Automobile signal detection system

Abstract

The invention discloses an automobile signal detection system which comprises an electric signal acquisition module, a conversion module, a CAN-FD signal acquisition module and an upper computer. The upper computer comprises a signal analysis module and a data display module; the electric signal acquisition module acquires electric signals in an automobile circuit in multiple paths; the conversion module converts the electric signal acquired by the electric signal acquisition module into a first CAN-FD signal and sends the first CAN-FD signal to the CAN-FD signal acquisition module; the CAN-FD signal acquisition module acquires a second CAN-FD signal on an automobile bus, sends the second CAN-FD signal to the upper computer, receives the first CAN-FD signal from the conversion module and forwards the first CAN-FD signal to the upper computer; the signal analysis module analyzes the first CAN-FD signal and the second CAN-FD signal to obtain an analysis result and then sends the analysis result to the signal analysis module; and the data display module displays the analysis result. According to the invention, eight paths of alternating current signals, four paths of alternating voltage signals, four paths of direct current signals and four paths of CAN-FD signals in an automobile circuit can be monitored at the same time.

Description

Technical Field

[0001] The invention belongs to the field of automobile signal detection, and in particular relates to an automobile signal detection system. Background Art

[0002] At present, with the rapid development of the automobile industry, automotive electronic technology is becoming increasingly complex and advanced. Automobiles are equipped with a large number of electronic control units (ECUs) and various sensors and actuators, which communicate and work together through electrical signals and buses. Especially during the charging and discharging process of electric vehicle batteries, in order to ensure the normal operation of the automotive electronic system, the detection of automotive electrical signals and bus signals becomes crucial.

[0003] In the existing technology, some detection systems have many limitations. For example, some systems can only detect a few specific signals and cannot meet the needs of simultaneous detection of multiple signals in complex automotive electronic systems. Some detection equipment has low accuracy and sensitivity, and it is difficult to accurately capture and analyze weak signals or rapidly changing signals, resulting in unreliable detection results. In addition, most detection solutions lack systematic hardware and software integration, and hardware devices and software programs are often designed separately, which not only increases the difficulty of use for users, but may also cause hardware and software incompatibility problems, affecting detection efficiency and accuracy. Summary of the invention

[0004] The purpose of the present invention is to provide a comprehensive, accurate and efficient system for detecting automobile electrical signals and bus signals, so as to solve the problems existing in the prior art such as limited detection signal types, insufficient accuracy and low software and hardware integration.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0006] A vehicle signal detection system, comprising:

[0007] The electrical signal acquisition module is used to collect electrical signals in the automotive circuit in multiple channels;

[0008] A conversion module, used to convert the electrical signal collected by the electrical signal collection module into a first CAN-FD signal and send it to the CAN-FD signal collection module;

[0009] A CAN-FD signal acquisition module, used for acquiring a second CAN-FD signal on the vehicle bus and sending it to the host computer, and also for receiving a first CAN-FD signal from the conversion module and forwarding it to the host computer;

[0010] A host computer, used for receiving a first CAN-FD signal and a second CAN-FD signal from a CAN-FD signal acquisition module; the host computer includes a signal analysis module and a data display module;

[0011] The signal analysis module is used to analyze the first CAN-FD signal and the second CAN-FD signal, and send the analysis results to the signal analysis module after obtaining them;

[0012] The data display module is used to display the analysis results.

[0013] Preferably, the electrical signal acquisition module includes 8-channel AC current signal acquisition submodules, 4-channel AC voltage signal acquisition submodules, and 4-channel DC current signal acquisition submodules;

[0014] The 8-channel AC current signal acquisition submodule is used to collect AC current signals in the automobile circuit through AC current sensors;

[0015] The 4-channel AC voltage signal acquisition submodule is used to acquire AC voltage signals in the automobile circuit through a voltage acquisition chip;

[0016] The 4-channel DC current signal acquisition submodule is used to acquire DC current signals in the automobile circuit through a DC current sensor.

[0017] Preferably, the conversion module includes a signal conditioning submodule and an analog-to-digital conversion submodule;

[0018] The signal conditioning submodule is used to amplify, filter, shunt and correct the electrical signal collected by the electrical signal acquisition module, and then output the corrected electrical signal to the analog-to-digital conversion submodule;

[0019] The analog-to-digital conversion submodule is used to uniformly convert all the corrected electrical signals output by the signal conditioning submodule into voltage signals, and then uniformly convert them into first CAN-FD signals and send them to the CAN-FD signal acquisition module.

[0020] Preferably, the signal conditioning submodule includes an amplifier circuit, a filter, and a shunt; the electrical signal collected by the electrical signal acquisition module is amplified by the amplifier circuit and filtered by the filter, and then input to the two ends of the shunt; the shunt corrects the current according to the voltage at its two ends, and the corrected current is output to the analog-to-digital conversion submodule.

[0021] Preferably, the signal conditioning submodule corrects the current in the following manner: full and full-scale current I full The relationship for setting the compensation impedance R is as follows:

[0022]

[0023] The relationship between the current I corrected by the shunt according to the voltage V at both ends is as follows:

[0024] V=I×R.

[0025] Preferably, the analog-to-digital conversion submodule converts the corrected current I1 into an induced voltage V2 by setting a pair of electromagnetic induction coils; assuming that the number of turns of one coil through which the current I1 flows is N1, the number of turns of the other coil is N2, and the self-inductance coefficient is L, then the relationship between the mutual inductance coefficient M is as follows:

[0026]

[0027] Assuming that the time that the corrected current I1 flows in a coil is t, the relationship between the induced voltage V2 is as follows:

[0028]

[0029] Preferably, the CAN-FD signal acquisition module includes 4 CAN-FD signal acquisition submodules; the 4 CAN-FD signal acquisition submodules include a bus interface chip, a transceiver, a controller, and a peripheral circuit;

[0030] The 4-channel CAN-FD signal acquisition submodule is used to collect the CAN-FD bus signals of the car.

[0031] Preferably, the signal analysis module is used to: analyze the first CAN-FD signal to obtain voltage and current information in the vehicle circuit, and analyze the voltage and current information to obtain the operating status and energy consumption of the vehicle circuit; the signal analysis module is also used to analyze the second CAN-FD signal to evaluate and diagnose the vehicle bus.

[0032] Preferably, the signal analysis module further comprises: after the host computer receives the first CAN-FD signal and the second CAN-FD signal, the signal analysis module first filters them; the signal analysis module adopts an adaptive filtering algorithm;

[0033] The adaptive filtering algorithm includes: when the signal analysis module has filtered n+1 times, it will iteratively update the filter coefficient n times;

[0034] Assume that the output signal of the nth filtering is y(n) and the expected signal is d(n), then the error of the nth filtering is e(n)=d(n)-y(n);

[0035] Set the hyperparameter μ. When the input signal of the nth filtering is x(n), the adaptive filtering algorithm updates the filter coefficient w(n+1) of the n+1th filtering according to the filter coefficient w(n) of the nth filtering. The relationship of w(n+1) is as follows:

[0036] w(n+1)=w(n)+2μe(n)x(n), where n≥2.

[0037] Preferably, the signal analysis module further comprises: after analyzing the first CAN-FD signal to obtain the voltage and current information in the automobile circuit, according to the weights of the m current sensors used by the electrical signal acquisition module to collect the current and the current values ​​measured by them, the current measurement result I is calculated by the data fusion and compensation algorithm. fused ; The data fusion and compensation algorithm includes the following calculation formula:

[0038]

[0039] Among them, w i is the weight of the i-th sensor, I i is the current value measured by the i-th sensor.

[0040] Beneficial effects:

[0041] The automobile signal detection system of the present invention has the following beneficial effects:

[0042] 1. Comprehensive signal detection: It can simultaneously monitor 8 AC current signals, 4 AC voltage signals, 4 DC current signals and 4 CAN-FD signals, covering multiple key signal types commonly found in automotive electronic systems, providing strong support for comprehensive detection of automotive electronic systems.

[0043] 2. High-precision detection: By adopting advanced sensor technology, shunt application and signal processing algorithm, the accuracy and sensitivity of signal acquisition are improved, which can accurately capture weak signals and rapidly changing signals, ensuring the accuracy and reliability of the detection results.

[0044] 3. Integrated hardware and software: A complete solution including acquisition hardware, conversion hardware and software is provided. The acquisition hardware is responsible for signal acquisition, the conversion hardware performs format conversion and preprocessing on the acquired signals, and the software analyzes, displays and manages the processed signals. This integrated design not only improves the compatibility and stability of the system, but also greatly reduces the difficulty of use for users, allowing users to conveniently and quickly detect automotive electrical signals and bus signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Shown is a first structural block diagram of an automobile signal detection system of an embodiment;

[0046] Figure 2 Shown is a second structural block diagram of an automobile signal detection system of an embodiment;

[0047] Figure 3 Shown is a third structural block diagram of an automobile signal detection system according to an embodiment. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0049] The technical solution of the present invention is described in detail below with specific embodiments.

[0050] Example

[0051] like Figures 1 to 3 As shown, a vehicle signal detection system of this embodiment includes:

[0052] The electrical signal acquisition module is used to collect electrical signals in the automotive circuit in multiple channels;

[0053] A conversion module, used to convert the electrical signal collected by the electrical signal collection module into a first CAN-FD signal and send it to the CAN-FD signal collection module;

[0054] A CAN-FD signal acquisition module, used for acquiring a second CAN-FD signal on the vehicle bus and sending it to the host computer, and also for receiving a first CAN-FD signal from the conversion module and forwarding it to the host computer;

[0055] A host computer, used for receiving a first CAN-FD signal and a second CAN-FD signal from a CAN-FD signal acquisition module; the host computer includes a signal analysis module and a data display module;

[0056] The signal analysis module is used to analyze the first CAN-FD signal and the second CAN-FD signal, and send the analysis results to the signal analysis module after obtaining them;

[0057] The data display module is used to display the analysis results.

[0058] Preferably, the electrical signal acquisition module includes 8-channel AC current signal acquisition submodules, 4-channel AC voltage signal acquisition submodules, and 4-channel DC current signal acquisition submodules;

[0059] The 8-channel AC current signal acquisition submodule is used to collect AC current signals in the automobile circuit through AC current sensors;

[0060] The 4-channel AC voltage signal acquisition submodule is used to acquire AC voltage signals in the automobile circuit through a voltage acquisition chip;

[0061] The 4-channel DC current signal acquisition submodule is used to acquire DC current signals in the automobile circuit through a DC current sensor.

[0062] Preferably, the conversion module includes a signal conditioning submodule and an analog-to-digital conversion submodule;

[0063] The signal conditioning submodule is used to amplify, filter, shunt and correct the electrical signal collected by the electrical signal acquisition module, and then output the corrected electrical signal to the analog-to-digital conversion submodule;

[0064] The analog-to-digital conversion submodule is used to uniformly convert all the corrected electrical signals output by the signal conditioning submodule into voltage signals, and then uniformly convert them into first CAN-FD signals and send them to the CAN-FD signal acquisition module.

[0065] Preferably, the signal conditioning submodule includes an amplifier circuit, a filter, and a shunt; the electrical signal collected by the electrical signal acquisition module is amplified by the amplifier circuit and filtered by the filter, and then input to the two ends of the shunt; the shunt corrects the current according to the voltage at its two ends, and the corrected current is output to the analog-to-digital conversion submodule.

[0066] Preferably, the signal conditioning submodule corrects the current in the following manner: full and full-scale current I full The relationship for setting the compensation impedance R is as follows:

[0067]

[0068] The relationship between the current I corrected by the shunt according to the voltage V at both ends is as follows:

[0069] V=I×R.

[0070] Preferably, the analog-to-digital conversion submodule converts the corrected current I1 into an induced voltage V2 by setting a pair of electromagnetic induction coils; assuming that the number of turns of one coil through which the current I1 flows is N1, the number of turns of the other coil is N2, and the self-inductance coefficient is L, then the relationship between the mutual inductance coefficient M is as follows:

[0071]

[0072] Assuming that the time that the corrected current I1 flows in a coil is t, the relationship between the induced voltage V2 is as follows:

[0073]

[0074] Preferably, the CAN-FD signal acquisition module includes 4 CAN-FD signal acquisition submodules; the 4 CAN-FD signal acquisition submodules include a bus interface chip, a transceiver, a controller, and a peripheral circuit;

[0075] The 4-channel CAN-FD signal acquisition submodule is used to collect the CAN-FD bus signals of the car.

[0076] Preferably, the signal analysis module is used to: analyze the first CAN-FD signal to obtain voltage and current information in the vehicle circuit, and analyze the voltage and current information to obtain the operating status and energy consumption of the vehicle circuit; the signal analysis module is also used to analyze the second CAN-FD signal to evaluate and diagnose the vehicle bus.

[0077] Preferably, the signal analysis module further comprises: after the host computer receives the first CAN-FD signal and the second CAN-FD signal, the signal analysis module first filters them; the signal analysis module adopts an adaptive filtering algorithm;

[0078] The adaptive filtering algorithm includes: when the signal analysis module has filtered n+1 times, it will iteratively update the filter coefficient n times;

[0079] Assume that the output signal of the nth filtering is y(n) and the expected signal is d(n), then the error of the nth filtering is e(n)=d(n)-y(n);

[0080] Set the hyperparameter μ. When the input signal of the nth filtering is x(n), the adaptive filtering algorithm updates the filter coefficient w(n+1) of the n+1th filtering according to the filter coefficient w(n) of the nth filtering. The relationship of w(n+1) is as follows:

[0081] w(n+1)=w(n)+2μe(n)x(n), where n≥2.

[0082] Preferably, the signal analysis module further comprises: after analyzing the first CAN-FD signal to obtain the voltage and current information in the automobile circuit, according to the weights of the m current sensors used by the electrical signal acquisition module to collect the current and the current values ​​measured by them, the current measurement result I is calculated by the data fusion and compensation algorithm. fused ; The data fusion and compensation algorithm includes the following calculation formula:

[0083]

[0084] Among them, w i is the weight of the i-th sensor, I i is the current value measured by the i-th sensor.

[0085] Specifically, the automobile signal detection system of this embodiment is composed of acquisition hardware, conversion hardware and software. The acquisition hardware is the front-end part of the entire detection system, mainly composed of 8-way AC current signal acquisition modules, 4-way AC voltage signal acquisition modules, 4-way DC current signal acquisition modules and 4-way CAN-FD signal acquisition modules. A variety of signal acquisition modules can ensure that the automobile signal detection system can accurately collect 8-way AC current signals, 4-way AC voltage signals, 4-way DC current signals and 4-way CAN-FD signals.

[0086] 8-channel AC current signal acquisition module: It uses high-precision current sensors to collect AC current signals in automotive circuits in real time and convert them into electrical signals suitable for subsequent processing. The module has high sensitivity and wide dynamic range, can adapt to AC current signals of different amplitudes, and can support the acquisition of mV and μA level current signals with an error of no more than ±1%.

[0087] 4-channel AC voltage signal acquisition module: Use a dedicated voltage acquisition chip to accurately collect voltage signals in automotive circuits. It can collect voltage signals in different ranges and has good linearity and stability to ensure that the collected voltage signals are accurate. According to different application scenarios, the ±2000V and ±200V ranges can be adjusted and output to the conversion module.

[0088] 4-channel DC current signal acquisition module: equipped with high-performance DC current sensors, used to collect DC current signals in automotive circuits. The module has high precision and low noise characteristics, can effectively suppress external interference, and provide pure DC current signal acquisition.

[0089] 4-channel CAN-FD signal acquisition module: Based on a dedicated CAN-FD bus interface chip, FPGA technology is used to integrate CAN-FD transceivers, controllers and peripheral circuits to achieve the acquisition of automotive CAN-FD bus signals. It can accurately identify the CAN-FD bus protocol, fully collect and analyze the signals on the bus, support ACK self-confirmation and detection of various error frames, is compatible with CAN2.0A / B, and complies with the definition and specification standards of the ISO-11898 protocol, providing a reliable data source for subsequent signal processing.

[0090] Furthermore, this embodiment also optimizes the circuit design of the acquisition module, and by optimizing the circuit structure, improves the performance and sensitivity of the acquisition module, reduces noise, and expands the dynamic range. Among them, for current signal measurement, a current sensor based on the Hall effect principle is selected, and its core component can sensitively sense the change of the magnetic field, accurately measure the current intensity, and can detect the current change at the milliampere or even microampere level, effectively improving the accuracy of small current signal acquisition; for voltage signal acquisition, a sensor module composed of a precision voltage divider resistor network and a high-precision operational amplifier is used; the voltage divider resistor network uses high-precision, low-temperature drift metal film resistors to ensure the stability of the voltage divider ratio, and the operational amplifier has low input offset voltage and high common mode rejection ratio, accurately amplifies and conditions weak voltage signals, and ensures the accuracy of voltage measurement.

[0091] Furthermore, the acquisition module also has a built-in automatic calibration circuit, which automatically performs zero-point and full-scale calibration when the system is started or regularly maintained. By comparing with a high-precision reference source, the sensor output is adjusted in real time to eliminate measurement errors caused by factors such as temperature drift and component aging. The sensor temperature compensation algorithm is used to dynamically compensate the measurement results based on the internal temperature sensor detection value. For example, for temperature-sensitive resistance sensors, the resistance value changes caused by temperature changes are corrected in real time based on the pre-established temperature-resistance characteristic curve to ensure measurement accuracy at different operating temperatures.

[0092] Furthermore, when the sensor temperature is T, the sensor temperature compensation algorithm is as follows:

[0093] R T =R0(1+α(T-T0));

[0094] Among them, R T is the resistance at temperature T, R0 is the initial resistance of the sensor, T0 is the initial temperature of the sensor, and α is the temperature coefficient of the sensor resistance.

[0095] Specifically, the conversion hardware is located between the acquisition hardware and the software, and plays a bridging role. It mainly includes a signal conditioning submodule and an analog-to-digital conversion submodule.

[0096] Signal conditioning submodule: pre-processes various electrical signals collected by the acquisition hardware, including signal amplification, filtering, isolation and other operations. The signal conditioning submodule can improve the quality of the signal, remove noise and interference, and make the signal more suitable for analog-to-digital conversion. The design of the signal conditioning submodule is based on the different types and qualities of the collected signals, and a suitable signal conditioning submodule is designed to ensure that noise and interference can be effectively removed and the signal quality is improved.

[0097] Shunt principle: It is based on the principle that current generates voltage when it passes through a resistor. It is a resistor with a very small resistance. When current passes through it, a voltage drop is generated at both ends. By measuring this voltage drop and converting it, large current measurement can be achieved. Its impedance R can be expressed as

[0098] Calculation, often used in conjunction with a DC ammeter, the full scale of the ammeter is the rated current value of the shunt, and the smaller the ratio of small current to large loop current, the better the linearity and more accurate the ammeter reading. There are many types, such as external and internal.

[0099] Furthermore, the shunt of this embodiment is made of low temperature coefficient, high precision manganese copper alloy material, its resistance value is stable, changes little with temperature, and can maintain accurate resistance value within a wide temperature range. The resistance value of the shunt is accurately calculated and precision processed to ensure that under different current loads, the voltage drop at both ends is strictly proportional to the measured current. The shunt uses a special four-terminal structure design to effectively reduce the influence of contact resistance and lead resistance on the measurement results, so that the measured current passes through the shunt more accurately, improving the measurement accuracy and reliability. The shunt is equipped with a dedicated signal conditioning submodule to amplify and filter the weak voltage signals at both ends of the shunt. The amplification circuit uses a low-noise, high-gain amplifier to amplify the millivolt signal to a level range suitable for analog-to-digital conversion, and at the same time, a carefully designed filter is used to filter out high-frequency noise and interference to improve the signal-to-noise ratio.

[0100] Furthermore, digital calibration technology is used to compensate for the nonlinearity and temperature errors of the shunt. By measuring and modeling the characteristics of the shunt under different current values ​​and temperature conditions, storing the compensation parameters, and correcting the results in real time during actual measurement, the current measurement accuracy based on the shunt is improved.

[0101] Analog-to-digital conversion submodule: converts voltage and current signals into CAN-FD signals, mainly based on the CAN-FD bus data acquisition module used in industrial scenarios, converts analog input and digital input signals into CAN-FD bus signals, and encapsulates multiple signals into a message frame. According to the definition and specification of ISO-11898, a message frame containing electrical signal data is generated, and data is transmitted on the CAN-FD bus. The precision control of the analog-to-digital conversion submodule uses a high-precision analog-to-digital converter, and through reasonable circuit design and parameter setting, it ensures that the converted digital signal has sufficient accuracy and resolution.

[0102] Specifically, the software is the core control and analysis part of the entire detection system. It mainly includes signal analysis module and data display module.

[0103] Signal analysis module: It has built-in advanced signal processing algorithms and mathematical logic operations. For current signals, it can analyze its amplitude, frequency, phase and other parameters; for voltage signals, it can analyze its stability, fluctuation, etc. After the specific current and voltage signals are collected, the power of the corresponding physical module and the energy consumption of the entire system can be calculated through the built-in logic operation script; for CAN-FD signals, it can perform protocol analysis, fault diagnosis and other operations. Through these analyses, the operating status of the automotive electronic system can be accurately judged.

[0104] Furthermore, the signal analysis module uses adaptive filtering algorithms, such as the least mean square (LMS) or recursive least squares (RLS) algorithm, to filter the collected signals in real time. The algorithm automatically adjusts the filter coefficients according to the statistical characteristics of the signal and noise, effectively removing interference components, including the electromagnetic interference of the automotive electrical system itself and environmental noise. The signal analysis module targets different types of signals, such as AC current and voltage signals, and the adaptive filter dynamically adjusts the filtering parameters according to their frequency characteristics and change laws to achieve the best filtering effect. For example, for specific frequency interference of AC current signals, the filter frequency response is accurately adjusted to filter out interference and retain the original signal characteristic information.

[0105] Furthermore, the signal analysis module uses data fusion and compensation algorithms to fuse data from multiple sensors or the same sensor at different times; for example, for multiple current sensor data, through weighted averaging, Kalman filtering and other methods, comprehensively consider the measurement accuracy, reliability and other factors of each sensor to obtain more accurate current measurement results. The signal analysis module uses data fusion and compensation algorithms to compensate for sensor nonlinear errors and temperature drift in real time, and through the establishment of error models, dynamically compensates for measurement data according to the measurement environment and sensor status; for example, using temperature sensors to monitor ambient temperature, correcting measurement data according to the pre-established temperature-error compensation curve to improve measurement accuracy and stability.

[0106] Data display module: Displays the analysis results of the signal analysis module to the user in an intuitive way. It can display charts, values ​​and other information of various signals, such as the amplitude curve of the current signal, the value list of the voltage signal, the protocol analysis results of the CAN-FD signal, etc. Users can quickly understand the working status of the automotive electronic system through these displayed information.

[0107] Specifically, the working principle of a vehicle signal detection system of this embodiment is as follows: each acquisition module in the acquisition hardware works simultaneously to collect various signals on the vehicle in real time. For AC current signals, the 8-way AC current signal acquisition module uses a high-precision current sensor to collect signals, converts them into electrical signals and sends them to the conversion hardware. For voltage signals, the 4-way voltage signal acquisition module uses a dedicated voltage acquisition chip to collect signals and sends them to the conversion hardware. For DC current signals, the 4-way DC current signal acquisition module uses a high-performance DC current sensor to collect signals and sends them to the conversion hardware. For CAN-FD signals, the 4-way CAN-FD signal acquisition module collects signals based on a dedicated CAN-FD bus interface chip and then sends them to the host computer for processing in conjunction with the conversion module. The signal conditioning submodule in the conversion hardware preprocesses the various electrical signals collected, such as amplification, filtering, isolation, etc., and then sends the processed signals to the analog-to-digital conversion submodule. The converted signal converts the electrical signal into a CAN-FD message frame through the built-in conversion logic, and the data on the bus is sent to the host computer software in conjunction with the CAN-FD acquisition module. After receiving the CAN-FD signal, the signal analysis module in the software uses the corresponding algorithm to analyze it according to the message ID and database file. For example, for the current signal, analyze its amplitude, frequency, phase and other parameters; for the voltage signal, analyze its stability, fluctuation, etc.; for the CAN-FD signal, perform protocol analysis, fault diagnosis and other operations. The analysis results are displayed to the user in an intuitive way by the data display module, and the specific values ​​of each signal are displayed and the signal change trend curve is drawn.

[0108] Furthermore, reasonable selection and integration of various signal acquisition modules: According to the characteristics of different signal types, suitable sensors and chips are selected to ensure the accurate acquisition of 8 AC current signals, 4 AC voltage signals, 4 DC current signals and 4 CAN-FD signals.

[0109] Circuit design optimization of the acquisition module: By optimizing the circuit structure, the performance of the acquisition module can be improved, such as increasing sensitivity, reducing noise, and expanding dynamic range.

[0110] The vehicle signal detection system of this embodiment has the following beneficial effects:

[0111] 1. Comprehensive detection capability: It can detect multiple types of automotive electrical signals and bus signals at the same time, covering AC current, voltage, DC current and CAN-FD signals, etc., which makes it possible to conduct comprehensive detection of automotive electronic systems and greatly improves the comprehensiveness and systematicness of detection.

[0112] 2. High-precision test results: Through advanced sensor technology, signal processing algorithms, and reasonable hardware circuit design, the accuracy and sensitivity of signal acquisition are improved, which can accurately capture weak signals and rapidly changing signals, ensure the accuracy and reliability of test results, and provide a strong basis for fault diagnosis of automotive electronic systems.

[0113] 3. Easy to use: A complete set of software and hardware integration solutions is provided. Users only need to perform simple installation and configuration to use the detection system. The software has a friendly interface, simple operation, and intuitive data display. Users can quickly understand the working status of the automotive electronic system, which reduces the user's usage threshold and improves the user experience.

[0114] 4. System stability and compatibility: The integrated design of software and hardware makes the system have good stability and compatibility. The acquisition hardware, conversion hardware and software work closely together and cooperate with each other to avoid the problem of software and hardware incompatibility, ensure the stable operation of the system, and improve the reliability and service life of the system.

[0115] The CAN-FD signals described in the present invention can all be written as CAD (FD) signals. Any automobile signal detection system capable of collecting and detecting CAD (FD) signals should also be within the protection scope of the present invention.

[0116] The above is a detailed description of an embodiment of a vehicle signal detection system provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A vehicle signal detection system, characterized in that: include: The electrical signal acquisition module is used to collect electrical signals in the automotive circuit in multiple channels; A conversion module, used to convert the electrical signal collected by the electrical signal collection module into a first CAN-FD signal and send it to the CAN-FD signal collection module; A CAN-FD signal acquisition module, used for acquiring a second CAN-FD signal on the vehicle bus and sending it to the host computer, and also for receiving a first CAN-FD signal from the conversion module and forwarding it to the host computer; A host computer, used for receiving a first CAN-FD signal and a second CAN-FD signal from a CAN-FD signal acquisition module; the host computer includes a signal analysis module and a data display module; The signal analysis module is used to analyze the first CAN-FD signal and the second CAN-FD signal, and send the analysis results to the signal analysis module after obtaining them; The data display module is used to display the analysis results.

2. The automobile signal detection system according to claim 1, characterized in that: The electrical signal acquisition module includes 8-channel AC current signal acquisition submodules, 4-channel AC voltage signal acquisition submodules, and 4-channel DC current signal acquisition submodules; The 8-channel AC current signal acquisition submodule is used to collect AC current signals in the automobile circuit through AC current sensors; The 4-channel AC voltage signal acquisition submodule is used to acquire AC voltage signals in the automobile circuit through a voltage acquisition chip; The 4-channel DC current signal acquisition submodule is used to acquire DC current signals in the automobile circuit through a DC current sensor.

3. The automobile signal detection system according to claim 1, characterized in that: The conversion module includes a signal conditioning submodule and an analog-to-digital conversion submodule; The signal conditioning submodule is used to amplify, filter, shunt and correct the electrical signal collected by the electrical signal acquisition module, and then output the corrected electrical signal to the analog-to-digital conversion submodule; The analog-to-digital conversion submodule is used to uniformly convert all the corrected electrical signals output by the signal conditioning submodule into voltage signals, and then uniformly convert them into first CAN-FD signals and send them to the CAN-FD signal acquisition module.

4. The automobile signal detection system according to claim 3, characterized in that: The signal conditioning submodule includes an amplifier circuit, a filter, and a shunt; the electrical signal collected by the electrical signal acquisition module is amplified by the amplifier circuit and filtered by the filter, and then input to the two ends of the shunt; the shunt corrects the current according to the voltage at its two ends, and the corrected current is output to the analog-to-digital conversion submodule.

5. The automobile signal detection system according to claim 4, characterized in that: The signal conditioning submodule corrects the current in the following manner: full and full-scale current I full The relationship for setting the compensation impedance R is as follows: The relationship between the current I corrected by the shunt according to the voltage V at both ends is as follows: V=I×R.

6. The automobile signal detection system according to claim 5, characterized in that: The analog-to-digital conversion submodule converts the corrected current I1 into an induced voltage V2 by setting a pair of electromagnetic induction coils; assuming that the number of turns of one coil through which the current I1 flows is N1, the number of turns of the other coil is N2, and the self-inductance coefficient is L, then the relationship between the mutual inductance coefficient M is as follows: Assuming that the time that the corrected current I1 flows in a coil is t, the relationship between the induced voltage V2 is as follows:

7. The automobile signal detection system according to claim 1, characterized in that: The CAN-FD signal acquisition module includes 4 CAN-FD signal acquisition submodules; the 4 CAN-FD signal acquisition submodules include a bus interface chip, a transceiver, a controller, and a peripheral circuit; The 4-channel CAN-FD signal acquisition submodule is used to collect the CAN-FD bus signals of the car.

8. The automobile signal detection system according to claim 2, characterized in that: The signal analysis module is used to: analyze the first CAN-FD signal to obtain voltage and current information in the vehicle circuit, and analyze the voltage and current information to obtain the operating status and energy consumption of the vehicle circuit; the signal analysis module is also used to analyze the second CAN-FD signal to evaluate and diagnose the vehicle bus.

9. The automobile signal detection system according to claim 8, characterized in that: The signal analysis module further includes: after the host computer receives the first CAN-FD signal and the second CAN-FD signal, the signal analysis module first filters them; the signal analysis module adopts an adaptive filtering algorithm; The adaptive filtering algorithm includes: when the signal analysis module has filtered n+1 times, it will iteratively update the filter coefficient n times; Assume that the output signal of the nth filtering is y(n) and the expected signal is d(n), then the error of the nth filtering is e(n)=d(n)-y(n); Set the hyperparameter μ. When the input signal of the nth filtering is x(n), the adaptive filtering algorithm updates the filter coefficient w(n+1) of the n+1th filtering according to the filter coefficient w(n) of the nth filtering. The calculation formula of w(n+1) is as follows: w(n+1)=w(n)+2μe(n)x(n), where n≥2.

10. The automobile signal detection system according to claim 8, characterized in that: The signal analysis module further includes: after analyzing the first CAN-FD signal to obtain voltage and current information in the automobile circuit, according to the weights of the m current sensors used by the electrical signal acquisition module to collect current and the current values ​​measured by them, a current measurement result I is calculated by a data fusion and compensation algorithm. fused ; The data fusion and compensation algorithm includes the following calculation formula: Among them, w i is the weight of the i-th sensor, I i is the current value measured by the i-th sensor.

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