CN219831122U - Wheel speed signal processing circuit for vehicle - Google Patents
Wheel speed signal processing circuit for vehicle Download PDFInfo
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- CN219831122U CN219831122U CN202320909359.5U CN202320909359U CN219831122U CN 219831122 U CN219831122 U CN 219831122U CN 202320909359 U CN202320909359 U CN 202320909359U CN 219831122 U CN219831122 U CN 219831122U
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Abstract
The utility model discloses a wheel speed signal processing circuit for a vehicle. The device comprises a diode D1, a high-side power supply switch module, a sensor open-short circuit diagnosis module, a low-side grounding switch module, an overcurrent protection module and a signal conversion module; the wheel speed sensor is connected with the vehicle-mounted power supply VBAT and the ground after passing through the high-side power supply switch module and the low-side grounding switch module respectively, the vehicle-mounted power supply VBAT is connected with the high-side power supply switch module through the diode D1, the wheel speed sensor is connected with the sensor open-short circuit diagnosis module, and meanwhile the low-side grounding switch module is connected with the overcurrent protection module and the signal conversion module respectively. The utility model can diagnose and protect the faults of the sensor, does not need a special integrated chip to process signals, reduces the dependence on the special chip and improves the use safety.
Description
Technical Field
The utility model discloses an automobile internal signal processing circuit, and particularly relates to an automobile wheel speed signal processing circuit.
Background
The decoding of the Hall wheel speed sensor of the passenger car uses a special integrated chip, and the defect of the integrated chip is that the threshold value of the sensor fault diagnosis cannot be adjusted, the specification of all sensors cannot be covered in use, and meanwhile, the integrated chip cannot diagnose the fault type of all the wheel speed sensors on the wheel speed sensor with certain specification.
Even if the integrated chip meets the application requirements, there is a shortage of chips, and the number requirements for mass production and use cannot be met. It is poor in replaceability.
Disclosure of Invention
In order to solve the problems in the background art, an object of the present utility model is to provide a wheel speed signal processing circuit for a vehicle.
The module circuit can convert the current signal of the Hall wheel speed sensor for the vehicle into a voltage signal which can be identified by the microcontroller, and the wheel speed signal processing circuit module can diagnose and protect faults of the sensor, such as open circuit faults, short circuit faults to ground, short circuit faults to power supply and overcurrent protection of the sensor.
The technical scheme of the utility model is realized as follows:
1. a wheel speed signal processing circuit for a vehicle:
the device comprises a diode D1, a high-side power supply switch module, a sensor open-short circuit diagnosis module, a low-side grounding switch module, an overcurrent protection module and a signal conversion module; the wheel speed sensor is connected with the vehicle-mounted power supply VBAT and the ground after passing through the high-side power supply switch module and the low-side grounding switch module respectively, the vehicle-mounted power supply VBAT is connected with the high-side power supply switch module through the diode D1, the wheel speed sensor is connected with the sensor open-short circuit diagnosis module, and meanwhile the low-side grounding switch module is connected with the overcurrent protection module and the signal conversion module respectively.
The high-side power supply switch module comprises a triode Q5, a resistor R1, a resistor R2, a triode Q2, a resistor R3, a resistor R5 and a capacitor C5;
the vehicle-mounted power supply VBAT is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the base electrode of the triode Q5 through the resistor R1, the cathode of the diode D1 is connected with the emitter of the triode Q5, the base electrode of the triode Q5 is connected with the collector electrode of the triode Q2 through the resistor R2, the collector electrode of the triode Q5 is connected with the positive electrode interface WSP of the wheel speed sensor, the emitter of the triode Q2 is grounded, the base electrode of the triode Q2 is connected with the collector electrode of the triode Q2 through the resistor R3, the base electrode of the triode Q2 is connected with the second driving output end MCU_CTR2 of the MCU through the resistor R5 and the MCU, and the base electrode of the triode Q2 is used for receiving a second level control signal from the MCU; the cathode of the diode D1 is connected with the collector of the triode Q5 and the sensor open-short circuit diagnosis module.
The sensor open-short circuit diagnosis module comprises a composite triode Q23, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20 and a resistor R21;
the cathode of the diode D1 is connected with a pin 4 of a composite triode Q23, a pin 3 of the composite triode Q23 is respectively connected with a cathode interface WSS of a wheel speed sensor and a collector electrode of a triode Q5 of a high-side power supply switch module after passing through a resistor R15 and a resistor R18, a pin 5 of the composite triode Q23 is directly connected with a pin 6, a pin 1 of the composite triode Q23 is grounded, and a pin 2 is connected to a third driving output end MCU_CTR3 of the MCU for receiving a third level control signal from the MCU;
the positive electrode interface WSP of the wheel speed sensor is grounded through a capacitor C5, the positive electrode interface WSP of the wheel speed sensor and the negative electrode interface WSS of the wheel speed sensor are respectively connected with the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU through a resistor R16 and a resistor R19, and simultaneously the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU are respectively grounded through a resistor R17 and a resistor R20, and the negative electrode interface WSS of the wheel speed sensor is connected with a low-side grounding switch module.
The composite triode Q23 is formed by connecting two triodes, wherein the base electrode of one triode is connected with the collector electrode of the other triode, the emitter electrode of the one triode is used as a No. 4 pin, the collector electrode of the one triode is used as a No. 3 pin, the base electrode of the one triode is used as a No. 5 pin, the collector electrode of the other triode is used as a No. 6 pin, the base electrode of the other triode is used as a No. 2 pin, and the emitter electrode of the other triode is used as a No. 1 pin.
The low-side grounding switch module comprises a triode Q3, a resistor R9, a resistor R6 and a resistor R4; the negative electrode interface WSS of the wheel speed sensor is connected with the collector electrode of the triode Q3, and the base electrode of the triode Q3 is connected to the first driving output end MCU_CTR1 of the MCU through a resistor R9 and is used for receiving a first level control signal from the MCU; the base electrode of the triode Q3 is directly connected with the collector electrode of the triode Q4, the emitter electrode of the triode Q3 is connected with the MCU_ADC3 through the resistor R21 and the third analog-to-digital sampling port of the MCU, and the base electrode of the triode Q3 is grounded through the resistor R6; the base electrode and the emitter electrode of the triode Q3 are connected with the overcurrent protection module, the emitter electrode of the triode Q3 is connected with the overcurrent protection module after passing through the resistor R4, and the emitter electrode of the triode Q3 is connected with the signal conversion module.
The overcurrent protection module comprises a resistor R4, a resistor R7, a resistor R8 and a triode Q4;
the emitter of the triode Q4 is connected with the emitter of the triode Q3 of the low-side grounding switch module through a resistor R4, the emitter of the triode Q3 is connected with the base of the triode Q4 after passing through a resistor R7, the emitter of the triode Q4 is grounded, and the emitter of the triode Q4 is connected with the base of the triode Q4 after passing through a resistor R8.
The signal conversion module comprises a resistor R4, a resistor R10, a capacitor C1, a resistor R12, a resistor R11, a capacitor C3, a capacitor C4, a capacitor C2 and a comparator U4; the positive input end of the comparator U4 is grounded after passing through the resistor R10 and the resistor R4 in sequence, meanwhile, the emitter of the triode Q3 of the low-side grounding switch module is led out between the resistor R10 and the resistor R4, the positive input end of the comparator U4 is grounded through the capacitor C1, the negative input end of the comparator U4 is grounded through the capacitor C3 and the resistor R12 respectively, the negative input end of the comparator U4 is grounded after passing through the resistor R11 and the capacitor C4 in sequence, a 3.3V power supply is led out between the resistor R11 and the capacitor C4, the positive end of the comparator U4 is simultaneously connected with the 3.3V power supply and grounded through the capacitor C2, the negative end of the comparator U4 is connected with the ground, and the output end of the comparator U4 is used as the output end of the wheel speed signal processing circuit for the vehicle and is connected to the wheel speed signal input port of the MCU.
In the utility model, the resistor R4 of the low-side grounding switch module, the resistor R4 of the overcurrent protection module and the resistor R4 of the signal conversion module share one resistor, namely the same resistor.
Although many circuits in the prior art have functions of power supply, overcurrent protection, open-short circuit diagnosis, signal conversion and the like, the circuits exist independently and are not simultaneously in an integrated circuit.
The utility model creatively integrates the functions of power supply, open-short circuit diagnosis, overcurrent protection, signal conversion and the like into one circuit through the circuit structure, realizes the functions of power supply, open-short circuit diagnosis, overcurrent protection, signal conversion and the like, and also realizes double redundancy controllable control of high-side power supply and low-side grounding.
The beneficial effects of the utility model are as follows:
the utility model utilizes a plurality of commonly used discrete components to construct the conversion of the signal type of the automotive Hall sensor, does not need a special integrated chip to process the signal, and reduces the dependence on the special chip.
The wheel speed signal processing circuit can diagnose and protect faults of the sensor, such as open-circuit faults of the sensor, short-circuit faults to ground, short-circuit faults to power supply and overcurrent protection faults, and improves the use safety.
Drawings
Fig. 1 is a schematic circuit diagram of a wheel speed signal processing circuit for a vehicle.
Detailed Description
The utility model is further described below with reference to the drawings and examples.
As shown in fig. 1, the circuit comprises a diode D1, a high-side power supply switch module, a sensor open-short circuit diagnosis module, a low-side grounding switch module, an overcurrent protection module and a signal conversion module; the wheel speed sensor is connected with the vehicle-mounted power supply VBAT and the ground after passing through the high-side power supply switch module and the low-side grounding switch module respectively, the vehicle-mounted power supply VBAT is connected with the high-side power supply switch module through the diode D1, the wheel speed sensor is connected with the sensor open-short circuit diagnosis module, and meanwhile the low-side grounding switch module is connected with the overcurrent protection module and the signal conversion module respectively.
The wheel speed sensor sends out a wheel speed signal to the sensor open-short circuit diagnosis module to be detected whether the wheel speed signal is abnormal or not, and the wheel speed sensor sends out the wheel speed signal to the signal conversion module to be analyzed and then input to the MCU. In addition, MCU control high limit power supply switch module, low limit earthing switch module's work and then realize the power supply to the wheel speed sensor, MCU control sensor open-short circuit diagnostic module carries out the self-checking before the wheel speed sensor at every turn works, carries out open circuit detection in real-time work in order to carry out the alarm processing of wheel speed signal, and overcurrent protection module real-time monitoring wheel speed sensor sends the electric current of wheel speed signal in order to avoid the excessive current to produce simultaneously.
The high-side power supply switch module comprises a triode Q5, a resistor R1, a resistor R2, a triode Q2, a resistor R3, a resistor R5 and a capacitor C5;
the vehicle-mounted power supply VBAT is connected with the anode at the 1 end of the diode D1, the cathode at the 2 end of the diode D1 is connected with the base electrode No. 3 of the triode Q5 after passing through the resistor R1, the cathode at the 2 end of the diode D1 is connected with the emitter No. 1 of the triode Q5, the base electrode No. 3 of the triode Q5 is connected with the collector No. 3 of the triode Q2 through the resistor R2, the collector No. 2 of the triode Q5 is connected with the positive electrode interface WSP of the wheel speed sensor, the emitter No. 1 of the triode Q2 is grounded, the base electrode No. 2 of the triode Q2 is connected with the collector No. 3 of the triode Q2 through the resistor R3, the base electrode No. 2 of the triode Q2 is connected with the MCU_CTR2 through the resistor R5 and the second driving output end MCU_CTR2 of the MCU, and is used for receiving a second level control signal for controlling the work of the high-side power supply switch module; the cathode of the end 2 of the diode D1 is connected with the collector No. 2 of the triode Q5 and the sensor open-short circuit diagnosis module.
The sensor open-short circuit diagnosis module comprises a composite triode Q23, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20 and a resistor R21;
the cathode of the 2 end of the diode D1 is connected with the No. 4 pin of the composite triode Q23, the No. 3 pin of the composite triode Q23 is respectively connected with the No. 2 collector of the triode Q5 of the high-side power supply switch module after passing through a resistor R15 and a resistor R18, the No. 5 pin of the composite triode Q23 is directly connected with the No. 6 pin, the No. 1 pin of the composite triode Q23 is grounded, the No. 2 pin is connected to the third driving output end MCU_CTR3 of the MCU, and the composite triode Q23 is used for receiving a third level control signal which is used for controlling the operation of the sensor open-short circuit diagnosis module from the MCU;
the positive electrode interface WSP of the wheel speed sensor is grounded through a capacitor C5, the positive electrode interface WSP of the wheel speed sensor and the negative electrode interface WSS of the wheel speed sensor are respectively connected with the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU through a resistor R16 and a resistor R19, and simultaneously the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU are respectively grounded through a resistor R17 and a resistor R20, and the negative electrode interface WSS of the wheel speed sensor is connected with a low-side grounding switch module.
The composite triode Q23 is formed by connecting two triodes, wherein the base electrode of one triode is connected with the collector electrode of the other triode, the emitter electrode of the one triode is used as a pin number 4, the collector electrode of the one triode is used as a pin number 3, the base electrode of the one triode is used as a pin number 5, the collector electrode of the other triode is used as a pin number 6, the base electrode of the other triode is used as a pin number 2, and the emitter electrode of the other triode is used as a pin number 1.
The low-side grounding switch module comprises a triode Q3, a resistor R9, a resistor R6 and a resistor R4; the negative electrode interface WSS of the wheel speed sensor is connected with the No. 3 collector electrode of the triode Q3, and the No. 2 base electrode of the triode Q3 is connected to the first driving output end MCU_CTR1 of the MCU through a resistor R9 and is used for receiving a first level control signal from the MCU for controlling the low-side grounding switch module to work; the base electrode of the triode Q3 is directly connected with the collector electrode of the triode Q4, the emitter electrode of the triode Q3 is connected with the MCU_ADC3 through the resistor R21 and the third analog-to-digital sampling port of the MCU, and the base electrode of the triode Q3 is grounded through the resistor R6; the base electrode No. 2 and the emitter electrode No. 1 of the triode Q3 are connected with the overcurrent protection module, the emitter electrode No. 1 of the triode Q3 is connected with the overcurrent protection module after passing through the resistor R4, and the emitter electrode No. 1 of the triode Q3 is connected with the signal conversion module.
The overcurrent protection module comprises a resistor R4, a resistor R7, a resistor R8 and a triode Q4;
the emitter 1 of the triode Q4 is connected with the emitter 1 of the triode Q3 of the low-side grounding switch module through a resistor R4, the emitter 1 of the triode Q3 is connected with the base 2 of the triode Q4 after passing through a resistor R7, the emitter 1 of the triode Q4 is grounded, and the emitter 1 of the triode Q4 is connected with the base 2 of the triode Q4 after passing through a resistor R8.
The signal conversion module comprises a resistor R4, a resistor R10, a capacitor C1, a resistor R12, a resistor R11, a capacitor C3, a capacitor C4, a capacitor C2 and a comparator U4; the positive input end of the No. 3 of the comparator U4 is grounded after passing through the resistor R10 and the resistor R4 in sequence, meanwhile, the emitter No. 1 of the triode Q3 of the low-side grounding switch module is led out between the resistor R10 and the resistor R4, the positive input end of the No. 3 of the comparator U4 is grounded through the capacitor C1, the negative input end of the No. 2 of the comparator U4 is grounded through the capacitor C3 and the resistor R12 respectively, the negative input end of the No. 2 of the comparator U4 is grounded after passing through the resistor R11 and the capacitor C4 in sequence, a 3.3V power supply is led out between the resistor R11 and the capacitor C4, the positive end of the No. 7 of the comparator U4 is simultaneously connected with the 3.3V power supply and the ground through the capacitor C2, the negative end of the No. 4 of the comparator U4 is connected with the ground, and the output end of the No. 6 of the comparator U4 is used as the output end of the wheel speed signal processing circuit and is connected to the wheel speed signal input port of the MCU.
And the No. 6 output end of the comparator U4 of the signal conversion module is also connected with a 3.3V power supply through a resistor R14.
As shown in fig. 1, the wheel speed signal processing circuit for the vehicle comprises a triode Q2, a triode Q3, a triode Q4, a triode Q5, a composite triode Q23, a wheel speed sensor and a comparator U4; and also an external MCU and a vehicle-mounted power supply VBAT.
The vehicle-mounted power supply VBAT is connected with the anode at the 1 end of the diode D1, the cathode at the 2 end of the diode D1 is connected with the base electrode No. 3 of the triode Q5 after passing through the resistor R1, and meanwhile, the cathode at the 2 end of the diode D1 is respectively connected with the pin No. 4 of the composite triode Q23 and the emitter No. 1 of the triode Q5,
the base electrode 3 of the triode Q5 is connected with the collector electrode 3 of the triode Q2 through a resistor R2, the emitter electrode 1 of the triode Q2 is grounded, the base electrode 2 of the triode Q2 is connected with the collector electrode 3 of the triode Q2 through a resistor R3, the base electrode 2 of the triode Q2 is connected with the MCU_CTR2 through a resistor R5 and a second driving output end MCU_CTR2 of the MCU, and the base electrode is used for receiving a second level control signal from the MCU;
the collector 2 of the triode Q5 is connected with the positive electrode interface WSP of the wheel speed sensor, the negative electrode interface WSS of the wheel speed sensor and the collector 2 of the triode Q5 are respectively connected with the pin 3 of the compound triode Q23 after passing through a resistor R15 and a resistor R18, the pin 5 of the compound triode Q23 is directly connected with the pin 6, the pin 1 of the compound triode Q23 is grounded, and the pin 2 is connected to the third driving output end MCU_CTR3 of the MCU for receiving a third level control signal from the MCU;
the positive electrode interface WSP of the wheel speed sensor is grounded through a capacitor C5, the positive electrode interface WSP of the wheel speed sensor and the negative electrode interface WSS of the wheel speed sensor are respectively connected with a first analog-digital sampling port MCU_ADC1 and a second analog-digital sampling port MCU_ADC2 of the MCU through a resistor R16 and a resistor R19, and meanwhile, the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU are respectively grounded through a resistor R17 and a resistor R20, and the negative electrode interface WSS of the wheel speed sensor is connected with a No. 3 collector electrode of a triode Q3;
the base electrode 2 of the triode Q3 is connected to a first drive output end MCU_CTR1 of the MCU through a resistor R9 and is used for receiving a first level control signal from the MCU; the base electrode No. 2 of the triode Q3 is directly connected with the collector electrode No. 3 of the triode Q4, the emitter electrode No. 1 of the triode Q3 is connected with the MCU_ADC3 through the resistor R21 and the third analog-to-digital sampling port of the MCU, the emitter electrode No. 1 of the triode Q3 is connected with the emitter electrode No. 1 of the triode Q4 through the resistor R4, the emitter electrode No. 1 of the triode Q3 is connected with the base electrode No. 2 of the triode Q4 after passing through the resistor R7, the collector electrode No. 3 of the triode Q4 is grounded after passing through the resistor R6, the emitter electrode No. 1 of the triode Q4 is grounded, and the emitter electrode No. 1 of the triode Q4 is connected with the base electrode No. 2 of the triode Q4 after passing through the resistor R8;
the emitter 1 of the triode Q3 is connected with the positive input end 3 of the comparator U4 through a resistor R10, the positive input end 3 of the comparator U4 is grounded through a capacitor C1, the negative input end 2 of the comparator U4 is grounded through a capacitor C3 and a resistor R12 respectively, the negative input end 2 of the comparator U4 is grounded after being sequentially grounded through a resistor R11 and a capacitor C4, a 3.3V power supply is led out between the resistor R11 and the capacitor C4,
the No. 6 output end of the comparator U4 is connected with a 3.3V power supply through a resistor R14, and the No. 6 output end of the comparator U4 is used as the output end of the wheel speed signal processing circuit for the vehicle and is connected to the wheel speed signal input port of the MCU.
And, the positive terminal of the No. 7 of the comparator U4 is simultaneously connected with a 3.3V power supply and grounded through a capacitor C2, and the negative terminal of the No. 4 of the comparator U4 is connected with the ground.
The high-side power supply switch module is composed of a triode Q5, a resistor R1, a resistor R2, a triode Q2, a resistor R3, a resistor R5 and a capacitor C5.
The triode Q3, the resistor R9, the resistor R6 and the resistor R4 form a low-side grounding switch module.
The composite triode Q23, the resistor R15, the resistor R16, the resistor R17, the resistor R18, the resistor R19, the resistor R20 and the resistor R21 form a sensor open-short circuit diagnosis module.
The resistor R4, the resistor R7, the resistor R8 and the triode Q4 form an overcurrent protection module.
The resistor R4, the resistor R10, the capacitor C1, the resistor R12, the resistor R11, the capacitor C3, the capacitor C4, the capacitor C2 and the comparator U4 form a signal conversion module.
The resistor R14 and the diode D1 do not belong to a high-side power supply switch module, a sensor open-short circuit diagnosis module, a low-side grounding switch module, an overcurrent protection module and a signal conversion module. The diode D1 functions to prevent reverse connection of the power supply.
The wheel speed sensor is a Hall sensor and has two output currents, which respectively represent the intensity of a magnetic field and correspond to different rotation positions of the wheel speed during rotation.
The MCU is a processor in the vehicle-mounted computer.
In the specific implementation, the triodes Q2 to Q4 are NPN triodes, and the triode Q5 is a PNP triode. The signal of the comparator U4 is LM2903, and the resistance of the sampling resistor R4 is 120Ω.
In the implementation, the WSP and the WSS are respectively connected with two ends of the wheel speed sensor, and the used wheel speed sensor is a Hall type wheel speed sensor which can generate 7mA and 14mA current signals according to concave-convex changes of the gear ring on the wheel. Comparator U4 model LM2903. The parameter values of the elements are set as follows:
transistor Q5 model QNSL12TT1, transistor Q2 model QmJE340, transistor Q3 model QmJE340, composite transistor Q23 model QmJE340, transistor Q4QmJE340.
Resistance 1K of resistor R1, resistance 10K of resistor R2, resistance 47K of resistor R3, resistance 1K of resistor R5, resistance 5.1K of resistor R9, resistance 100K of resistor R6, resistance 120 Ω of resistor R4, resistance 10K of resistor R15, resistance 30K of resistor R16, resistance 10K of resistor R17, resistance 10K of resistor R18, resistance 30K of resistor R19, resistance 10K of resistor R20, resistance 5.1K of resistor R21, resistance 4K of resistor R7, resistance 1K of resistor R8, resistance 5.1K of resistor R10, resistance 4.7K of resistor R12, resistance 8.3K of resistor R11, capacitance 10nF of capacitor C5, capacitance 10nF of capacitor C1, capacitance 100nF of capacitor C3, capacitance 100nF of capacitor C4, capacitance 100nF of capacitor C2.
The specific implementation working process of the utility model is as follows:
1) Power supply
In the high-side power supply switch module:
when the MCU's second drive output end MCU_CTR2 outputs low level (0V), triode Q2 does not switch on for triode Q5's No. 1 projecting pole is unanimous with the potential of No. 3 base, does not produce pressure differential between, makes triode Q5 non-conducting, and vehicle-mounted power supply VBAT can't reach the anodal interface WSP of wheel speed sensor through triode Q5.
When the MCU's second drive output end MCU_CTR2 outputs high level (3.3V), then triode Q2 switches on for triode Q5's No. 1 projecting pole is greater than 0.7V with the potential difference of No. 3 base, and produces pressure differential, makes triode Q5 switch on, and vehicle-mounted power supply VBAT reaches triode Q5's No. 2 collector pin through diode D1 and triode Q5, and then reaches wheel speed sensor's anodal interface WSP.
In the low side ground switch module:
when the MCU's first drive output end MCU_CTR1 outputs low level (0V), the potential of the No. 2 base electrode and the No. 1 base electrode of the triode Q3 are consistent, no pressure difference is generated between the base electrodes, so that the triode Q3 is not conducted, the low-side grounding switch module is disconnected, and the negative electrode interface WSS of the wheel speed sensor cannot be grounded and conducted through the triode Q3.
When the MCU output end MCU_CTR2 outputs high level (3.3V), a voltage difference is generated between the potential of the No. 2 base electrode and the potential of the No. 1 emitter electrode of the triode Q3, so that the triode Q3 is conducted, the low-side grounding switch module is closed, and the negative electrode interface WSS of the wheel speed sensor is grounded and conducted through the triode Q3.
Before the automobile needs to work of the wheel speed sensor, the second driving output end MCU_CTR2 of the MCU and the second driving output end MCU_CTR2 of the MCU are controlled to output high level (3.3V), and the two ends of the wheel speed sensor are driven to be conducted and electrified, so that the power supply to the wheel speed sensor is realized.
2) Open-short circuit diagnosis
The second driving output terminals mcu_ctr2, mcu_ctr1 and mcu_ctr3 of the MCUs are controlled in the following manner, usually immediately after the ignition start of the car, before the above four short circuit diagnoses.
Firstly, controlling a second driving output end MCU_CTR2 and MCU_CTR1 of the MCU to output low level (0V) so that a high-side triode Q5 of a high-side power supply switch module and a low-side triode Q3 of a low-side grounding switch module are disconnected; and the third driving output end mcu_ctr3 of the control MCU outputs a high potential (3.3V).
Before the wheel speed sensor works, the second driving output end MCU_CTR2 of the control MCU and the second driving output end MCU_CTR2 of the MCU both output high level, drive the two ends of the wheel speed sensor to be conducted and electrified, and realize the power supply to the wheel speed sensor.
Detecting the short circuit and open circuit condition of the wheel speed sensor by the sensor open-short circuit diagnosis module in combination with the MCU in a period of time just after the ignition and the start of the automobile;
in any electrifying working process of the wheel speed sensor, the wheel speed signal output by the wheel speed sensor is analyzed through the signal conversion module and then sent to the MCU, and overcurrent protection is carried out in real time through the overcurrent protection module.
In the sensor open-short circuit diagnosis module, a first driving output end MCU_CTR1 and a second driving output end MCU_CTR2 of the MCU are firstly controlled to output a low level, a third driving output end MCU_CTR3 outputs a high level according to the following mode, and then the following steps are carried out:
and then the MCU_CTR3 at the third driving output end of the MCU is controlled to output a low level instead, and judgment is carried out:
if the voltage acquired by the MCU_ADC1 of the first analog-to-digital sampling port of the MCU is more than 3V, the positive electrode interface WSP of the wheel speed sensor is short-circuited to the power supply VBAT; otherwise, the positive electrode interface WSP of the wheel speed sensor is not short-circuited to the power supply VBAT;
if the voltage acquired by the MCU_ADC2 of the second analog-to-digital sampling port of the MCU is more than 3V, the negative electrode interface WSS of the wheel speed sensor is short-circuited to the power supply VBAT; otherwise, the negative electrode interface WSS of the wheel speed sensor is not short-circuited to the power supply VBAT;
then, the MCU_CTR3 at the third driving output end of the MCU is controlled to output a high level instead, and judgment is carried out:
if the voltage acquired by the MCU_ADC1 of the first analog-to-digital sampling port of the MCU is more than 3V, the positive electrode interface WSP of the wheel speed sensor is short-circuited to the ground; otherwise, the positive electrode interface WSP of the wheel speed sensor is not short-circuited to the ground;
if the voltage acquired by the MCU_ADC2 of the second analog-to-digital sampling port of the MCU is more than 3V, the negative electrode interface WSS of the wheel speed sensor is short-circuited to ground; otherwise, the negative electrode interface WSS of the wheel speed sensor is not short-circuited to the ground;
then, the MCU is controlled to output a high level by the MCU_CTR1 at the first driving output end and the MCU_CTR2 at the second driving output end, and judgment is carried out:
if the voltage acquired by the MCU_ADC3 of the third analog-to-digital sampling port of the MCU is smaller than the voltage obtained by multiplying the lowest output current of the wheel speed sensor by the resistor R4, the wheel speed sensor is opened; otherwise the wheel speed sensor is not open.
In the overcurrent protection module, overcurrent protection is performed in the following manner: when the voltage difference between the base electrode and the emitter electrode of the triode Q4 is larger than 0.7V, the triode Q4 is conducted and grounded, the base electrode of the triode Q3 is grounded and turned off, the cathode interface WSS of the wheel speed sensor cannot be conducted through the grounding of the triode Q3, and a loop where the wheel speed sensor is located is turned off by overcurrent;
in the signal conversion module, the wheel speed signal of the wheel speed sensor is analyzed according to the following mode and then sent to the MCU:
the inverting input of the comparator U4 sets the threshold voltage between power and ground through resistors R12, R11,
the voltage drop voltage generated by the current output by the wheel speed sensor flowing through the resistor R4 is input to the non-inverting input end of the comparator U4, and the comparator U4 compares the voltage drop voltage with the threshold voltage to judge:
when the drop voltage is lower than the threshold voltage, the wheel speed sensor outputs lower current, and the output end of the comparator U4 outputs low to the MCU;
when the drop voltage is higher than the threshold voltage, the wheel speed sensor outputs a higher current, and the output end of the comparator U4 outputs a high voltage to the MCU.
Claims (7)
1. The utility model provides a wheel speed signal processing circuit for vehicle which characterized in that:
the device comprises a diode D1, a high-side power supply switch module, a sensor open-short circuit diagnosis module, a low-side grounding switch module, an overcurrent protection module and a signal conversion module; the wheel speed sensor is connected with the vehicle-mounted power supply VBAT and the ground after passing through the high-side power supply switch module and the low-side grounding switch module respectively, the vehicle-mounted power supply VBAT is connected with the high-side power supply switch module through the diode D1, the wheel speed sensor is connected with the sensor open-short circuit diagnosis module, and meanwhile the low-side grounding switch module is connected with the overcurrent protection module and the signal conversion module respectively.
2. The wheel speed signal processing circuit for vehicle according to claim 1, wherein:
the high-side power supply switch module comprises a triode Q5, a resistor R1, a resistor R2, a triode Q2, a resistor R3, a resistor R5 and a capacitor C5;
the vehicle-mounted power supply VBAT is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the base electrode of the triode Q5 through the resistor R1, the cathode of the diode D1 is connected with the emitter of the triode Q5, the base electrode of the triode Q5 is connected with the collector electrode of the triode Q2 through the resistor R2, the collector electrode of the triode Q5 is connected with the positive electrode interface WSP of the wheel speed sensor, the emitter of the triode Q2 is grounded, the base electrode of the triode Q2 is connected with the collector electrode of the triode Q2 through the resistor R3, the base electrode of the triode Q2 is connected with the second driving output end MCU_CTR2 of the MCU through the resistor R5 and the MCU, and the base electrode of the triode Q2 is used for receiving a second level control signal from the MCU; the cathode of the diode D1 is connected with the collector of the triode Q5 and the sensor open-short circuit diagnosis module.
3. The wheel speed signal processing circuit for vehicle according to claim 1, wherein:
the sensor open-short circuit diagnosis module comprises a composite triode Q23, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20 and a resistor R21;
the cathode of the diode D1 is connected with a pin 4 of a composite triode Q23, a pin 3 of the composite triode Q23 is respectively connected with a cathode interface WSS of a wheel speed sensor and a collector electrode of a triode Q5 of a high-side power supply switch module after passing through a resistor R15 and a resistor R18, a pin 5 of the composite triode Q23 is directly connected with a pin 6, a pin 1 of the composite triode Q23 is grounded, and a pin 2 is connected to a third driving output end MCU_CTR3 of the MCU for receiving a third level control signal from the MCU;
the positive electrode interface WSP of the wheel speed sensor is grounded through a capacitor C5, the positive electrode interface WSP of the wheel speed sensor and the negative electrode interface WSS of the wheel speed sensor are respectively connected with the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU through a resistor R16 and a resistor R19, and simultaneously the first analog-digital sampling port MCU_ADC1 and the second analog-digital sampling port MCU_ADC2 of the MCU are respectively grounded through a resistor R17 and a resistor R20, and the negative electrode interface WSS of the wheel speed sensor is connected with a low-side grounding switch module.
4. A wheel speed signal processing circuit for a vehicle according to claim 3, wherein:
the composite triode Q23 is formed by connecting two triodes, wherein the base electrode of one triode is connected with the collector electrode of the other triode, the emitter electrode of the one triode is used as a No. 4 pin, the collector electrode of the one triode is used as a No. 3 pin, the base electrode of the one triode is used as a No. 5 pin, the collector electrode of the other triode is used as a No. 6 pin, the base electrode of the other triode is used as a No. 2 pin, and the emitter electrode of the other triode is used as a No. 1 pin.
5. The wheel speed signal processing circuit for vehicle according to claim 1, wherein:
the low-side grounding switch module comprises a triode Q3, a resistor R9, a resistor R6 and a resistor R4; the negative electrode interface WSS of the wheel speed sensor is connected with the collector electrode of the triode Q3, and the base electrode of the triode Q3 is connected to the first driving output end MCU_CTR1 of the MCU through a resistor R9 and is used for receiving a first level control signal from the MCU; the base electrode of the triode Q3 is directly connected with the collector electrode of the triode Q4, the emitter electrode of the triode Q3 is connected with the MCU_ADC3 through the resistor R21 and the third analog-to-digital sampling port of the MCU, and the base electrode of the triode Q3 is grounded through the resistor R6; the base electrode and the emitter electrode of the triode Q3 are connected with the overcurrent protection module, the emitter electrode of the triode Q3 is connected with the overcurrent protection module after passing through the resistor R4, and the emitter electrode of the triode Q3 is connected with the signal conversion module.
6. The wheel speed signal processing circuit for vehicle according to claim 1, wherein:
the overcurrent protection module comprises a resistor R4, a resistor R7, a resistor R8 and a triode Q4;
the emitter of the triode Q4 is connected with the emitter of the triode Q3 of the low-side grounding switch module through a resistor R4, the emitter of the triode Q3 is connected with the base of the triode Q4 after passing through a resistor R7, the emitter of the triode Q4 is grounded, and the emitter of the triode Q4 is connected with the base of the triode Q4 after passing through a resistor R8.
7. The wheel speed signal processing circuit for vehicle according to claim 1, wherein:
the signal conversion module comprises a resistor R4, a resistor R10, a capacitor C1, a resistor R12, a resistor R11, a capacitor C3, a capacitor C4, a capacitor C2 and a comparator U4; the positive input end of the comparator U4 is grounded after passing through the resistor R10 and the resistor R4 in sequence, meanwhile, the emitter of the triode Q3 of the low-side grounding switch module is led out between the resistor R10 and the resistor R4, the positive input end of the comparator U4 is grounded through the capacitor C1, the negative input end of the comparator U4 is grounded through the capacitor C3 and the resistor R12 respectively, the negative input end of the comparator U4 is grounded after passing through the resistor R11 and the capacitor C4 in sequence, a 3.3V power supply is led out between the resistor R11 and the capacitor C4, the positive end of the comparator U4 is simultaneously connected with the 3.3V power supply and grounded through the capacitor C2, the negative end of the comparator U4 is connected with the ground, and the output end of the comparator U4 is used as the output end of the wheel speed signal processing circuit for the vehicle and is connected to the wheel speed signal input port of the MCU.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320909359.5U CN219831122U (en) | 2023-04-21 | 2023-04-21 | Wheel speed signal processing circuit for vehicle |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320909359.5U CN219831122U (en) | 2023-04-21 | 2023-04-21 | Wheel speed signal processing circuit for vehicle |
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| Publication Number | Publication Date |
|---|---|
| CN219831122U true CN219831122U (en) | 2023-10-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202320909359.5U Active CN219831122U (en) | 2023-04-21 | 2023-04-21 | Wheel speed signal processing circuit for vehicle |
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| Country | Link |
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| CN (1) | CN219831122U (en) |
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- 2023-04-21 CN CN202320909359.5U patent/CN219831122U/en active Active
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