High-precision signal simulation test device for automobile sensor

Abstract

The invention relates to the technical field of sensor testing, and discloses an automobile sensor high-precision signal simulation testing device, which comprises a signal generation module, a signal conditioning module, a main control module, a man-machine interaction module, an interface adaptation module and a power supply module, the signal generation module is used for generating a high-precision and high-resolution basic waveform signal and a complex signal simulating a specific waveform of an automobile sensor, and the signal conditioning module is connected with the signal generation module and is used for amplifying, attenuating, filtering and the like of the generated signal; and the amplitude, frequency range and noise characteristic requirements of the actual output signal of the automobile sensor are met. The automobile sensor signal simulation test device has the advantages and effects that the precision of automobile sensor signal simulation test can be effectively improved, the accuracy of a test result is enhanced, various different types of automobile sensor signals can be simulated, the application range is widened, and the universality of the device in use is improved.

Description

Technical Field

[0001] The present application relates to the technical field of sensor testing, and in particular to a high-precision signal simulation testing device for automobile sensors. Background Art

[0002] Automotive sensors are input devices for automotive computer systems. They convert various operating information during vehicle operation, such as vehicle speed, temperature of various media, engine operating conditions, etc., into electrical signals and transmit them to the computer so that the engine is in the best working condition. With the continuous improvement of automobile electronics and intelligence, automotive sensors, as key components for obtaining vehicle operating status information, are increasing in types and quantity, and performance requirements are becoming more and more stringent. In the research and development, production, and after-sales maintenance of automotive sensors, sensors need to be accurately tested to ensure the accuracy and reliability of their output signals.

[0003] The sensor signal simulation test devices in the related technology have at least the following shortcomings: although some general signal generators can simulate some basic waveforms, the simulation accuracy of the complex actual working signals of automobile sensors is poor, and the test results are not accurate enough. The signal simulation test devices specifically for automobile sensors often have single functions and can only be adapted to one or several specific sensors. The scope of application is limited and cannot meet diverse testing needs.

[0004] Therefore, we propose a high-precision signal simulation test device for automobile sensors to solve the above problems. Summary of the invention

[0005] The purpose of this application is to provide a high-precision signal simulation test device for automobile sensors, which can effectively improve the accuracy of automobile sensor signal simulation testing, enhance the accuracy of test results, and simulate a variety of different types of automobile sensor signals, thereby enhancing the scope of application and improving the versatility of the device when used.

[0006] The above technical purpose of the present application is achieved through the following technical solutions: a high-precision signal simulation test device for automobile sensors, including a signal generating module, a signal conditioning module, a main control module, a human-computer interaction module, an interface adapter module and a power supply module. The signal generating module is used to generate high-precision, high-resolution basic waveform signals and complex signals that simulate specific waveforms of automobile sensors. The signal conditioning module is connected to the signal generating module and is used to amplify, attenuate, filter and other processes on the generated signals so that they meet the amplitude, frequency range and noise characteristic requirements of the actual output signal of the automobile sensor. The main control module is used to coordinate the work between the modules, receive instructions from the human-computer interaction module, control the signal generating module to generate corresponding signals, command the signal conditioning module to adjust parameters, and process and store test data. The human-computer interaction module is used for operators to input test parameters and view test results, device status and other information in real time. The interface adapter module is used to electrically connect with the automobile sensor, and the power supply module provides a stable and pure power supply for the entire device.

[0007] The present application is further configured as follows: the signal generating module includes a digital signal processor, a programmable logic chip, a digital-to-analog converter and a waveform memory.

[0008] The present application is further configured as follows: the signal conditioning module includes an amplifier, a filter, an attenuator and an analog switch.

[0009] The present application is further configured as follows: the amplifier includes a variable gain amplifier, a fixed gain amplifier and an isolation amplifier. The variable gain amplifier can dynamically adjust the amplification factor according to the instructions of the main control module to adapt to the amplitude enhancement requirements of different sensor output signals. The fixed gain amplifier is used for amplifying and conditioning sensor signals with some common and fixed amplitude range requirements. The isolation amplifier uses isolation technologies such as optical coupling and magnetic coupling to cut off the electrical connection between the sensor signal and the subsequent circuit, only transmits the effective information of the signal, effectively suppresses common mode noise, and ensures the integrity and accuracy of weak sensor signals.

[0010] The present application is further configured as follows: the main control module includes a high-performance microcontroller, a memory, a data processing unit, an interrupt controller and a high-precision data acquisition card.

[0011] The present application is further configured as follows: a touch display screen is provided on the human-computer interaction module.

[0012] The present application is further configured as follows: the touch display screen develops a customized software interface based on the Android system, and the test parameters input by the operator are automatically verified through the software algorithm.

[0013] The present application is further configured as follows: the frequency error of the signal generated by the signal generating module is within ±0.01%, and the amplitude error is within ±0.1%.

[0014] The present application is further configured as follows: the signal conditioning module automatically selects a suitable conditioning circuit and adjusts its parameters according to the instructions of the main control module, and the main control module issues instructions according to the automobile sensor parameter database pre-stored in the internal memory.

[0015] The present application is further configured as follows: the interface adapter module is designed with a variety of universal interfaces, including a CAN interface, a LIN interface, and an analog interface, and can achieve seamless connection with different types of automotive sensors by automatically identifying the sensor interface type and intelligently switching the connection mode.

[0016] The present application includes at least one of the following beneficial technical effects:

[0017] 1. This application uses the signal generation technology of the digital signal processor and the programmable logic chip in the signal generation module to achieve nanosecond level signal accuracy control, with a frequency error within ±0.01% and an amplitude error within ±0.1%, ensuring that the analog signal is highly consistent with the actual sensor signal, effectively improving the accuracy of the test results.

[0018] 2. This application can simulate a variety of automotive sensor signals, such as crankshaft position sensor, wheel speed sensor, temperature sensor, etc., by utilizing the joint cooperation of the signal generation module, signal conditioning module, main control module, human-computer interaction module, interface adapter module and power supply module, thereby improving the versatility of the device when used.

[0019] 3. This application simplifies the entire simulation test operation process by utilizing the human-computer interaction module, can automatically verify input parameters, and display test results in real time. Combined with the intelligent control of the main control module, the entire test process is efficient and convenient, which reduces the technical threshold of operators and improves test efficiency.

[0020] 4. This application utilizes a signal conditioning module to automatically adjust parameters according to different sensor types, adapt to the output characteristic requirements of different sensors, and ensure the applicability of analog signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural block diagram of this embodiment.

[0022] Figure 2 It is the structural block diagram of the signal generation module.

[0023] Figure 3 It is the structural block diagram of the signal conditioning module.

[0024] Figure 4 It is the structural block diagram of the main control module.

[0025] Figure 5 It is a simulation test flow chart of this embodiment. DETAILED DESCRIPTION

[0026] The technical solution of the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0027] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The present application provides a high-precision signal simulation test device for automobile sensors, including a signal generation module, a signal conditioning module, a main control module, a human-computer interaction module, an interface adapter module and a power supply module, wherein:

[0028] The signal generation module is used to generate high-precision, high-resolution basic waveform signals and complex signals that simulate specific waveforms of automotive sensors. The signal generation module is responsible for generating various basic waveform signals, such as sine waves, square waves, triangle waves, etc., as well as complex signals that can simulate specific waveforms of automotive sensors. It has the ability to generate signals with high precision and high resolution. The signal conditioning module is connected to the signal generation module and is used to amplify, attenuate, filter, and other processing on the generated signals to make them meet the amplitude, frequency range, and noise characteristic requirements of the actual output signals of automotive sensors. The signal conditioning module has a variety of built-in switchable analog circuits, including amplifiers with different gains, filters with different cutoff frequencies, etc., which can be used according to The instructions of the main control module automatically adjust the signal conditioning parameters. The main control module is used to coordinate the work between the modules, receive instructions from the human-computer interaction module, control the signal generation module to generate corresponding signals, command the signal conditioning module to adjust parameters, and process and store test data. The human-computer interaction module is used for operators to input test parameters and view test results, device status and other information in real time. The interface adapter module is used to electrically connect with the vehicle sensor. The power module provides a stable and pure power supply for the entire device. The power module adopts multi-stage filtering and voltage stabilization circuits to ensure that the device can work normally under different power supply environments. At the same time, it has overvoltage and overcurrent protection functions to ensure the safety of the device.

[0029] In this embodiment, the signal generation module includes a digital signal processor, a programmable logic chip, a digital-to-analog converter and a waveform memory. By utilizing the collaborative work of the digital signal processor and the programmable logic chip, the digital signal processor is responsible for the operation of complex algorithms, such as generating a specific waveform according to the mathematical model of the automobile sensor, and the programmable logic chip uses its high-speed parallel processing capability to quickly realize the digital construction of the signal. The combination of the two can achieve nanosecond-level signal precision control. The frequency error of the signal generated by the signal generation module is within ±0.01%, and the amplitude error is within ±0.1%, which is much higher than the precision level of the existing ordinary signal generator. The programmable logic chip is a field programmable gate array technology, which can flexibly generate the required waveform through programming. The digital-to-analog converter is responsible for converting the digital waveform signal output by the programmable logic chip into an analog signal for subsequent conditioning and testing. It is a key bridge connecting digital circuits and analog circuits. Its conversion accuracy and speed directly affect the quality of the final output analog signal. High-performance digital-to-analog converters usually have higher resolutions, such as 16 bits, 18 bits or even higher, and can accurately convert digital signals into analog circuits. The digital-to-analog converter can quickly update the output analog signal when simulating high-frequency vibration, rapidly changing pressure and other signals in automotive sensors to ensure the real-time and accuracy of the signal and avoid waveform distortion caused by conversion delay. The waveform memory is used to pre-store some common basic waveform data, such as discrete sampling point values ​​of standard waveforms such as sine waves, square waves, and triangle waves. When these basic waveforms need to be generated, the digital signal processor and the programmable logic chip can directly retrieve data from the waveform memory without real-time calculation, which greatly improves the generation speed of the basic waveform. For example, when quickly testing some sensors that do not require high waveform accuracy but have requirements for response speed, directly calling the data in the waveform memory can quickly output the standard waveform, saving computing resources and time. The waveform memory can use the existing high-speed static random access memory or dynamic random access memory, with a large storage capacity, and can store a variety of basic waveforms with different parameters (such as frequency, amplitude, phase), which is convenient for flexible selection and calling according to test requirements.

[0030] In this embodiment, the signal conditioning module includes an amplifier, a filter, an attenuator and an analog switch. The amplifier includes a variable gain amplifier, a fixed gain amplifier and an isolation amplifier. The variable gain amplifier can dynamically adjust the amplification factor according to the instructions of the main control module to adapt to the amplitude enhancement requirements of different sensor output signals. For example, for a pressure sensor with a weak output signal, its weak voltage signal can be amplified to a suitable test range to ensure the accuracy of subsequent processing and analysis. Its gain adjustment range can be from several times to thousands of times to meet diverse amplification requirements, and it has a low noise coefficient to avoid introducing too much interference during the amplification process; the fixed gain amplifier is used for amplification and conditioning of sensor signals for some common and fixed amplitude range requirements. For example, for a specific model of temperature sensor, it is known that its output signal usually only needs to be amplified 10 times to meet the subsequent circuit processing requirements. At this time, the corresponding fixed gain amplifier can be selected. Compared with the variable gain amplifier, it has lower cost and simpler circuit structure, and can improve the signal conditioning module in scenarios that meet the requirements. Cost-effectiveness; the isolation amplifier uses isolation technologies such as optocouplers and magnetic couplers to cut off the electrical connection between the sensor signal and the subsequent circuit, only transmits the effective information of the signal, effectively suppresses common-mode noise, and ensures the integrity and accuracy of weak sensor signals. The role of the attenuator is that in some cases, the sensor output signal amplitude is too large and exceeds the input range of the subsequent circuit or test equipment. The attenuator can reduce the signal amplitude proportionally. For example, when some high-precision force sensors are subjected to a large impact force, the output voltage amplitude is high. The attenuator can attenuate it to an appropriate level to ensure the normal operation of the signal conditioning module and subsequent modules. The attenuation ratio can be adjusted continuously or graded within a certain range according to demand, such as 1 / 2, 1 / 10, 1 / 100, etc. The analog switch is the switching hub in the signal conditioning circuit. According to the instructions of the main control module, it quickly switches different conditioning circuit branches. For example, when simulating different types of sensors, the corresponding amplifier and filter combination are quickly connected to achieve flexible and efficient signal conditioning path selection. It has fast switching speed and low on-resistance, and has little effect on signal transmission quality.

[0031] In this embodiment, the above-mentioned filters include low-pass filters, high-pass filters and band-pass filters: the low-pass filter is used to filter out high-frequency noise and clutter in the signal, and only allows signals below the set cut-off frequency to pass. When simulating the automobile speed sensor signal, electromagnetic interference in the actual working environment may introduce high-frequency components. The low-pass filter can ensure that only the low-frequency effective signal representing the vehicle speed enters the subsequent test link. The cut-off frequency can usually be flexibly adjusted between a few hertz and a few hundred hertz according to the characteristics of the sensor to achieve accurate filtering; the high-pass filter is opposite to the low-pass filter, and is used to block low-frequency signals and allow signals above the cut-off frequency to pass. When testing, for example, an engine vibration sensor, its output signal Mixed with some low-frequency mechanical vibration background noise, the high-pass filter can remove these low-frequency interferences and highlight the high-frequency vibration signals related to the engine fault characteristics. The cut-off frequency is set according to the normal operating frequency range of the engine and the sensor characteristics, generally ranging from tens of Hz to thousands of Hz; the band-pass filter combines the characteristics of the low-pass filter and the high-pass filter, and only allows signals within a certain frequency band to pass, accurately screening out the required sensor signal frequency band. For example, when processing the audio sensor signal in the car audio system, in order to accurately analyze the sound signal quality within a specific audio frequency range, the band-pass filter can set the center frequency and bandwidth, remove useless signals outside the frequency band, and improve the test pertinence and accuracy.

[0032] In this embodiment, the main control module includes a high-performance microcontroller, a memory, a data processing unit, an interrupt controller and a high-precision data acquisition card. The high-performance microcontroller is the core processing unit of the main control module, which is responsible for executing various complex instructions and algorithms and controlling the entire test process. For example, it is responsible for receiving operation instructions from the human-computer interaction module, parsing these instructions and converting them into specific control signals for operations such as the signal generation module, the signal conditioning module and the data acquisition module, so as to ensure that each module works as required. Among them, the high-performance microcontroller can adopt the existing ARMCortex-M series microcontroller, which has efficient computing power and can quickly process a large amount of data to meet the real-time requirements in the process of automobile sensor testing. For example, in the simulation of multiple sensors switching test scenarios quickly, the parameter configuration and control instructions of different sensors can be quickly completed. The data processing unit is used to be specifically responsible for in-depth analysis and processing of the collected sensor feedback data. For example, the feedback signal of the sensor obtained from the high-precision data acquisition card is compared with the standard signal pre-stored in the memory, and an advanced error meter is used. The algorithm accurately calculates the key indicators of the signal, such as the amplitude error, frequency error, and phase deviation. Through complex digital signal processing technology, such as fast Fourier transform (FFT), the feedback signal is analyzed by spectrum analysis to determine whether the sensor has abnormal conditions such as harmonic interference, and provide detailed data support for operators to accurately evaluate the performance of the sensor. The interrupt controller is responsible for handling various interrupt events during the operation of the system to ensure that the main control module can respond to emergencies in a timely manner and make corresponding processing. When the human-computer interaction module has a new operation instruction input, the data acquisition card completes a data acquisition, or a module has an abnormal situation (such as the amplifier overload of the signal conditioning module), an interrupt signal will be triggered. The interrupt controller quickly identifies the interrupt source and guides the main control module to suspend the current task and give priority to emergency events. For example, if the data collected by the data acquisition card has an abnormal jump, the interrupt controller immediately notifies the main control module to suspend subsequent data processing, and instead investigates the cause of the data abnormality, or restarts the acquisition process to ensure the stability and reliability of the test process. The high-precision data acquisition card is used to collect the feedback signal of the sensor.

[0033] In this embodiment, a touch screen is provided on the human-computer interaction module. The touch screen is a customized software interface developed based on the Android system. The test parameters input by the operator will be automatically verified by the software algorithm, which can avoid test failure caused by inputting wrong parameters. At the same time, the interface can also intuitively display the signal changes during the test in the form of charts, compare the differences between the actual sensor standard signal and the analog signal, and other information, which is convenient for the operator to quickly analyze and judge.

[0034] In this embodiment, the signal conditioning module automatically selects a suitable conditioning circuit and adjusts its parameters according to the instruction of the main control module, and the main control module issues instructions according to the automobile sensor parameter database pre-stored in the internal memory.

[0035] In this embodiment, the interface adapter module is designed with a variety of universal interfaces, including CAN interface, LIN interface, and analog interface. It can automatically identify the sensor interface type and intelligently switch the connection mode to achieve seamless connection with different types of automotive sensors.

[0036] Through the above structure, the working principle of the high-precision signal simulation test device for automobile sensors provided by this application is as follows:

[0037] After starting the device, the automobile sensor to be tested is first connected to the simulation test device through the interface adapter module, and then the operator selects the type of automobile sensor to be simulated, such as crankshaft position sensor, wheel speed sensor, thermistor temperature sensor, etc., through the human-computer interaction module, and enters the corresponding test parameters, including the expected signal amplitude, frequency, operating temperature range, etc.;

[0038] After receiving the instruction, the main control module first retrieves the standard parameter information of the sensor from the internal memory, and then issues a signal generation instruction to the signal generation module, which quickly generates an initial signal according to the instruction;

[0039] The initial signal enters the signal conditioning module and is processed according to the conditioning scheme selected by the main control module based on the sensor type to obtain a simulated test signal that meets the requirements;

[0040] The simulated test signal is transmitted to the automotive sensor to be tested, and at the same time the main control module starts the data acquisition function to collect the sensor's feedback signal through the high-precision data acquisition card connected in the test loop;

[0041] The main control module compares and analyzes the collected feedback signal with the pre-stored standard signal, calculates the error value, and displays the test result in real time on the display screen of the human-computer interaction module, so that the operator can judge the performance of the sensor based on it;

[0042] If the test error does not exceed the set threshold, it means that the sensor is qualified. If the test error exceeds the set threshold, the sensor can be further debugged or the cause of the fault can be analyzed.

[0043] In this embodiment, for example, when simulating a test of a crankshaft position sensor of a certain model of automobile:

[0044] First, the crankshaft position sensor to be tested is connected to the simulation test device through the interface adapter module. Then the operator selects "crankshaft position sensor" on the touch screen of the human-computer interaction module, and inputs the expected signal frequency of 500Hz, the amplitude of 5V, and the working temperature is set to room temperature 25℃. After receiving the instruction, the main control module retrieves the standard parameters of the crankshaft position sensor from the memory, and issues an instruction to generate the corresponding waveform signal to the signal generation module. The signal generation module uses the digital signal processor and field programmable gate array technology to quickly generate a sinusoidal initial signal with a frequency of 500Hz and an amplitude of 5V. The signal enters the signal conditioning module, and after appropriate amplification and filtering, and removal of interference such as high-frequency noise, a simulation test signal that meets the actual output characteristics of the crankshaft position sensor is obtained. The simulation test signal is transmitted to the crankshaft position sensor or the automotive electronic control system connected thereto. The main control module collects the feedback signal through the data acquisition card and compares it with the standard signal. If the error is within ±5%, the sensor performance is determined to be qualified, otherwise the operator is prompted to further check the sensor or the test device.

[0045] In this embodiment, for example, when simulating the test of the thermistor temperature sensor of an automobile:

[0046] First, the thermistor temperature sensor to be tested is connected to the simulation test device through the interface adapter module. Then the operator selects "thermistor temperature sensor" and enters the expected temperature change range from 0℃ to 100℃. The corresponding signal amplitude change range is set according to the sensor graduation table. The main control module operates according to the process. The signal generation module generates the initial signal. The signal conditioning module enables the low-noise amplifier circuit and the filter circuit with a specific cutoff frequency to condition the signal. The simulated test signal acts on the thermistor temperature sensor. The main control module collects the feedback signal and compares it with the standard signal to judge the sensor performance. Similarly, the error is qualified within the set threshold.

[0047] It can be seen from the above description that the high-precision signal simulation test device for automobile sensors of the present invention can accurately simulate a variety of automobile sensor signals, providing an efficient and accurate testing method for the research and development, production, and maintenance of automobile sensors.

[0048] The above is a detailed introduction to a high-precision signal simulation test device for automobile sensors provided by the present application. Specific embodiments are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A high-precision signal simulation test device for automobile sensors, characterized in that: It includes a signal generating module, a signal conditioning module, a main control module, a human-computer interaction module, an interface adapter module and a power supply module. The signal generating module is used to generate high-precision, high-resolution basic waveform signals and complex signals simulating specific waveforms of automobile sensors. The signal conditioning module is connected to the signal generating module and is used to amplify, attenuate, filter and other processes on the generated signals to make them meet the amplitude, frequency range and noise characteristic requirements of the actual output signal of the automobile sensor. The main control module is used to coordinate the work between the modules, receive instructions from the human-computer interaction module, control the signal generating module to generate corresponding signals, command the signal conditioning module to adjust parameters, and process and store test data. The human-computer interaction module is used for operators to input test parameters and view test results, device status and other information in real time. The interface adapter module is used to electrically connect with the automobile sensor, and the power supply module provides a stable and pure power supply for the entire device.

2. The high-precision signal simulation test device for automobile sensors according to claim 1 is characterized in that: The signal generation module includes a digital signal processor, a programmable logic chip, a digital-to-analog converter and a waveform memory.

3. The high-precision signal simulation test device for automobile sensors according to claim 1 is characterized in that: The signal conditioning module includes an amplifier, a filter, an attenuator and an analog switch.

4. The high-precision signal simulation test device for automobile sensors according to claim 3 is characterized in that: The amplifier includes a variable gain amplifier, a fixed gain amplifier and an isolation amplifier. The variable gain amplifier can dynamically adjust the amplification factor according to the instructions of the main control module to adapt to the amplitude enhancement requirements of different sensor output signals. The fixed gain amplifier is used to amplify and condition some common sensor signals with fixed amplitude range requirements. The isolation amplifier uses isolation technologies such as optical coupling and magnetic coupling to cut off the electrical connection between the sensor signal and the subsequent circuit, only transmits the effective information of the signal, effectively suppresses common mode noise, and ensures the integrity and accuracy of weak sensor signals.

5. The high-precision signal simulation test device for automobile sensors according to claim 1, characterized in that: The main control module includes a high-performance microcontroller, a memory, a data processing unit, an interrupt controller and a high-precision data acquisition card.

6. The high-precision signal simulation test device for automobile sensors according to claim 1, characterized in that: The human-computer interaction module is provided with a touch display screen.

7. The high-precision signal simulation test device for automobile sensors according to claim 6 is characterized in that: The touch display screen develops a customized software interface based on the Android system, and the test parameters input by the operator will be automatically verified through the software algorithm.

8. The high-precision signal simulation test device for automobile sensors according to claim 2, characterized in that: The signal generated by the signal generating module has a frequency error within ±0.01% and an amplitude error within ±0.1%.

9. The high-precision signal simulation test device for automobile sensors according to claim 4, characterized in that: The signal conditioning module automatically selects a suitable conditioning circuit and adjusts its parameters according to the instruction of the main control module, and the main control module issues instructions according to the automobile sensor parameter database pre-stored in the internal memory.

10. The high-precision signal simulation test device for automobile sensors according to claim 1, characterized in that: The interface adapter module is designed with a variety of universal interfaces, including CAN interface, LIN interface, and analog interface. It can achieve seamless connection with different types of automotive sensors by automatically identifying the sensor interface type and intelligently switching the connection mode.

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