Headlamp detection system

Abstract

The utility model relates to the technical field of headlight detection, in particular to a headlight detection system, which comprises a power supply module, a shunt resistor, an INA237 chip, a microcontroller, an alarm module and a communication module, the power supply module is used for being connected with an automobile power supply and supplying power to a circuit, the shunt resistor is connected in series in an automobile headlight power supply loop and used for current sampling, and the INA237 chip is connected with the microcontroller. The microcontroller is in communication connection with the INA237 chip and used for receiving and processing current, voltage and temperature data, the alarm module is connected with the microcontroller and used for receiving abnormal signals output by the microcontroller and giving an alarm, and the communication module is connected with the microcontroller and used for transmitting detection data to external equipment. The utility model provides a high-integration and high-precision detection circuit based on an INA237 chip, which realizes real-time monitoring and abnormal alarm of current, voltage and temperature of an automobile headlamp.

Description

TECHNICAL FIELD

[0001] The utility model relates to headlamp detection technical field, concretely is a headlamp detection system. BACKGROUND

[0002] The automobile headlamp is as the important part of vehicle safe driving, and the real -time detection of its working condition is important to the traffic safety.

[0003] In the prior art, the automobile headlamp detection circuit with the announcement number CN202669636U, the utility model discloses an automobile headlamp detection circuit, including 555 integrated circuit, singlechip and alarm lamp, the first foot of 555 integrated circuit is connected with the anode of automobile headlamp after series connection diode, the input end of diode is connected with the first foot of 555 integrated circuit, the output end of diode is connected with the anode of automobile headlamp, the second foot of 555 integrated circuit is connected with the first foot of singlechip, and the second foot of singlechip is connected with alarm lamp, which can automatically detect the working condition of automobile headlamp after the opening of automobile headlamp.

[0004] The existing detection circuit usually adopts discrete components or low-precision sensors, which has the problems of insufficient detection precision and low integration, therefore, we provide a headlamp detection system. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a headlamp detection system to solve the problems in the above background.

[0006] To achieve the above object, the utility model provides the following technical scheme.

[0007] A headlamp detection system, comprising:

[0008] A power module is used for connecting automobile power supply and supplying power for the circuit.

[0009] A shunt resistor is connected in series in the automobile headlamp power supply loop and is used for current sampling.

[0010] An INA237 chip is connected with the two ends of the shunt resistor through the differential input end, and the bus voltage input end is connected with the positive pole of automobile power supply, which is used for collecting bus voltage, shunt differential voltage and monitoring temperature.

[0011] A microcontroller is connected with the INA237 chip in communication and is used for receiving and processing current, voltage and temperature data.

[0012] An alarm module is connected with the microcontroller and is used for receiving abnormal signal outputted by the microcontroller and executing alarm.

[0013] A communication module, connected with the microcontroller, is configured to transmit the detection data to an external device.

[0014] Preferably, the power module comprises a step-down voltage regulator and a low-dropout linear regulator, the step-down voltage regulator converts the automobile power into 5V voltage, and the low-dropout linear regulator converts the 5V voltage into 3.3V voltage to supply power to the INA237 chip, the microcontroller and the communication module.

[0015] Preferably, the INA237 chip is configured with an adjustable ADC conversion time, the ADC conversion time is adjustable in a range of 50 µs to 4.12 ms, and supports 1x to 1024x sampling average adjustment to reduce the noise of the measurement data.

[0016] Preferably, the alarm module comprises an audible and light alarm unit, the audible and light alarm unit comprises a light-emitting diode and a buzzer, both of which are connected with a signal output end of the microcontroller, and are configured to receive an abnormal trigger signal output by the microcontroller and perform audible and light alarm.

[0017] Preferably, the communication module supports CAN / LIN bus protocol and integrates a wireless communication unit, the wireless communication unit supports Wi-Fi or Bluetooth transmission protocol, and is configured to upload the detection data to a vehicle-mounted ECU or an external terminal device.

[0018] Preferably, the power of the shunt resistor is greater than or equal to 2W, the resistance value is selected according to the rated current of the automobile headlamp, and the resistance value accuracy of the shunt resistor is less than or equal to ±1%.

[0019] Preferably, the INA237 chip has a current detection accuracy of ±0.1%, a bus voltage detection accuracy of ±0.25%, and a temperature detection accuracy of ±1°C.

[0020] Compared with the prior art, the utility model has the beneficial effects that:

[0021] The utility model is based on INA237 super-precision digital power monitoring chip, through shunt resistance gathers headlamp loop current, monitors bus voltage and chip temperature simultaneously. The microcontroller processes data in real time and realizes abnormal early warning and data uploading through the alarm module and the communication module. The circuit has the advantages of high precision, wide dynamic range, low power consumption and the like, and is suitable for real-time state detection of various automobile headlamps. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic view of the utility model. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0024] Please refer to Figure 1 A headlamp detection system comprises:

[0025] The power module, the current voltage acquisition module (shunt resistor and INA237 chip), the microcontroller (MCU), the alarm module and the communication module are integrated through the printed circuit board (PCB) to realize high-precision detection and real-time feedback on the working state of the automobile headlamp.

[0026] The automobile power supply (12V or 24V) is connected to the circuit through the fuse F1, and the input voltage is first converted to 5V through the voltage stabilizer U1 (model LM7805) to supply power to the buzzer (working voltage 5V) of the alarm module.

[0027] The 5V voltage is further converted to 3.3V through the low-dropout linear voltage stabilizer U2 (model AMS1117-3.3) to supply power to the microcontroller (model STM32F103C8T6), the INA237 chip (supply pin VCC connected to 3.3V) and the communication module (such as CAN transceiver TJA1050).

[0028] Filter circuit: 10uF electrolytic capacitor and 0.1uF ceramic capacitor are connected in parallel at the output end of the 5V and 3.3V power supply to suppress power supply ripple and ensure power supply stability.

[0029] The shunt resistor R_sense (power 2W, resistance 10mΩ, accuracy ±1%) is connected in series in the positive loop of the automobile headlamp (i.e. between the positive pole +B of the automobile power supply and the input end of the headlamp).

[0030] The differential input end VIN+ of the INA237 chip is connected to the side close to +B of R_sense, and VIN- is connected to the side close to the headlamp of R_sense, which is used to collect the differential voltage (ΔV=I×R_sense) between the two ends of the shunt.

[0031] Bus voltage and temperature acquisition: the VBUS pin of INA237 is directly connected to the positive pole +B of the automobile power supply, which is used to monitor the bus voltage (supporting range -0.3V~+85V);

[0032] The built-in temperature sensor of the chip collects the die temperature in real time, with an accuracy of ±1°C, which can indirectly reflect the ambient temperature of the headlamp.

[0033] Write parameters to the configuration register of INA237 through the I2C interface (SCL / SDA pins) of the microcontroller:

[0034] ADC conversion time: set to 200 μs (typical automotive circuit noise suppression scenario);

[0035] Sample average: select 128x oversampling (reduce high-frequency noise and improve signal-to-noise ratio);

[0036] Operating mode: configure as continuous measurement mode to ensure real-time performance.

[0037] Microcontroller (MCU) data processing logic

[0038] Communication interface:

[0039] The microcontroller periodically reads the register data of INA237 through the I2C bus (clock frequency 400 kHz), including:

[0040] Current register (calculation method: I = ΔV / R_sense, accuracy ±0.1%); bus voltage register (accuracy ±0.25%);

[0041] Temperature register (die temperature, converted to ambient temperature in combination with PCB heat dissipation design).

[0042] Threshold judgment logic: preset the following detection thresholds (can be remotely configured by vehicle ECU or external device):

[0043] Current anomaly: the measured current exceeds ±10% of the headlight rated current (e.g. rated 5A, trigger threshold set to 4.5A~5.5A);

[0044] Voltage anomaly: bus voltage is lower than 10V or higher than 15V (adapted to 12V automotive power supply system);

[0045] Temperature anomaly: detected temperature exceeds 85°C (default safety threshold, to prevent headlight overheating).

[0046] Data processing flow: the microcontroller reads INA237 data every 100ms, and if it exceeds the threshold for 3 consecutive times, it is determined to be abnormal, triggering an alarm and recording the fault code (e.g. 0x01 for overcurrent, 0x02 for overtemperature).

[0047] Acoustic and optical alarm circuit:

[0048] Light-emitting diode (LED): select red LED D1, connected to the GPIO pin (e.g. PA5) of the microcontroller through current-limiting resistor R1 (1kΩ), output high level to light up the LED when abnormal;

[0049] Buzzer: Active buzzer BZ1 (5V power supply) is driven by transistor Q1 (model S8050), and the microcontroller GPIO pin (such as PA6) outputs high level to enable the transistor, and the buzzer emits continuous buzzing sound.

[0050] Alarm release condition: After the detection parameter returns to normal, the microcontroller continues to monitor for 5s without exception, stops the alarm and clears the fault code.

[0051] Vehicle bus communication: The communication module integrates CAN transceiver U3 (model TJA1050), and the microcontroller is connected with the vehicle CAN bus through the CAN controller (built-in STM32) to send detection data at 250kbps baud rate. The data frame format includes:

[0052] Bus voltage (2 bytes, precision 0.01V);

[0053] Headlight current (2 bytes, precision 0.01A); Temperature (1 byte, unit °C);

[0054] Fault code (1 byte, 0x00 when no fault).

[0055] Optional Bluetooth module (such as HC-05) or Wi-Fi module (such as ESP8266) is connected with the microcontroller through UART interface, which supports real-time viewing of headlight status through mobile phone APP or vehicle terminal, and realizes remote diagnosis.

[0056] Shunt resistor is placed near INA237 chip, and differential input wiring uses equal length and parallel wiring to reduce electromagnetic interference (EMI);

[0057] Power module and signal processing module are partitioned and laid out, and are isolated by ground copper foil.

[0058] Electrostatic protection: TVS diode (model SMBJ15A) is connected in parallel at the input end of the automobile power supply to prevent surge voltage from damaging the circuit;

[0059] INA237 VBUS pin is connected in series with a 10Ω resistor to suppress voltage spikes.

[0060] Workflow:

[0061] Power module converts automobile power supply to 3.3V / 5V, and starts the circuit;

[0062] INA237 real-time collects headlight loop current, bus voltage and temperature, and transmits them to the microcontroller through I2C;

[0063] The microcontroller processes the data and determines whether the abnormal threshold is triggered;

[0064] The abnormality alarm module starts sound and light alarm, and the communication module uploads fault data to the vehicle-mounted system or external equipment;

[0065] In the normal state, the detection data is periodically uploaded for the ECU to monitor the working state of the headlamp.

[0066] The high-precision acquisition capability (current ±0.1%, voltage ±0.25%, temperature ±1°C) of the INA237 chip and the logic processing of the microcontroller realize the real-time detection of the multiple parameters of the automobile headlamp, compared with the traditional discrete component scheme, the integration is improved by 50%, the detection precision is improved by 3 times, the power consumption is reduced by 40%, and the high reliability and high precision requirements of the vehicle-mounted electronic are met.

[0067] Although the embodiments of the utility model have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A headlamp detection system characterized by, The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system.

2. The headlamp detection system of claim 1, wherein The application relates to a high-precision automobile headlamp current and voltage monitoring system.

3. The headlamp detection system of claim 1, wherein The application relates to a high-precision automobile headlamp current and voltage monitoring system.

4. The headlamp detection system of claim 1, wherein The application relates to a high-precision automobile headlamp current and voltage monitoring system.

5. The headlamp detection system of claim 1, wherein The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-precision automobile headlamp current and voltage monitoring system. The application relates to a high-

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