Knock sensor fault detection method, circuit and system

Abstract

The embodiment of the application discloses a knock sensor fault detection method, circuit and system, the method comprises the following steps: determining whether the knock sensor has an open circuit fault according to the partial pressure voltage of the knock sensor and the open circuit fault voltage threshold; if the knock sensor does not have an open circuit fault, and the engine is in a zero speed mode, then determining whether the knock sensor has a hardware interference fault according to the static integral voltage of the passage of all cylinders of the engine and the static threshold; if the knock sensor does not have an open circuit fault, and the engine speed is higher than the dynamic fault speed threshold, then determining whether the knock sensor has a sensor falling-off fault according to the dynamic integral voltage of the passage of the cylinder of the engine and the dynamic background noise threshold. The knock sensor open circuit and sensor falling-off faults can be quickly and accurately located, and the risk of abnormal engine operation is reduced.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a method, circuit, and system for detecting knock sensor faults. Background Technology

[0002] Knocking is an abnormal combustion phenomenon in an engine that not only worsens fuel economy and emissions but also causes significant impacts to engine components such as the cylinder head, potentially damaging the engine. A knock sensor, mounted on the engine block, detects knocking; its failure can severely disrupt normal engine operation.

[0003] Background noise is the voltage signal output by the knock sensor during normal engine operation when no knocking occurs. In existing technology, knock sensor malfunctions are detected by collecting the background noise voltage during engine operation as a reference value and comparing it with the set upper and lower limit reference voltages for normal knock sensor operation, thereby identifying knock sensor malfunctions.

[0004] Existing knock sensor fault detection solutions require high accuracy in the upper and lower limit calibration of fault comparisons, and can only identify sensor failures, but cannot accurately distinguish between knock sensor detachment from the body and open circuit faults in the knock signal line. Summary of the Invention

[0005] Therefore, this application provides a method, circuit, and system for detecting knock sensor faults, which can quickly and accurately locate open circuit and sensor detachment faults in the knock sensor, reducing the risk of abnormal engine operation.

[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0007] According to a first aspect of the embodiments of this application, a method for detecting a knock sensor fault is provided, the method comprising:

[0008] The knock sensor's voltage is acquired through a voltage divider circuit, and the knock sensor is connected to several engine cylinders.

[0009] The number of open-circuit faults is determined based on the voltage divider voltage and open-circuit fault voltage threshold of the knock sensor. If the number of open-circuit faults reaches the threshold, it is determined that the knock sensor has an open-circuit fault.

[0010] If the knock sensor does not have an open circuit fault and the engine is in zero-speed mode, then the knock sensor is determined to have a hardware interference fault based on the static integral voltage and static threshold of all cylinder channels of the engine.

[0011] If the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold, then the knock sensor is determined to have a sensor detachment fault based on the dynamic integral voltage of all engine cylinder channels and the dynamic background noise threshold.

[0012] Optionally, before determining the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold, the method further includes:

[0013] The voltage divider of the knock sensor is read according to the set period. After confirming that the voltage sampling is stable based on the voltage difference between periods, the open circuit fault detection is initiated.

[0014] Optionally, determining whether the knock sensor has a hardware interference fault based on the static integral voltage and static threshold of all cylinder channels of the engine includes:

[0015] If the static integral voltage of any cylinder channel of the engine is greater than the static threshold, the knock sensor is determined to have a hardware interference fault, and a hardware interference fault warning is issued.

[0016] Optionally, determining whether the knock sensor has a sensor detachment fault based on the dynamic integral voltage and dynamic background noise threshold of all engine cylinder channels includes:

[0017] If the dynamic integral voltage of a cylinder channel is less than the dynamic background noise threshold, the number of channel sensor failures is incremented by one.

[0018] When the cumulative number of channel sensor failures exceeds the dynamic failure number threshold, it is determined that the knock sensor has a sensor detachment fault, and a sensor detachment fault prompt is issued.

[0019] Optionally, determining the number of open-circuit faults based on the voltage divider of the knock sensor and the open-circuit fault voltage threshold includes:

[0020] If the voltage divider of the knock sensor is higher than the open circuit fault voltage threshold, the number of open circuit faults is incremented by one.

[0021] According to a second aspect of the embodiments of this application, a knock sensor fault detection circuit is provided, which applies the knock sensor fault detection method described in the first aspect. The knock sensor fault detection circuit includes a power supply, a microcontroller, a knock sensor, a voltage acquisition circuit, and a switch output circuit.

[0022] The microcontroller outputs high and low levels through a switching output circuit to control the power supply to be turned on or off.

[0023] The voltage acquisition circuit detects knock sensor malfunctions by acquiring the voltage of the knock sensor.

[0024] Optionally, a current-limiting third resistor and a MOSFET are provided between the microcontroller and the power supply, a current-limiting fourth resistor is provided between the microcontroller and the knock sensor, and an equivalent second resistor is provided between the power supply and the knock sensor.

[0025] According to a third aspect of the embodiments of this application, a knock sensor fault detection system is provided, the system comprising:

[0026] A voltage acquisition module is used to acquire the voltage divider voltage of the knock sensor through a voltage divider circuit. The knock sensor is connected to several engine cylinders.

[0027] An open-circuit fault detection module is used to determine the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold. If the number of open-circuit faults reaches the threshold, it is determined that the knock sensor has an open-circuit fault.

[0028] The static fault detection module is used to determine whether the knock sensor has a hardware interference fault if the knock sensor does not have an open circuit fault and the engine is in zero speed mode, based on the static integral voltage and static threshold of the channels of all cylinders of the engine.

[0029] The dynamic fault detection module is used to determine whether the knock sensor has a sensor detachment fault based on the dynamic integral voltage of the channels of all engine cylinders and the dynamic background noise threshold if the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold.

[0030] According to a fourth aspect of the present application, an electronic device is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect above.

[0031] According to a fifth aspect of the present application, a computer-readable storage medium is provided that stores computer-readable instructions thereon, which can be executed by a processor to implement the method described in the first aspect above.

[0032] In summary, this application provides a method, circuit, and system for detecting knock sensor faults. It acquires the voltage divider voltage of the knock sensor, which is connected to several engine cylinders. The number of open-circuit faults is determined based on the knock sensor's voltage divider voltage and an open-circuit fault voltage threshold. If the number of open-circuit faults reaches the threshold, the knock sensor is determined to have an open-circuit fault. If the knock sensor does not have an open-circuit fault and the engine is in zero-speed mode, the presence of hardware interference faults in the knock sensor is determined based on the static integrated voltage and static threshold of all cylinder channels. If the knock sensor does not have an open-circuit fault and the engine speed is higher than a dynamic fault speed threshold, the sensor detachment fault is determined based on the dynamic integrated voltage and dynamic background noise threshold of all cylinder channels. This method can quickly and accurately locate open-circuit and detachment faults in the knock sensor, reducing the risk of abnormal engine operation. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] Figure 1 This is a schematic flowchart of a knock sensor fault detection method provided in an embodiment of this application;

[0036] Figure 2 This application provides a hardware detection circuit for a knock sensor failure.

[0037] Figure 3 This is a flowchart of the knock sensor fault detection process provided in an embodiment of this application;

[0038] Figure 4 A block diagram of a knock sensor fault detection system provided in this application embodiment;

[0039] Figure 5 This illustration shows a structural schematic diagram of an electronic device provided in an embodiment of this application;

[0040] Figure 6 A schematic diagram of a computer-readable storage medium provided in an embodiment of this application is shown. Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0042] Figure 1 This application illustrates a knock sensor fault detection method provided in an embodiment, the method comprising:

[0043] Step 101: Acquire the voltage divider voltage of the knock sensor through a voltage divider circuit, wherein the knock sensor is connected to several engine cylinders;

[0044] Step 102: Determine the number of open-circuit faults based on the voltage divider of the knock sensor and the open-circuit fault voltage threshold. If the number of open-circuit faults reaches the threshold, it is determined that the knock sensor has an open-circuit fault.

[0045] Step 103: If the knock sensor does not have an open circuit fault and the engine is in zero speed mode, then determine whether the knock sensor has a hardware interference fault based on the static integral voltage and static threshold of all cylinder channels of the engine.

[0046] Step 104: If the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold, then determine whether the knock sensor has a sensor detachment fault based on the dynamic integral voltage of all engine cylinder channels and the dynamic background noise threshold.

[0047] In one possible implementation, before determining the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold in step 102, the method further includes:

[0048] The voltage divider of the knock sensor is read according to the set period. After confirming that the voltage sampling is stable based on the voltage difference between periods, the open circuit fault detection is initiated.

[0049] The open-circuit fault voltage threshold is set based on the resistance of the voltage divider circuit. For example, if the knock sensor resistor R1 is 10MΩ and R2 is 10MΩ, and considering the transistor voltage drop, the voltage sampled when the voltage divider circuit is not open is approximately 2V, and the voltage sampled when an open circuit occurs is close to 5V, the open-circuit detection threshold can be set to 3V.

[0050] In one possible implementation, determining the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold in step 102 includes:

[0051] If the voltage divider of the knock sensor is higher than the open circuit fault voltage threshold, the number of open circuit faults is incremented by one.

[0052] The number of open-circuit faults is set based on the actual engine configuration. Multiple cylinders in the engine share a single knock detection sensor, and each cylinder undergoes an open-circuit test. The test result is considered valid when all cylinders sharing the same knock sensor detect an open circuit.

[0053] In one possible implementation, step 103, determining whether the knock sensor has a hardware interference fault based on the static integrated voltage and static threshold of all cylinder channels of the engine, includes:

[0054] If the static integral voltage of any cylinder channel of the engine is greater than the static threshold, the knock sensor is determined to have a hardware interference fault, and a hardware interference fault warning is issued.

[0055] When the engine is not running and there are no faults, there are no knock signals. The static threshold is determined by integrating the knock signal of each cylinder over time when the engine is not running. The integrated voltage value is usually less than 500mV. If a large integrated voltage is detected at this time, it is considered that there is an interference signal.

[0056] In one possible implementation, step 104, determining whether the knock sensor has a sensor detachment fault based on the dynamic integrated voltage of all engine cylinder channels and the dynamic background noise threshold, includes:

[0057] If the dynamic integral voltage of a cylinder channel is less than the dynamic background noise threshold, the number of channel sensor failures is incremented by one; when the accumulated number of channel sensor failures exceeds the dynamic failure number threshold, it is determined that the knock sensor has a sensor detachment fault, and a sensor detachment fault prompt is issued.

[0058] During engine operation, knock integral signal detection is performed. Even without knocking, as long as the engine operates under certain conditions, there will be a minimum background noise. The dynamic background noise threshold is the minimum integral voltage value. When the engine speed is higher than the set speed, such as 1000 rpm, if the background noise integral voltage is less than 300mV, the sensor is considered abnormal. Combined with the open circuit fault detection results, if there is no open circuit, it is determined that the sensor has detached.

[0059] The dynamic fault speed threshold is determined based on the principle that multiple cylinders share a single knock sensor, ensuring consistent detection results.

[0060] Based on the same technical concept, this application embodiment also provides a detonation sensor fault detection circuit, applying the aforementioned detonation sensor fault detection method. The detonation sensor fault detection circuit includes a microcontroller, a detonation sensor, a voltage acquisition circuit, and a switch output circuit. The microcontroller outputs high and low levels through the switch output circuit to control the power supply to be turned on or off. The voltage acquisition circuit detects detonation sensor faults by acquiring the voltage of the detonation sensor.

[0061] In one possible implementation, a current-limiting third resistor and a MOSFET are provided between the microcontroller and the power supply, a current-limiting fourth resistor is provided between the microcontroller and the knock sensor, and an equivalent second resistor is provided between the power supply and the knock sensor.

[0062] This application provides a knock sensor fault detection scheme, which consists of two parts: hardware detection circuit and software strategy design.

[0063] Hardware detection circuit such as Figure 2 As shown, the piezoelectric knock sensor is mounted on the machine body. It utilizes the piezoelectric effect to convert mechanical vibration into a voltage signal, which is then transmitted to the ECU for knock detection. The piezoelectric knock sensor itself has a certain internal resistance. The equivalent resistors R1 and R2 form a voltage divider circuit, and fault diagnosis is performed based on different voltage values ​​collected. R3 and R4 are used for current limiting protection and are not related to this invention. A current limiting resistor R3 and a MOSFET are provided between the microcontroller and the power supply; a current limiting resistor R4 is provided between the microcontroller and the knock sensor; and an equivalent resistor R2 is provided between the power supply and the knock sensor.

[0064] Compared to the original knock signal processing circuit, a 5V pull-up control circuit for the positive knock signal and a voltage sampling circuit have been added. Depending on the engine's operating conditions, the microcontroller controls the switch output to high or low levels, thus enabling or disabling the 5V pull-up. By switching the 5V pull-up switch state through hardware circuitry, the circuit distinguishes between two fault states: an open circuit in the knock sensor signal line and the sensor detaching from the engine block. This facilitates rapid and accurate location and repair of knock sensor faults, reducing the risk of abnormal engine operation.

[0065] Figure 3 The specific knock sensor fault detection process is illustrated, divided into three stages. In the fault detection process, one can choose to perform open-circuit fault detection first, followed by static fault detection, and then dynamic fault detection. Alternatively, open-circuit fault detection can be performed first, followed by dynamic fault detection. Or, the three stages can be performed independently.

[0066] Phase 1: Detection of open circuit faults in knock sensors.

[0067] Typically, a single knock sensor is shared by multiple cylinders on an engine. Open-circuit fault detection of the knock sensor is performed during power-on initialization, and the detection process is as follows:

[0068] (a) When the pull-up 5V power supply is turned on, the voltage divider circuit formed by the equivalent resistors R1 and R2 in the above figure has a voltage divider relationship, and the microcontroller will collect the voltage divider voltage of the knock sensor.

[0069] (b) Read the sensor voltage at fixed intervals, such as every 10ms, and compare it with the sampled value of the previous 10ms. After confirming that the sampled voltage is stable, set the open circuit fault valid position to start the open circuit fault judgment.

[0070] (c) Open circuit fault detection is a diagnostic process that is triggered once for each cylinder. The knock sensor voltage is read. When the sampled voltage is higher than the open circuit fault identification threshold voltage, the number of open circuit fault detections is accumulated.

[0071] (d) If the cumulative number of open-circuit fault detections for a sensor exceeds the open-circuit fault determination threshold, the knock sensor is considered to have an open-circuit fault, and the open-circuit fault bit is set. Otherwise, the open-circuit fault bit is cleared to zero.

[0072] (e) After the fault detection is completed, the 5V power supply is turned off.

[0073] Phase 2: Static fault detection of the knock sensor.

[0074] Static fault detection for knock sensors is primarily used to detect hardware circuit faults and interference on the sensor signal lines. Static fault detection is performed after open-circuit fault detection has concluded, and the entry conditions are that there are currently no open-circuit faults in the sensor and the engine is in 0 RPM mode. Under normal circumstances, when the engine is not running, the knock integral voltage will be very small because there is no signal injected into the sensor harness. The detection process is as follows:

[0075] (a) Perform fixed-time knock signal integration processing on the channel of each cylinder to obtain the processed integrated voltage;

[0076] (b) Collect the static integrated voltage of all cylinder channels. If the collected integrated voltage exceeds the static integrated threshold, an abnormal signal is considered to exist, and a knock signal abnormality fault is reported. Otherwise, it is in normal condition, and the knock sensor static fault detection is exited.

[0077] It should be noted that if an abnormal signal is detected in the channel of any cylinder, a knock signal abnormality fault will be reported.

[0078] Phase 3: Dynamic fault detection of knock sensor.

[0079] Dynamic fault detection of knock sensors is mainly used to detect faults caused by knock sensors detaching from the engine block. When the sensor detaches from the engine block, the vibration signal on the engine block cannot be converted into a valid piezoelectric signal. Fault detection is performed by identifying the background noise of the engine during operation and the integrated voltage actually collected by the sensor.

[0080] The testing process is as follows:

[0081] (a) Enable dynamic fault detection of the knock sensor when the engine speed is higher than the dynamic fault diagnosis speed threshold and there is no open circuit fault of the knock sensor in the current channel.

[0082] (b) Based on the actual operating conditions of the engine, the knock signal of all cylinder channels is integrated to obtain the integrated voltage after processing.

[0083] (c) When the integrated voltage collected is less than the dynamic minimum background noise voltage threshold, the number of sensor fault identifications for the corresponding channel is accumulated. When the accumulated number exceeds the fault confirmation threshold, it is considered that there is a knock sensor detachment fault, and the knock sensor detachment fault is reported.

[0084] It can accurately distinguish between a knock sensor detaching from the engine body and a knock signal line open circuit fault, facilitating quick and accurate location and repair of knock sensor malfunctions and reducing the risk of abnormal engine operation.

[0085] In summary, this application provides a method and circuit for detecting knock sensor faults. It acquires the voltage divider voltage of the knock sensor via a voltage divider circuit, and the knock sensor is connected to several engine cylinders. The number of open-circuit faults is determined based on the knock sensor's voltage divider voltage and an open-circuit fault voltage threshold. If the number of open-circuit faults reaches the threshold, the knock sensor is determined to have an open-circuit fault. If the knock sensor does not have an open-circuit fault and the engine is in zero-speed mode, the presence of hardware interference faults in the knock sensor is determined based on the static integrated voltage and static threshold of all cylinder channels. If the knock sensor does not have an open-circuit fault and the engine speed is higher than a dynamic fault speed threshold, the sensor detachment fault is determined based on the dynamic integrated voltage and dynamic background noise threshold of all cylinder channels. This method can quickly and accurately locate open-circuit and detachment faults in the knock sensor, reducing the risk of abnormal engine operation.

[0086] Based on the same technical concept, embodiments of this application also provide a knock sensor fault detection system, such as... Figure 4 As shown, the system includes:

[0087] The voltage acquisition module 401 is used to acquire the voltage divider voltage of the knock sensor through a voltage divider circuit, wherein the knock sensor is connected to several engine cylinders;

[0088] The open circuit fault detection module 402 is used to determine the number of open circuit faults based on the voltage divider voltage of the knock sensor and the open circuit fault voltage threshold. If the number of open circuit faults reaches the threshold, it is determined that the knock sensor has an open circuit fault.

[0089] The static fault detection module 403 is used to determine whether the knock sensor has a hardware interference fault based on the static integral voltage and static threshold of the channels of all cylinders of the engine if the knock sensor does not have an open circuit fault and the engine is in zero speed mode.

[0090] The dynamic fault detection module 404 is used to determine whether the knock sensor has a sensor detachment fault based on the dynamic integral voltage of the channels of all engine cylinders and the dynamic background noise threshold if the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold.

[0091] This application also provides an electronic device corresponding to the method provided in the foregoing embodiments. Please refer to... Figure 5The diagram illustrates an electronic device provided by some embodiments of this application. The electronic device 20 may include: a processor 200, a memory 201, a bus 202, and a communication interface 203, wherein the processor 200, the communication interface 203, and the memory 201 are connected via the bus 202; the memory 201 stores a computer program that can run on the processor 200, and when the processor 200 runs the computer program, it executes the method provided by any of the foregoing embodiments of this application.

[0092] The memory 201 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one physical port 203 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network.

[0093] Bus 202 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory 201 is used to store programs. After receiving an execution instruction, the processor 200 executes the program. The method disclosed in any of the foregoing embodiments of this application can be applied to the processor 200, or implemented by the processor 200.

[0094] The processor 200 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 200 or by instructions in software form. The processor 200 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 201. The processor 200 reads the information in memory 201 and, in conjunction with its hardware, completes the steps of the above method.

[0095] The electronic devices and methods provided in the embodiments of this application are based on the same inventive concept and have the same beneficial effects as the methods they employ, operate, or implement.

[0096] This application also provides a computer-readable storage medium corresponding to the method provided in the foregoing embodiments. Please refer to... Figure 6 The computer-readable storage medium shown is an optical disc 30, on which a computer program (i.e., a program product) is stored, which, when run by a processor, executes the methods provided in any of the foregoing embodiments.

[0097] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical and magnetic storage media, which will not be elaborated here.

[0098] The computer-readable storage medium provided in the above embodiments of this application and the method provided in the embodiments of this application are based on the same inventive concept and have the same beneficial effects as the methods adopted, run or implemented by the applications stored therein.

[0099] It should be noted that:

[0100] The algorithms and displays provided herein are not inherently related to any particular computer, virtual device, or other equipment. Various general-purpose devices can also be used in conjunction with the teachings herein. The required structure for constructing such devices is apparent from the above description. Furthermore, this application is not directed to any particular programming language. It should be understood that the content of this application described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of this application.

[0101] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0102] Similarly, it should be understood that, in order to simplify this application and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of this application, various features of this application are sometimes grouped together into a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0103] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0104] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0105] The various component embodiments of this application can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components in the virtual machine creation apparatus according to embodiments of this application. This application can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such an implementation of this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0106] It should be noted that the above embodiments are illustrative of this application and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0107] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting a knock sensor fault, characterized in that, The method includes: The knock sensor's voltage is acquired through a voltage divider circuit, and the knock sensor is connected to several engine cylinders. The number of open-circuit faults is determined based on the voltage divider voltage and open-circuit fault voltage threshold of the knock sensor. If the number of open-circuit faults reaches the threshold, it is determined that the knock sensor has an open-circuit fault. If the knock sensor does not have an open circuit fault and the engine is in zero-speed mode, then the knock sensor is determined to have a hardware interference fault based on the static integral voltage and static threshold of all cylinder channels of the engine. If the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold, then the knock sensor is determined to have a sensor detachment fault based on the dynamic integral voltage of all engine cylinder channels and the dynamic background noise threshold. The step of determining whether the knock sensor has a sensor detachment fault based on the dynamic integral voltage and dynamic background noise threshold of all engine cylinder channels includes: if the dynamic integral voltage of a cylinder channel is less than the dynamic background noise threshold, the channel sensor fault count is incremented by one; when the accumulated channel sensor fault count exceeds the dynamic fault count threshold, the knock sensor is determined to have a sensor detachment fault, and a sensor detachment fault prompt is issued.

2. The method as described in claim 1, characterized in that, Before determining the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold, the method further includes: The voltage divider of the knock sensor is read according to the set period. After confirming that the voltage sampling is stable based on the voltage difference between periods, the open circuit fault detection is initiated.

3. The method as described in claim 1, characterized in that, The determination of whether the knock sensor has a hardware interference fault based on the static integrated voltage and static threshold of all cylinder channels of the engine includes: If the static integral voltage of any cylinder channel of the engine is greater than the static threshold, the knock sensor is determined to have a hardware interference fault, and a hardware interference fault warning is issued.

4. The method as described in claim 1, characterized in that, The step of determining the number of open-circuit faults based on the voltage divider of the knock sensor and the open-circuit fault voltage threshold includes: If the voltage divider of the knock sensor is higher than the open circuit fault voltage threshold, the number of open circuit faults is incremented by one.

5. A knock sensor fault detection circuit, employing the knock sensor fault detection method according to any one of claims 1-4, characterized in that, The knock sensor fault detection circuit includes a power supply, a microcontroller, a knock sensor, a voltage acquisition circuit, and a switch output circuit. The microcontroller outputs high and low levels through the switch output circuit to control the power supply to be turned on or off. The voltage acquisition circuit detects knock sensor malfunctions by acquiring the voltage of the knock sensor.

6. The knock sensor fault detection circuit as described in claim 5, characterized in that, A current-limiting third resistor and a MOSFET are provided between the microcontroller and the power supply; a current-limiting fourth resistor is provided between the microcontroller and the knock sensor; and an equivalent second resistor is provided between the power supply and the knock sensor.

7. A knock sensor fault detection system, characterized in that, The system includes: A voltage acquisition module is used to acquire the voltage divider voltage of the knock sensor through a voltage divider circuit. The knock sensor is connected to several engine cylinders. An open-circuit fault detection module is used to determine the number of open-circuit faults based on the voltage divider voltage of the knock sensor and the open-circuit fault voltage threshold. If the number of open-circuit faults reaches the threshold, it is determined that the knock sensor has an open-circuit fault. The static fault detection module is used to determine whether the knock sensor has a hardware interference fault if the knock sensor does not have an open circuit fault and the engine is in zero speed mode, based on the static integral voltage and static threshold of the channels of all cylinders of the engine. The dynamic fault detection module is used to determine whether the knock sensor has a sensor detachment fault if the knock sensor does not have an open circuit fault and the engine speed is higher than the dynamic fault speed threshold, based on the dynamic integrated voltage and dynamic background noise threshold of all engine cylinder channels. The determination of whether the knock sensor has a sensor detachment fault based on the dynamic integrated voltage and dynamic background noise threshold of all engine cylinder channels includes: if the dynamic integrated voltage of a cylinder channel is less than the dynamic background noise threshold, incrementing the channel sensor fault count by one; when the accumulated channel sensor fault count exceeds the dynamic fault count threshold, determining that the knock sensor has a sensor detachment fault and issuing a sensor detachment fault warning.

8. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method as claimed in any one of claims 1-4.

9. A computer-readable storage medium, characterized in that, It stores computer-readable instructions that can be executed by a processor to implement the method as described in any one of claims 1-4.

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