Interlock failure detection method, interlock failure detection device, and vehicle

Abstract

This application proposes an interlock fault detection method, an interlock fault detection device, and a vehicle, relating to the field of vehicle technology. The vehicle's high-voltage system includes a power conversion module and multiple target first components connected to the power conversion module. Each target first component has an electrical signal sensor. The interlock fault detection method includes: responding to an interlock self-test command, controlling the power conversion module to output characteristic signals to each target first component; detecting the signal strength of the input signal of each target first component through its electrical signal sensor; determining that the corresponding target first component has not experienced an interlock fault if the signal strength of the input signal of each target first component is greater than a preset signal strength; otherwise, determining that the corresponding target first component has experienced an interlock fault. The technical solution provided by this application can improve the problem of existing technologies being unable to accurately locate the specific faulty component when an interlock fault occurs.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to an interlock fault detection method, an interlock fault detection device, and a vehicle. Background Technology

[0002] In electric vehicles, high-voltage interlock detection is typically included to check the connection integrity of various electrical components in the high-voltage network and prevent safety accidents caused by exposed high voltage or arcing. However, existing high-voltage interlock detection solutions cannot accurately pinpoint which specific electrical component has experienced the interlock failure when an interlock fault is detected in the vehicle's high-voltage system. Summary of the Invention

[0003] The main purpose of this application is to propose an interlock fault detection method, interlock fault detection device and vehicle, which aims to improve the problem that the existing technology cannot accurately locate the specific faulty component when an interlock fault occurs.

[0004] To achieve the above objectives, this application proposes an interlock fault detection method based on a vehicle high-voltage system. The vehicle high-voltage system includes a power conversion module and multiple target first components connected to the power conversion module. Each target first component has an electrical signal sensor. The interlock fault detection method includes:

[0005] In response to the interlock self-test command, the control power conversion module outputs characteristic signals to each target first component; The input signal of each target first component is detected by the electrical signal sensor of each target first component, and the signal strength of the corresponding feature signal in the input signal of each target first component is determined. If the signal strength of the corresponding feature signal in the input signals of each target first component is greater than the preset signal strength, it is determined that the corresponding target first component has not experienced an interlocking fault. If the signal strength of the characteristic signal corresponding to the input signal of each target first component is not greater than the preset signal strength, it is determined that the corresponding target first component has an interlocking fault.

[0006] In one embodiment, the plurality of target first components include a battery management system and a plurality of high-voltage components, wherein the battery management system is connected to the power conversion module and each high-voltage component through a high-voltage main circuit and a pre-charge circuit, respectively. The step of controlling the power conversion module to output characteristic signals to each target first component in response to the interlock self-test command includes: In response to the interlock self-test command, the precharge circuit is turned on, and the high-voltage main circuit is turned off. With the precharge circuit on and the high-voltage main circuit off, the control power conversion module outputs characteristic signals to each target first component.

[0007] In one embodiment, the step of controlling the power conversion module to output characteristic signals to each target first component when the pre-charge circuit is on and the high-voltage main circuit is off includes: When the pre-charge circuit is on and the high-voltage main circuit is off, the power conversion module is controlled to output the characteristic signal within a preset diagnostic window. The diagnostic window is set within the pre-charge time period when the vehicle's high-voltage system is pre-charged.

[0008] In one embodiment, the step of controlling the power conversion module to output characteristic signals to each target first component in response to the interlock self-test command includes: In response to the interlock self-test command, the control power conversion module outputs a characteristic signal with a preset frequency to each target first component; The step of detecting the input signal of each target first component through the electrical signal sensor of each target first component and determining the signal strength corresponding to the feature signal in the input signal of each target first component includes: The electrical signal sensors of each of the target first components are controlled to collect the input signals of each of the target first components at a preset sampling frequency, wherein the preset sampling frequency is greater than twice the preset frequency; Based on the input signals of each target first component and the preset frequency, the signal strength corresponding to the feature signal in the input signals of each target first component is determined.

[0009] In one embodiment, the control power conversion module outputs a characteristic signal with a preset frequency to each target first component, including: Based on the voltage calculation value of a preset time-varying function, the power conversion module is controlled to output. The time-varying function is... ,in, Where A is the DC bias voltage, f is the amplitude, and t is the preset frequency; When the power conversion module is controlled to output according to a preset time-varying function, the actual output voltage of the power conversion module is sampled, and the real-time dynamic error is calculated. The formula for calculating the real-time dynamic error is as follows: ,in, This is the actual output voltage; Based on the real-time dynamic error, the voltage calculation value of the time-varying function is corrected so that the actual output voltage approaches the voltage calculation value of the time-varying function.

[0010] In one embodiment, determining the signal strength corresponding to the feature signal in the input signal of each of the target first components based on the input signal of each target first component and the preset frequency includes: According to the preset frequency, the sampled data of the input signals of each of the target first components are filtered to obtain filtered data; The root mean square (RMS) value of the filtered data is calculated using the RMS method. The calculation formula is as follows: Where E is the root mean square value, Let N be the value of the i-th filtered data, and N be the number of sampling points, where the number of sampling points is the number of sampling points covering an integer number of the characteristic signal periods; The calculated root mean square value is determined as the signal strength corresponding to the characteristic signal.

[0011] In one embodiment, the vehicle high-voltage system further includes a plurality of target second components, each of which has an interlock detection module, and the interlock fault detection method further includes: The interlocking status of each of the target second components is detected by the interlocking detection module of each of the target second components. If no interlocking fault occurs in any of the target first component and target second component, it is determined that the overall interlocking of the vehicle high-voltage system is normal. If an interlocking failure occurs in either the first or second target component, the overall interlocking failure of the vehicle's high-voltage system is determined.

[0012] This application also provides an interlock fault detection device, which is configured to implement the interlock fault detection method based on the vehicle high-voltage system described above.

[0013] This application also provides a vehicle that includes the interlock fault detection device and the vehicle high-voltage system as described above. The vehicle high-voltage system includes a power conversion module and multiple high-voltage components connected to the power conversion module, each of which has an electrical signal sensor.

[0014] In one embodiment, the plurality of high-voltage components include one or more of a battery management system, a motor controller, a positive temperature coefficient heater, a compressor, and a high-voltage distribution box.

[0015] In summary, the interlock fault detection method for a vehicle high-voltage system provided in this application can control the power conversion module of the vehicle high-voltage system to output characteristic signals to each target first component when an interlock self-test command is triggered. Subsequently, based on the signal strength of the input signal detected by the local electrical signal sensor of each target first component, if the signal strength is not greater than a preset signal strength, it can be independently determined that the corresponding target first component has experienced an interlock fault. Thus, this method can directly pinpoint the specific target first component that has become loose or disconnected when one or more of multiple target first components fail, improving upon the problem of existing technologies being unable to accurately locate the specific faulty component when an interlock fault occurs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 2 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 3 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 4 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 5 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 6 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 7 A flowchart of an embodiment of the interlock fault detection method based on a vehicle high-voltage system provided in this application; Figure 8 A circuit diagram of an embodiment of the vehicle high-voltage system provided in this application.

[0018] Icon labels: 10. Vehicle high-voltage system; 20. Target first component; 30. Target second component; 40. Power conversion module.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0022] It should be noted that step designations such as S100 and S200 are used in this document for the purpose of more clearly and concisely describing the corresponding content, and do not constitute a substantial limitation on the order. In specific implementation, those skilled in the art may execute S200 first and then S100, etc., but these should all be within the protection scope of this application.

[0023] In new energy vehicles, numerous electrical components, such as the battery management system, motor controller, power conversion module, and air conditioning compressor, are connected in parallel within the vehicle's high-voltage network. Interlock detection is used to check the physical connection integrity of these components. When any electrical connection is faulty, the interlock circuit responds and triggers the vehicle controller to cut off the high-voltage power supply, effectively preventing high-voltage arcing caused by exposed high-voltage wiring, accidental electric shock, or live plugging and unplugging, ensuring absolute safety during vehicle operation and maintenance. However, traditional interlock detection schemes use a circuit structure that connects the interlock pins of each high-voltage component in series. This results in only a global fault alarm being issued when an interlock fault is detected in the vehicle's high-voltage network. Based on this global alarm, it is impossible to accurately pinpoint which specific electrical component in the high-voltage network has experienced an interlock fault.

[0024] Therefore, this application proposes an interlock fault detection method based on the vehicle high-voltage system 10, aiming to improve the problem that the existing technology cannot accurately locate the specific faulty component when an interlock fault occurs.

[0025] In one embodiment of this application, as Figure 8As shown, the vehicle high-voltage system 10 includes a power conversion module 40 and a plurality of target first components 20 connected to the power conversion module 40, each of the target first components 20 having an electrical signal sensor.

[0026] The power conversion module 40 can be an existing transformer in the vehicle, such as a DC-DC converter. The power conversion module 40 internally includes multiple power switching devices, such as MOSFETs or IGBTs. By changing the control commands for these power switching devices at the software level, such as the PWM duty cycle, the high-frequency switching on and off of the power switching devices can be controlled. This generates a time-varying waveform with a preset frequency, such as a sine wave, at the output of the power conversion module 40, which can be used as the characteristic signal in this application.

[0027] The target first component 20 is the object of the interlock fault detection. The interlock fault detection method in this application can accurately detect the physical connection status of each target first component 20 in the high-voltage network, as well as the connection integrity of its corresponding high-voltage wiring harness connector. The target first component 20 can be an electrical device in the vehicle's high-voltage network, including one or more of the following: battery management system, motor controller, positive temperature coefficient heater, compressor, and high-voltage distribution box. Of course, it can also be other devices, which are not limited here. Each target first component 20 has an electrical signal sensor, which is a built-in detection hardware of each target first component 20 to realize its own conventional functions. It can be a built-in voltage sensor or current sensor. The electrical signal sensor can collect the electrical signals input to the corresponding target first component 20 in real time and report the sampled data to the vehicle controller for analysis. Optionally, the power conversion module 40 and each target first component 20 are electrically connected through the vehicle's high-voltage bus.

[0028] In one embodiment, such as Figure 1 As shown, the interlock fault detection method includes steps S100 to S400.

[0029] In this embodiment, step S100 involves responding to an interlock self-test command by controlling the power conversion module to output characteristic signals to each target first component.

[0030] The interlock self-test command can be actively triggered by the user (or maintenance and diagnostic personnel) through the vehicle's infotainment interface or external diagnostic equipment, or it can be automatically triggered by the vehicle's high-voltage system 10 when specific conditions are met. In the case of automatic triggering, it can have various different triggering logics. For example, it can be triggered after the vehicle's low-voltage components have successfully undergone power-on initialization, or it can be triggered when specific wake-up events occur, such as vehicle unlocking or door opening. Of course, the triggering conditions for this interlock self-test command are not limited here.

[0031] The power conversion module 40 is electrically connected to each of the target first components 20 via the vehicle's existing high-voltage bus (i.e., high-voltage line). In diagnostic mode, the power conversion module 40 uses the vehicle's low-voltage battery, such as an external 12V power supply, as its working power source. Under the control of the vehicle controller, it generates and outputs the characteristic signal by adjusting the duty cycle of the pulse width modulation (PWM) switch of its internal power switching device. This characteristic signal is transmitted to each of the target first components 20 via the high-voltage bus.

[0032] It is understood that the characteristic signal is an electrical signal that can be detected in real time by the electrical signal sensors of each target first component 20, and its signal strength can be accurately calculated by the data processing algorithm built into the vehicle controller. Optionally, the characteristic signal can be an AC sine wave electrical signal with a preset frequency (e.g., 1000Hz). For example, at the receiving end, the vehicle controller can accurately obtain (i.e. extract) the effective components of the characteristic signal by performing digital bandpass filtering on the raw data collected by the sensor based on the preset frequency, and further perform energy calculation on the filtered data by using the root mean square (RMS) method to finally determine the signal strength of the characteristic signal input to each target first component 20.

[0033] Specifically, the characteristic signal is a characteristic signal, and the interlock fault detection method of this application can be executed in a safe pre-operation state where the high-voltage main circuit of the vehicle's high-voltage system 10 is not connected. During this detection phase, the power conversion module 40 is not connected to the high-voltage DC power of the power battery, but can safely generate the characteristic signal solely using the vehicle's external low-voltage power supply (such as a 12V battery). This avoids the risk of electric shock or arcing to personnel due to high-voltage exposure during the detection process.

[0034] In this embodiment, step S200 involves detecting the input signal of each target first component using the electrical signal sensor of each target first component, and determining the signal strength of the corresponding feature signal in the input signal of each target first component.

[0035] Under ideal conditions where the physical connection of the vehicle's high-voltage interlock network is normal, each target first component 20 can successfully receive the characteristic signal output by the power conversion module 40. Therefore, in step S200, the input signal input to each target first component 20 can be detected in real time by its local built-in electrical signal sensor, and the signal strength of the input signal can be further calculated. In the connected state, the input signal is an electrical signal that includes the characteristic signal output by the power conversion module 40.

[0036] It is particularly important to note that, because the characteristic signals are independently generated detection signals, and the vehicle's main contactor is in an open state during the output of the characteristic signals, the high-voltage power supply of the power battery is not connected to the entire vehicle's high-voltage network. Therefore, the input signals collected by each electrical signal sensor consist only of the characteristic signals output by the power conversion module 40 and the weak background noise on the high-voltage wiring harness, without containing any high-voltage DC components. This ensures the success rate and detection accuracy of the weak characteristic signals, while also guaranteeing absolute electrical safety during the interlock self-test process.

[0037] In this embodiment, in step S300, if the signal strength of the corresponding feature signal in the input signals of each target first component is greater than the preset signal strength, it is determined that the corresponding target first component has not experienced an interlocking fault.

[0038] The preset signal strength is equivalent to a safety benchmark threshold calibrated internally by the system, which can be 50%, 70%, or 80% of the normal value; no specific limitation is made here. When the vehicle controller (or the local diagnostic module of each target first component 20) finds that the characteristic signal strength extracted by a certain target first component 20 is greater than the preset signal strength, it means at the physical level that the high-voltage bus and its high-voltage connectors along the route from the power conversion module 40 (signal transmitter) to the target first component 20 (signal receiver) are in a good physical connection state. At this time, the contact impedance of the line is within the normal safety range, and the characteristic signal does not experience abnormal energy attenuation during transmission. Therefore, it can be determined that the interlocking circuit of the branch where the specific target first component 20 is located is safely closed, that is, it can be determined that the corresponding target first component 20 has not experienced an interlocking fault.

[0039] In this embodiment, in step S400, if the signal strength of the corresponding feature signal in the input signals of each target first component is not greater than the preset signal strength, it is determined that the corresponding target first component has an interlocking fault.

[0040] When the signal strength of the input signal of a certain target first component 20 is severely attenuated, resulting in the calculated strength value not being greater than the preset signal strength, or when the sensor of the target first component 20 does not detect any characteristic signal that conforms to the preset frequency (signal strength is approximately zero), it means at the physical level that the high-voltage physical link to the specific target first component 20 has been abnormally disconnected, or the terminal is severely corroded, causing the contact resistance to increase dramatically, resulting in the characteristic signal being blocked or severely attenuated and unable to effectively reach the endpoint.

[0041] It is particularly important to emphasize that, because this application employs a distributed parallel diagnostic architecture where each target first component 20 receives and detects independently locally, when an interlock fault is determined based on the above logic for a certain target first component 20, the fault conclusion is directly bound to that specific target first component 20. The vehicle controller can immediately pinpoint the fault source and generate a precise fault code (DTC) containing the physical location or communication ID of that specific target first component 20. This solves the technical pain point of traditional serial interlock schemes, which can only trigger global alarms and cannot locate specific breakpoints, greatly improving the efficiency of fault diagnosis during vehicle after-sales maintenance.

[0042] In summary, the interlock fault detection method based on the vehicle high-voltage system 10 provided in this application can control the power conversion module 40 of the vehicle high-voltage system 10 to output characteristic signals to each target first component 20 when the interlock self-test command is triggered. Subsequently, based on the signal strength of the input signal detected by the local electrical signal sensor of each target first component 20, if the signal strength is not greater than a preset signal strength, it can be independently determined that the corresponding target first component 20 has experienced an interlock fault. Thus, this method can directly pinpoint the specific target first component 20 that has become loose or disconnected when one or more of the multiple target first components 20 fail, improving the problem of existing technologies being unable to accurately locate the specific faulty component when an interlock fault occurs.

[0043] In one embodiment, such as Figure 8 As shown, the multiple target first components 20 include a battery management system and multiple high-voltage components. The battery management system is connected to the power conversion module 40 and each high-voltage component through a high-voltage main circuit and a pre-charge circuit, respectively.

[0044] It is understood that the battery management system is connected to a power battery, which can be a single battery pack or a battery module formed by combining multiple battery cells; this is not limited here. The high-voltage main circuit may include a main positive relay and a main negative relay, which can serve as the core safety physical switch controlling the on / off connection of main power transmission between the power battery pack and the vehicle's high-voltage bus. The pre-charge circuit may include a pre-charge relay and a pre-charge resistor, mainly used to perform current-limited pre-charge on the distributed capacitors on the vehicle's high-voltage bus before the high-voltage main circuit is fully closed, to prevent instantaneous high-current surges from burning out high-voltage components.

[0045] Optionally, such as Figure 8 As shown, Figure 8 K1 is the pre-charge relay, K2 is the main positive relay, and K3 is the main negative relay.

[0046] In one feasible embodiment, both the main positive relay and the main negative relay are connected to the respective target first component 20, and both the main positive relay and the main negative relay are connected to the power conversion module 40. A pre-charge relay and a pre-charge resistor are connected in series and in parallel with the main positive relay, thereby providing a bypass conduction path for the detection signal or pre-charge current when the main positive relay is disconnected.

[0047] In one embodiment, such as Figure 2 As shown, step S100, in response to the interlock self-test command, controls the power conversion module to output characteristic signals to each target first component, which may include steps S110 and S120.

[0048] Step S110: In response to the interlock self-test command, control the precharge circuit to be turned on and control the high voltage main circuit to be turned off.

[0049] Step S120: When the precharge circuit is on and the high-voltage main circuit is off, the control power conversion module outputs characteristic signals to each target first component.

[0050] Understandably, controlling the disconnection of the high-voltage main circuit ensures that the high-voltage DC power from the power battery does not directly flow into the bus network, fundamentally guaranteeing the low-voltage safety of the testing environment. Conversely, controlling the conduction of the pre-charge circuit establishes a physically connected micro-signal transmission channel between the battery management system and the power conversion module 40. This allows the characteristic signal emitted by the power conversion module 40 to reach the electrical signal acquisition terminal of the battery management system through the pre-charge branch, verifying the interlocked connection status of this core branch. It should be noted that the pre-charge circuit can be activated either during vehicle charging or after the interlocked self-test command is triggered.

[0051] This embodiment ensures that the circuit remains low-voltage throughout the entire interlock fault detection phase, completely eliminating the risk of electric shock or connector arcing caused by accidental high-voltage energization during detection. Furthermore, this application deeply reuses the original vehicle's pre-charge circuit topology and internal switching devices of each component, constructing a complete signal transmission and acquisition channel. This achieves precise location of interlock fault nodes without increasing the overall vehicle hardware cost.

[0052] In one feasible embodiment, each of the multiple high-voltage components has a switching device, and each high-voltage component is connected to the power conversion module 40 through the switching device. The switching device can serve as a component for controlling the on / off connection between the high-voltage component and the power conversion module 40, and can be a high-voltage contactor, relay, or an internally integrated power switch (such as an IGBT or MOSFET). These switches are physical switches that each high-voltage component has built-in to achieve its own conventional functions or safety protection, and no additional hardware is needed for the interlock detection of this application. It is also understood that while performing step S110, the switching devices of each high-voltage component can also be controlled to close, so that the characteristic signal emitted by the power conversion module 40 can be effectively collected by the electrical signal sensors inside each component, thereby completing the signal strength detection of each branch. For example, the high-voltage components include a positive temperature coefficient heater, an air conditioning compressor, and a motor controller. When sending the characteristic signal, the power switching device inside the positive temperature coefficient heater, as well as the power inverter bridge arm inside the air conditioning compressor and the motor controller, can be controlled to briefly close. This measure ensures that a complete electrical conduction path is formed between each core high-voltage component and the busbar, so that the injected characteristic signals can be smoothly and accurately collected and detected by the corresponding voltage or current sensors inside each high-voltage component.

[0053] In one embodiment, step S120, when the pre-charge circuit is on and the high-voltage main circuit is off, controls the power conversion module to output characteristic signals to each target first component, may also include step S121, when the pre-charge circuit is on and the high-voltage main circuit is off, controls the power conversion module to output the characteristic signals within a preset diagnostic window, wherein the diagnostic window is set within the pre-charge time period during which the vehicle's high-voltage system is pre-charged.

[0054] The preset diagnostic window is a very short time segment precisely defined within the entire pre-charge period. Since transient pre-charge inrush currents and accompanying electromagnetic fluctuations often occur in the initial stage after the pre-charge circuit is turned on, this diagnostic window is preferably set during the electrical stability period after the pre-charge inrush current has stabilized and before the high-voltage main circuit is officially closed, to ensure that the characteristic signal is not interfered with. Within this dedicated diagnostic window, the power conversion module 40 outputs characteristic signals with a preset frequency, and the electrical signal sensors of each target first component 20 synchronously complete high-speed sampling, thereby extracting the purest signal strength at the optimal time without interference from strong inrush currents.

[0055] In this way, the entire vehicle's interlock nodes can be checked without increasing the vehicle's additional power-on waiting time, ensuring ultimate safety while improving the vehicle's start-up response speed and user experience.

[0056] In one embodiment, step S100, responding to the interlock self-test command, controlling the power conversion module to output a feature signal to each target first component, may include step S140, responding to the interlock self-test command, controlling the power conversion module to output a feature signal with a preset frequency to each target first component.

[0057] Vehicle high-voltage networks are often filled with various complex electromagnetic interferences, including DC bias noise and low-frequency or high-frequency noise from other electrical equipment. To ensure accurate identification of the interlock detection signal amidst this complex background noise, this embodiment specifically defines the characteristic signal as an AC time-varying signal with a preset frequency, such as a 1000Hz sine wave. Of course, the specific value of the preset frequency is not limited here and depends on the actual application requirements.

[0058] In this embodiment, as Figure 3 As shown, step S200, which involves detecting the input signal of each target first component through the electrical signal sensor of each target first component and determining the signal strength of the corresponding feature signal in the input signal of each target first component, may include steps S210 and S220.

[0059] In this embodiment, step S210 involves controlling the electrical signal sensors of each of the target first components to collect the input signals of each of the target first components at a preset sampling frequency, wherein the preset sampling frequency is greater than twice the preset frequency.

[0060] It should be noted that the input signals actually received by the local electrical signal sensors of each target first component 20 are often analog mixed electrical signals containing characteristic signals and various background noises. In order to convert this analog signal into a digital signal without loss for analysis by the vehicle controller, this application adopts the Nyquist-Shannon sampling theorem. That is, the preset sampling frequency of the electrical signal sensor is limited to more than twice the preset frequency of the characteristic signal (for example, if the characteristic signal frequency is 1kHz, then the sampling frequency is set to 5kHz). In this way, signal aliasing is fundamentally prevented during the digital sampling process, ensuring that the waveform characteristics such as the peaks, troughs, and phases of the characteristic signal are completely and truthfully preserved in the sampling data, avoiding waveform distortion and subsequent energy calculation errors caused by insufficient sampling rate.

[0061] In this embodiment, step S220 involves determining the signal strength corresponding to the feature signal in the input signal of each target first component based on the input signal of each target first component and the preset frequency.

[0062] In one feasible implementation, the vehicle controller can invoke a digital bandpass filter whose center frequency matches the preset frequency to filter the sampled data containing various noises. This filters out DC components and high-frequency / low-frequency noise that are not within the preset frequency band, leaving clean, filtered data containing only the characteristic signal component. Subsequently, the system uses a signal processing algorithm (such as root mean square RMS calculation) to perform energy integration on the clean, filtered data. The final value is then accurately determined as the true signal strength corresponding to the characteristic signal at the input terminal of the first target component 20.

[0063] In one embodiment, such as Figure 4 As shown, the control power conversion module in step S140 outputs a characteristic signal with a preset frequency to each target first component, which may include steps S141 to S143.

[0064] In this embodiment, step S141 involves controlling the power conversion module to output based on the voltage calculation value of a preset time-varying function, where the time-varying function is... .

[0065] in, t is the DC bias voltage, A is the amplitude, f is the preset frequency, and t is the time.

[0066] It is understandable that this time-varying function As an ideal reference target, a DC bias voltage is introduced. The reference noise floor voltage ensures that the generated signal is always within the positive voltage range; while the amplitude A and the preset frequency f define the AC waveform characteristics superimposed on the bias voltage. During operation, the vehicle controller (or the microcontroller inside the power conversion module 40) will calculate the target discrete value of the time-varying function at each time microelement with high frequency and continuously as time t progresses, and use this as the basis for the control commands of the underlying hardware to generate waves.

[0067] In this embodiment, step S142 involves controlling the power conversion module to output according to a preset time-varying function, sampling the actual output voltage of the power conversion module, and calculating the real-time dynamic error. The formula for calculating the real-time dynamic error is as follows: .

[0068] in, This is the actual output voltage, which varies with time.

[0069] It should be noted that due to the dead time of the power switching devices, the parasitic inductance and stray capacitance on the high-voltage bus, and the load effect brought by each target first component 20, the actual output voltage of the power conversion module 40 is subject to change. It is often not perfectly equivalent to the target instruction calculated by the mathematical model. Therefore, this application introduces a high-frequency voltage sampling feedback mechanism at the output of the power conversion module 40, that is, to collect the current actual output voltage in real time. and compare it with the theoretical target value at the same time t. By subtracting the values, the real-time dynamic error e(t) of the current hardware output deviating from the ideal target can be accurately captured.

[0070] In this embodiment, step S143 involves correcting the voltage calculation value of the time-varying function based on the real-time dynamic error, so that the actual output voltage approaches the voltage calculation value of the time-varying function.

[0071] Optionally, the calculated real-time dynamic error e(t) is input to the internal closed-loop regulator. Based on the direction and magnitude of this error, the regulator corrects the control parameters of the underlying power switching devices in real time, such as fine-tuning the duty cycle of the pulse width modulation (PWM). If the actual voltage is too low, the duty cycle is increased to boost the voltage; if the actual voltage is too high, the duty cycle is decreased. This allows the actual output voltage to be adjusted. Infinitely approaching the time-varying function The ideal trajectory is obtained, thus stably outputting high-quality sinusoidal characteristic signals in complex vehicle wiring harness environments.

[0072] In one feasible implementation, the above closed-loop waveform control process is illustrated by example: assuming a DC bias voltage is set... The voltage is 12V, the amplitude A is 5V, and the preset frequency f is 1000Hz. At a specific moment... Based on the time-varying function, the target voltage for the current very short time is calculated to be 16.5V (i.e. At this time, the actual output voltage of the power conversion module 40 sampled by the feedback sensor is only 16V (i.e., Then the real-time dynamic error is calculated. Based on this 0.5V undervoltage error, the internal PID controller responds quickly, slightly increasing the PWM duty cycle command for the next switching cycle. In the subsequent... At a certain moment, the actual output voltage is successfully boosted and approaches the new time-varying function target value. This process repeats continuously, eventually forming a smooth 1000Hz characteristic signal waveform on the bus.

[0073] In one embodiment, such as Figure 5 As shown, step S220, determining the signal strength corresponding to the feature signal in the input signal of each target first component based on the input signal of each target first component and the preset frequency, may include steps S221 to S223.

[0074] In this embodiment, step S221 involves filtering the sampled data of the input signals of each of the target first components according to the preset frequency to obtain filtered data.

[0075] Due to electromagnetic interference present in the high-voltage network environment of vehicles, such as DC bias and high-frequency switching noise generated by inverters, the data collected by electrical signal sensors often contains a large amount of non-target frequency noise. Therefore, for example, based on a known preset frequency, a digital bandpass filter (e.g., an IIR or FIR filter) with a center frequency matching the preset frequency is invoked to perform targeted bandpass filtering on the sampled data. In this way, the DC component and high- and low-frequency noise can be completely filtered out, resulting in a purer characteristic signal component, i.e., the filtered data.

[0076] In this embodiment, step S222 involves calculating the root mean square (RMS) value of the filtered data using the RMS method. The formula for the RMS method is: .

[0077] Where E is the root mean square value. Let N be the value of the i-th filtered data, and let N be the number of sampling points, where N is the number of sampling points covering an integer number of the characteristic signal periods.

[0078] It is important to emphasize that the root mean square (RMS) algorithm is used to integrate and sum the AC signal energy within a certain time window. The formula specifically limits the number of sampling points N to cover an integer number of characteristic signal periods, ensuring the stability of the signal strength calculation. Understandably, if the extracted analysis data does not contain complete signal periods, the calculated RMS value will exhibit uncontrollable periodic fluctuations and deviations. Therefore, by aligning the calculation to an integer number of periods, an extremely stable RMS value that accurately reflects the effective energy of the injected characteristic signal can be obtained.

[0079] In this embodiment, step S223 involves determining the calculated root mean square value as the signal strength corresponding to the feature signal.

[0080] Understandably, this root mean square (RMS) value, mathematically and physically, represents the effective level energy of the characteristic signal after transmission and attenuation through the high-voltage bus and connectors along the way, finally reaching the input terminal of the first target component 20. Therefore, this RMS value is determined as the final signal strength for subsequent interlock fault diagnosis and judgment.

[0081] In one feasible implementation, assuming the preset frequency of the characteristic signal injected by the power conversion module 40 is 1000Hz, and the preset sampling frequency of the electrical signal sensor of each target first component 20 is 10kHz, to ensure the stability of energy calculation, the calculation time window is set to cover 10 complete characteristic signal cycles. Under this setting, the number of sampling points N in the aforementioned root mean square formula is 100 (10 sampling points / cycle × 10 cycles = 100 sampling points). The vehicle controller extracts these 100 consecutive sampling point data, performs squaring, summation, averaging, and square root operations, and obtains an effective value (i.e., root mean square value) with high anti-interference capability and numerical stability, thereby accurately representing the actual signal strength currently received by the target first component 20. Subsequently, this signal strength is input to the subsequent threshold comparison stage to finally determine whether the corresponding target first component 20 has an interlocking fault.

[0082] In one embodiment, the vehicle high-voltage system 10 further includes a plurality of target second components 30, each of the target second components 30 having an interlock detection module.

[0083] The target second component 30 is a non-core high-voltage component that serves as an external interface or auxiliary function, such as a DC charging dock, an AC charging dock, or a manual maintenance switch (MSD). The specific component referred to as the target second component 30 is not specified here. Since the target second component 30 may not possess complex high-frequency electrical signal sampling capabilities, it retains a traditional hardware interlock detection module to ensure accurate identification of the target second component 30 experiencing an interlock fault.

[0084] Based on this, such as Figure 6 As shown, the interlock fault detection method further includes steps S500 to S700.

[0085] Step S500: The interlock status of each of the target second components is detected by the interlock detection module of each of the target second components.

[0086] In this embodiment, the interlock detection module of each target second component 30 monitors the electrical status of its internal low-voltage interlock circuit. When the high-voltage connector of the target second component 30 is in a properly connected state, the interlock detection module determines that the interlock status is normal; when the connector is loose or disconnected, the low-voltage circuit is physically cut off, and the interlock detection module immediately determines that the interlock status is open, i.e., a fault. Optionally, each target second component 30 will report its interlock status to the vehicle controller in real time through a vehicle communication network (such as a CAN bus).

[0087] Step S600: If no interlocking fault occurs in any of the target first component and target second component, determine that the overall interlocking of the vehicle high-voltage system is normal.

[0088] Understandably, the vehicle controller will simultaneously collect and verify the results from both diagnostic architectures. When it is determined that the input signal strength of all target first components 20 is greater than the preset signal strength, and the interlock status reported by all target second components 30 is normal, the vehicle controller will determine that the overall interlock of the vehicle high-voltage system 10 is normal. Under these circumstances, the vehicle controller can then execute the subsequent high-voltage power-on process (such as closing the main negative relay and the main positive relay to conduct the high-voltage main circuit and cut off the pre-charge circuit), thereby eliminating the risk of powering on with a fault at the physical source.

[0089] Step S700: In the event of an interlocking failure in either the first or second target component, determine that the overall interlocking failure of the vehicle's high-voltage system is a failure.

[0090] It is particularly important to emphasize that, whether it is a sudden drop in the characteristic signal strength of the first target component 20 or a break in the hardware detection circuit of the second target component 30, as long as any abnormal node occurs in either of them, the vehicle controller will immediately trigger the global protection mechanism, determine the overall interlock fault of the vehicle high-voltage system 10, and prohibit high-voltage output.

[0091] More importantly, based on this distributed reporting mechanism, not only can we know that the system has malfunctioned, but we can also directly pinpoint which target component 20 failed to receive the characteristic signal or which target component 30's interlock module reported a disconnection by capturing the communication node identifier corresponding to the abnormal signal. Thus, while ensuring the absolute safety of the entire vehicle, we perfectly achieve precise location of the specific faulty component.

[0092] In one feasible implementation, such as Figure 7 As shown, after starting and responding to the interlock self-test command, the system first performs preparatory actions in parallel, such as closing the pre-charge circuit relay by the battery management system and setting a safety diagnostic window during the pre-charge period. Then, the control power conversion module 40 injects characteristic signals into the high-voltage network within this dedicated diagnostic window. Next, the system performs dual-track parallel diagnostic testing: on one hand, the core high-voltage component (i.e., target component 20) synchronously collects and processes electrical signals to establish signal strength; on the other hand, the non-core component (i.e., target component 30) performs local interlock hardware circuit status detection. After acquiring the two sets of test data, the system enters an arbitration phase to determine whether the overall interlock is normal. If the overall determination is normal, the overall interlock is confirmed to be intact, allowing the vehicle to continue receiving high-voltage power. If a fault is determined, i.e., the signal strength of any core component is insufficient or the hardware circuit of any non-core component is disconnected, the overall interlock is confirmed to be faulty, the power-on process is cut off, and the specific fault source node is accurately located through the underlying communication network, ultimately ending the diagnostic process.

[0093] This application also provides an interlock fault detection device configured to implement the interlock fault detection method based on the vehicle high-voltage system 10 described above.

[0094] It should be noted that the specific implementation method of the interlock fault detection method based on the vehicle high-voltage system 10 refers to the above embodiments. Since this interlock fault detection device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0095] This application also provides a vehicle that includes the interlock fault detection device as described above. It should be noted that the specific implementation of the interlock fault detection device refers to the above embodiments. Since this vehicle adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0096] In one embodiment, the vehicle further includes a vehicle high-voltage system 10, which includes a power conversion module 40 and a plurality of high-voltage components connected to the power conversion module 40, each of the high-voltage components having an electrical signal sensor.

[0097] In one embodiment, the plurality of high-voltage components include one or more of a battery management system, a motor controller, a positive temperature coefficient heater, a compressor, and a high-voltage distribution box.

[0098] It is understood that, for the vehicle described in this application, the interlock fault detection device can be implemented in various flexible ways in terms of physical form. In a preferred embodiment, the interlock fault detection device can be directly the vehicle's existing vehicle control unit (VCU). Developers only need to embed or flash the corresponding interlock fault diagnosis algorithm program into the underlying software architecture of the VCU to schedule the execution of the above-mentioned interlock fault detection method by the VCU without adding any new control hardware. Alternatively, in another embodiment, for some vehicles using a distributed or domain control architecture, the interlock fault detection device can also be an independent physical electronic control unit (ECU) component. This independent component is connected to the vehicle's internal communication network (such as CAN bus or Ethernet) as a new diagnostic node, specifically used for coordinating and issuing characteristic signal injection commands and summarizing the signal strength data of each component to independently execute the above-mentioned interlock fault detection method and send the final diagnostic conclusion to the vehicle system. This application does not limit the specific hardware form and integration location of the interlock fault detection device.

[0099] like Figure 8The diagram shows a hardware topology of a vehicle high-voltage system 10 provided in this application. The high-voltage end of the power conversion module 40 (such as a DC-DC converter) is coupled to the vehicle's high-voltage bus (shown by solid lines in the diagram). The electrical equipment in the vehicle network is divided into two categories: one category consists of multiple target first components 20 (e.g., the positive temperature coefficient heater PTC, compressor M, power battery assembly and BMS, motor controller, and other core high-voltage components shown on the left and in the middle of the diagram). These components do not require additional traditional low-voltage interlocking harnesses; instead, they directly reuse the high-voltage bus to receive characteristic signals injected by the power conversion module 40 and perform high-frequency detection through its internally integrated electrical signal sensor. The other category consists of multiple target second components 30 (e.g., the AC / DC charging interface shown in the lower right corner of the diagram, and other non-core auxiliary components). These components retain and are equipped with independent traditional low-voltage interlocking detection circuits and modules. Furthermore, the vehicle controller (VCU) communicates via an internal communication network (… Figure 8 The CAN signal lines (shown by the dashed line) establish communication connections with the power conversion module 40, each target first component 20, and each target second component 30, respectively.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no technical conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for detecting interlock faults in a vehicle high-voltage system, characterized in that, The vehicle high-voltage system includes a power conversion module and multiple target first components connected to the power conversion module. Each target first component has an electrical signal sensor. The interlock fault detection method includes: In response to the interlock self-test command, the control power conversion module outputs characteristic signals to each target first component; The input signal of each target first component is detected by the electrical signal sensor of each target first component, and the signal strength of the corresponding feature signal in the input signal of each target first component is determined. If the signal strength of the corresponding feature signal in the input signals of each target first component is greater than the preset signal strength, it is determined that the corresponding target first component has not experienced an interlocking fault. If the signal strength of the characteristic signal corresponding to the input signal of each target first component is not greater than the preset signal strength, it is determined that the corresponding target first component has an interlocking fault.

2. The interlock fault detection method based on a vehicle high-voltage system as described in claim 1, characterized in that, The multiple target first components include a battery management system and multiple high-voltage components. The battery management system is connected to the power conversion module and each high-voltage component through a high-voltage main circuit and a pre-charge circuit, respectively. The step of controlling the power conversion module to output characteristic signals to each target first component in response to the interlock self-test command includes: In response to the interlock self-test command, the precharge circuit is turned on, and the high-voltage main circuit is turned off. With the precharge circuit on and the high-voltage main circuit off, the control power conversion module outputs characteristic signals to each target first component.

3. The interlock fault detection method based on a vehicle high-voltage system as described in claim 2, characterized in that, When the pre-charge circuit is on and the high-voltage main circuit is off, the control power conversion module outputs characteristic signals to each target first component, including: When the pre-charge circuit is on and the high-voltage main circuit is off, the power conversion module is controlled to output the characteristic signal within a preset diagnostic window. The diagnostic window is set within the pre-charge time period when the vehicle's high-voltage system is pre-charged.

4. The interlock fault detection method based on a vehicle high-voltage system as described in claim 1, characterized in that, The step of controlling the power conversion module to output characteristic signals to each target first component in response to the interlock self-test command includes: In response to the interlock self-test command, the control power conversion module outputs a characteristic signal with a preset frequency to each target first component; The step of detecting the input signal of each target first component through the electrical signal sensor of each target first component and determining the signal strength corresponding to the feature signal in the input signal of each target first component includes: The electrical signal sensors of each of the target first components are controlled to collect the input signals of each of the target first components at a preset sampling frequency, wherein the preset sampling frequency is greater than twice the preset frequency; Based on the input signals of each target first component and the preset frequency, the signal strength corresponding to the feature signal in the input signals of each target first component is determined.

5. The interlock fault detection method based on a vehicle high-voltage system as described in claim 4, characterized in that, The control power conversion module outputs characteristic signals with preset frequencies to each target first component, including: Based on the voltage calculation value of a preset time-varying function, the power conversion module is controlled to output. The time-varying function is... ,in, Where A is the DC bias voltage, f is the amplitude, and t is the preset frequency; When the power conversion module is controlled to output according to a preset time-varying function, the actual output voltage of the power conversion module is sampled, and the real-time dynamic error is calculated. The formula for calculating the real-time dynamic error is as follows: ,in, This is the actual output voltage; Based on the real-time dynamic error, the voltage calculation value of the time-varying function is corrected so that the actual output voltage approaches the voltage calculation value of the time-varying function.

6. The interlock fault detection method based on a vehicle high-voltage system as described in claim 4, characterized in that, The step of determining the signal strength corresponding to the feature signal in the input signal of each target first component based on the input signal of each target first component and the preset frequency includes: According to the preset frequency, the sampled data of the input signals of each of the target first components are filtered to obtain filtered data; The root mean square (RMS) value of the filtered data is calculated using the RMS method, and the formula for the RMS method is as follows: Where E is the root mean square value, Let N be the value of the i-th filtered data, and N be the number of sampling points, where the number of sampling points is the number of sampling points covering an integer number of the characteristic signal periods; The calculated root mean square value is determined as the signal strength corresponding to the characteristic signal.

7. The method for detecting interlock faults in a vehicle high-voltage system as described in any one of claims 1 to 6, characterized in that, The vehicle high-voltage system also includes multiple target second components, each of which has an interlock detection module. The interlock fault detection method further includes: The interlocking status of each of the target second components is detected by the interlocking detection module of each of the target second components. If no interlocking fault occurs in any of the target first component and target second component, it is determined that the overall interlocking of the vehicle high-voltage system is normal. If an interlocking failure occurs in either the first or second target component, the overall interlocking failure of the vehicle's high-voltage system is determined.

8. An interlock fault detection device, characterized in that, The interlock fault detection device is configured to implement the interlock fault detection method based on the vehicle high-voltage system as described in any one of claims 1 to 7.

9. A vehicle, characterized in that, The vehicle includes the interlock fault detection device as described in claim 8 and the vehicle high-voltage system; The vehicle high-voltage system includes a power conversion module and multiple high-voltage components connected to the power conversion module, each of which has an electrical signal sensor.

10. The vehicle as claimed in claim 9, characterized in that, The plurality of high-voltage components include one or more of a battery management system, a motor controller, a positive temperature coefficient heater, a compressor, and a high-voltage distribution box.

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