Limphome safety control system of automobile IGN relay

Abstract

The invention relates to a Limphome safety control system of an automobile IGN relay, which comprises an IGN relay and an IGN power supply module, an input module comprises a plurality of input sources, namely a master control MCU and a power management chip SBC, the input of the IGN relay is connected with the output of a high-side MOS tube, the output of the power management chip SBC is connected with the input of a signal conversion module, and the signal conversion module is connected with the input of the IGN relay. The output of the signal conversion module is connected with the input of the IGN output self-protection module, and the output of the IGN output self-protection module is connected with the input of the high-side MOS tube; the output of the main control MCU is connected with the input of the IGNONVCC self-hold module, the output of the IGNONVCC self-hold module is connected with the input of the high-side MOS tube, and the IGNONVCC self-hold module has disconnection delay; the master control MCU is further provided with an expansion chip, the output of the expansion chip is connected with the input of the IGN output self-protection module, and the expansion chip has an output self-locking function. And when the MCU or the power management chip SBC is abnormal, the Limphome slope is kept home to normally work.

Description

Technical Field

[0001] The invention relates to the technical field of safety control, in particular to a Limphome safety control system of an automobile IGN relay. Background Art

[0002] When a car (fuel / new energy) is in motion, multiple control modules require IGN to work in normal mode. When IGNON_VCC (safe power supply) is abnormal, the vehicle control system will fail, which will lead to unexpected driving hazards. For example, during vehicle operation, the engine or motor cannot suddenly stop working, and the lights cannot suddenly go out when driving at night. Summary of the invention

[0003] Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides a Limphome safety control system of an automotive IGN relay. When an abnormality occurs in the main control MCU or the power management chip SBC, the Limphome safety control system can work normally.

[0004] The technical solution of the present invention is a Limphome safety control system for an automotive IGN relay, comprising: IGN relay, which is controlled by input module input and gives corresponding feedback signal; IGN power supply module, which is used to receive the feedback signal from the IGN relay and cut off the power supply of IGNON_VCC; The input module includes multiple input sources: main control MCU, power management chip SBC, and the input of the IGN relay is connected to the output of the high-side MOS tube; The output of the power management chip SBC is connected to the input of the signal conversion module, the output of the signal conversion module is connected to the input of the IGN output self-protection module, and the output of the IGN output self-protection module is connected to the input of the high-side MOS tube; The output of the main control MCU is connected to the input of the IGNON_VCC self-holding module, and the output of the IGNON_VCC self-holding module is connected to the input of the high-side MOS tube. The IGNON_VCC self-holding module has a disconnection delay function. When the power supply end AWO of the MCU is abnormal, the SBC will immediately determine the fault and trigger the LimpHome function, so that the signal conversion module maintains the input to the IGN output self-protection module; the main control MCU is also equipped with an expansion chip, and the output of the expansion chip is connected to the input of the IGN output self-protection module. The expansion chip has an output self-locking function. When the MCU fails, the expansion chip locks the original control state and maintains the input to the IGN output self-protection module.

[0005] Beneficial effects of the present invention: A new design of Limphome safety control system is proposed, the core of which is its highly intelligent and fault-tolerant design. The circuit realizes stable operation under various complex working conditions, especially when key components such as main control MCU, power management chip SBC, and power supply end AWO have single or multiple abnormal working conditions, IGN relay and IGNON_VCC (safe power supply) can still maintain normal operation, thus avoiding failure of multiple control modules on the vehicle, and then ensuring the continuity and safety of system functions, so that the vehicle can realize the basic operation function of Limphome without affecting driving safety.

[0006] Preferably, it also includes a vehicle-mounted battery VBAT1 / VBAT2. When IGNON_VCC or AWO is abnormal, VBAT1 / VBAT2 can be used to power the IGN output self-protection module, and the IGN output self-protection module is used as an input source and input to the high-side MOS tube.

[0007] Preferably, the power supply end of the expansion chip is also AWO, mainly to reduce the power supply module and optimize the design cost.

[0008] Preferably, the IGNON_VCC self-holding module has a 400us power-off delay output; when the SBC is abnormal in AWO, it determines the fault after 40uS and triggers the LimpHome function. During the delay power-on period of the IGNON_VCC self-holding module, it is ensured that the SBC starts successfully. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A control system diagram of a specific embodiment of the present invention; Figure 2 is a circuit diagram of an IGN power supply module in a specific embodiment of the present invention; Figure 3 It is a circuit connection diagram of the main control MCU, expansion chip, power management chip SBC, and signal conversion module in a specific embodiment of the present invention; Figure 4 It is a circuit diagram of the IGNON_VCC self-holding module in a specific embodiment of the present invention; Figure 5 It is a circuit diagram of an IGN output self-protection module in a specific embodiment of the present invention; Figure 6 It is a circuit connection diagram of a MOS tube and an IGN relay in a specific embodiment of the present invention.

[0010] In the figure: IGN power supply module ①, main control MCU ②, expansion chip ③, power management chip SBC ④, signal conversion module ⑤, IGNON_VCC self-holding module ⑥, IGN output self-protection module ⑦, MOS tube ⑧, IGN relay ⑨. DETAILED DESCRIPTION

[0011] like Figure 1-6 As shown, a Limphome safety control system of an automobile IGN relay of the present invention comprises: IGN relay, which is controlled by input module input and gives corresponding feedback signal; IGN power supply module, which is used to receive the feedback signal from the IGN relay and cut off the power supply of IGNON_VCC. The IGN power supply module has a transistor. When the feedback ignition is turned on, the transistor is turned on, so that the IGNON_VCC (safety power supply) power supply can be output normally. The input module includes multiple input sources: main control MCU, power management chip SBC, expansion chip and IGN output self-protection module. The input of the IGN relay is connected to the output OUT2 _HS port of the high-side MOS tube. The high-side MOS tube adopts TLE75080-ESH. The output of the power management chip SBC is connected to the input of the signal conversion module, the output of the signal conversion module is connected to the input of the IGN output self-protection module, and the output of the IGN output self-protection module is connected to the input of the high-side MOS tube; The output of the master control MCU is connected to the input of the IGNON_VCC self-holding module, and the output of the IGNON_VCC self-holding module is connected to the input of the high-side MOS tube. The IGNON_VCC self-holding module has a disconnection delay function. When the power supply end AWO of the MCU is abnormal, the SBC will immediately determine the fault and trigger the LimpHome function, so that the signal conversion module maintains the input to the IGN output self-protection module; The main control MCU is also equipped with an expansion chip PCA9539, the output of which is connected to the input of the IGN output self-protection module. The expansion chip has an output self-locking function. When the MCU fails, the expansion chip acts as an input source, locks the original control state and maintains the input to the IGN output self-protection module. The power supply end of the expansion chip is also AWO; It also includes the vehicle battery VBAT1 / VBAT2, VBAT1 / VBAT2 is connected to the high-side MOS tube, the power supply voltage of the IGN output self-protection module comes from the output of the MOS tube, and its voltage is powered by VBAT1 / VBAT2. When IGNON_VCC or AWO is abnormal, VBAT1 / VBAT2 can be used to power the IGN output self-protection module, and the IGN output self-protection module is used as an input source and input to the high-side MOS tube.

[0012] Specifically, the IGNON_VCC self-holding module has a 400us power-off delay output; when the SBC is abnormal in AWO, it judges the fault after 40uS and triggers the LimpHome function.

[0013] The control system of the present invention has multiple input sources such as a main control MCU, an expansion chip PCA9539, a power management chip SBC and an IGN output self-protection module. When any one of the input sources works normally, the IGN relay and IGNON_VCC (safety power supply) can maintain normal operation.

[0014] MCU fault (code error, chip physical damage, etc.) When the MCU fails, the port output state of ING_Realy_EN_H cannot be maintained. At this time, the expansion chip PCA9539 can latch the original control state and maintain the output. Therefore, the IGN output self-protection module can stably output a high level to the IN0 port of the MOS tube TLE75080. The MOS maintains the output, thereby ensuring the stable operation of the IGN relay. AWO abnormality on the power supply end (short circuit, voltage problem...) When the power supply AWO is abnormal, the MCU cannot maintain the output state, and the IGNON_VCC self-holding module maintains the 400us power-off delay output function. The SBC will determine the fault after 40uS and trigger the LimpHome function, thereby ensuring that the signal conversion module Limphome_OUT maintains the output, the input of the IGN output self-protection module, and then ensure the stable output of the MOS tube, and maintain the stable operation of the IGN relay;

[0015] The SBC itself fails (code runs away, chip is physically damaged, etc.), the MCU detects the SBC abnormality, the MCU and the expansion chip PCA9539 maintain the output, ensuring that the MOS tube input is valid, thereby ensuring the normal operation of the back-end IGN relay.

[0016] The vehicle battery VBAT1 / VBAT2 can be used to power the IGN output self-protection module, which can directly input the high-side MOS tube to maintain the stable operation of the IGN relay.

Claims

1. A Limphome safety control system for an automotive IGN relay, characterized in that: include: IGN relay, which is controlled by input module input and gives corresponding feedback signal; IGN power supply module, which is used to receive the feedback signal from the IGN relay and cut off the power supply of IGNON_VCC; The input module includes multiple input sources: main control MCU, power management chip SBC, and the input of the IGN relay is connected to the output of the high-side MOS tube; The output of the power management chip SBC is connected to the input of the signal conversion module, the output of the signal conversion module is connected to the input of the IGN output self-protection module, and the output of the IGN output self-protection module is connected to the input of the high-side MOS tube; The output of the master control MCU is connected to the input of the IGNON_VCC self-holding module, and the output of the IGNON_VCC self-holding module is connected to the input of the high-side MOS tube. The IGNON_VCC self-holding module has a disconnection delay function. When the power supply end AWO of the MCU is abnormal, the SBC will immediately determine the fault and trigger the LimpHome function, so that the signal conversion module maintains the input to the IGN output self-protection module; The main control MCU is also equipped with an expansion chip, the output of which is connected to the input of the IGN output self-protection module. The expansion chip has an output self-locking function. When the MCU fails, the expansion chip locks the original control state and maintains the input to the IGN output self-protection module.

2. The Limphome safety control system of an automotive IGN relay according to claim 1, characterized in that: It also includes the vehicle battery VBAT1 / VBAT2. When IGNON_VCC or AWO is abnormal, VBAT1 / VBAT2 can be used to power the IGN output self-protection module, and the IGN output self-protection module can be used as an input source and input to the high-side MOS tube.

3. The Limphome safety control system of an automotive IGN relay according to claim 1, characterized in that: The power supply end of the expansion chip is also AWO.

4. The Limphome safety control system of an automotive IGN relay according to claim 1, characterized in that: The expansion chip uses PCA9539.

5. The Limphome safety control system of an automotive IGN relay according to claim 1, characterized in that: The IGNON_VCC self-holding module has a 400us power-off delay output; when the SBC is abnormal in AWO, it will judge the fault after 40uS and trigger the LimpHome function.

6. The Limphome safety control system of an automotive IGN relay according to claim 1, characterized in that: The high-side MOS tube uses TLE75080-ESH.

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