Automobile tail lamp circuit based on LIN communication control

Abstract

The utility model relates to the technical field of automobile lamps, and discloses an automobile tail lamp circuit based on LIN communication control, which comprises a main lamp module and an auxiliary lamp module which are respectively connected with an automobile body, the main lamp module comprises an input detection circuit, an LIN transceiver, an MCU chip, an LDO chip, a CAN transceiver, an LED drive circuit and an LED load, the input end of the input detection circuit is connected with a vehicle body, the output end of the input detection circuit is connected with the input end of the LIN transceiver and the input end of the LED drive circuit, the output end of the LIN transceiver is connected with the input end of the MCU chip, and the output end of the MCU chip is connected with the input end of the CAN transceiver and the input end of the LED drive circuit. The CAN transceiver outputs to the auxiliary lamp module through a CAN bus, and the LED drive circuit outputs to the LED load. According to the utility model, an LIN signal is converted into a CAN signal through the MCU and then transmission control is carried out, so that the system complexity is simplified and the signal transmission rate is improved at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive headlights, in particular to an automotive tail light circuit based on LIN communication control. Background Technique

[0002] LIN (Local Interconnect Network) is a low-cost, low-speed serial communication bus for distributed applications at the bottom of automobiles. Most automotive electronic systems on the market currently adopt LIN communication technology, and the vehicle body provides LIN communication to control vehicle lamps. However, due to the relatively slow data transmission rate of LIN communication, it is easy to cause system time delay, resulting in an out-of-sync phenomenon between automotive tail lights. Content of the Utility Model

[0003] The purpose of the utility model is to provide an automotive tail light circuit based on LIN communication control to solve the problems raised in the above background technique.

[0004] To achieve the above purpose, the utility model provides the following technical solution: An automotive tail light circuit based on LIN communication control includes a main light module and a secondary light module respectively connected to the vehicle body. The secondary light module includes a plurality of lamps connected in parallel. The main light module includes an input detection circuit, a LIN transceiver, an MCU chip, an LDO chip, a CAN transceiver, an LED driving circuit, and an LED load. The input end of the input detection circuit is connected to the vehicle body through a LIN communication line, and the output end of the input detection circuit is respectively connected to the input ends of the LIN transceiver and the LED driving circuit through a LIN signal line and a wire. The output end of the LIN transceiver is connected to the input end of the MCU chip. The output end of the MCU chip is respectively connected to the input ends of the CAN transceiver and the LED driving circuit. The CAN transceiver outputs to the secondary light module through a CAN bus. The output end of the LED driving circuit is connected to the input end of the LDO chip. The output end of the LDO chip is respectively connected to the LIN transceiver, the MCU chip, and the CAN transceiver. The LED driving circuit outputs to the LED load.

[0005] The following improvements are made in the solution of this application. The input detection circuit includes an anti-reverse diode PD1, a resistor PR2, and an MOS transistor Q4 connected in series in sequence. A TVS diode PT1, a capacitor PC3, a capacitor PC4, and a resistor PR1 are connected in parallel between the anti-reverse diode PD1 and the input voltage. An anti-reverse diode PD3, a triode PQ1, and a triode PQ2 are connected in parallel between the resistor PR2 and the MOS transistor Q4. Pin 1 of the anti-reverse diode PD3 is connected to the resistor PR2, and pin 2 of the anti-reverse diode PD3 is grounded. Pin 1 of the MOS transistor Q4 is connected in series with a resistor R7 and externally connected to an MCU chip. A resistor R9 and a capacitor C32 are connected in parallel between the resistor R7 and the MOS transistor Q4. Pin 2 of the MOS transistor Q4 is grounded.

[0006] The following improvements are made in the solution of this application. The MCU chip is an S9KEAZ128 series chip, and the MCU chip is equipped with a PWM output pin 26, a LIN enable pin 37, a LIN TXD communication pin 47, a LIN RXD communication pin 48, a CAN TXD pin 51, and a CAN RXD pin 52. A resistor MR6 is connected in series on the CAN TXD pin 51. A resistor MR7 is connected in series on the CAN RXD pin 52. A capacitor MC3 and a capacitor MC4 are connected in parallel between pin 7 and pin 10 of the MCU chip. A resistor MR3 is connected in series on pin 19 of the MCU chip. A capacitor MC5 and a capacitor MC2 are connected in parallel between pin 41 and pin 41 of the MCU chip.

[0007] The following improvements are made in the solution of this application. The LIN transceiver uses a TJA1021T model chip. A resistor R12 is connected in series on the RXD pin of the LIN transceiver. The first end of the resistor R12 is connected to the power supply, and the second end is grounded through a capacitor C14. The NSLP pin of the LIN transceiver is grounded through a resistor R13. A resistor R16 and a capacitor C23 are connected in parallel on the TXD pin of the LIN transceiver. One end of the resistor R16 is connected to the power supply, and one end of the capacitor C23 is grounded. An anti-reverse diode D1 and a resistor R1 are connected in series between the LIN pin and the INH pin of the LIN transceiver. The VBAT pin of the LIN transceiver is connected to the power supply through a parallel-connected capacitor C16 and a capacitor C17.

[0008] The following improvements are made in the solution of this application. The CAN transceiver uses a TCAN1044 model chip. The VCC pin of the CAN transceiver is connected to the power supply through the parallel-connected capacitor C28 and capacitor C27. A circuit is provided between the CANL pin and the CANH pin of the CAN transceiver. The circuit includes a resistor R17, a resistor R19, a coil inductor L1, and an ESD protection diode T4 connected in parallel. The resistor R17 and the resistor R19 are grounded through a capacitor C26. The pin 1 of the ESD protection diode T4 is connected to the pin 4 of the coil inductor L1. The pin 2 of the ESD protection diode T4 is connected to the pin 3 of the coil inductor L1. The pin 3 of the ESD protection diode T4 is grounded. The pin 3 and the pin 4 of the coil inductor L1 are grounded through a capacitor C25 and a capacitor C29 respectively. The STB pin of the CAN transceiver is grounded through a resistor R18.

[0009] The following improvements are made in the solution of this application. The LED driving circuit includes a plurality of LED devices connected in series and parallel, and a capacitor is connected in parallel to each LED device. A triode linear constant current driving circuit is adopted to effectively maintain the stability of the LED current.

[0010] Compared with the prior art, the utility model provides an automotive taillight circuit based on LIN communication control, and has the following beneficial effects:

[0011] The utility model converts the LIN signal into a CAN signal through the MCU for transmission control, solves the problems of limited LIN bus nodes that cannot connect too many lamps, the cost generated by adding multiple LIN buses, and the relatively slow LIN communication data transmission rate, simplifies the system complexity while improving the signal transmission rate, and also meets the synchronization of automotive taillight dynamic lighting, enabling the lamps to make corresponding animation effects in the shortest time in response to vehicle body instructions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is the structural block diagram of the utility model;

[0013] Figure 2 is the schematic diagram of the input detection circuit;

[0014] Figure 3 is the schematic diagram of the MCU chip circuit;

[0015] Figure 4 is the schematic diagram of the LDO chip circuit;

[0016] Figure 5 is the schematic diagram of the LIN transceiver circuit;

[0017] Figure 6 is the schematic diagram of the CAN transceiver circuit;

[0018] Figure 7 It is the schematic diagram of the LED driving circuit. Specific implementation mode

[0019] The technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention:

[0020] As Figure 1 shown, an automotive taillight circuit based on LIN communication control includes a main light module and a sub-light module. The main light module and the sub-light module are respectively connected to the vehicle body through a power line and a ground wire. The sub-light module includes a plurality of lamps arranged in parallel. The main light module includes an input detection circuit, a LIN transceiver, an MCU chip, an LDO chip, a CAN transceiver, an LED driving circuit, and an LED load. The input end of the input detection circuit is connected to the vehicle body through a LIN communication line. The output end of the input detection circuit is respectively connected to the input ends of the LIN transceiver and the LED driving circuit through a LIN signal line and a wire. The output end of the LIN transceiver is connected to the input end of the MCU chip. The output end of the MCU chip is respectively connected to the input ends of the CAN transceiver and the LED driving circuit. The CAN transceiver outputs to the sub-light module through a CAN bus. The output end of the LED driving circuit is connected to the input end of the LDO chip. The output end of the LDO chip is respectively connected to the LIN transceiver, the MCU chip, and the CAN transceiver. The LED driving circuit outputs to the LED load; the main light module is connected to the vehicle body, inputs a LIN signal, converts it into a CAN signal through the MCU, and then outputs it to the sub-light module, further controlling the LED loads of multiple lamps to synchronously achieve an animation effect.

[0021] As Figure 2As shown, the input detection circuit includes an anti-reverse diode PD1, a resistor PR2, and a MOS transistor Q4 connected in series in sequence. A TVS diode PT1, a capacitor PC3, a capacitor PC4, and a resistor PR1 are connected in parallel between the anti-reverse diode PD1 and the input voltage. An anti-reverse diode PD3, a triode PQ1, and a triode PQ2 are connected in parallel between the resistor PR2 and the MOS transistor Q4. Pin 1 of the anti-reverse diode PD3 is connected to the resistor PR2, and pin 2 of the anti-reverse diode PD3 is grounded. Pin 1 of the MOS transistor Q4 is connected in series with a resistor R7 and externally connected to an MCU chip. A resistor R9 and a capacitor C32 are connected in parallel between the resistor R7 and the MOS transistor Q4. Pin 2 of the MOS transistor Q4 is grounded. Among them, the TVS diode PT1 provides overvoltage protection for the circuit. The capacitors PC3, PC4, and the resistor PR1 play a role in filtering the input voltage. The anti-reverse diode PD1 can prevent the vehicle body from being damaged due to circuit failure. Then, the constant current control of the drive circuit is carried out through the triodes PQ1 and PQ2. The MOS transistor Q4 receives the PWM signal output by the MCU to control the on and off of the LED circuit. When the MCU outputs a PWM signal, the MOS transistor conducts and the LED lights up. This circuit is suitable for the simple on and off of the LED. For some complex functions, a linear chip can be used to achieve them.

[0022] As Figure 3 shown, the MCU chip is an S9KEAZ128 series chip, powered by 5V, with more IO interfaces and the FLASH memory capacity doubled, which is more suitable for the situation where the dynamic effects of vehicle lights are more complex; the MCU chip is equipped with a PWM output pin 26, a LIN enable pin 37, a LIN TXD communication pin 47, a LIN RXD communication pin 48, a CAN TXD pin 51, and a CAN RXD pin 52. A resistor MR6 is connected in series on the CAN TXD pin 51, and a resistor MR7 is connected in series on the CAN RXD pin 52. A capacitor MC3 and a capacitor MC4 are connected in parallel between pin 7 and pin 10 of the MCU chip. A resistor MR3 is connected in series on pin 19 of the MCU chip. A capacitor MC5 and a capacitor MC2 are connected in parallel between pin 41 and pin 41 of the MCU chip. The LIN signal is input to the MCU chip through the LIN transceiver. The MCU chip outputs an enable signal to wake up the LIN, and at the same time converts the LIN signal into a CAN signal and outputs it to the CAN transceiver. By converting the LIN signal into a CAN signal through the MCU chip, the synchronous on and off of multiple lamps is controlled. This communication method greatly reduces the communication delay phenomenon between the taillights and also speeds up the response speed of the control system.

[0023] As Figure 4As shown, the model of the LDO chip is NSR31050. Through this chip, the voltage of LED+ can be reduced to +5V for regulated output, which can provide 5V voltage for the MCU, CAN, and LIN chips. The output current is up to 150mA, which can ensure the current values of the CAN, LIN, and MCU chips under normal working conditions. This LDO has thermal shutdown and short-circuit protection functions, and the input voltage can reach up to 40V, which can effectively protect the entire circuit.

[0024] As Figure 5 shown, the LIN transceiver uses a TJA1021T model chip. A resistor R12 is connected in series on the RXD pin of the LIN transceiver. The first end of the resistor R12 is connected to the power supply, and the second end is grounded through a capacitor C14. The NSLP pin of the LIN transceiver is grounded through a resistor R13. A resistor R16 and a capacitor C23 are connected in parallel on the TXD pin of the LIN transceiver. One end of the resistor R16 is connected to the power supply, and one end of the capacitor C23 is grounded. An anti-reverse diode D1 and a resistor R1 are connected in series between the LIN pin and the INH pin of the LIN transceiver. The VBAT pin of the LIN transceiver is connected to the power supply through the parallel capacitors C16 and C17. After the vehicle body provides the LIN signal, the LIN transceiver sends the signal to the MCU chip, and the MCU chip controls the sleep wake-up of the LIN transceiver through the enable signal.

[0025] As Figure 6 shown, the CAN transceiver uses a TCAN1044 model chip. The VCC pin of the CAN transceiver is connected to the power supply through the parallel capacitors C28 and C27. A circuit is provided between the CANL pin and the CANH pin of the CAN transceiver. The circuit includes a resistor R17, a resistor R19, a coil inductor L1, and an ESD protection diode T4 connected in parallel. The resistor R17 and the resistor R19 are grounded through a capacitor C26. The pin 1 of the ESD protection diode T4 is connected to the pin 4 of the coil inductor L1. The pin 2 of the ESD protection diode T4 is connected to the pin 3 of the coil inductor L1. The pin 3 of the ESD protection diode T4 is grounded. The pin 3 and pin 4 of the coil inductor L1 are grounded through capacitors C25 and C29 respectively. The STB pin of the CAN transceiver is grounded through a resistor R18. When the MCU chip outputs a CAN signal, the signal outputs CAN HIGH and CAN LOW through the TCAN1044 and is transmitted to the auxiliary lamp module through a twisted pair, thereby controlling the lighting and extinguishing of all LEDs. By sending control signals through CAN communication, the rapid transmission of signals can be effectively achieved, and the phenomenon of out-of-sync between various lamps can also be avoided.

[0026] As Figure 7As shown, the LED driving circuit includes six LED devices arranged in series and parallel, and a capacitor is connected in parallel to each LED device. The circuit is a mesh structure, which can achieve the effect that the rest of the LEDs can work normally when one LED fails, thus meeting the regulatory requirements of automotive tail lights. At the same time, since this circuit is a triode constant current driving circuit, it is only applicable to the case where the number of LED particles is small and the LED current is small. For the case of hundreds of LEDs with complex dynamic effects, the driving circuit needs to be completed by a linear driving chip.

[0027] The above embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

Claims

1. An automotive tail light circuit based on LIN communication control, comprising a main light module and a secondary light module respectively connected to the vehicle body, wherein the secondary light module includes a plurality of lamps arranged in parallel, and is characterized in that: The main lamp module includes an input detection circuit, a LIN transceiver, an MCU chip, an LDO chip, a CAN transceiver, an LED driving circuit, and an LED load. The input end of the input detection circuit is connected to the vehicle body through a LIN communication line. The output end of the input detection circuit is respectively connected to the input ends of the LIN transceiver and the LED driving circuit through a LIN signal line and a wire. The output end of the LIN transceiver is connected to the input end of the MCU chip. The output end of the MCU chip is respectively connected to the input ends of the CAN transceiver and the LED driving circuit. The CAN transceiver outputs to the auxiliary lamp module through a CAN bus. The output end of the LED driving circuit is connected to the input end of the LDO chip. The output end of the LDO chip is respectively connected to the LIN transceiver, the MCU chip, and the CAN transceiver. The LED driving circuit outputs to the LED load.

2. The automotive tail lamp circuit based on LIN communication control according to claim 1, wherein: The input detection circuit includes an anti-reverse diode PD1, a resistor PR2, and a MOS transistor Q4 connected in series in sequence. A TVS diode PT1, a capacitor PC3, a capacitor PC4, and a resistor PR1 are connected in parallel between the anti-reverse diode PD1 and the input voltage. An anti-reverse diode PD3, a triode PQ1, and a triode PQ2 are connected in parallel between the resistor PR2 and the MOS transistor Q4. The pin 1 of the anti-reverse diode PD3 is connected to the resistor PR2. The pin 2 of the anti-reverse diode PD3 is grounded. The pin 1 of the MOS transistor Q4 is connected in series with a resistor R7 and externally connected to the MCU chip. A resistor R9 and a capacitor C32 are connected in parallel between the resistor R7 and the MOS transistor Q4. The pin 2 of the MOS transistor Q4 is grounded.

3. The automotive taillight circuit based on LIN communication control according to claim 1, characterized in that: The MCU chip is an S9KEAZ128 series chip, and the MCU chip is equipped with a PWM output pin 26, a LIN enable pin 37, a LIN TXD communication pin 47, a LIN RXD communication pin 48, a CAN TXD pin 51, and a CAN RXD pin 52. A resistor MR6 is connected in series on the CAN TXD pin 51. A resistor MR7 is connected in series on the CAN RXD pin 52. A capacitor MC3 and a capacitor MC4 are connected in parallel between the pin 7 and the pin 10 of the MCU chip. A resistor MR3 is connected in series on the pin 19 of the MCU chip. A capacitor MC5 and a capacitor MC2 are connected in parallel between the pin 41 and the pin 41 of the MCU chip.

4. A taillight circuit of an automobile based on LIN communication control according to claim 1, characterized in that: The LIN transceiver uses a TJA1021T model chip. A resistor R12 is connected in series on the RXD pin of the LIN transceiver. The first end of the resistor R12 is connected to the power supply, and the second end is grounded through a capacitor C14. The NSLP pin of the LIN transceiver is grounded through a resistor R13. A resistor R16 and a capacitor C23 are connected in parallel on the TXD pin of the LIN transceiver. One end of the resistor R16 is connected to the power supply, and one end of the capacitor C23 is grounded. An anti-reverse diode D1 and a resistor R1 are connected in series between the LIN pin and the INH pin of the LIN transceiver. The VBAT pin of the LIN transceiver is connected to the power supply through a parallel-connected capacitor C16 and a capacitor C17.

5. A taillight circuit for an automobile based on LIN communication control according to claim 1, wherein: The CAN transceiver uses a TCAN1044 model chip. The VCC pin of the CAN transceiver is connected to the power supply through the parallel capacitors C28 and C27. There is a circuit between the CANL pin and the CANH pin of the CAN transceiver. The circuit includes a resistor R17, a resistor R19, a coil inductor L1, and an ESD protection diode T4 connected in parallel. The resistor R17 and the resistor R19 are grounded through a capacitor C26. The pin 1 of the ESD protection diode T4 is connected to the pin 4 of the coil inductor L1. The pin 2 of the ESD protection diode T4 is connected to the pin 3 of the coil inductor L1. The pin 3 of the ESD protection diode T4 is grounded. The pin 3 and the pin 4 of the coil inductor L1 are grounded through a capacitor C25 and a capacitor C29 respectively. The STB pin of the CAN transceiver is grounded through a resistor R18.

6. The automotive taillight circuit based on LIN communication control according to claim 1, characterized in that: The LED driving circuit includes a plurality of LED devices connected in series and parallel, and a capacitor is connected in parallel to each LED device.

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