System for entering functional safety mode based on vehicle taillight ECU with MCU failure

Abstract

The utility model belongs to the technical field of vehicle lamp circuits, and specifically relates to a system for a vehicle taillight ECU to enter a functional safety mode based on an MCU failure, comprising: a LIN transceiver, a first control circuit, a second control circuit, an MCU microcontroller, an LDO circuit, a DC-DC circuit, a CAN transceiver, an LED drive circuit, and an LED, wherein the LIN transceiver, the first control circuit, and the second control circuit are all connected to a vehicle body KL30 power supply module, the LIN transceiver is connected to an ICAS vehicle body end LIN signal module, the LIN transceiver, the second control circuit, the LDO circuit, and the CAN transceiver are all connected to an MCU microcontroller, the LIN transceiver is connected to the first control circuit, the first control circuit, the second control circuit, and the CAN transceiver are all connected to the LDO circuit, and the second control circuit, the LED drive circuit, and the LED are all connected to the DC-DC circuit. The utility model provides a system for a vehicle taillight ECU to enter a functional safety mode based on an MCU failure, and adds a safety mechanism to monitor the MCU and the MCU power supply module.

Description

Technical Field

[0001] The utility model belongs to the technical field of vehicle lamp circuits, and in particular relates to a system for a vehicle tail lamp ECU to enter a functional safety mode based on a failed MCU. Background Art

[0002] In the current commonly used LIN taillight project, when the KL30 power supply is powered, the LIN transceiver will be powered first, and the LDO module integrated inside the LIN transceiver will output 5V to power the MCU and turn on the DC-DC circuit by default to power the lamp driver chip and LED, so that the MCU communicates with the CAN transceiver, and the CAN transceiver communicates with the driver chip to achieve the final lighting and extinguishing effect.

[0003] This method uses the dog door module integrated inside the LIN transceiver to monitor whether the MCU fails, and uses the limp-home mode of the LIN transceiver itself to put the system into functional safety mode. However, the limp-home mode of the LIN transceiver is affected by many other factors of the LIN chip itself and will trigger this mode, not just the failure of the MCU.

[0004] As the control logic of the taillight system of the LIN bus becomes more and more complex, and the MCU is the only main control unit of the lamp, the failure of the MCU is particularly important. Therefore, it is necessary to increase the safety mechanism as much as possible to monitor the MCU and the MCU power supply module. Utility Model Content

[0005] The purpose of the utility model is to provide a system for the vehicle taillight ECU to enter a functional safety mode based on the MCU failure, so as to solve the technical problem in the prior art that the MCU is the only main control unit of the lamp and the LIN transceiver cannot monitor the MCU failure alone. In order to solve the above technical problems, the utility model provides a system for the vehicle taillight ECU to enter a functional safety mode based on the MCU failure, and adds a safety mechanism to monitor the MCU and the MCU power supply module.

[0006] The utility model provides a system for a vehicle taillight ECU to enter a functional safety mode based on an MCU failure, comprising:

[0007] LIN transceiver, a first control circuit, a second control circuit, an MCU microcontroller, an LDO circuit, a DC-DC circuit, a CAN transceiver, an LED drive circuit and an LED, wherein the LIN transceiver, the first control circuit and the second control circuit are all connected to the vehicle body KL30 power supply module, the LIN transceiver is connected to the ICAS vehicle body end LIN signal module, the LIN transceiver, the second control circuit, the LDO circuit and the CAN transceiver are all connected to the MCU microcontroller, the LIN transceiver is connected to the first control circuit, the first control circuit, the second control circuit and the CAN transceiver are all connected to the LDO circuit, and the second control circuit, the LED drive circuit and the LED are all connected to the DC-DC circuit.

[0008] Furthermore, the ICAS vehicle body end LIN signal module is connected to the LIN transceiver via a LIN bus.

[0009] Furthermore, the VCC pin of the LIN transceiver chip is connected to the IN pin of the LDO circuit chip through a first control circuit.

[0010] Furthermore, the LIN transceiver and the CAN transceiver are both connected to the MCU microcontroller via a UART bus.

[0011] Furthermore, the MCU microcontroller chip is connected to the BUCK chip of the DC-DC circuit via the I / O port via the second control circuit.

[0012] Furthermore, the MCU microcontroller chip is connected to the LDO circuit chip via an I / O port.

[0013] Furthermore, the LDO circuit chip is connected to the BUCK chip of the DC-DC circuit via the WDO pin via the second control circuit.

[0014] Furthermore, the CAN transceiver is connected to the LED driving circuit via a CAN bus.

[0015] Furthermore, the MCU microcontroller is an S32K144 chip from NXP.

[0016] Furthermore, the driving chip of the LED driving circuit is an E522.94 chip from ELMOS.

[0017] Furthermore, the LIN transceiver is an integrated SBC TJA1028 from NXP.

[0018] Furthermore, the BUCK chip is TLF51801ELV from Infineon Technologies.

[0019] Furthermore, the LDO circuit chip is TPS7B6333 from TI.

[0020] Furthermore, the CAN transceiver chip adopts TCAN1044 from TI.

[0021] The utility model discloses a system for entering a functional safety mode based on the taillight ECU of a vehicle with MCU failure. First, the LDO output integrated in the LIN chip is monitored. The RSTN pin of the LIN chip is connected to the IO port of the MCU. Once the LDO output is abnormal, the MCU will monitor the voltage abnormality and provide feedback to the outside. Meanwhile, the MCU cannot work completely normally. At the same time, the watchdog integrated in the external LDO chip is used to monitor the MCU. Once the MCU dog feeding times out, the LDO chip is triggered to output a low level. This reset mode only monitors the MCU and is not affected by other modules and other factors, so that the system enters the functional safety mode.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a system architecture diagram of the utility model based on the MCU failure vehicle taillight ECU entering the functional safety mode;

[0025] Figure 2 This is a system connection diagram of the utility model based on the vehicle taillight ECU entering the functional safety mode when the MCU fails;

[0026] Figure 3 This is a control flow chart of the system of the utility model based on the MCU failure vehicle taillight ECU entering the functional safety mode.

[0027] In the figure:

[0028] 1. LIN transceiver; 2. First control circuit; 3. Second control circuit; 4. MCU microcontroller; 5. LDO circuit; 6. DC-DC circuit; 7. CAN transceiver; 8. LED drive circuit; 9. LED; 10. Body KL30 power supply module; 20. ICAS body end LIN signal module. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] like Figures 1 to 3 As shown, the utility model provides a system for a vehicle taillight ECU to enter a functional safety mode based on an MCU failure, comprising:

[0031] LIN transceiver 1, first control circuit 2, second control circuit 3, MCU microcontroller 4, LDO circuit 5, DC-DC circuit 6, CAN transceiver 7, LED drive circuit 8 and LED 9, LIN transceiver 1, first control circuit 2 and second control circuit 3 are all connected to the vehicle body KL30 power supply module 10, LIN transceiver 1 is connected to the ICAS vehicle body end LIN signal module 20, LIN transceiver 1, second control circuit 3, LDO circuit 5 and CAN transceiver 7 are all connected to the MCU microcontroller 4, LIN transceiver 1 is connected to the first control circuit 2, the first control circuit 2, the second control circuit 3 and CAN transceiver 7 are all connected to the LDO circuit 5, the second control circuit 3, LED drive circuit 8 and LED 9 are all connected to the DC-DC circuit 6.

[0032] The system of the utility model for entering the functional safety mode based on the taillight ECU of a vehicle with MCU failure can be divided into a sensing end and an execution end. The front end includes a body KL30 power supply module 10 and an ICAS body end LIN signal module 20. The middle includes a LIN transceiver 1, an MCU microcontroller 4, a DC-DC circuit 6 for power supply, an LDO circuit 5 for powering a CAN transceiver 7, a CAN transceiver 7 and an LED driver chip. The back end serves as an execution end for an LED module.

[0033] The LIN transceiver 1 is an integrated SBC TJA1028 from NXP, the first control circuit 2 and the second control circuit 3 are both built with MOS tube circuits, the MCU microcontroller 4 is the S32K144 chip from NXP, the LDO circuit 5 chip is the TPS7B6333 from TI, the BUCK chip of the DC-DC circuit 6 is the TLF51801ELV from Infineon, the CAN transceiver 7 chip uses the TCAN1044 from TI, and the driver chip of the LED driver circuit 8 is the E522.94 chip from ELMOS.

[0034] The LIN signal module 20 at the vehicle body end of the ICAS is connected to the LIN transceiver 1 through the LIN bus, the VCC pin of the LIN transceiver 1 chip is connected to the IN pin of the LDO circuit 5 chip through the first control circuit 2, the LIN transceiver 1 and the CAN transceiver 7 are both connected to the MCU microcontroller 4 through the UART bus, the MCU microcontroller 4 chip is connected to the BUCK chip of the DC-DC circuit 6 through the I / O port through the second control circuit 3, the MCU microcontroller 4 chip is connected to the LDO circuit 5 chip through the I / O port, the LDO circuit 5 chip is connected to the BUCK chip of the DC-DC circuit 6 through the second control circuit 3 through the WDO pin, and the CAN transceiver 7 is connected to the LED drive circuit 8 through the CAN bus.

[0035] like Figure 2 As shown, the VCC pin of the LIN transceiver 1 chip is connected to the IN pin of the LDO circuit 5 chip through the first control circuit 2, so that the LDO chip and the MCU microcontroller 4 are powered at the same time. While the MCU microcontroller 4 is initialized, the LDO chip and the CAN transceiver 7 are initialized in advance before the MCU microcontroller 4 is initialized. The pin of the MCU microcontroller 4 is connected to the WD pin of the LDO chip. When the MCU feeds the watchdog integrated in the LDO regularly, the MCU itself is monitored. At the same time, the pin of the MCU microcontroller 4 is connected to the VIN pin of the Buck chip through the second control circuit 3, and the pin of the MCU microcontroller 4 is connected to the EN pin of the LDO chip through the second control circuit 3. The WDO pin of the LDO chip is connected to the VIN pin of the BUCK chip through the second control circuit 3. The second control circuit 3 is an OR gate circuit, which is controlled by the MCU pin or the WDO pin of the LDO, and can turn on the power supply of the BUCK chip, so that when the MCU fails to feed the dog, the WDO pin outputs a low level to turn on the Buck power supply circuit to power the driver chip and the LED.

[0036] like Figure 3 As shown, in the system of the utility model, the MCU failed vehicle taillight ECU enters the functional safety mode, the LIN transceiver 1 chip receives the vehicle body LIN signal, and converts it into a UART signal to transmit to the MCU microcontroller 4, the MCU microcontroller 4 controls the circuit enable of the BUCK chip, and processes the UART signal to receive the lighting or closing instruction, and transmits it to the CAN transceiver 7 through the UART signal, the CAN transceiver 7 converts it into a differential signal and finally controls the driver chip, and at the same time, the MCU microcontroller 4 needs to feed the dog to the LDO chip through the WD pin regularly, the LDO chip detects whether the feeding signal is in the watchdog window period, if it times out, the LDO chip will send a low level through the WDO pin to control the circuit enable of the BUCK chip, so that the lighting system enters the functional safety state.

[0037] In summary, the system of the utility model based on the MCU failure vehicle taillight ECU entering the functional safety mode first monitors the LDO output integrated in the LIN chip. The RSTN pin of the LIN chip is connected to the IO port of the MCU. Once the LDO output is abnormal, the MCU will monitor the voltage abnormality and provide feedback to the outside. At the same time, the MCU cannot work completely normally. At the same time, the watchdog integrated in the external LDO chip is used to monitor the MCU. Once the MCU dog feeding times out, the LDO chip is triggered to output a low level. This reset mode only monitors the MCU and is not affected by other modules and other factors, so that the system enters the functional safety mode.

[0038] The various devices selected in this application are all universal standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0039] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A system based on the MCU failure vehicle taillight ECU entering functional safety mode, characterized in that: include: A LIN transceiver (1), a first control circuit (2), a second control circuit (3), an MCU microcontroller (4), an LDO circuit (5), a DC-DC circuit (6), a CAN transceiver (7), an LED drive circuit (8) and an LED (9); the LIN transceiver (1), the first control circuit (2) and the second control circuit (3) are all connected to a vehicle body KL30 power supply module (10); the LIN transceiver (1) is connected to an ICAS vehicle body end LIN signal module (20); the LIN transceiver (1), the second control circuit (3), the LDO circuit (5) and the CAN transceiver (7) are all connected to the MCU microcontroller (4); the LIN transceiver (1) is connected to the first control circuit (2); the first control circuit (2), the second control circuit (3) and the CAN transceiver (7) are all connected to the LDO circuit (5); the second control circuit (3), the LED drive circuit (8) and the LED (9) are all connected to the DC-DC circuit (6).

2. The system for entering functional safety mode based on the MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The ICAS vehicle body end LIN signal module (20) is connected to the LIN transceiver (1) via a LIN bus.

3. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The VCC pin of the LIN transceiver (1) chip and the IN pin of the LDO circuit (5) chip are connected via a first control circuit (2).

4. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The LIN transceiver (1) and the CAN transceiver (7) are both connected to the MCU microcontroller (4) via a UART bus.

5. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The MCU microcontroller (4) chip is connected to the BUCK chip of the DC-DC circuit (6) via the I / O port via the second control circuit (3).

6. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The MCU microcontroller (4) chip is connected to the LDO circuit (5) chip via an I / O port.

7. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The LDO circuit (5) chip is connected to the BUCK chip of the DC-DC circuit (6) via the WDO pin via the second control circuit (3).

8. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The CAN transceiver (7) is connected to the LED driving circuit (8) via a CAN bus.

9. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The MCU microcontroller (4) is a S32K144 chip from NXP.

10. The system for entering functional safety mode based on MCU failure vehicle taillight ECU as claimed in claim 1, characterized in that: The driving chip of the LED driving circuit (8) is an E522.94 chip from ELMOS.

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