Automobile connector contact impedance detection method and system

Abstract

The invention relates to the technical field of connector detection, in particular to an automobile connector contact impedance detection method and system. The method comprises the following steps: acquiring a plugging operation signal and charging current data of the automobile connector in a charging process; acquiring sampling data of all sensors connected with the automobile connector by using a stable delay acquisition unit based on the plugging operation signal; comparing each sampling data with a preset historical reference value to obtain each drift sampling comparison value; based on the charging current data, each drift sampling comparison value and a sampling drift threshold value corresponding to each drift sampling comparison value, obtaining a measurement reference value after calibration of each sensor; and detecting the contact impedance of the automobile connector based on each measurement reference value to obtain a detection result of the contact impedance. The objective of the invention is to solve the problems in the prior art that measurement errors and real degradation signals cannot be accurately distinguished, and charging safety of an electric vehicle and reliable operation of a connector are difficult to guarantee.

Description

Technical Field

[0001] The present invention relates to the technical field of connector detection, and in particular to a method and system for detecting contact impedance of an automobile connector. Background Art

[0002] When charging an electric vehicle, the high-voltage connector within its charging port, a critical component for energy transmission, must carry hundreds of amperes of DC current. To ensure safe charging and long-term reliable operation of the connector, distributed online detection methods are often used to monitor the contact impedance of key conductive paths within the connector in real time.

[0003] However, the charging connector of an electric vehicle will experience a large number of plugging and unplugging operations throughout its entire service life. Since the connector needs to withstand long-term frequent plugging and unplugging operations and continuous vehicle operation vibration, the internal microstructure used to precisely fix each sensor unit is prone to cumulative small deformation or loosening, which in turn causes unpredictable slow changes in the relative position or physical coupling state between the sensor unit and the monitored conductive path. The contact impedance measurement error caused by long-term plugging and unplugging and vibration causes the position drift or coupling state change of the internal sensors (such as voltage probes, current sensors, and temperature sensors), which will cause the monitoring system to misjudge non-real impedance changes as early degradation of the connector, thereby triggering unnecessary warnings or repairs, increasing maintenance costs. Existing technologies cannot accurately distinguish between measurement errors and real degradation signals, making it difficult to ensure the charging safety of electric vehicles and the reliable operation of connectors. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for detecting the contact impedance of an automobile connector, which is used to solve the problem that the existing technology cannot accurately distinguish between measurement errors and true degradation signals, making it difficult to ensure the charging safety of electric vehicles and the reliable operation of connectors.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical solution: a method for detecting contact impedance of an automobile connector, comprising:

[0006] Obtain the plug-in and pull-out operation signals and charging current data of the vehicle connector during the charging process;

[0007] Based on the plug-in operation signal, a stable delay acquisition unit is used to collect sampling data of all sensors connected to the vehicle connector;

[0008] Comparing each of the sampled data with a preset historical reference value to obtain each drift sampling comparison value;

[0009] Obtaining a calibrated measurement reference value for each sensor based on the charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value;

[0010] Based on each of the measurement reference values, the contact impedance of the automobile connector is detected to obtain a detection result of the contact impedance.

[0011] Furthermore, the present application also proposes that the steps of obtaining the calibrated measurement reference value of each sensor based on the charging current data, each drift sampling comparison value, and the sampling drift threshold corresponding to each drift sampling comparison value include:

[0012] If any of the drift sampling comparison values ​​is greater than its corresponding sampling drift threshold, the sampling data is calibrated using the charging current data, and the calibrated sampling data is used as a measurement reference value;

[0013] If any of the drift sampling comparison values ​​is not greater than its corresponding sampling drift threshold, the preset historical reference value is used as the measurement reference value.

[0014] Furthermore, the present application also proposes that before the step of obtaining the calibrated measurement reference value of each sensor based on the charging current data, each drift sampling comparison value, and the sampling drift threshold corresponding to each drift sampling comparison value, the step also includes:

[0015] Based on each drift sampling comparison value, determining whether each drift sampling comparison value meets a preset drift fuzzy feature; if any of the drift sampling comparison values ​​meets the preset drift fuzzy feature, obtaining change trend data of the drift sampling comparison value of each sensor during the charging process, and temperature data and current data at the corresponding position of the sensor;

[0016] Based on the change trend data, the temperature data and the current data at the corresponding position of the sensor, determining whether the automobile connector has deteriorated, and obtaining a degradation result;

[0017] If the degradation result indicates that the automotive connector has not deteriorated, the position or coupling state of each sensor is calibrated to obtain a measurement reference value for each sensor;

[0018] If the degradation result indicates that the automotive connector has deteriorated, an early warning message is issued.

[0019] Furthermore, the present application also proposes that the steps of calibrating the sampled data using the charging current data and using the calibrated sampled data as the measurement reference value include:

[0020] Based on the charging current data, obtaining expected current data of the sensor corresponding to each sampling data under the current charging condition;

[0021] obtaining a calibration coefficient based on the charging current data and the expected current data;

[0022] The sampling data is calibrated based on the calibration coefficient, and the calibrated sampling data is used as a measurement reference value.

[0023] Furthermore, the present application also proposes that the steps of obtaining a calibration coefficient based on the charging current data and the expected current data include:

[0024] Determining a comprehensive impact of the environment on each sensor based on the charging current data and the expected current data;

[0025] The calibration coefficient is determined based on the comprehensive influence amount of each sensor and the preset influence threshold.

[0026] Furthermore, the present application also proposes that the steps of determining the comprehensive impact of the environment on each sensor based on the charging current data and the expected current data include:

[0027] acquiring environmental response data of each sensor based on the charging current data;

[0028] Based on the expected current data, acquiring historical environmental response data of each sensor;

[0029] Based on the environmental response data of each sensor and the historical environmental response data of each sensor, a comprehensive impact of the environment on each sensor is determined.

[0030] Furthermore, the present application also proposes that the steps of collecting sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal include:

[0031] Based on the plugging and unplugging operation signal, a stable delay acquisition unit is used to perform delay processing to determine whether the plugging and unplugging operation of the automobile connector is in a stable state;

[0032] After the plugging and unplugging operation of the automobile connector is in a stable state, sampling data of all sensors connected to the automobile connector are collected.

[0033] Furthermore, the present application also proposes that after the plugging and unplugging operation of the automobile connector is in a stable state, the step of collecting sampling data of all sensors connected to the automobile connector includes:

[0034] After the plugging and unplugging operation of the automobile connector is in a stable state, collecting preliminary sampling data of all sensors connected to the automobile connector;

[0035] The preliminary sampling data is averaged or filtered to obtain sampling data of all sensors connected to the vehicle connector.

[0036] Furthermore, the present application also proposes that the contact impedance of the automobile connector is detected based on each of the measurement reference values, and the steps of obtaining the detection result of the contact impedance include:

[0037] Based on each of the measurement reference values, the contact impedance of the automobile connector is detected using a detection algorithm to obtain a detection result of the contact impedance.

[0038] The present invention also provides an automotive connector contact impedance detection system, the system comprising:

[0039] An acquisition module is used to obtain the plugging and unplugging operation signals of the vehicle connector and the charging current data during the charging process;

[0040] An acquisition module, configured to acquire sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal;

[0041] A comparison module, configured to compare each of the sampled data with a preset historical reference value to obtain each drift sample comparison value;

[0042] A calibration module, configured to obtain a calibrated measurement reference value for each sensor based on charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value;

[0043] The detection module is used to detect the contact impedance of the automobile connector based on each of the measurement reference values ​​to obtain a detection result of the contact impedance.

[0044] Compared with the prior art, the automotive connector contact impedance detection method and system of the present invention have the following advantages:

[0045] A method and system for detecting the contact impedance of an automotive connector, according to the present invention, acquires plug-in and unplug operation signals and charging current data during the charging process, then uses a stable delay acquisition unit to perform delay processing to collect sampled data from all sensors connected to the automotive connector. Each collected sampled data is compared with a preset historical baseline value to obtain a drift sampling comparison value, which reflects the deviation of the current sensor reading from its initial calibration state. Based on the charging current data, each drift sampling comparison value, and the sampling drift threshold corresponding to each drift sampling comparison value, a calibrated measurement baseline value is obtained for each sensor. The drift sampling comparison value and sampling drift threshold are used to determine the significance of drift and guide the degree of calibration. This method can distinguish measurement changes caused by sensor drift from those caused by changes in the connector's actual impedance, compensating for the former to obtain a measurement baseline. The automotive connector's contact impedance is then tested to obtain a contact impedance detection result. By using the calibrated baseline value for calculations, errors caused by sensor drift can be eliminated or significantly reduced, resulting in more reliable contact impedance detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0047] Figure 1 The present invention is a flow chart of a method for detecting contact impedance of an automobile connector.

[0048] Figure 2 This is a structural block diagram of an automobile connector contact impedance detection system of the present invention.

[0049] In the figure: acquisition module 210, acquisition module 220, comparison module 230, calibration module 240, and detection module 250.

[0050] The implementation and advantages of the functions of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0051] The following diagrams illustrate various embodiments of the present invention. For clarity, many practical details are included in the following description. However, it should be understood that these practical details are not intended to limit the present invention. In other words, in some embodiments of the present invention, these practical details are not essential. Furthermore, to simplify the drawings, some commonly used structures and components are depicted in simplified schematic form.

[0052] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0053] In addition, in the present invention, descriptions such as "first" and "second" are only used for descriptive purposes and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] The existing distributed contact impedance detection method for high-voltage connectors of electric vehicle charging interfaces is prone to cumulative deformation or loosening of the structure used to fix the internal sensor unit when the connector is subjected to high-frequency plug-in and unplug operations and continuous vehicle operation vibration for a long time, resulting in changes in the relative position or physical coupling state between the sensor unit and the monitored conductive path, which in turn causes the measurement reference of the sensor unit to drift, introducing measurement errors. The measured contact impedance value may be inaccurate, and it is difficult to distinguish whether it is actual degradation of the connector or drift of the sensor itself.

[0055] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0056] See also Figure 1 The present invention provides a method for detecting contact impedance of an automobile connector, comprising the following steps:

[0057] S100: Acquire plugging and unplugging operation signals and charging current data of the vehicle connector during the charging process. The plugging and unplugging operation signals are signals used to instruct the vehicle connector to connect or disconnect. The charging current data is measured current flowing through the connector during the vehicle charging process and can be acquired using a Hall effect sensor.

[0058] S200. Based on the plugging and unplugging operation signal, utilize a stable delay acquisition unit to collect sampled data from all sensors connected to the vehicle connector. Specifically, the stable delay acquisition unit is an acquisition module with a delay function, utilizing a hardware delay circuit, a software timer, or state machine control logic. It primarily waits for the connector state to stabilize after the plugging and unplugging operation is complete, thereby preventing transient interference from impacting data collection. For example, the stable delay acquisition unit may be configured to delay data collection for 500 milliseconds after the plugging and unplugging signal is triggered.

[0059] S300: Compare each sampled data with a preset historical reference value to obtain each drift sample comparison value. The preset historical reference value refers to a sensor measurement reference value established during initial installation or calibration of the connector. The historical reference value is obtained by averaging multiple stable state acquisitions and serves as an initial reference for determining whether sensor measurement drift has occurred.

[0060] S400. Based on the charging current data, each drift sampling comparison value and the sampling drift threshold corresponding to each drift sampling comparison value, the measurement reference value of each sensor after calibration is obtained. Specifically, the drift sampling comparison value refers to the difference between the currently collected sensor sampling data and the preset historical reference value, which is obtained by simple numerical subtraction and is used to quantify the degree of deviation of the sensor measurement relative to the initial reference. The sampling drift threshold refers to the preset limit used to determine whether the drift sampling comparison value exceeds the acceptable range, and is used to determine whether the sensor sampling data needs to be calibrated. The measurement reference value refers to the reference value of the sensor measurement after calibration or confirmation, which is achieved by using the calibrated sampling data or directly using the preset historical reference value, and is used as an accurate input for contact impedance detection.

[0061] S500 : Based on each of the measurement reference values, detect the contact impedance of the automobile connector to obtain a detection result of the contact impedance.

[0062] This invention captures plugging and unplugging operation signals and charging current data during the charging process, providing foundational information for subsequent analysis and calibration. Based on the plugging and unplugging operation signals, a stable delay acquisition unit performs delay processing. This ensures that after the connector plugging and unplugging operation is completed, the system waits for the connector to reach a stable physical and electrical state. At this point, sampled data from all sensors connected to the vehicle connector is collected. Delayed acquisition is required because transient voltage and current fluctuations, or mechanical vibration, may occur during plugging and unplugging. Directly collected data may contain interference, affecting accuracy. Each collected sampled data is compared with a preset historical baseline value to generate a drift sample comparison value, which reflects the deviation of the current sensor reading from its initial calibration state. Since the sensor unit may experience slight displacement due to mechanical stress or vibration, causing its measurement baseline to drift, this comparison can reveal the presence and extent of this drift. Based on the charging current data, each drift sample comparison value, and the corresponding sample drift threshold, the system determines the calibrated measurement baseline value for each sensor. Charging current data reflects environmental factors such as the connector's workload and temperature, which may affect sensor readings. Therefore, incorporating this into the calibration process can improve accuracy. The drift sampling comparison value and sampling drift threshold are used to determine drift significance and guide the degree of calibration. This allows the system to distinguish measurement changes caused by sensor drift from those caused by changes in the connector's true impedance, compensating for the former to achieve a more realistic measurement baseline. The automotive connector's contact impedance is measured based on each calibrated measurement baseline value, generating contact impedance test results. This allows the system to accurately track and evaluate changes in the true contact impedance of each conductive path, even with slight dynamic changes in the sensor unit's fixed baseline. This prevents the sensor system's own measurement drift from being misinterpreted as an actual connector fault, reducing false alarms and improving fault diagnosis accuracy. It also prevents measurement errors from masking early signs of connector degradation, ensuring reliable monitoring of connector status and improving charging safety and connector lifespan.

[0063] Based on some of the above embodiments, the present application further proposes that the steps of obtaining a calibrated measurement reference value of each sensor based on charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value include:

[0064] If any of the drift sampling comparison values ​​is greater than its corresponding sampling drift threshold, the sampled data is calibrated using the charging current data, and the calibrated sampled data is used as the measurement reference value. Specifically, a mathematical model is established between the sampled data and the charging current, and an ideal sampled value is predicted based on the current charging current. The deviation between the actual sampled value and the predicted value is then calculated as the calibration value. This eliminates or reduces errors introduced into the sampled data by drift in the position or coupling state of the sensing unit itself, as well as environmental factors. The calibrated sampled data more accurately reflects the actual state of the monitored point, providing a more reliable input for the subsequent determination of the measurement reference value.

[0065] If any of the drift sampling comparison values ​​is not greater than its corresponding sampling drift threshold, the preset historical reference value is used as the measurement reference value.

[0066] In this embodiment, the sensor status is classified into two categories: significant drift and insignificant drift by comparing the drift sampling comparison value with the sampling drift threshold. When the drift sampling comparison value is greater than the sampling drift threshold, it indicates that the sensor measurement value deviates significantly from the historical baseline value, which may be caused by sensor unit drift. In this case, the historical baseline value is not directly used, but the current sampling data is calibrated using charging current data. Charging current data reflects the workload and environmental conditions of the connector and is correlated with the sensor measurement value. Calibration based on charging current data can compensate for the effects of changes in sensor unit position or coupling state, as well as environmental factors, on the sampled data, resulting in calibrated sampled data that is closer to the actual situation. This calibrated sampled data is used as the new measurement baseline for subsequent contact impedance testing. This can address significant sensor unit drift and avoid misinterpreting measurement deviations caused by drift as connector degradation. When the drift sampling comparison value is less than the sampling drift threshold, the deviation between the sensor measurement value and the historical baseline value is within an acceptable range, indicating that the sensor unit drift is insignificant or the deviation is caused by minor changes in the connector itself. At this point, the preset historical baseline value is considered to still have reference value and is directly used as the measurement baseline value. This maintains the stability of the test results, avoids unnecessary calibration when there is no significant drift, reduces computational complexity, and ensures that even when connector degradation occurs, comparisons and judgments can still be made based on the stable historical baseline value. After acquiring the raw sampled data and comparing it with the historical baseline value, the entire solution intelligently selects a method for determining the measurement baseline value based on the comparison result, thereby improving the accuracy and robustness of the entire contact impedance detection method and enabling more effective differentiation between sensor unit drift and actual connector degradation.

[0067] Based on some of the above embodiments, the present application further proposes that before the step of obtaining the calibrated measurement reference value of each sensor based on the charging current data, each drift sampling comparison value, and the sampling drift threshold corresponding to each drift sampling comparison value, the step further includes:

[0068] Based on each drift sampling comparison value, a determination is made as to whether each drift sampling comparison value meets a preset drift fuzzy signature. If any drift sampling comparison value meets the preset drift fuzzy signature, data on the drift sampling comparison value change trend during each charging process of the sensor, as well as temperature and current data at the corresponding location of the sensor, are obtained. The preset drift fuzzy signature refers to a non-simple threshold judgment standard for identifying sensor drift. The classification rules for distinguishing normal fluctuations from abnormal drift, derived through machine learning model training, can more accurately identify potential sensor drift and avoid misjudgments.

[0069] Based on the change trend data, temperature data, and current data at the corresponding sensor location, a determination is made as to whether the automotive connector has degraded, yielding a degradation result. Specifically, whether degradation has occurred is determined based on the acquired change trend data, temperature data, and current data, and the health of the automotive connector is assessed. This is accomplished by establishing a degradation determination model to distinguish between sensor drift and actual connector degradation.

[0070] If the degradation result indicates that the automotive connector has not degraded, each sensor is calibrated for position or coupling status to obtain a baseline measurement value. Specifically, if the connector is determined to be non-degraded but exhibits drift, the sensor is adjusted to restore its measurement accuracy. This calibration is not a simple correction of the measurement data, but rather an adjustment of the sensor's physical state. For example, for a voltage probe, the contact pressure or position relative to the monitoring point can be adjusted. For a non-contact sensor, the relative distance or angle relative to the measured current path can be adjusted. This calibration can be achieved through mechanical actuators, fundamentally eliminating measurement errors caused by changes in the sensor's physical state.

[0071] If the degradation result indicates that the automotive connector has deteriorated, an early warning message is issued.

[0072] Specifically, based on each drift sampling comparison value, determining whether it conforms to a preset drift fuzzy signature can be accomplished using a pre-trained classification model. For example, a support vector machine model can be trained using historically collected normal fluctuation data and known sensor drift data. This model receives the drift sampling comparison value as input and outputs a classification result indicating whether it conforms to the drift fuzzy signature. If the classification result conforms to the preset drift fuzzy signature, the system triggers subsequent data collection. For example, data on the changing trend of the drift sampling comparison value of each sensor during the charging process can be obtained by recording the average value sequence of the drift sampling comparison value of each sensor during the stable charging phase over the last 10 consecutive charging cycles. Temperature data at the corresponding location of the sensor can be obtained by a temperature sensor adjacent to the sensor, and current data can be obtained by a current sensor in the main charging circuit. Based on the change trend data, the temperature data and current data at the sensor's corresponding location, a rule-based expert system can be used to determine whether the vehicle connector has degraded. For example, if the drift trend data shows that the drift sampling comparison value has a monotonically increasing trend for five consecutive charging cycles, the temperature data at the sensor's corresponding location remains above a certain threshold, and the charging current data is within the normal operating range, then the vehicle connector is determined to have degraded. If the degradation result indicates that the vehicle connector has not degraded, calibration of the position or coupling state of each sensor can be performed using a micro-actuator. For example, for a voltage probe, a piezoelectric ceramic driver can be used to fine-tune the contact position between the probe and the contact until the drift sampling comparison value returns to a preset range. If the degradation result indicates that the vehicle connector has degraded, a warning message can be issued by sending a fault code to the instrument panel via the vehicle's communication bus and displaying a corresponding warning icon on the user interface. This application can more accurately identify sensor drift, avoiding misjudgments caused by simple threshold judgments. It can distinguish between sensor drift and degradation of the vehicle connector itself, and adopt different treatments for different situations. In cases where sensor drift occurs but connector degradation persists, calibration of sensor position or coupling status improves measurement baseline accuracy. In cases of connector degradation, timely warnings are issued, enhancing system safety. This solution thus improves the accuracy and reliability of automotive connector contact impedance detection.

[0073] Based on some of the above embodiments, the present application further proposes that the steps of calibrating the sampled data using the charging current data and using the calibrated sampled data as the measurement reference value include:

[0074] Based on the charging current data, expected current data of the sensor under the current charging conditions corresponding to each sampled data is obtained. Specifically, the expected current data refers to the current measurement value that the sensor should have under the current charging current conditions, either theoretically or predicted based on historical data, and is achieved using a model established based on historical data.

[0075] Based on the charging current data and the expected current data, a calibration coefficient is obtained. The calibration coefficient refers to a correction factor or offset used to correct the sampled data to reduce measurement errors, and is calculated based on the difference between the actual sampled data and the expected current data, such as a scaling factor.

[0076] The sampling data is calibrated based on the calibration coefficient, and the calibrated sampling data is used as a measurement reference value.

[0077] In this embodiment, a calibration coefficient is calculated based on charging current data and expected current data, thereby performing refined calibration of the sampled data. Specifically, based on the current charging current data, the expected current data for each sensor under the current charging conditions is obtained. This expected data reflects the sensor's measurement value under ideal or normal conditions and provides a reference for subsequent deviation analysis. Next, the actual charging current data and the obtained expected current data are combined to calculate a calibration coefficient. This calibration coefficient quantifies the deviation between the actual sampled data and the expected data, accounting for the impact of charging current on the sensor response. Finally, the calculated calibration coefficient is used to correct the original sampled data to obtain the calibrated sampled data, which is used as the measurement baseline value. This method combines the mechanism used in the previous solution to determine whether calibration is needed based on the drift comparison value. When significant drift in the sampled data is detected, a dynamic and precise calibration is performed based on the current charging conditions and the expected sensor response, rather than simply applying a preset calibration. This makes the calibration process more intelligent and adaptive, effectively compensating for measurement errors caused by environmental changes or sensor characteristics, thereby obtaining a more accurate measurement baseline value and improving the accuracy and reliability of subsequent contact impedance detection.

[0078] Based on the above embodiments, in this embodiment, after the reference calibration triggered by the plugging and unplugging operation signal is completed, the slow change check is triggered during the charging cycle according to conditions such as a preset time interval or the charging current entering a stable phase.

[0079] Specifically, during the ramp check, the monitoring system obtains the current readings of one or more selected sensor units. Simultaneously, the system calculates the expected readings for each sensor unit based on the current primary charging parameter (e.g., charging current) and a pre-defined relationship model for the sensor unit in a drift-free state (e.g., the proportionality coefficient between the voltage sensor reading and the current value, or the range of voltage sensor readings at a specific current).

[0080] The monitoring system compares the current reading of the sensor unit with the calculated expected reading. If the deviation between the two exceeds the preset slow change judgment threshold, and the deviation characteristics (for example, only the voltage reading changes while the current reading remains unchanged, or the change trend does not conform to the logic of thermal or electrical effects caused by contact resistance changes) are inconsistent with the characteristics of the impedance change of the connector's conductive path itself, then the sensor unit is determined to have a slow change.

[0081] Once a slow change is detected, the monitoring system calculates a compensation based on the deviation. This compensation is then subtracted or added to the original reading of the sensor unit in subsequent contact impedance calculations until the next charging and unplugging event triggers a new baseline calibration. Once the new baseline calibration is complete, the compensation generated by the slow change check becomes invalid, and the new calibration result determines the baseline. This method improves the accuracy of measurement data between plug-in calibration events by monitoring and compensating for slow changes in the sensor unit during the charging cycle.

[0082] Based on some of the above embodiments, the present application further proposes that the steps of obtaining a calibration coefficient based on the charging current data and the expected current data include:

[0083] Based on the charging current data and the expected current data, the comprehensive environmental impact on each sensor is determined. The comprehensive impact refers to the degree to which environmental factors (such as temperature, humidity, and electromagnetic fields) interfere with the sensor's measurement results. This is determined by analyzing the difference between the actual measured data and the ideal expected data and attributing the difference to the environmental factors. The purpose is to quantify the impact of environmental factors on sensor readings.

[0084] The calibration coefficient is determined based on the combined impact of each sensor and a preset impact threshold. Specifically, the preset impact threshold is a threshold used to determine whether the environmental impact on the sensor is significant and whether calibration is necessary. This threshold is set based on the sensor's characteristics, application scenario, and acceptable measurement error range to determine the degree of calibration.

[0085] In this embodiment, the comprehensive impact of the environment on each sensor is determined based on the charging current data and the expected current data, and the calibration coefficient is determined based on the comprehensive impact and the preset impact threshold. Because the comprehensive impact of environmental factors on each sensor is fully considered and quantified when calculating the calibration coefficient, the calibration coefficient can more accurately reflect the deviation of the sensor under the current environmental conditions, thereby enabling more accurate calibration of the sampled data. This is different from the method of directly calculating the calibration coefficient based solely on the charging current data and the expected current data. The latter method fails to distinguish between deviations caused by the environment and deviations caused by other factors (such as sensor drift). By incorporating environmental impact into the determination process of the calibration coefficient, the solution of the present application can effectively compensate for the impact of environmental factors on the sensor measurement benchmark, making the calibrated measurement benchmark value closer to the actual state of the sensor, thereby improving the accuracy of subsequent contact impedance detection. This refined processing of environmental impact enables the system to maintain high detection reliability even under complex and changing environmental conditions, helping to more accurately distinguish impedance changes caused by actual connector degradation from measurement drift caused by the environment or the sensor itself, thereby avoiding misjudgment and omission.

[0086] Based on some of the above embodiments, the present application further proposes that the steps of determining the comprehensive impact of the environment on each sensor based on the charging current data and the expected current data include:

[0087] Based on the charging current data, environmental response data of each sensor is obtained. The environmental response data refers to the component extracted from the charging current data that represents the deviation of the sensor measurement value from the ideal value under the current environmental conditions, reflecting the impact of the current environmental factors on the sensor performance.

[0088] Based on the expected current data, historical environmental response data of each sensor is obtained. The historical environmental response data refers to the components extracted from the expected current data that represent the deviation of sensor measurement values ​​from ideal values ​​under historical environmental conditions, reflecting the response characteristics of the sensor under known environmental conditions.

[0089] The comprehensive environmental impact of each sensor is determined based on its environmental response data and historical environmental response data. Specifically, the comprehensive impact is a numerical value that quantifies the impact of environmental factors on sensor measurements, obtained by comparing current environmental response data with historical environmental response data. This value is used to assess the overall offset of the sensor's measurement baseline caused by the current environment relative to historical environments.

[0090] In this embodiment, the charging current data and expected current data are processed in a more refined manner to accurately determine the comprehensive environmental impact on each sensor. Specifically, first, environmental response data for each sensor is obtained based on the charging current data. This is because the actual collected charging current data directly reflects the immediate impact of current environmental factors on the sensor's measurement results. By analyzing this data, the degree of offset in the sensor's measurement value under the current environmental conditions can be quantified. Next, based on the expected current data, historical environmental response data for each sensor is obtained. The expected current data represents the current value under known environmental conditions. By analyzing this data, a response model for the sensor under a baseline environment can be established or a reference value for historical environmental impact can be obtained. Finally, based on the environmental response data of each sensor and its historical environmental response data, the comprehensive environmental impact on each sensor is determined. By comparing the sensor response under the current environment with the sensor response under historical or baseline environments, the net impact of environmental factors can be effectively separated and quantified, avoiding the errors that may be introduced by rough estimation using raw current data. The more accurate comprehensive environmental impact quantity obtained in this way can provide a more reliable input for the subsequent determination of the calibration coefficient based on the impact quantity and the preset impact threshold, thereby improving the calculation accuracy of the calibration coefficient, and then improving the effect of calibrating the sampling data, and ultimately improving the accuracy of automotive connector contact impedance detection.

[0091] Based on some of the above embodiments, the present application further proposes that the steps of collecting sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal include:

[0092] Based on the plugging and unplugging operation signal, a stable delay acquisition unit is used to perform delay processing to determine that the plugging and unplugging operation of the automobile connector is in a stable state.

[0093] After the plugging and unplugging operation of the automobile connector is in a stable state, sampling data of all sensors connected to the automobile connector are collected.

[0094] In this embodiment, the stable delay acquisition unit can be an embedded controller, such as a microcontroller, which receives the plug-in and unplug operation signal from the connector plug-in and unplug detection switch or the vehicle communication bus. When the rising edge of the signal (indicating the start of plug-in and unplugging) or the falling edge (indicating the end of plug-in and unplugging) is detected, a timer inside the controller is started. The timer is preset to a duration of, for example, several hundred milliseconds to several seconds. When the timer count reaches a preset value, the controller determines that the plug-in and unplugging operation has stabilized. Then, through its integrated analog-to-digital converter (ADC) interface, it sequentially reads the analog or digital output signals of all sensors connected to different channels, such as voltage sensors, current sensors, and temperature sensors, and converts these signals into digital sampled data for storage or sends them to a subsequent processing module. When the plug-in and unplugging operation signal of the vehicle connector is detected, the stable delay acquisition unit does not immediately trigger data acquisition, but instead starts a delay timer. This delay is set to cover the time period from the start of plug-in and unplugging to the time when the mechanical and electrical conditions of the connector stabilize. After the delay ends, the system determines that the plug-in and unplugging operation has entered a stable state. At this time, the stable delay acquisition unit triggers the data acquisition function and begins to acquire sampled data from all sensors connected to the vehicle connector. This strategy of delaying before collecting ensures that data collection is performed when the connector is in a stable and reliable physical and electrical connection state. This method of collecting data in a stable state improves the accuracy of the collected data, and accurate data collection is the basis for subsequent steps (comparison, calibration, and detection). Accurate sampling data makes the drift sampling comparison value more accurate, the calibrated measurement reference value more reliable, and the final contact impedance detection result is closer to the actual situation. Therefore, this improvement enables the overall detection method to more effectively identify the measurement drift of the sensing unit itself and distinguish it from the actual degradation of the connector contacts, thereby improving the reliability and diagnostic accuracy of the entire detection system.

[0095] Based on some of the above embodiments, the present application further proposes that after the plugging and unplugging operation of the automobile connector is in a stable state, the step of collecting sampling data of all sensors connected to the automobile connector includes:

[0096] After the plugging and unplugging operation of the vehicle connector reaches a stable state, preliminary sampling data is collected from all sensors connected to the vehicle connector. Preliminary sampling data refers to a set of raw, unprocessed sensor measurement values ​​collected over a period of time after the plugging and unplugging operation of the vehicle connector reaches a stable state. This data is obtained using methods such as continuous, intermittent, or triggered acquisition.

[0097] The preliminary sampled data is averaged or filtered to obtain sampled data from all sensors connected to the vehicle connector. Specifically, averaging can be achieved by calculating the arithmetic mean of the preliminary sampled data set, and filtering can be achieved by applying a digital filter (e.g., a moving average filter, a low-pass filter, or a median filter) to improve data stability and accuracy.

[0098] In this embodiment, after the plugging and unplugging operation of the automotive connector reaches a stable state, the system does not immediately acquire final sampled data. Instead, it first performs a preliminary data acquisition process, which obtains a series of raw measurement values ​​that may contain noise and transient fluctuations. The system then averages or filters these preliminary sampled data. Averaging effectively mitigates the effects of random noise and outliers by integrating information from multiple data points. Filtering, based on a preset algorithm, removes high-frequency noise components from the data, preserving a more stable signal trend. This process transforms the raw preliminary sampled data into smoother, more reliable sampled data. This processing mechanism, combined with the determination of a stable state, ensures that data acquisition is performed under the premise of a relatively stable physical state of the connector. Post-processing of the collected raw data further improves data quality. This combined approach enables subsequent contact impedance testing based on these sampled data to be based on more accurate data, thereby improving the reliability and accuracy of the entire detection method and effectively addressing the data instability caused by transient interference and noise in existing technologies.

[0099] Based on some of the above embodiments, the present application further proposes that the contact impedance of the automotive connector is detected based on each of the measurement reference values, and the steps of obtaining the detection result of the contact impedance include:

[0100] Based on each of the measured reference values, the contact impedance of the automotive connector is detected using a detection algorithm to obtain a contact impedance detection result. In this embodiment, the detection algorithm refers to a series of calculation rules or models used to process the measured reference values ​​to determine the contact impedance of the automotive connector. The purpose of the detection algorithm is to extract valid contact impedance information from the measured reference values ​​and distinguish between actual impedance changes and potential measurement errors.

[0101] Specifically, the detection of the contact impedance of the automotive connector is achieved by processing each measurement reference value using a detection algorithm. After obtaining the calibrated measurement reference values, the detection algorithm is applied to these reference values. Unlike simple direct calculations, the detection algorithm can perform more complex analysis, such as time series analysis of the measurement reference values, correlation and comparison with other sensor data, application of filtering technology to remove noise, or use of pre-trained models to identify patterns associated with specific contact impedance states. By adopting the detection algorithm, the system can more deeply explore the information contained in the measurement reference values ​​and effectively distinguish between the true impedance changes caused by the degradation of the connector itself and the signal fluctuations caused by other factors (such as environmental fluctuations or small residual measurement errors). This algorithm-based processing method, combined with the calibrated measurement reference values ​​provided by the previous step, forms a more robust and accurate contact impedance detection mechanism, thereby solving the problem of insufficient accuracy caused by relying solely on raw or simply processed measurement values ​​for judgment.

[0102] Based on any of the above examples, please refer to Figure 2 The present invention also provides a vehicle connector contact impedance detection system, which includes an acquisition module 210, an acquisition module 220, a comparison module 230, a calibration module 240 and a detection module 250.

[0103] The acquisition module 210 is used to obtain the plugging and unplugging operation signals of the vehicle connector and the charging current data during the charging process;

[0104] The acquisition module 220 is used to collect sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal;

[0105] The comparison module 230 is used to compare each of the sampled data with a preset historical reference value to obtain each drift sampling comparison value;

[0106] The calibration module 240 is configured to obtain a calibrated measurement reference value for each sensor based on the charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value;

[0107] The detection module 250 is configured to detect the contact impedance of the automobile connector based on each of the measurement reference values ​​to obtain a detection result of the contact impedance.

[0108] This application utilizes an acquisition module 210 to receive plug-in and unplug operation signals and charging current data during the charging process, providing raw input for subsequent processing. Based on the plug-in and unplug operation signals, the acquisition module 220 utilizes a stable delay acquisition unit to control the acquisition of sensor data. This stable delay acquisition unit ensures that data acquisition is performed only after the plug-in and unplug operation stabilizes, preventing transient signal fluctuations from interfering with data accuracy and thereby improving the reliability of the collected data. The comparison module 230 receives the collected sampled data and compares it with a preset historical reference value to obtain a drift sampling comparison value, which is used to identify drift in the sensor data. The calibration module 240 calibrates the sensor data based on the charging current data, the drift sampling comparison value, and the corresponding sampling drift threshold to obtain a calibrated measurement reference value. The calibration process uses the charging current data to compensate for errors caused by the environment or the sensor's own characteristics, thereby improving the accuracy of the measurement reference value. The detection module 250 receives the calibrated measurement reference value and, based on this data, executes a contact impedance detection algorithm to obtain the final contact impedance detection result. By having the above multiple modules work together in a predetermined process sequence to form an automated detection chain, the system can overcome the measurement errors caused by the drift of the sensor unit itself, accurately evaluate the true contact impedance state of the connector, and solve the problems of low manual detection efficiency and misjudgment caused by sensor unit drift.

[0109] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for detecting contact impedance of an automobile connector, characterized in that: include: Obtain the plug-in and pull-out operation signals and charging current data of the vehicle connector during the charging process; Based on the plug-in operation signal, a stable delay acquisition unit is used to collect sampling data of all sensors connected to the vehicle connector; Comparing each of the sampled data with a preset historical reference value to obtain each drift sampling comparison value; Obtaining a calibrated measurement reference value for each sensor based on the charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value; Based on each of the measurement reference values, the contact impedance of the automobile connector is detected to obtain a detection result of the contact impedance.

2. The method for detecting contact impedance of an automobile connector according to claim 1, wherein: The step of obtaining a calibrated measurement reference value of each sensor based on the charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value includes: If any of the drift sampling comparison values ​​is greater than its corresponding sampling drift threshold, the sampling data is calibrated using the charging current data, and the calibrated sampling data is used as a measurement reference value; If any of the drift sampling comparison values ​​is not greater than its corresponding sampling drift threshold, the preset historical reference value is used as the measurement reference value.

3. The method for detecting contact impedance of an automobile connector according to claim 1, wherein: Before the step of obtaining the calibrated measurement reference value of each sensor based on the charging current data, each drift sampling comparison value, and the sampling drift threshold corresponding to each drift sampling comparison value, the step further includes: Based on each drift sampling comparison value, determining whether each drift sampling comparison value meets a preset drift fuzzy feature; if any of the drift sampling comparison values ​​meets the preset drift fuzzy feature, obtaining change trend data of the drift sampling comparison value of each sensor during the charging process, and temperature data and current data at the corresponding position of the sensor; Based on the change trend data, the temperature data and the current data at the corresponding position of the sensor, determining whether the automobile connector has deteriorated, and obtaining a degradation result; If the degradation result indicates that the automotive connector has not deteriorated, the position or coupling state of each sensor is calibrated to obtain a measurement reference value for each sensor; If the degradation result indicates that the automotive connector has deteriorated, an early warning message is issued.

4. The method for detecting contact impedance of an automobile connector according to claim 1, wherein: The step of calibrating the sampled data using the charging current data and using the calibrated sampled data as a measurement reference value includes: Based on the charging current data, obtaining expected current data of the sensor corresponding to each sampling data under the current charging condition; obtaining a calibration coefficient based on the charging current data and the expected current data; The sampling data is calibrated based on the calibration coefficient, and the calibrated sampling data is used as a measurement reference value.

5. The method for detecting contact impedance of an automobile connector according to claim 4, wherein: The step of obtaining a calibration coefficient based on the charging current data and the expected current data includes: Determining a comprehensive impact of the environment on each sensor based on the charging current data and the expected current data; The calibration coefficient is determined based on the comprehensive influence amount of each sensor and the preset influence threshold.

6. The method for detecting contact impedance of an automobile connector according to claim 5, wherein: The step of determining a comprehensive impact of the environment on each sensor based on the charging current data and the expected current data includes: acquiring environmental response data of each sensor based on the charging current data; Based on the expected current data, acquiring historical environmental response data of each sensor; Based on the environmental response data of each sensor and the historical environmental response data of each sensor, a comprehensive impact of the environment on each sensor is determined.

7. The method for detecting contact impedance of an automobile connector according to claim 1, wherein: The step of collecting sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal includes: Based on the plugging and unplugging operation signal, a stable delay acquisition unit is used to perform delay processing to determine whether the plugging and unplugging operation of the automobile connector is in a stable state; After the plugging and unplugging operation of the automobile connector is in a stable state, sampling data of all sensors connected to the automobile connector are collected.

8. The method for detecting contact impedance of an automobile connector according to claim 7, wherein: After the plugging and unplugging operation of the automobile connector is in a stable state, the step of collecting sampling data of all sensors connected to the automobile connector includes: After the plugging and unplugging operation of the automobile connector is in a stable state, collecting preliminary sampling data of all sensors connected to the automobile connector; The preliminary sampling data is averaged or filtered to obtain sampling data of all sensors connected to the vehicle connector.

9. The method for detecting contact impedance of an automobile connector according to claim 1, wherein: The step of detecting the contact impedance of the automobile connector based on each of the measurement reference values ​​to obtain a detection result of the contact impedance includes: Based on each of the measurement reference values, the contact impedance of the automobile connector is detected using a detection algorithm to obtain a detection result of the contact impedance.

10. An automotive connector contact impedance detection system, characterized in that: The system includes: An acquisition module is used to obtain the plugging and unplugging operation signals of the vehicle connector and the charging current data during the charging process; An acquisition module, configured to acquire sampling data of all sensors connected to the vehicle connector using a stable delay acquisition unit based on the plug-in operation signal; A comparison module, configured to compare each of the sampled data with a preset historical reference value to obtain each drift sample comparison value; A calibration module, configured to obtain a calibrated measurement reference value for each sensor based on charging current data, each drift sampling comparison value, and a sampling drift threshold corresponding to each drift sampling comparison value; The detection module is used to detect the contact impedance of the automobile connector based on each of the measurement reference values ​​to obtain a detection result of the contact impedance.

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