A new energy light truck low-voltage wire harness fault self-diagnosis and positioning system

Abstract

The application discloses a new energy light truck low-voltage wire harness fault self-diagnosis and positioning system, relates to the technical field of new energy vehicles, and comprises a data acquisition unit, which is used for collecting various real-time electrical parameters of each low-voltage wire harness section of a new energy light truck and corresponding vehicle working condition parameters, pre-processing the real-time electrical parameters, and obtaining effective electrical parameters of each low-voltage wire harness section; and an abnormality diagnosis unit, which is used for adaptively correcting preset wire harness parameter judgment thresholds based on the vehicle working condition parameters, comparing the effective electrical parameters with the corrected wire harness parameter judgment thresholds in sections, and screening abnormal wire harness sections. The application realizes accurate identification and positioning of low-voltage wire harness faults through the working condition adaptive threshold and reflection signal topology positioning, realizes differential early warning and preventive maintenance through fault grading, aging trend analysis and life assessment, effectively improves the diagnosis and repair efficiency, and reduces the misjudgment risk and vehicle operation and maintenance cost.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle technology, specifically to a self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks. Background Technology

[0002] As the level of intelligence and electrification of new energy vehicles continues to increase, the number of controllers, sensors, actuators and various low-voltage electrical devices in the vehicle's low-voltage electrical system continues to increase. As an important carrier for power transmission and signal interaction between various electronic control units, power systems and low-voltage loads in new energy vehicles, low-voltage wiring harnesses are usually distributed in the cab, body, chassis and other functional areas, and are characterized by long wiring spans, many branch nodes, a large number of connectors and complex operating environments.

[0003] During long-term vehicle operation, low-voltage wiring harnesses are susceptible to factors such as vibration and shock, alternating high and low temperatures, moisture erosion, friction and wear, and compression and pulling, leading to faults such as insulation aging, poor connector contact, loose wiring, partial open circuits, short circuits, abnormal grounding, and wiring harness wear. Currently, the detection and diagnosis of low-voltage wiring harness faults in new energy vehicles typically employ manual inspection, fixed threshold testing, and detection methods based on time-domain or frequency-domain reflection.

[0004] Manual inspection mainly relies on multimeters, ammeters, resistance testers, or continuity testing tools to perform segment-by-segment testing of the voltage, current, resistance, and continuity status at both ends of the wiring harness. This is combined with visual inspection to determine whether the wiring harness has open circuits, short circuits, or grounding faults. Fixed threshold testing mainly uses the vehicle body controller, motor controller, etc., to collect relevant voltage, current, or resistance signals of the wiring harness and compares the real-time detection values ​​with preset fixed thresholds. When the detection value exceeds the set range, a fault code is generated or an alarm is triggered. Time-domain reflection or frequency-domain reflection detection technology applies a detection signal to the wiring harness under test and collects the reflected waveforms generated at the impedance discontinuities. The fault type is determined based on the characteristics of the reflected signal, such as time delay, amplitude, or polarity. At the same time, the fault location is estimated by combining the signal propagation delay, thereby realizing wiring harness fault detection and location.

[0005] However, existing fault detection technologies for low-voltage wiring harnesses in new energy vehicles still have significant limitations. Manual inspection typically requires disassembling interior trim, wiring harness covers, or fixed structures, and measuring segment by segment and point by point. This process is time-consuming and costly to maintain. Moreover, it is mainly applicable to obvious faults such as open circuits, short circuits, or visible damage. It is difficult to identify early, latent faults such as slight wear of the wiring harness, decreased insulation performance, loose connectors, intermittent poor contact, and slow resistance drift in a timely manner. Furthermore, it cannot continuously monitor the vehicle while it is in operation, and fault location can often only determine the general area, still requiring further disassembly and investigation by maintenance personnel.

[0006] While fixed threshold detection can achieve a certain degree of online monitoring, the voltage, current, resistance, and voltage drop parameters of the low-voltage circuit will fluctuate normally under different operating conditions such as start-stop, load switching, temperature changes, and vibration and shock in new energy vehicles. A single fixed threshold is difficult to adapt to complex dynamic operating conditions, and is prone to false alarms in normal conditions or missed alarms for minor faults. At the same time, it can usually only determine that there is an abnormality in a certain functional circuit, and it is difficult to further determine the specific abnormal wiring harness segment or fault node.

[0007] While detection methods based on time-domain or frequency-domain reflection have a certain fault location capability, existing solutions typically rely on external professional testing equipment and are more suitable for wiring harness testing under static, power-off conditions. In the environment of new energy vehicles operating with power and dynamic load changes, the detection signal is easily affected by electromagnetic interference from the vehicle and fluctuations in operating conditions, resulting in distortion of the reflected waveform and a decrease in positioning accuracy. Therefore, it is difficult to simultaneously meet the needs of online real-time diagnosis, latent fault identification, and accurate fault location for low-voltage wiring harnesses in new energy vehicles.

[0008] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0009] The purpose of this application is to provide a self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks, so as to solve the problems in the background art mentioned above.

[0010] To achieve the above objectives, this application provides the following technical solution: a self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks, comprising: The data acquisition unit is used to collect various real-time electrical parameters of each low-voltage wiring harness segment of the new energy light truck and the corresponding vehicle operating parameters, and to preprocess the real-time electrical parameters to obtain the effective electrical parameters of each low-voltage wiring harness segment. The anomaly diagnosis unit is used to adaptively correct the preset wiring harness parameter judgment threshold based on the vehicle operating condition parameters, and to compare the effective electrical parameters with the corrected wiring harness parameter judgment threshold in segments to screen abnormal wiring harness segments. The fault location unit is used to transmit detection signals to abnormal wire harness segments, collect reflected signals generated at the fault location, calculate the fault distance based on the propagation delay of the reflected signals, match the fault distance with preset wire harness topology data, and locate the fault location. The fault analysis unit is used to identify the fault type and fault level based on the characteristics of the reflected signal corresponding to the fault location, the degree of deviation of electrical parameters, the duration and recurrence frequency, and output differentiated early warning information corresponding to the fault level. The life assessment unit is used to analyze aging trends by utilizing historical electrical parameters of each low-voltage wiring harness segment, vehicle operating parameters, and fault levels. It assesses the remaining service life of the low-voltage wiring harness through an iteratively trained wiring harness life model and outputs preventive maintenance information.

[0011] Preferably, each low-voltage wiring harness segment is configured with a corresponding segment identifier, and the real-time electrical parameters are established with a time correspondence between the acquisition time and the vehicle operating condition parameters. The valid electrical parameters retain the corresponding segment identifier and the vehicle operating condition parameters.

[0012] Preferably, the real-time electrical parameters include multiple parameters such as real-time resistance, contact resistance, operating voltage, loop current, insulation resistance to ground, and dynamic voltage drop; the real-time resistance is obtained based on the operating potential and loop current at both ends of the low-voltage harness segment, and the contact resistance is obtained based on the operating potential and corresponding loop current on both sides of the connector.

[0013] Preferably, the insulation resistance to ground is obtained during the operation period when the low-voltage harness segment meets the preset insulation detection conditions. When the load changes or the current operating state does not meet the preset insulation detection conditions, the acquisition of the insulation resistance to ground is suspended until the operation period that meets the preset insulation detection conditions is entered.

[0014] Preferably, the preprocessing includes smoothing the continuously sampled data, removing outliers that exceed the physical range of the corresponding electrical parameters and do not have continuous variation characteristics, and correcting the data baseline based on the normal state parameters of the corresponding low-voltage harness segment.

[0015] Preferably, the threshold values ​​for determining wiring harness parameters correspond to the low-voltage wiring harness segmentation, electrical parameter type, and operating condition, respectively; when the current vehicle operating condition parameters are between adjacent operating condition reference points, the parameter determination range is continuously adjusted according to the position of the current vehicle operating condition parameters between adjacent operating condition reference points.

[0016] Preferably, the threshold for determining the wiring harness parameters of real-time resistance is adjusted according to the ambient temperature, the threshold for determining the wiring harness parameters of dynamic voltage drop is adjusted according to the vehicle load power and circuit current, the abnormal judgment of contact resistance is based on the vehicle body vibration amplitude, and the threshold for determining the wiring harness parameters of ground insulation resistance corresponds to the ambient temperature and the segmented operating status of the low-voltage wiring harness.

[0017] Preferably, the preset harness topology data is configured with low-voltage harness segmentation identifiers and corresponding detection start positions, branch node positions, actual path lengths, upstream and downstream connection relationships, associated electrical equipment, reference reflection information, and effective propagation speeds, which are used to establish a mapping relationship between fault distance and actual fault location.

[0018] Preferably, after abnormal harness segment screening, the corresponding detection start position and target transmission path are selected from the preset harness topology data according to the abnormal harness segment identifier, and the fault distance matching range corresponding to the reflected signal is limited by the branch to which the abnormal harness segment belongs.

[0019] Preferably, the detection signal is a pulse detection signal with a defined emission time. It is emitted when the circuit corresponding to the abnormal harness segment is in the operation period that allows detection, and the reflection acquisition time window is opened with the emission time of the detection signal as the starting point to obtain the corresponding reflection signal.

[0020] Preferably, the reference reflection information includes the reflection distance and reflection characteristics corresponding to the normal branch node, normal connector position, and wiring position of the associated electrical equipment; when the current reflection signal produces new reflection, amplitude change, polarity change, or position change relative to the reference reflection information, the corresponding reflection signal is used for fault location analysis.

[0021] Preferably, the fault distance is calculated by converting the propagation delay of the reflected signal into the effective propagation speed corresponding to the abnormal wire harness segment. The effective propagation speed is obtained in advance based on the round-trip propagation time of the detection signal corresponding to the low-voltage wire harness with a known actual path length.

[0022] Preferably, the fault distance is mapped segment by segment according to the topological connection order from the detection start position to the abnormal harness segment and the actual path length of each low-voltage harness segment. The remaining distance after deducting the cumulative length of the previous path is mapped to the inside of the abnormal harness segment, branch node, connector position or wiring position of associated electrical equipment.

[0023] Preferably, the fault type is identified by the reflected signal characteristics and effective electrical parameters corresponding to the fault location. When the reflected signal and effective electrical parameters point to the same abnormal wire harness segment and are within the same abnormal event time range, the two are associated to distinguish between open circuit, short circuit, contact abnormality and insulation performance abnormality.

[0024] Preferably, the degree of electrical parameter deviation represents the extent to which the effective electrical parameter exceeds the corrected wire harness parameter judgment threshold. The duration is accumulated from the first time the parameter exceeds the corresponding judgment range until recovery. When the same type of abnormality occurs again after recovery, it is counted as a new abnormal event and included in the recurrence frequency within the preset statistical period.

[0025] Preferably, the fault level is divided into minor fault, intermittent fault, critical fault and fatal fault according to the degree of deviation of electrical parameters, duration, recurrence frequency and functional status of related electrical equipment, and corresponding to status record, text prompt, sound and light warning and emergency warning respectively.

[0026] Preferably, the historical electrical parameters of each low-voltage wiring harness segment are stored in chronological order and associated with the corresponding vehicle operating parameters and fault levels. The aging trend is characterized by comparing the changes in resistance, contact resistance, and insulation resistance to ground, as well as the changes in fault status within different life assessment cycles.

[0027] Preferably, the wiring harness life model uses historical electrical parameters, vehicle operating parameters, fault levels, cumulative usage time, and maintenance results of the low-voltage wiring harness during normal use until it reaches the end of its lifespan for iterative training. Based on the aging trend corresponding to the current low-voltage wiring harness segment, the model assesses the remaining service life of the low-voltage wiring harness and outputs preventive maintenance information.

[0028] The technical effects and advantages provided by this application in the above technical solution are as follows: This application synchronously acquires real-time electrical parameters of each low-voltage wiring harness segment of a new energy light truck with the vehicle's operating parameters, and dynamically adjusts the wiring harness parameter judgment threshold based on ambient temperature, load status, and vehicle operating status. This effectively distinguishes between normal operating condition fluctuations and actual fault anomalies. Furthermore, by screening abnormal wiring harness segments in conjunction with reflected signal ranging and matching preset wiring harness topology data, it can continuously identify open circuits, short circuits, poor contact, insulation abnormalities, and intermittent faults, and further pinpoint the fault range to specific wiring harness segments or corresponding fault locations, effectively improving the accuracy of fault identification and maintenance location efficiency in complex vehicle environments.

[0029] This application extends fault status judgment to fault level identification and wiring harness life assessment. It classifies different fault states by the degree of deviation of electrical parameters, duration of abnormality, and frequency of fault recurrence, and outputs corresponding early warning information according to the fault level, thereby avoiding the use of the same handling method for faults of different severities. At the same time, it continuously accumulates historical electrical parameters of each low-voltage wiring harness segment and vehicle operating parameters, and assesses the remaining service life through aging trend analysis and iteratively trained wiring harness life model. This expands fault handling from passive maintenance after a fault occurs to preventive maintenance before a fault occurs, effectively reducing the risk of repeated repairs and the long-term maintenance cost of the vehicle. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0031] Figure 1 A schematic diagram of the overall functional architecture of the self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0033] like Figure 1 As shown, this application provides a self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks, including: The data acquisition unit is used to collect various real-time electrical parameters of each low-voltage wiring harness segment of the new energy light truck and the corresponding vehicle operating parameters, and to preprocess the real-time electrical parameters to obtain the effective electrical parameters of each low-voltage wiring harness segment. The anomaly diagnosis unit is used to adaptively correct the preset wiring harness parameter judgment threshold based on the vehicle operating condition parameters, and to compare the effective electrical parameters with the corrected wiring harness parameter judgment threshold in segments to screen abnormal wiring harness segments. The fault location unit is used to transmit detection signals to abnormal wire harness segments, collect reflected signals generated at the fault location, calculate the fault distance based on the propagation delay of the reflected signals, match the fault distance with preset wire harness topology data, and locate the fault location. The fault analysis unit is used to identify the fault type and fault level based on the characteristics of the reflected signal corresponding to the fault location, the degree of deviation of electrical parameters, the duration and recurrence frequency, and output differentiated early warning information corresponding to the fault level. The life assessment unit is used to analyze aging trends by utilizing historical electrical parameters of each low-voltage wiring harness segment, vehicle operating parameters, and fault levels. It assesses the remaining service life of the low-voltage wiring harness through an iteratively trained wiring harness life model and outputs preventive maintenance information.

[0034] This embodiment provides a method for self-diagnosis and location of low-voltage wiring harness faults in new energy light trucks. After the new energy light truck is powered on and the low-voltage circuit enters the allowable detection state, the following continuous processing relationship is executed: low-voltage wiring harness segmentation, real-time electrical parameter acquisition, vehicle operating condition parameter acquisition, adaptive threshold correction, abnormal wiring harness segmentation screening, reflected signal acquisition, fault distance calculation, preset wiring harness topology data matching, fault type and fault level identification, differentiated early warning, aging trend analysis, and low-voltage wiring harness remaining service life assessment.

[0035] Before implementation, the testing range is divided into segments according to the actual electrical connection relationship of the low-voltage wiring harness of the new energy light truck. Each low-voltage wiring harness segment is configured with a unique segment identifier. At the same time, the corresponding starting point, ending point, branch node position, associated electrical equipment, actual path length, testing starting position, upstream and downstream connection relationship, and connection order with adjacent low-voltage wiring harness segments are recorded.

[0036] For low-voltage harness areas with multiple branch paths, the cumulative path length from the detection start position to each branch node, the starting point of each low-voltage harness segment, and the wiring position of each associated electrical equipment is recorded to establish preset harness topology data.

[0037] The preset harness topology data is used to describe the correspondence between the detection start position, low-voltage harness segments, branch nodes, associated electrical equipment and actual path distance, so that the fault distance calculated from the reflected signal can be mapped to the fault location in the actual low-voltage harness of the new energy light truck.

[0038] When establishing the preset wiring harness topology data, reference electrical parameters under normal conditions are recorded for different low-voltage wiring harnesses in segments. The reference electrical parameters include at least the normal resistance range, normal contact resistance range, normal operating voltage range, normal circuit current range, normal insulation resistance to ground range, and normal dynamic voltage drop range. For parameters affected by ambient temperature, vehicle load power, vehicle speed, and vehicle body vibration amplitude, the normal value ranges corresponding to different operating conditions are recorded separately.

[0039] Ambient temperature can be correlated with multiple temperature ranges, for example, using -40 degrees Celsius, -20 degrees Celsius, 0 degrees Celsius, 25 degrees Celsius, 50 degrees Celsius, and 85 degrees Celsius as temperature reference points; load status can be correlated with no load, half load, and full load; vehicle operating status can be correlated with parked, idling, and driving states. The specific reference points mentioned above are used to illustrate one implementation method. In actual use, the reference points can be increased, decreased, or reset according to the vehicle model's operating range.

[0040] The data acquisition unit continuously collects various real-time electrical parameters and corresponding vehicle operating parameters from each low-voltage wiring harness segment of the new energy light truck. The real-time electrical parameters include multiple parameters such as real-time resistance, contact resistance, operating voltage, circuit current, insulation resistance to ground, and dynamic voltage drop; the vehicle operating parameters include multiple parameters such as ambient temperature, vehicle load power, vehicle speed, and vehicle body vibration amplitude.

[0041] Each set of real-time electrical parameters records the corresponding acquisition time and low-voltage harness segment identifier, and establishes a time correlation with the vehicle operating condition parameters corresponding to the same acquisition time, so that the real-time electrical parameters can reflect the low-voltage harness status under specific operating conditions.

[0042] For obtaining the real-time resistance, when the target low-voltage harness segment is in a calculation-allowed conducting state, the working potential at both ends of the target low-voltage harness segment and the loop current flowing through the target low-voltage harness segment are obtained simultaneously. The current real-time resistance is characterized by the correspondence between the potential difference at both ends of the target low-voltage harness segment and the loop current at the same time.

[0043] When the loop current is in an area that cannot reflect the segmented resistance of the target low-voltage harness, the calculation result at that moment will not be used for anomaly diagnosis. Instead, the corresponding sampling record will be retained. The real-time resistance will be obtained again after the loop current enters the preset effective range to avoid fluctuations in the resistance result caused by a very small loop current.

[0044] To address contact resistance, the operating potentials on both sides of the connector and the loop current through the connector are simultaneously acquired at the corresponding location. The contact resistance is obtained by comparing the difference in operating potentials on both sides with the loop current at the same moment. The contact resistance data maintains a time-dependent relationship with the vehicle body vibration amplitude. When the contact resistance changes repeatedly during vehicle vibration, the relevant changes serve as an important basis for subsequent identification of loose connections and intermittent poor contact in the connector.

[0045] If the contact resistance shows only a single transient change and no corresponding trend is observed in subsequent sampling, it is not directly judged as a contact anomaly, but continues to proceed to the subsequent preprocessing.

[0046] The dynamic voltage drop is obtained by measuring the difference between the operating potential of the input side and the operating potential of the target low-voltage harness segment, while simultaneously recording the circuit current and the vehicle load power. Different normal dynamic voltage drops are allowed for the same low-voltage harness segment under different load conditions. Therefore, the dynamic voltage drop is not directly compared with a single fixed value, but rather with the harness parameter judgment threshold corresponding to the current vehicle load power and circuit current, thereby distinguishing between voltage drop changes caused by normal load variations and voltage drop changes caused by abnormal low-voltage harness conditions.

[0047] The data acquisition method for ground insulation resistance is based on preset insulation testing conditions. After the target low-voltage harness segment enters the operating period where insulation testing is allowed, a detection electrical signal that can be distinguished from the normal operating electrical state is applied to the target low-voltage harness segment. The changes in the ground response before and after the application of the detection electrical signal are recorded, and the ground insulation resistance is obtained based on the relationship between the detection electrical signal and the corresponding ground response.

[0048] Permissible operating periods for insulation testing include those when the target circuit is not in a rapid load switching state, when the target circuit's current function allows for short-term testing, and when the current electrical state meets the insulation testing requirements. When the vehicle is undergoing load switching or the target circuit's current state is unsuitable for insulation testing, the current insulation testing process is paused, and the insulation resistance to ground is acquired again in a subsequent operating period that meets the preset insulation testing conditions.

[0049] In this way, the insulation resistance to ground can be used for online diagnostics, while avoiding the direct interpretation of load transient changes as changes in insulation performance.

[0050] After acquiring real-time electrical parameters, these parameters are preprocessed. Preprocessing includes continuous sampling smoothing, outlier removal, and data baseline correction. Continuous sampling smoothing uses five consecutive sample values ​​to calculate the current effective change state, preventing single electromagnetic disturbances from directly triggering anomaly diagnosis.

[0051] Outlier removal is only performed on data that exceeds the physical acceptable range of the corresponding parameter, occurs only once, and does not show the same trend in adjacent consecutive samples. When a parameter exceeds the normal range for multiple consecutive sampling times, all consecutive abnormal data are retained and not processed as outliers, so as to avoid filtering out real open circuits, short circuits, insulation abnormalities, and contact abnormalities.

[0052] Data baseline correction uses the baseline electrical parameters recorded during the normal operation of each low-voltage harness segment as a reference. For the normal initial differences between different low-voltage harness segments, corresponding baseline electrical parameters are selected according to the low-voltage harness segment identification, and a relative change relationship is established between the current acquired value and the corresponding baseline electrical parameter.

[0053] Data collected at different times are all referenced to the baseline state of the same low-voltage wiring harness segment, thus avoiding the interpretation of inherent electrical differences between different low-voltage wiring harness segments as faults. After preprocessing, the effective electrical parameters of each low-voltage wiring harness segment are obtained, and the effective electrical parameters retain the time correspondence with the vehicle's operating parameters.

[0054] The anomaly diagnosis unit adaptively corrects the preset wiring harness parameter judgment thresholds based on the vehicle's operating condition parameters. The wiring harness parameter judgment thresholds are correlated with low-voltage wiring harness segments, electrical parameter types, and operating conditions.

[0055] When the ambient temperature is at a preset temperature reference point, the parameter judgment range corresponding to that temperature reference point is directly used; when the ambient temperature is between two adjacent temperature reference points, the parameter judgment ranges corresponding to the two temperature reference points are continuously adjusted according to the current ambient temperature's position between the two adjacent temperature reference points to obtain the parameter judgment range corresponding to the current ambient temperature.

[0056] The same approach is used to handle situations where the vehicle load power is between adjacent load reference states, so that the wiring harness parameter judgment threshold can be continuously adjusted according to changes in actual operating conditions, rather than only changing at preset discrete operating point.

[0057] The threshold for determining the harness parameter of real-time resistance is primarily corrected based on the normal resistance change relationship corresponding to ambient temperature, avoiding the use of a resistance reference that is incompatible with the current temperature. The threshold for determining the harness parameter of dynamic voltage drop is corrected based on the vehicle load power and circuit current, ensuring that normal voltage drop changes caused by increased load can be distinguished from abnormal voltage drops in low-voltage harnesses. The determination of contact resistance also considers ambient temperature and vehicle body vibration amplitude to identify recurring contact anomalies under vibration conditions.

[0058] The threshold values ​​for determining the wire harness insulation resistance to ground are adjusted based on the ambient temperature and the current operating status of the target circuit. By applying appropriate operating condition information to different effective electrical parameters, a wire harness parameter determination threshold value that matches the actual operating status of the current vehicle can be obtained.

[0059] After completing the adaptive correction of the harness parameter judgment threshold, the effective electrical parameters are compared with the corrected harness parameter judgment threshold in segments. Each low-voltage harness segment is only compared with the harness parameter judgment threshold corresponding to its current operating condition, and data from other low-voltage harness segments are not used as substitutes.

[0060] For parameters with upper limit requirements, when the effective electrical parameter exceeds the current upper limit, the magnitude of the exceedance is recorded; for parameters with lower limit requirements, when the effective electrical parameter is below the current lower limit, the magnitude of the fall below the lower limit is recorded; for parameters with upper and lower limit ranges, when the effective electrical parameter exceeds any boundary of the range, the magnitude of the exceedance of the corresponding boundary is recorded. This yields the degree of deviation of the electrical parameter.

[0061] The duration is accumulated from the moment the effective electrical parameter first exceeds the corrected harness parameter judgment threshold, until the corresponding effective electrical parameter recovers to the allowable range of the current harness parameter judgment threshold. If the same parameter exceeds the tolerance again after recovery, it is recorded as a new abnormal event. Within the preset statistical period, the number of similar abnormal events occurring in the same low-voltage harness segment is accumulated, and the accumulated number is used as the recurrence frequency.

[0062] Abnormal states are described by the degree of deviation of electrical parameters, duration, and frequency of recurrence, which can distinguish between single transient changes, intermittent abnormalities, and persistent abnormalities.

[0063] When at least one of the following valid electrical parameters exceeds the corrected wiring harness parameter judgment threshold and meets the corresponding duration or recurrence frequency conditions, the corresponding low-voltage wiring harness segment is screened as an abnormal wiring harness segment. At the same time, the abnormal wiring harness segment identifier, abnormal parameter type, electrical parameter deviation degree, duration, recurrence frequency, and corresponding vehicle operating condition parameters are saved.

[0064] The screening results are used to limit the scope of subsequent fault location, so that the reflected signal detection is performed segment by segment on the abnormal wire harness, rather than continuously performing the same location process on all low-voltage wire harnesses.

[0065] After screening abnormal harness segments, the fault location unit queries the preset harness topology data based on the abnormal harness segment identifier to obtain the detection start position, transmission path, upstream branch node, downstream branch node, and actual path length corresponding to the abnormal harness segment.

[0066] When multiple branch paths exist, the branch to which the abnormal wire harness segment belongs is used as the path constraint condition for subsequent fault distance matching. Position matching is only performed within the target transmission path containing the abnormal wire harness segment, thereby avoiding the same fault distance corresponding to multiple candidate positions on different branch paths.

[0067] When detecting abnormal wiring harness segments, a pulse detection signal with a clearly defined emission time is used. The duration of the pulse detection signal is set according to the length of the target low-voltage wiring harness segment and the minimum fault distance to be distinguished, so that reflected signals from different locations can be distinguished in time sequence.

[0068] The start time is recorded when the detection signal is emitted, and the corresponding reflection acquisition time window is opened after the detection signal is emitted. Only the return signal within the corresponding time window is used as the candidate reflection signal for the current abnormal harness segment, so as to reduce the impact of other operating signals on the propagation delay identification.

[0069] When the vehicle is energized and both normal power supply and detection signals are present, the detection signal is transmitted preferentially during the operating period when the load state of the target circuit has not changed rapidly. When the vehicle load power, circuit current, or operating voltage changes continuously within a short period of time and reaches the preset load switching conditions, the transmission of the current detection signal is temporarily suspended, and the transmission is resumed after the target circuit enters the allowable detection state.

[0070] The detection signal adopts a short-time detection method that can be distinguished from normal power supply changes in terms of duration characteristics. At the same time, the moment the detection signal is emitted is used as the starting point for reflection acquisition. By limiting the reflection acquisition time window, the confusion between normal electrical fluctuations of the vehicle and fault reflection signals is reduced.

[0071] During the establishment of the preset harness topology data, reference reflection information under normal conditions for each detection path is also recorded. The reference reflection information includes at least the reflection distance and corresponding reflection characteristics generated by normal branch nodes, normal connector positions, and wiring positions of associated electrical equipment.

[0072] When performing current fault location, the collected reflected signals are compared with the reference reflection information corresponding to the target transmission path. Return signals that correspond to normal node positions and normal reflection characteristics are processed as inherent topological reflection information. For cases of new reflections, changes in the amplitude of existing reflections, changes in the polarity of existing reflections, or changes in the position of existing reflections, the corresponding reflected signals are used as the objects of fault location analysis. This allows for the differentiation between inherent reflections generated by normal branch structures of low-voltage harnesses and reflection changes caused by abnormal conditions.

[0073] The detection signal propagates along the transmission path of the abnormal harness segment and generates a reflected signal when it passes through a location where the impedance state changes. The fault location unit collects the propagation delay, amplitude, polarity, and continuous change status of the reflected signal, and establishes a correspondence between the reflected signal and the current abnormal harness segment identifier.

[0074] The propagation delay is the time difference between the moment the detection signal is emitted and the moment the corresponding reflected signal returns to the acquisition position. Different reflected signals are recorded in the order of their return times, so that the reflection information corresponding to multiple branch nodes or multiple abnormal locations can be retained separately.

[0075] The fault distance is obtained based on the effective propagation speed of the detection signal in the transmission path of the target low-voltage harness and the propagation delay of the reflected signal. The fault distance is represented by half the product of the effective propagation speed and the propagation delay, reflecting the path distance from the detection starting position to the abnormal position along the actual low-voltage harness transmission path. The effective propagation speed is not directly taken as the speed of light in a vacuum, but is pre-obtained for the corresponding detection path during the preset harness topology data establishment phase.

[0076] Specifically, low-voltage harness segments with known actual path lengths can be selected, and the round-trip propagation time of the detection signal in the known path can be recorded. The effective propagation speed corresponding to the detection path can be obtained based on the known actual path length and round-trip propagation time. Low-voltage harness segments with the same propagation characteristics can use the same effective propagation speed, while low-voltage harness segments with different propagation characteristics should have their corresponding effective propagation speeds recorded separately.

[0077] After obtaining the fault distance, it is matched with the preset harness topology data. First, the target transmission path is locked based on the abnormal harness segment identifier. Then, the actual path length and branch node position of each upstream low-voltage harness segment are read sequentially according to the topology connection order from the detection start position to the abnormal harness segment. When the fault distance exceeds the cumulative length of the upstream path, the cumulative length of the upstream path is subtracted from the fault distance, and the remaining distance is mapped to the interior of the abnormal harness segment to locate the fault location.

[0078] For example, if the actual path length from the detection start position to the first branch node is 0.8 meters, and the actual path length from the first branch node to the start position of the abnormal harness segment is 0.6 meters, the calculated fault distance is 2.1 meters. Therefore, the fault location corresponds to 0.7 meters after the start position of the abnormal harness segment. This mapping relationship is only executed within the target transmission path to which the abnormal harness segment belongs; therefore, when the same cumulative distance exists on different branch paths, mutual confusion will not occur.

[0079] When the fault distance corresponds to a branch node, connector location, or wiring location of associated electrical equipment, the fault location is recorded as the corresponding node location; when the fault distance is between two known nodes, the fault location is recorded as the path location within the corresponding low-voltage harness segment. The fault distance represents the distance from the detection start position along the actual transmission path to the abnormal location, while the fault location represents the actual low-voltage harness location obtained by mapping the fault distance to the preset harness topology data. The two remain consistent in subsequent fault assessment processes.

[0080] After locating the fault, the fault assessment unit identifies the fault type and level based on the characteristics of the reflected signal, the degree of deviation of electrical parameters, the duration, and the frequency of recurrence corresponding to the fault location. Fault type identification does not solely rely on the polarity of the reflected signal but also considers changes in the effective electrical parameters corresponding to the fault location. If the reflected signal shows a positive amplitude change, and the loop current decreases or the conduction state becomes abnormal, it is identified as an open circuit or a micro-open circuit. If the reflected signal shows a negative amplitude change, and the operating voltage, loop current, or dynamic voltage drop exhibits abnormal changes corresponding to a short circuit, it is identified as a short circuit.

[0081] When contact resistance and dynamic voltage drop repeatedly exceed tolerances, and the reflected signal continuously changes at the corresponding connector location, it is identified as a loose connection or intermittent poor contact of the connector; when the insulation resistance to ground continuously decreases, and the corresponding reflection characteristics change at the fault location, it is identified as an abnormal insulation performance; when the real-time resistance continuously changes over multiple statistical periods and the reflected signal shows small, continuous changes, the corresponding state can be identified as an abnormality related to wire harness aging.

[0082] For situations where multiple abnormal characteristics occur simultaneously, the consistency of fault location and the consistency of multi-parameter time are used as correlation conditions. Only when the fault location corresponding to the reflected signal is consistent with the low-voltage harness segment corresponding to the effective electrical parameter abnormality, and the change in the reflected signal and the effective electrical parameter abnormality are within the same abnormal event time range, are both types of information used for fault type identification.

[0083] If different parameters point to different low-voltage harness segments, their respective abnormal events are retained and not merged into the same fault, thereby avoiding multiple simultaneous abnormalities being incorrectly classified into one fault location.

[0084] The fault level is classified according to the degree of deviation of electrical parameters, duration, recurrence frequency and related functional status.

[0085] Level 1 Minor Fault corresponds to valid electrical parameters exceeding the current normal range, but not reaching the associated functional abnormality condition, and the degree of abnormality is within the preset minor change range; this level is mainly used to record early resistance changes, insulation performance changes, or contact condition changes. Level 2 Intermittent Fault corresponds to abnormal states that repeatedly occur within a preset statistical period and can recover spontaneously; it is commonly seen in connector loose connections and intermittent poor contact under conditions of vehicle body vibration, temperature changes, or load changes. Level 3 Critical Fault corresponds to valid electrical parameters continuously exceeding the current wiring harness parameter judgment threshold for a preset duration, or associated electrical equipment exhibiting intermittent functional abnormalities. Level 4 Fatal Fault corresponds to a complete open circuit, short circuit, severe insulation abnormality, or the corresponding circuit being unable to maintain normal power supply.

[0086] In the fault level classification, the preset slight change range, preset statistical period, and preset duration are set according to the normal operating data and maintenance requirements of the vehicle model, and corresponding relationships are established with the low-voltage wiring harness segment and parameter type, respectively. Different parameters do not need to use the same duration conditions.

[0087] For example, a complete open circuit and a short circuit can directly enter a level four fatal fault after meeting the corresponding electrical condition conditions; intermittent poor contact is classified according to the recurrence frequency and single duration within a preset statistical period. Through this processing relationship, it is possible to avoid using a single duration condition for all faults.

[0088] After identifying the fault type and fault level, output differentiated early warning information corresponding to the fault level.

[0089] Level 1 minor faults record the abnormal harness segment, fault location, fault type, effective electrical parameters, vehicle operating parameters, degree of electrical parameter deviation, and time of occurrence, and incorporate the relevant data into subsequent aging trend analysis. Level 2 intermittent faults output text prompts and save the ambient temperature, vehicle load power, vehicle speed, and vehicle vibration amplitude at the time of the anomaly for future understanding of the specific operating conditions under which the anomaly is likely to occur. Level 3 critical faults output audible and visual warnings, display the abnormal harness segment, fault type, and fault location, and output maintenance prompts. Level 4 fatal faults output emergency warnings and the corresponding fault location, and simultaneously query the associated electrical equipment and power supply circuits corresponding to the fault location based on preset harness topology data.

[0090] For power supply circuits involved in Level 4 fatal faults, a distinction is made between non-critical circuits that allow for power supply limitation and critical circuits that need to maintain the vehicle's ability to transition to a safe state before outputting power supply limitation information. When non-critical circuits meet preset limitation conditions, corresponding power supply limitation information is output to reduce the risk of persistent short circuits, severe insulation abnormalities, or abnormal overheating. Critical circuits, on the other hand, retain the power supply conditions required for the vehicle's safe state transition, while simultaneously outputting emergency warning information to guide the vehicle into a preset safe handling state. This avoids directly applying the same power supply limitation method to all circuits after fault classification.

[0091] During continuous vehicle operation, the life assessment unit stores historical electrical parameters, vehicle operating condition parameters, and fault levels separately for each low-voltage wiring harness segment. Historical electrical parameters are arranged by acquisition time and include at least several historical records from real-time resistance, contact resistance, operating voltage, loop current, insulation resistance to ground, and dynamic voltage drop. Vehicle operating condition parameters store the ambient temperature, vehicle load power, vehicle speed, and vehicle vibration amplitude corresponding to each set of historical electrical parameters. Fault levels store the level, duration, and recurrence frequency of each abnormal event. Different low-voltage wiring harness segments store their corresponding historical records separately to avoid mixing aging states of different segments.

[0092] Aging trend analysis is performed according to the preset life assessment cycle. Real-time electrical parameter acquisition, abnormal wiring harness segmentation screening, and fault location are continuously performed under the vehicle's permissible operating conditions; aging trend analysis and low-voltage wiring harness remaining service life assessment can be performed in 30-day cycles. The 30-day cycle is only an implementation example; in practice, the life assessment cycle can be set based on vehicle usage frequency, cumulative operating time, or cumulative mileage.

[0093] When performing aging trend analysis, historical electrical parameters of the same low-voltage harness segment in multiple life assessment cycles are extracted in chronological order. The direction, magnitude, and fault level of change of real-time resistance, contact resistance, and insulation resistance to ground relative to the corresponding normal reference are continuously recorded for each cycle.

[0094] If the real-time resistance continues to increase, the insulation resistance to ground continues to decrease, or the frequency of abnormal recurrence of contact resistance continues to increase across multiple life assessment cycles, the corresponding changes will be recorded as aging trend information for that low-voltage wiring harness segment. If a parameter change only occurs under specific vehicle load power, ambient temperature, or vehicle vibration conditions, the corresponding vehicle operating condition parameters will also be retained to distinguish normal parameter changes caused by operating condition changes from long-term aging changes.

[0095] Before being put into use, the wiring harness life model establishes an initial correspondence using historical operating data of similar low-voltage wiring harnesses. The initial data includes historical electrical parameters continuously recorded from the start of normal use of the low-voltage wiring harness until it reaches the end of its lifespan, corresponding vehicle operating parameters, fault levels, cumulative operating time, and maintenance results.

[0096] The lifespan termination conditions include at least one of the following: low-voltage harness segment reaching a preset termination fault level, key electrical parameters continuously exceeding allowable ranges, an unrecoverable continuity anomaly occurring, insulation resistance to ground reaching a preset maintenance boundary, or the need for replacement during actual maintenance. Each historical operation record establishes corresponding remaining service life reference information based on the time relationship between its acquisition time and the occurrence of the lifespan termination condition.

[0097] After the new energy light trucks are put into operation, the historical electrical parameters, vehicle operating parameters, fault levels, cumulative usage time, and subsequent maintenance results of each low-voltage wiring harness segment are added to the existing data according to the preset life assessment cycle, and the wiring harness life model is iteratively trained. During the iterative training process, the correspondence between the low-voltage wiring harness segment status information, corresponding operating conditions, and actual usage results is maintained, so that newly emerging wiring harness aging states can continuously supplement the existing life correspondence.

[0098] Therefore, the wiring harness life model can use the historical electrical parameters of the current low-voltage wiring harness segment, vehicle operating parameters, and fault level to assess the remaining service life of the low-voltage wiring harness corresponding to the current state.

[0099] When assessing the remaining service life of the low-voltage wiring harness, the life assessment unit extracts historical electrical parameters, vehicle operating parameters, fault levels, and aging trend information from the most recent life assessment cycles of the current low-voltage wiring harness segment. It then matches the current state with the life stage correspondence in the wiring harness life model to obtain the remaining service life from the current state until the end of the lifespan.

[0100] For low-voltage wiring harness segments that are subjected to high temperature, high load, or frequent vibration conditions for a long time, the corresponding exposure information is simultaneously entered into the life assessment process, so that low-voltage wiring harness segments under different operating conditions can obtain their respective remaining service life.

[0101] After obtaining the remaining service life of the low-voltage wiring harness, preventative maintenance information is output. When the remaining service life of the low-voltage wiring harness is still within the normal maintenance cycle range, real-time electrical parameter acquisition, vehicle operating condition parameter recording, and aging trend analysis continue. When the remaining service life of the low-voltage wiring harness enters a preset maintenance cycle, the corresponding low-voltage wiring harness segment, fault location, historical fault type, current fault level, remaining service life, and recommended maintenance timing are output. For low-voltage wiring harness segments with recurring level-two intermittent faults and continuously shortening remaining service life, preventative inspection or replacement prompts are output. For low-voltage wiring harness segments that have reached the end of their service life, maintenance and handling information is output.

[0102] Through the above continuous processing, the real-time electrical parameters and vehicle operating condition parameters obtained by the data acquisition unit are preprocessed to obtain the effective electrical parameters of each low-voltage wiring harness segment; the anomaly diagnosis unit adaptively corrects the preset wiring harness parameter judgment threshold based on the vehicle operating condition parameters, and then compares the effective electrical parameters with the corrected wiring harness parameter judgment threshold segment by segment to screen abnormal wiring harness segments; the fault location unit emits detection signals for abnormal wiring harness segments, collects the reflected signals generated at the fault location, calculates the fault distance based on the propagation delay of the reflected signals, and then matches the fault distance with the preset wiring harness topology data to locate the fault location.

[0103] The fault analysis unit identifies the fault type and fault level based on the characteristics of the reflected signal corresponding to the fault location, the degree of deviation of electrical parameters, the duration and recurrence frequency, and outputs differentiated early warning information corresponding to the fault level. The life assessment unit uses the historical electrical parameters of each low-voltage wiring harness segment, the vehicle operating parameters and the fault level to perform aging trend analysis, evaluates the remaining service life of the low-voltage wiring harness through the iteratively trained wiring harness life model, and outputs preventive maintenance information. In this way, the continuous implementation process of real-time self-diagnosis of low-voltage wiring harness faults in new energy light trucks, abnormal segment screening, fault location, fault classification, differentiated early warning and life assessment is completed.

[0104] The foregoing has only described certain exemplary embodiments of this application by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of this application. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of this application.

Claims

1. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks, characterized in that, include: The data acquisition unit is used to collect various real-time electrical parameters of each low-voltage wiring harness segment of the new energy light truck and the corresponding vehicle operating parameters, and to preprocess the real-time electrical parameters to obtain the effective electrical parameters of each low-voltage wiring harness segment. The anomaly diagnosis unit is used to adaptively correct the preset wiring harness parameter judgment threshold based on the vehicle operating condition parameters, and to compare the effective electrical parameters with the corrected wiring harness parameter judgment threshold in segments to screen abnormal wiring harness segments. The fault location unit is used to transmit detection signals to abnormal wire harness segments, collect reflected signals generated at the fault location, calculate the fault distance based on the propagation delay of the reflected signals, match the fault distance with preset wire harness topology data, and locate the fault location. The fault analysis unit is used to identify the fault type and fault level based on the characteristics of the reflected signal corresponding to the fault location, the degree of deviation of electrical parameters, the duration and recurrence frequency, and output differentiated early warning information corresponding to the fault level. The life assessment unit is used to analyze aging trends by utilizing historical electrical parameters of each low-voltage wiring harness segment, vehicle operating parameters, and fault levels. It assesses the remaining service life of the low-voltage wiring harness through an iteratively trained wiring harness life model and outputs preventive maintenance information.

2. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, Each low-voltage wiring harness segment is configured with a corresponding segment identifier. Real-time electrical parameters are established in a time correspondence with vehicle operating parameters based on the time of acquisition. Valid electrical parameters retain the corresponding segment identifier and vehicle operating parameters.

3. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, Real-time electrical parameters include various parameters such as real-time resistance, contact resistance, operating voltage, loop current, insulation resistance to ground, and dynamic voltage drop. The real-time resistance is obtained based on the working potential and circuit current at both ends of the low-voltage harness segment, while the contact resistance is obtained based on the working potential and corresponding circuit current on both sides of the connector.

4. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 3, characterized in that, The insulation resistance to ground is acquired during the operation period when the low-voltage harness segment meets the preset insulation test conditions. When the load changes or the current operating state does not meet the preset insulation test conditions, the acquisition of the insulation resistance to ground is suspended until the operation period that meets the preset insulation test conditions is entered.

5. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, Preprocessing includes smoothing the continuously sampled data, removing outliers that exceed the physical range of the corresponding electrical parameters and do not have continuous variation characteristics, and correcting the data baseline based on the normal state parameters of the corresponding low-voltage harness segment.

6. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, The threshold values ​​for determining wiring harness parameters correspond to the low-voltage wiring harness segment, electrical parameter type, and operating condition, respectively. When the current vehicle operating condition parameters are between adjacent operating condition reference points, the parameter determination range is continuously adjusted according to the position of the current vehicle operating condition parameters between adjacent operating condition reference points.

7. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 6, characterized in that, The threshold values ​​for determining the wiring harness parameters of real-time resistance are adjusted according to the ambient temperature. The threshold values ​​for determining the wiring harness parameters of dynamic voltage drop are adjusted according to the vehicle load power and circuit current. The abnormal judgment of contact resistance is based on the vehicle body vibration amplitude. The threshold values ​​for determining the wiring harness parameters of ground insulation resistance correspond to the ambient temperature and the segmented operating status of the low-voltage wiring harness.

8. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, The preset harness topology data includes low-voltage harness segment identifiers and corresponding detection start positions, branch node positions, actual path lengths, upstream and downstream connection relationships, associated electrical equipment, reference reflection information, and effective propagation speeds.

9. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 8, characterized in that, After abnormal harness segmentation and screening, the corresponding detection start position and target transmission path are selected from the preset harness topology data according to the abnormal harness segment identifier, and the fault distance matching range corresponding to the reflected signal is limited by the branch to which the abnormal harness segment belongs.

10. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, The detection signal uses a pulse detection signal with a defined emission time. It is emitted when the circuit corresponding to the abnormal harness segment is in the operation period that allows detection. The reflection acquisition time window is opened with the emission time of the detection signal as the starting point to acquire the corresponding reflection signal.

11. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 8, characterized in that, The reference reflection information includes the reflection distance and reflection characteristics corresponding to normal branch nodes, normal connector locations, and wiring locations of associated electrical equipment; When the current reflected signal produces new reflections, amplitude changes, polarity changes, or position changes relative to the reference reflected information, the corresponding reflected signal will be used for fault location analysis.

12. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 10, characterized in that, The fault distance is calculated by converting the propagation delay of the reflected signal into the effective propagation speed corresponding to the abnormal wire bundle segment; The effective propagation speed is obtained in advance based on the round-trip propagation time of the detection signal corresponding to the low-voltage harness with a known actual path length.

13. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 8, characterized in that, The fault distance is mapped segment by segment according to the topological connection order from the detection start position to the abnormal harness segment and the actual path length of each low-voltage harness segment. The remaining distance after deducting the cumulative length of the previous path is mapped to the inside of the abnormal harness segment, branch node, connector position or wiring position of associated electrical equipment.

14. The self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, Fault types are identified by combining the characteristics of reflected signals corresponding to the fault location with valid electrical parameters. When the reflected signal and the effective electrical parameters point to the same abnormal wire harness segment and are within the same abnormal event time range, the two are correlated to distinguish between open circuit, short circuit, contact abnormality, and insulation performance abnormality.

15. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, The degree of electrical parameter deviation represents the extent to which the effective electrical parameter exceeds the corrected wire harness parameter judgment threshold. The duration is accumulated from the first time the parameter exceeds the corresponding judgment range until recovery. When the same type of abnormality occurs again after recovery, it is counted as a new abnormal event and included in the recurrence frequency within the preset statistical period.

16. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 15, characterized in that, The fault levels are classified into minor faults, intermittent faults, critical faults, and fatal faults based on the degree of deviation of electrical parameters, duration, frequency of recurrence, and functional status of related electrical equipment. These faults are respectively accompanied by status records, text prompts, audible and visual warnings, and emergency warnings.

17. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 1, characterized in that, Historical electrical parameters of each low-voltage wiring harness segment are stored in chronological order and associated with corresponding vehicle operating parameters and fault levels. The aging trend is characterized by comparing the changes in resistance, contact resistance, and insulation resistance to ground, as well as the changes in fault status within different life assessment cycles.

18. A self-diagnosis and location system for low-voltage wiring harness faults in new energy light trucks according to claim 17, characterized in that, The wiring harness life model uses historical electrical parameters, vehicle operating parameters, fault levels, cumulative usage time, and maintenance results of the low-voltage wiring harness during normal use until it reaches the end of its lifespan for iterative training. Based on the aging trend corresponding to the current low-voltage wiring harness segment, it assesses the remaining service life of the low-voltage wiring harness and outputs preventive maintenance information.

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