquisition port to send the battery voltage of the battery system to the analog front-end chip according to the first channel selection signal; the analog front-end chip processes the battery voltage and then sends it to the microcontroller. The microcontroller generates a second channel selection signal for gating temperature acquisition and sends it to the multiplexer, the multiplexer selects the fourth acquisition port according to the second channel selection signal to send the output signal of the temperature sensor to the analog front-end chip, and the analog front-end chip sends the output signal of the temperature sensor to the microcontroller after processing; when fire light appears in the environment, the output signal of the fire light sensor is sent to the analog front-end chip through the fourth acquisition port, and the analog front-end chip sends the output signal of the fire light sensor to the microcontroller after processing; The microcontroller generates a third channel selection signal for gating gas acquisition and sends it to the multiplexer, the multiplexer selects the third acquisition port according to the third channel selection signal to send the output signal of the gas sensor to the analog front-end chip, and the analog front-end chip sends the output signal of the gas sensor to the microcontroller after processing; The microcontroller generates a fourth channel selection signal for gating pressure acquisition and sends it to the multiplexer, the multiplexer selects the second acquisition port according to the fourth channel selection signal to send the output signal of the pressure sensor to the analog front-end chip, and the analog front-end chip sends the output signal of the pressure sensor to the microcontroller after processing.

[0059] The multi-sensor signal acquisition device and method for the battery system provided by the embodiment have at least the following beneficial effects: (1) The acquisition circuits of various sensor signals related to battery system monitoring are integrated, the channels and modules are multiplexed, the wiring is simplified, the integration degree of the device is improved, the power consumption is reduced, and the application scene requirements of low power consumption and limited volume of battery system monitoring are met; (2) The hierarchical power supply architecture is adopted, the microcontroller, the analog front-end chip, the anti-interference driving circuit and the multiplexer are powered by an external power supply, and the battery system converts the battery voltage into a working voltage through a DC / DC conversion circuit to power multiple sensors and the multi-signal acquisition module. This design retains the flexibility of external power supply while enabling the battery to independently power specific modules, thereby reducing the redundancy of the system and improving reliability, and simplifying the internal power management structure; (3) The pressure detection constant voltage driving module ensures that the voltage across the pressure sensor is fixed, so that the working point of the pressure sensor remains stable even if the supply voltage or system load changes, so that the resistance value corresponding to the same pressure remains consistent, eliminating the nonlinear measurement error caused by changes in applied voltage, significantly improving the measurement stability and repeatability, and ensuring that the pressure sensor works under stable voltage conditions, eliminating the voltage-dependent error in the traditional voltage division measurement architecture; (4) It has excellent anti-wire parasitic interference ability, and is suitable for long-distance wiring environment.

[0060] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they learn of the basic inventive concepts. Therefore, the appended claims are intended to encompass within their scope all such variations and modifications as are included within the scope of the application. It should be apparent that those skilled in the art can make modifications and variations to the application without departing from the scope or spirit of the application. Accordingly, it is intended to be covered by the following claims and their equivalents.

Claims

1. A multi-sensor signal acquisition device for a battery system, characterized by, The application relates to a multi-channel signal acquisition module for a microcontroller, an analog front-end chip, a multiplexer, a multi-channel signal acquisition module and a plurality of sensors; the multi-channel signal acquisition module, a battery system and the plurality of sensors are connected in cooperation, the multiplexer is connected with the multi-channel signal acquisition module, the multiplexer is also connected with the analog front-end chip, and the microcontroller is connected with the analog front-end chip and the multiplexer; The multi-channel signal acquisition module acquires output signals of the plurality of sensors based on voltage division acquisition, constant voltage driving, threshold comparison, current sampling, filtering and amplification; the output signals of the plurality of sensors are selected and sent to the analog front-end chip through the multiplexer, the output signals of the sensors are sent to the microcontroller after being processed by the analog front-end chip, and the microcontroller controls the multiplexer to switch and select the output signals of the plurality of sensors.

2. The apparatus of claim 1, wherein, The microcontroller is connected with the multiplexer through an anti-interference driving circuit, the microcontroller, the analog front-end chip, the anti-interference driving circuit and the multiplexer are powered by an external power supply, and the anti-interference circuit is used for realizing stable output of channel selection signals of the microcontroller.

3. The apparatus of claim 1, wherein, The plurality of sensors include a temperature sensor, a light sensor, a pressure sensor and a gas sensor, the battery system converts a battery voltage into a working voltage through a DC / DC conversion circuit to supply power for the plurality of sensors and the multi-channel signal acquisition module.

4. The apparatus of claim 3, wherein, The multi-channel signal acquisition module includes a voltage acquisition channel, a temperature acquisition voltage division module, a light detection voltage division threshold comparison module, a pressure detection constant voltage driving module, a pressure detection current sampling module, a gas detection voltage division module, a gas detection filtering module and an amplification module; the multiplexer includes a first acquisition port, a second acquisition port, a third acquisition port and a fourth acquisition port; The voltage acquisition channel is connected with two poles of the battery system and is used for acquiring a battery voltage of the battery system and sending the battery voltage to the first acquisition port; output signals of the temperature sensor are acquired through voltage division of the temperature acquisition voltage division module and are multiplexed and sent to the fourth acquisition port through the voltage acquisition channel; the light detection voltage division threshold comparison module and the temperature acquisition module multiplex the fourth acquisition port, the output signals of the temperature sensor are acquired by the fourth acquisition port when there is no light in the environment, when the light sensor detects light, the output signals of the light sensor are acquired through voltage division and voltage threshold comparison of the light detection voltage division threshold comparison module, and the output signals of the light sensor are sent to the fourth acquisition port through the conduction of corresponding channels; the output signals of the gas sensor are acquired through voltage division of the gas detection voltage division module and are sent to the third acquisition port after being filtered through the gas detection filtering module; the battery voltage is provided with constant excitation for the pressure sensor through dynamic voltage adjustment and current limiting of the pressure detection constant voltage driving module, and the output signals of the pressure sensor are sampled through the pressure detection current sampling module, are amplified through the amplification module and are sent to the second acquisition port.

5. The apparatus of claim 4, wherein, The temperature acquisition and voltage division module constitutes a voltage division detection loop based on a first voltage division resistor module and a battery system, a mapping voltage output by the temperature sensor is subjected to voltage division acquisition by the first voltage division resistor module, a voltage difference is formed between the voltage division and a battery voltage of the battery system, and the voltage difference is used to calculate temperature information.

6. The apparatus of claim 4, wherein, The firelight detection and voltage division threshold comparison module constitutes a voltage division network based on a second voltage division resistor module and the firelight sensor, an output signal of the firelight sensor is subjected to acquisition by the second voltage division resistor module, and is subjected to voltage threshold comparison by a current limiting resistor and a transistor, and according to a comparison result, a corresponding channel is turned on to send the output signal of the firelight sensor to the fourth acquisition port.

7. The apparatus of claim 4, wherein, The gas detection and voltage division module constitutes a potential voltage division network of the gas sensor based on a third voltage division resistor module, the gas detection and filtering module is an RC filtering network, and after the output signal of the gas sensor is subjected to voltage division acquisition by the third voltage division resistor module, the output signal is sent to the RC filtering network for filtering, and after filtering, the output signal is sent to the third acquisition port.

8. The apparatus of claim 7, wherein, In the pressure detection and constant voltage driving module, part of the third voltage division resistor module in the gas detection and voltage division module is multiplexed to drive the pressure sensor at a constant voltage, and the voltage across the pressure sensor is dynamically adjusted by the joint action of an operational amplifier, a current limiting resistor and a field effect transistor; after the output signal of the pressure sensor is sampled by the current limiting detection resistor in the pressure detection and current sampling module, a sampling current signal is formed and sent to the amplification module, and the amplification module amplifies and filters the sampling current signal based on two-stage amplification and an active filtering network, and then sends the sampling current signal to the second acquisition port.

9. The apparatus of claim 4, wherein, The multi-channel signal acquisition module further includes a filtering module composed of multiple capacitors, and the filtering module is connected with the first acquisition port, the second acquisition port, the third acquisition port and the fourth acquisition port of the multiplexer.

10. A multi-sensor signal acquisition method for a battery system applied to the device according to any one of claims 1 to 9, characterized in that, The control multi-channel signal acquisition module acquires output signals of multiple sensors based on voltage division acquisition, constant voltage driving, threshold comparison, current acquisition, filtering and amplification. The microcontroller generates a channel selection signal and sends the channel selection signal to the multiplexer, the multiplexer selects an output signal of a corresponding sensor according to the channel selection signal and sends the output signal to the analog front-end chip, and the analog front-end chip processes the output signal of the sensor and then sends the output signal to the microcontroller. ​

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