Method for realizing low-beam ASIL-B by using filtering acceptance check based on CAN communication

Abstract

The invention discloses a method for realizing low beam ASIL-B by using filtering acceptance based on CAN communication, which comprises the following steps: an OR logic circuit electrically connected with a transceiver module, an MCU and a DC-DC module respectively writes a message with ID = 9 as a start for the transceiver module as a wake-up source, and when an upper layer vehicle body controller sends a request of turning on a low beam through a bus, the upper layer vehicle body controller sends the request of turning on the low beam through the bus; synchronously sending a message of which the ID beginning is 9 to the transceiver module; the OR logic circuit is arranged, the OR logic circuit is electrically connected with the transceiver module, the MCU and the DC-DC module, the vehicle lamp can be turned on through two independent control paths, compared with the prior art that the vehicle lamp is turned on only through the MCU, reliable control over the dipped headlight by the vehicle body can still be maintained when the MCU breaks down, and the vehicle lamp can be turned on through the two independent control paths. And effective safety redundancy is formed. The CAN signal is converted into hard wire direct control, so that the signal transfer link is reduced, and the response speed and the communication reliability are improved.

Description

Technical Field

[0001] This invention belongs to the field of vehicle lighting technology, specifically relating to a method for achieving ASIL-B low beam based on CAN communication and using filter acceptance. Background Technology

[0002] ASIL-B functional safety level requirements stipulate that the system can detect and handle random hardware failures with a high coverage rate. For vehicle headlight systems, the low beam lamps must meet the ASIL-B level. For CAN communication-based low beam control systems (e.g., the body control module (BCM) sends low beam activation commands to the headlight control module (ECU) via the CAN bus), an ASIL-B compliant MCU chip is typically required to ensure that the system's random hardware failure rate is lower than the corresponding probability value. This is a mandatory requirement for systems involving communication.

[0003] like Figure 2 As shown, in traditional solutions, a conventional transceiver communicates with the vehicle body and transmits signals to a microcontroller (MCU). The MCU, as the decision-making core of the entire system, undertakes signal calculation and information processing, and then sends control commands to the power (DC-DC) module. The DC-DC module executes energy output or shutdown operations according to the commands, thereby controlling the low beam headlights. Since the MCU plays a crucial role in the entire drive architecture, its performance and reliability directly determine the level of functional safety achieved by the system. To ensure that the low beam headlight function meets ASIL-B safety requirements, an ASIL-B compliant MCU chip must be selected. If a non-compliant MCU is used, its hardware random failure rate will increase significantly, thus introducing higher safety risks. Furthermore, ASIL-B compliant MCU chips are typically expensive, which is a major challenge in terms of resource investment for traditional solutions.

[0004] In traditional automotive lighting control solutions, the MCU, as the core decision-making unit, must use a high-reliability chip that meets the ASIL-B standard. This not only brings high cost pressure, but also poses functional safety risks when the MCU fails. Summary of the Invention

[0005] The purpose of this invention is to provide a method for achieving ASIL-B low beam headlights using filtered acceptance based on CAN communication, thereby solving the problems mentioned in the background art. The method for achieving ASIL-B low beam headlights using filtered acceptance based on CAN communication provided by this invention has the characteristic of maintaining reliable control of the low beam headlights by the vehicle body even in the event of MCU failure, thus forming effective safety redundancy.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for implementing ASIL-B low beam headlights using filtered acceptance based on CAN communication, comprising an OR logic circuit electrically connected to a transceiver module, an MCU, and a DC-DC module respectively, writing a message starting with ID=9 to the transceiver module as a wake-up source, and setting the upper-level body controller to send a "turn on low beam headlights" request via the bus, and synchronously sending a message starting with ID=9 to the transceiver module;

[0007] Includes the following steps:

[0008] S1. The upper-level body controller sends a "turn on low beam headlights" request via the bus and simultaneously sends a message with an ID starting with 9.

[0009] S2. When the MCU is working normally, after receiving the request, the MCU executes the normal control logic. At the same time, the transceiver module receives the message with the ID starting with 9, activates its low beam enable pin, and outputs a high-level enable signal to one input of the OR logic circuit. One of the general-purpose I / O pins of the MCU also outputs a high-level signal to the other input of the OR logic circuit. At least one of the two inputs of the OR logic circuit is a high-level signal, and the OR logic circuit outputs an enable signal to the DC-DC module. The DC-DC module outputs power to drive the low beam to light up.

[0010] S3. When the MCU fails, it cannot work. The transceiver module receives a message with an ID starting with 9, activates its low beam enable pin, and outputs a high-level enable signal to one input of the OR logic circuit, or at least one of the two inputs of the logic circuit is a high-level signal, or the logic circuit outputs an enable signal to the DC-DC module, and the DC-DC module outputs power to drive the low beam to light up.

[0011] In this invention, the logic circuit is further described as a diode OR gate circuit or an OR gate chip.

[0012] In this invention, the transceiver module is a programmable CAN transceiver that meets ASIL-B requirements.

[0013] In this invention, the DC-DC module is a power module that conforms to ASIL-B level.

[0014] In this invention, the MCU is further defined as a QM-level MCU.

[0015] In this invention, the logic circuit receives two input signals: one is a control signal output from the general-purpose IO pin of the MCU, and the other is an enable signal output from the low beam enable pin of the transceiver module. When either of the two input signals is high, the logic circuit outputs an enable signal to the DC-DC module.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. This invention incorporates an OR logic circuit. By electrically connecting the OR logic circuit to the transceiver module, the MCU, and the DC-DC module respectively, two independent control paths can be implemented to turn on the vehicle lights. Compared with the prior art, which only controls the vehicle lights through the MCU, this invention can still maintain reliable control of the low beam headlights by the vehicle body when the MCU fails, forming an effective safety redundancy and ensuring that the core safety functions are not lost.

[0018] 2. This invention converts CAN signals into hard-wired direct control, reducing signal relay links and improving response speed and communication reliability.

[0019] 3. This invention reduces the reliance on ASIL-B level MCU chips, allowing the system to use QM level MCUs. Only the DC-DC module and transceiver module need to use ASIL-B level chips, which helps to optimize the overall cost.

[0020] 4. The transceiver module, DC-DC module, and / or logic circuit of the present invention are highly independent of the MCU in terms of both physical and electrical aspects, thus avoiding common-cause failures.

[0021] 5. This invention uses a message with a specific ID as a trigger condition. This is not only an instruction, but also a "heartbeat" or "diagnostic" mechanism. Being able to receive and respond to this message proves that the communication link and transceiver are functioning normally.

[0022] 6. This invention decomposes the safety requirements (ASIL-B) of the headlight system onto different components. The MCU can use a lower level of QM, while the critical safety tasks are assigned to the transceiver module and DC-DC module that meet the ASIL-B level. This optimizes the cost while ensuring that the functional safety ASIL-B requirements are met. The cost of using a QM-level MCU is less than the cost of adding a simple OR logic circuit. Attached Figure Description

[0023] Figure 1 This is a connection diagram of the vehicle body, headlight driver, and low beam module of the present invention.

[0024] Figure 2 This is a diagram showing the connection relationship between the vehicle body, the headlight driver, and the low beam module in the existing technology. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this invention, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used merely for distinction in description and have no special meaning.

[0029] Example 1

[0030] Please see Figure 1 This embodiment provides the following technical solution: a method for implementing ASIL-B low beam headlights using filtered acceptance based on CAN communication, including OR logic circuits electrically connected to the transceiver module, MCU and DC-DC module respectively, writing a message starting with ID=9 to the transceiver module as a wake-up source, and setting the upper body controller to send a "turn on low beam headlights" request through the bus, and synchronously sending a message starting with ID=9 to the transceiver module.

[0031] When the MCU is working normally, the following steps are included:

[0032] S1. The upper-level body controller sends a "turn on low beam headlights" request via the bus and simultaneously sends a message with an ID starting with 9.

[0033] S2. After receiving the request, the MCU executes normal control logic. At the same time, the transceiver module receives a message with an ID starting with 9, activates its low beam enable pin, and outputs a high-level enable signal to one input of the OR logic circuit. One of the MCU's general-purpose I / O pins also outputs a high-level signal to the other input of the OR logic circuit. At least one of the two inputs of the OR logic circuit is a high-level signal. The OR logic circuit outputs an enable signal to the DC-DC module, and the DC-DC module outputs power to drive the low beam to light up.

[0034] By adopting the above technical solution, the activation of the low beam headlights is jointly accomplished by the communication control of the MCU and the hard-wired control of the low beam headlight enable pin, and the two are synchronized.

[0035] Example 2

[0036] Please see Figure 1 This embodiment provides the following technical solution: a method for implementing ASIL-B low beam headlights using filtered acceptance based on CAN communication, including OR logic circuits electrically connected to the transceiver module, MCU and DC-DC module respectively, writing a message starting with ID=9 to the transceiver module as a wake-up source, and setting the upper body controller to send a "turn on low beam headlights" request through the bus, and synchronously sending a message starting with ID=9 to the transceiver module.

[0037] When an MCU malfunctions, the following steps are included:

[0038] S1. The upper-level body controller sends a "turn on low beam headlights" request via the bus and simultaneously sends a message with an ID starting with 9.

[0039] S2. When the MCU fails to work, the transceiver module receives a message with an ID starting with 9, activates its low beam enable pin, and outputs a high-level enable signal to one input of the OR logic circuit. Although the MCU input is invalid, because the low beam enable pin input is high, at least one of the two inputs of the OR logic circuit is a high-level signal, and the OR logic circuit outputs an enable signal to the DC-DC module, the DC-DC module outputs power to drive the low beam to light up.

[0040] Specifically, the logic circuit is a diode OR gate circuit or an OR gate chip, and in this embodiment, a diode OR gate circuit is preferred.

[0041] Specifically, the transceiver module is a programmable CAN transceiver that meets ASIL-B requirements.

[0042] Specifically, the DC-DC module is a power module that conforms to ASIL-B standards.

[0043] Specifically, the MCU is a QM-level MCU.

[0044] Specifically, the OR logic circuit receives two input signals: one is a control signal output from the general-purpose I / O pin of the MCU, and the other is an enable signal output from the low beam enable pin of the transceiver module. When either of the two input signals is high, the OR logic circuit outputs an enable signal to the DC-DC module.

[0045] In summary, this invention incorporates an OR logic circuit. By electrically connecting this OR logic circuit to the transceiver module, MCU, and DC-DC module respectively, two independent control paths can be established to activate the vehicle lights. Compared to existing technologies that rely solely on the MCU to control the lights, this invention maintains reliable control of the low beam headlights even in the event of an MCU failure, providing effective safety redundancy. This invention converts CAN signals to hard-wired direct control, reducing signal relay links and improving response speed and communication reliability. Furthermore, this invention reduces reliance on ASIL-B grade MCU chips, allowing the system to use QM grade MCUs. Only the DC-DC module and transceiver module need to use ASIL-B grade chips, contributing to overall cost optimization.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for implementing low beam ASIL-B using filter acceptance based on CAN communication, characterized in that: The or logic circuit is electrically connected with the transceiver module, the MCU and the DC-DC module respectively, and writes a message starting with ID=9 as a wake-up source for the transceiver module; when the upper body controller sends a "turn on low beam" request through the bus, a message starting with ID=9 is synchronously sent to the transceiver module; The method comprises the following steps: S1, the upper body controller sends a "turn on low beam" request through the bus, and synchronously sends a message starting with ID=9; S2, when the MCU works normally, the MCU receives the request and executes normal control logic; at the same time, the transceiver module receives the message starting with ID=9, activates the low beam enable pin, outputs a high-level enable signal to one input end of the or logic circuit, a general IO pin of the MCU also outputs a high-level signal to another input end of the or logic circuit, at least one of the two input ends of the or logic circuit is a high-level signal, the or logic circuit outputs an enable signal to the DC-DC module, the DC-DC module outputs power to drive the low beam to light up; S3, when the MCU fails, the MCU cannot work, the transceiver module receives the message starting with ID=9, activates the low beam enable pin, outputs a high-level enable signal to one input end of the or logic circuit, at least one of the two input ends of the or logic circuit is a high-level signal, the or logic circuit outputs an enable signal to the DC-DC module, the DC-DC module outputs power to drive the low beam to light up.

2. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, wherein: The or logic circuit is a diode or a gate circuit.

3. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, characterized in that: The or logic circuit is an or gate chip.

4. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, characterized in that: The transceiver module is a CAN transceiver meeting the ASIL-B level requirement.

5. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 4, characterized in that: The transceiver module is a programmable CAN transceiver.

6. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, wherein: The DC-DC module is a power module meeting the ASIL-B level requirement.

7. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, wherein: The MCU is a QM level MCU.

8. The method for realizing ASIL-B of low beam based on CAN communication and filter acceptance according to claim 1, wherein: The or logic circuit receives two input signals, one from the control signal output by the general IO pin of the MCU, and the other from the enable signal output by the low beam enable pin of the transceiver module; when either of the two input signals is a high-level signal, the or logic circuit outputs an enable signal to the DC-DC module.

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