OBD diagnostic instrument tamper-proofing monitoring system and method based on two-way data comparison

Abstract

The invention discloses an OBD diagnostic instrument tamper-proof monitoring system and method based on double-path data comparison, and belongs to the technical field of motor vehicle emission supervision. The problems that an existing OBD diagnostic instrument calibration device based on a single standard signal source cannot recognize cheating behaviors to be tested, and supervision and evidence obtaining are not persuasive are solved. The system comprises a standard signal simulation unit, a real signal bypass acquisition unit, a data monitoring and obtaining unit and a two-way verification analysis engine. Besides a standard signal simulation unit, a real signal bypass acquisition unit is introduced, a double-path data source of standard simulation signals and bypass real signals is constructed, and actual uploading data of the OBD diagnostic apparatus to be tested and the double-path data are subjected to cross comparison and analysis through a double-path verification analysis engine. The method can identify and distinguish test-taking cheating for analog signals, inherent reading deviation of a diagnostic instrument and active tampering behaviors, and realizes the crossing from single equipment calibration to all-around intelligent supervision.

Description

Technical Field

[0001] This invention relates to the field of motor vehicle fault diagnosis and emission testing technology, and in particular to a system and method for monitoring and obtaining evidence of whether there is tampering during the data upload process of an OBD diagnostic instrument. Background Technology

[0002] OBD diagnostic tools are key equipment for the periodic inspection of vehicle emissions, and the authenticity of the data they upload directly affects the effectiveness of environmental protection policies. However, some unscrupulous testing agencies in the market use illegal means to tamper with OBD diagnostic tools in order to help unqualified vehicles pass the inspection. Common methods include implanting cheating programs into the device so that when it reads specific fault codes or excessive data, it automatically replaces them with normal data before uploading; or interfering with the communication between the diagnostic tool and the vehicle through external devices.

[0003] The prior art patent with publication number CN120128433A provides a tamper-proof OBD diagnostic instrument calibration device. This solution generates standard data through a host computer, simulates vehicle signals through a slave computer, and then verifies whether the data uploaded by the OBD diagnostic instrument is consistent with the standard data. This solution provides a useful approach to solving the problem of tampering.

[0004] However, long-term practice has revealed certain limitations of this existing technical solution. First, it relies entirely on an idealized analog signal source. In actual supervision, when the system alarms, the regulated party may argue that there are inherent differences between the analog signal and the real vehicle, or that there are reasonable errors in the signal analysis of different brands of diagnostic instruments. This weakens the authority of supervision to some extent. Second, this solution is mainly suitable for periodic equipment calibration and is difficult to integrate into the continuous and seamless supervision of the large number of real vehicle testing operations conducted by testing agencies on a daily basis. More importantly, some cunning cheating programs have the ability to perform tests. When they detect standard signals from the simulator, they will behave normally and upload real data. However, once connected to a real vehicle, they will initiate tampering logic. The existing single signal source solution is powerless against such cheating behavior.

[0005] Therefore, there is an urgent need in this field for a new anti-tampering monitoring solution that is more convincing and closer to complex real-world detection scenarios. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned shortcomings of the prior art by providing an OBD diagnostic instrument anti-tampering monitoring system and method based on dual-channel data comparison. This system, by introducing dual-channel data sources and an intelligent comparison engine, aims to achieve accurate and irrefutable identification of OBD diagnostic instrument tampering behavior and effectively identify exam cheating.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison, the system includes a standard signal simulation unit for generating and outputting preset simulated vehicle OBD data signals; The real signal bypass acquisition unit is used to non-destructively acquire real vehicle data streams from the OBD interface of the vehicle under inspection. The data monitoring and acquisition unit is used to capture data packets uploaded by the OBD diagnostic instrument under test to the monitoring platform; The dual-channel verification and analysis engine is connected to the standard signal simulation unit, the real signal bypass acquisition unit, and the data monitoring and acquisition unit, respectively. It is used to compare and analyze the actual uploaded data of the OBD diagnostic instrument under test with the simulated vehicle data and the real vehicle data stream, and output the judgment conclusion.

[0008] Furthermore, the real signal bypass acquisition unit is a high-impedance, passive signal coupler that is connected in parallel to the OBD interface of the vehicle under test.

[0009] Furthermore, the dual-path verification analysis engine is configured to execute the following decision logic: If the actual uploaded data is consistent with the standard simulation data but inconsistent with the real vehicle data, it will be judged as cheating in the test. If the actual transmitted data is consistent with the real vehicle data but inconsistent with the standard simulation data, it is determined that the diagnostic tool has an inherent bias. If the actual transmitted data is inconsistent with both the standard simulation data and the real vehicle data, it is determined to be an act of deliberate tampering.

[0010] Furthermore, the system also includes a mode switching and task configuration interface, which allows users to switch between calibration mode and monitoring mode. The calibration mode is a mode that compares the actual uploaded data of the OBD diagnostic instrument under test only with the simulated vehicle data generated by the standard signal simulation unit.

[0011] Furthermore, the system also includes an intelligent early warning and report generation unit connected to a dual-path verification and analysis engine. The intelligent early warning and report generation unit is configured to receive a judgment conclusion, trigger an early warning signal based on the conclusion, and generate a structured and reliable regulatory report.

[0012] A method for preventing tampering in OBD diagnostic instruments based on dual-channel data comparison includes the following steps: Step a: Receive user instructions, select calibration mode or monitoring mode, and initialize the corresponding unit; Step b: If in calibration mode, the standard signal simulation unit outputs a standard analog signal to the OBD diagnostic instrument under test; Step c: If it is in monitoring mode, the real signal bypass acquisition unit starts to bypass and acquire the real data stream from the OBD interface of the vehicle under test. Step d: The data monitoring and acquisition unit begins to capture the uploaded data from the OBD diagnostic instrument under test; Step e: The dual-path verification analysis engine calls the corresponding comparison algorithm to perform consistency, logical rationality and statistical feature analysis on the acquired multi-path data according to the current mode; Step f: The intelligent early warning and report generation unit generates early warning information of different levels based on the analysis results, and automatically compiles a complete regulatory report containing data snapshots, comparison processes and judgment conclusions.

[0013] Furthermore, in step e, the comparison algorithm includes a dynamic weight allocation algorithm. This algorithm assigns appropriate weights to different verification dimensions based on the importance of the data items and key parameters such as engine speed and vehicle speed, and quantifies the tampering risk level through weighted comprehensive scoring, thereby improving the accuracy and adaptability of the judgment.

[0014] Furthermore, in step c, the credible regulatory report generated in monitoring mode simultaneously displays the numerical and waveform comparisons of standard simulation data, real vehicle data collected by bypass, and the actual data transmitted by the OBD diagnostic instrument under test in a side-by-side view, and highlights data points with significant differences, making it easier for users to intuitively identify data anomalies and tampering traces.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention constructs a closed loop of cross-verification by introducing a dual verification mechanism of standard signals and real vehicle signals. In monitoring mode, the system simultaneously acquires standard simulated data, bypass real data, and data uploaded by the diagnostic instrument. Any abnormal deviation between any data streams can be effectively captured. In particular, when there is a logical conflict between the uploaded data and the two reference data streams, the system can form irrefutable evidence of tampering, thereby enhancing the authority and credibility of regulatory conclusions.

[0016] The dual-path working mode design of this invention can effectively identify and deal with intelligent adaptive cheating programs. These programs output normal data to pass calibration when they detect simulated signals, but tamper with the data in real scenarios. In monitoring mode, this invention can directly expose the cheating behavior of the diagnostic instrument when facing real vehicles by using the real data stream collected by the bypass, thus rendering its adaptive strategy ineffective and solving the problem of test cheating that is difficult to detect by existing spot checks.

[0017] This invention achieves a seamless extension from static calibration to dynamic monitoring. The system can not only be used for traditional equipment factory calibration and periodic spot checks, but also flexibly integrate into the online inspection process of any real vehicle. This capability extends the scope of supervision from discrete point spot checks to continuous area monitoring, significantly expanding the coverage and randomness of supervision, thereby forming a continuous and powerful deterrent against potential tampering. Attached Figure Description

[0018] Figure 1 This is a block diagram of the overall structure of the present invention; Figure 2 This is a flowchart of an embodiment of the present invention.

[0019] In the diagram: 101, Standard signal simulation unit; 102, Real signal bypass acquisition unit; 103, Data monitoring and acquisition unit; 104, Dual-channel verification and analysis engine; 105, Intelligent early warning and report generation unit; 106, Mode switching and task configuration interface. Detailed Implementation

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

[0021] Example 1 like Figures 1-2 As shown, this embodiment provides an OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison. This system fundamentally innovates upon existing technologies in its architecture. It should be noted that the basic functions and implementation methods of the standard signal simulation unit 101 and the calibration mode mentioned later (e.g., generating standard protocol data via a host computer and performing signal conversion via a slave computer) have already been disclosed in existing technologies (such as patent publication number CN120128433A), and are existing technical features known to those skilled in the art. The core improvement of this invention lies in the introduction of a completely new data source and comparison logic, specifically structured as follows: The system includes a standard signal simulation unit 101, which is used to generate and output preset simulated vehicle OBD data signals; The real signal bypass acquisition unit 102 is used to non-destructively acquire real vehicle data streams from the OBD interface of the vehicle under inspection. The data monitoring and acquisition unit 103 is used to capture data packets uploaded by the OBD diagnostic instrument under test to the monitoring platform; The dual-channel verification and analysis engine 104 is connected to the standard signal simulation unit 101, the real signal bypass acquisition unit 102, and the data monitoring and acquisition unit 103 respectively. It is used to compare and analyze the actual uploaded data of the OBD diagnostic instrument under test with the simulated vehicle data and the real vehicle data stream, and output the judgment conclusion. The real signal bypass acquisition unit 102 is a high-impedance, passive signal coupler connected in parallel to the OBD interface of the vehicle under test. The dual-channel verification and analysis engine 104 is configured to execute the following judgment logic: If the actual uploaded data is consistent with the standard simulation data but inconsistent with the real vehicle data, it will be judged as cheating in the test. If the actual transmitted data is consistent with the real vehicle data but inconsistent with the standard simulation data, it is determined that the diagnostic tool has an inherent bias. If the actual transmitted data is inconsistent with both the standard simulation data and the real vehicle data, it will be judged as an act of deliberate tampering. The system also includes a mode switching and task configuration interface 106, which allows users to switch between calibration mode and monitoring mode. The calibration mode is a mode that compares the actual uploaded data of the OBD diagnostic instrument under test only with the simulated vehicle data generated by the standard signal simulation unit 101. The system also includes an intelligent early warning and report generation unit 105, which is connected to the dual-path verification and analysis engine 104. The intelligent early warning and report generation unit 105 is configured to: receive a judgment conclusion, trigger an early warning signal based on the conclusion, and generate a structured and reliable regulatory report. This invention also provides a method for tamper-proof monitoring of OBD diagnostic instruments based on dual-channel data comparison, comprising the following steps: Step a: Receive user instructions, select calibration mode or monitoring mode, and initialize the corresponding unit; Step b: If in calibration mode, the standard signal simulation unit 101 outputs a standard analog signal to the OBD diagnostic instrument under test. Step c: If it is in monitoring mode, the real signal bypass acquisition unit 102 starts to bypass and acquire the real data stream from the OBD interface of the vehicle under test. Step d: The data monitoring and acquisition unit 103 begins to capture the uploaded data of the OBD diagnostic instrument under test; Step e: The dual-path verification analysis engine 104 calls the corresponding comparison algorithm to perform consistency, logical rationality and statistical feature analysis on the acquired multi-path data according to the current mode; Step f: The intelligent early warning and report generation unit 105 generates early warning information of different levels based on the analysis results, and automatically compiles a complete regulatory report containing data snapshots, comparison processes and judgment conclusions.

[0022] In step e, the comparison algorithm includes a dynamic weight allocation algorithm, which assigns appropriate weights to different verification dimensions based on the importance of data items (such as key parameters like engine speed and vehicle speed), and quantifies the tampering risk level through weighted comprehensive scoring, thereby improving the accuracy and adaptability of the judgment.

[0023] In step c, the credible regulatory report generated in monitoring mode simultaneously displays the numerical and waveform comparisons of standard simulation data, real vehicle data collected by bypass, and the actual data transmitted by the OBD diagnostic instrument under test in a side-by-side view, and highlights data points with significant differences, making it easy for users to intuitively identify data anomalies and tampering traces.

[0024] In a preferred embodiment, the standard signal simulation unit 101 is used to generate a preset simulated vehicle OBD data signal as a reference for the system. The real signal bypass acquisition unit 102 is the first innovation of this invention. It is an independent hardware module. Its core is a high-impedance, passive signal coupler, which is physically connected in parallel to the OBD interface of the vehicle under inspection. Its purpose is to acquire the original data stream from the real vehicle without any tampering, thereby providing a second, unforgeable reference signal source for supervision. The data monitoring and acquisition unit 103 is used to capture the data packets that the OBD diagnostic instrument under test actually transmits to the monitoring platform; The dual-path verification analysis engine 104 is the second innovation of this invention. It is connected to the three units mentioned above. Its core function is to perform the second comparison analysis in the monitoring mode, that is, to cross-compare the actual uploaded data of the OBD diagnostic instrument under test with the standard simulation data and the real vehicle data collected by the bypass, and to make a judgment based on the new logic. The intelligent early warning and report generation unit 105 is used to generate early warnings and credible regulatory reports containing multi-channel data comparisons based on the judgment conclusions; The mode switching and task configuration interface 106 is used by users to switch working modes. Here, it needs to be further clarified that the function of the calibration mode, which compares the actual uploaded data of the OBD diagnostic instrument under test with the simulated vehicle data generated by the standard signal simulation unit 101, is entirely within the scope of existing technology. This invention retains this mode to be compatible with traditional equipment calibration processes, while the core value and all the creativity of this invention are reflected in the brand-new monitoring mode.

[0025] Example 2 The working process of the present invention will be described in detail below with reference to specific embodiments: This embodiment simulates a typical regulatory scenario: regulatory personnel conduct a surprise on-site inspection of an OBD diagnostic instrument at a testing station that is suspected of being equipped with cheating programs for taking exams.

[0026] S1: System Deployment and Initialization The regulatory personnel selected the monitoring mode and then carried out the following on-site deployment: The real signal bypass acquisition unit 102 (a compact passive acquisition device) is physically connected to the OBD interface of the vehicle under inspection; The testing station operators are required to connect the OBD diagnostic instrument to be tested to the same OBD interface to enable it to enter normal working condition. The data monitoring and acquisition unit 103 (an independent network gateway) is connected to the core switch of the local area network of the testing station and configured as a bypass mirroring mode to capture all uplink data packets sent by the diagnostic instrument under test without loss.

[0027] S2: Multi-channel synchronous data acquisition and acquisition After the detection process is initiated, the system begins to simultaneously collect data from three sources: First path (real baseline): The real signal bypass acquisition unit 102 directly acquires the raw data stream from the vehicle's OBD bus, such as the real-time reading TR of the nitrogen oxide (NOx) sensor (assumed to be 800 ppm), indicating the vehicle's current actual emission status. The second channel (tested data): After the OBD diagnostic instrument under test reads the vehicle data, it processes and encapsulates it into a data packet, which is then prepared to be uploaded to the remote monitoring platform. When this data packet is transmitted over the network, it is intercepted and parsed by the data monitoring and acquisition unit 103, and the NOx value DR reported is 150 ppm. The third channel (standard reference): The standard signal analog unit 101 continuously outputs a preset standard analog signal with a NOx value SR of 100 ppm, which serves as a constant reference within the system.

[0028] S3: Dual-path verification and intelligent analysis The dual-channel verification analysis engine 104 simultaneously receives the above three channels of data and executes the preset comparison analysis logic: First comparison: The consistency of the data DR (150 ppm) uploaded by the diagnostic instrument and the actual data TR (800 ppm) collected by the bypass was checked. The result was: |DR - TR|> the preset threshold α, indicating a serious inconsistency. A second comparison was performed: the consistency of the diagnostic instrument's uploaded data DR (150 ppm) and the standard simulated data SR (100 ppm) was checked. The result was: |DR - SR| < the preset threshold β, and the two were very close within the allowable error range. Based on the above comparison results and in conjunction with the relevant judgment logic, the analysis engine concludes that the data uploaded by the OBD diagnostic instrument under test is seriously deviating from the actual state of the vehicle, but deliberately catering to the normal range of the standard analog signal. This behavioral characteristic meets the judgment conditions for cheating on the analog signal test. Therefore, it is finally determined that the diagnostic instrument has actively tampered with the data.

[0029] S4: Early Warning and Report Generation Based on the judgment result, the intelligent early warning and report generation unit 105 immediately triggers a high-level alarm prompt. At the same time, it automatically generates a structured and reliable regulatory report, the core part of which is clearly presented in a comparative view (such as a side-by-side table). Actual NOx value obtained via bypass sampling: 800 ppm; The diagnostic instrument actually reported a NOx value of 150 ppm. The standard simulated NOx reference value is 100 ppm. The report clearly states in its conclusion section that the data reported by the diagnostic instrument under test is seriously inconsistent with the actual vehicle data, indicating malicious tampering and demonstrating evasion of standard calibration.

[0030] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A tamper-proof monitoring system for OBD diagnostic instruments based on dual-channel data comparison, characterized in that, include: The standard signal simulation unit (101) is used to generate and output preset simulated vehicle OBD data signals; The real signal bypass acquisition unit (102) is used to non-destructively acquire real vehicle data streams from the OBD interface of the vehicle under inspection; The data monitoring and acquisition unit (103) is used to capture data packets uploaded by the OBD diagnostic instrument under test to the monitoring platform; The dual-channel verification analysis engine (104) is connected to the standard signal simulation unit (101), the real signal bypass acquisition unit (102), and the data monitoring and acquisition unit (103) respectively. It is used to compare and analyze the actual uploaded data of the OBD diagnostic instrument under test with the simulated vehicle data and the real vehicle data stream, and output the judgment conclusion.

2. The OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison according to claim 1, characterized in that, The real signal bypass acquisition unit (102) is a high-impedance, passive signal coupler that is connected in parallel to the OBD interface of the vehicle under test.

3. The OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison according to claim 1, characterized in that, The dual-path verification analysis engine (104) is configured to execute the following decision logic: If the actual uploaded data is consistent with the standard simulation data but inconsistent with the real vehicle data, it will be judged as cheating in the test. If the actual transmitted data is consistent with the real vehicle data but inconsistent with the standard simulation data, it is determined that the diagnostic tool has an inherent bias. If the actual transmitted data is inconsistent with both the standard simulation data and the real vehicle data, it is determined to be an act of deliberate tampering.

4. The OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison according to claim 1, characterized in that, The system also includes an intelligent early warning and report generation unit (105) connected to the dual-path verification and analysis engine (104). The intelligent early warning and report generation unit (105) is configured to receive the judgment conclusion, trigger an early warning signal based on the conclusion, and generate a structured and credible regulatory report.

5. The OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison according to claim 1, characterized in that, The system also includes a mode switching and task configuration interface (106) for users to switch between calibration mode and monitoring mode. The calibration mode is a mode in which the actual uploaded data of the OBD diagnostic instrument under test is compared only with the simulated vehicle data generated by the standard signal simulation unit (101).

6. A method for preventing tampering in OBD diagnostic instruments based on dual-channel data comparison, employing the OBD diagnostic instrument anti-tampering monitoring system based on dual-channel data comparison described in 1-5, characterized in that, Includes the following steps: Step a: Receive user instructions, select calibration mode or monitoring mode, and initialize the corresponding unit; Step b: If it is in calibration mode, the standard signal simulation unit (101) outputs a standard analog signal to the OBD diagnostic instrument under test; Step c: If it is in monitoring mode, the real signal bypass acquisition unit (102) starts to bypass and acquire the real data stream from the OBD interface of the vehicle under test; Step d: The data monitoring and acquisition unit (103) begins to capture the uploaded data of the OBD diagnostic instrument under test; Step e: The dual-path verification analysis engine (104) calls the corresponding comparison algorithm to perform consistency, logical rationality and statistical feature analysis on the acquired multi-path data according to the current mode; Step f, Intelligent Early Warning and Report Generation Unit (105) generates early warning information of different levels based on the analysis results, and automatically compiles a complete regulatory report containing data snapshots, comparison process and judgment conclusions.

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