A multi-channel test instrument for on-board nitrogen oxygen sensor

Abstract

The utility model discloses a kind of multi-channel pair of for vehicle nitrogen oxygen sensor test instrument, comprising: MCU control module, as the core control unit of test instrument;CAN data communication module is connected with the MCU control module, for being connected with vehicle CAN bus to receive real-time data, and data is forwarded to the nitrogen oxygen sensor to be tested, and the data stored in SD storage module is sent through CAN bus to realize data playback;SD storage module is connected with the MCU control module, for independently storing CAN bus data, realizes offline data recording function;The test instrument designed in the application records all data in CAN bus through SD card, without connecting computer or vehicle system, can automatically carry out data recording after power on.This function improves the convenience and flexibility of test, especially in the case of unable to connect computer in real time, still can independently complete data storage.

Description

Technical Field

[0001] This utility model relates to the field of benchmarking tester technology, specifically a multi-channel benchmarking tester for vehicle-mounted nitrogen and oxygen sensors. Background Technology

[0002] With increasingly stringent vehicle emission standards, accurate testing of the performance of onboard nitrogen oxide sensors, as key emission monitoring components, has become crucial. Traditional nitrogen oxide sensor benchmarking testing equipment typically relies on the vehicle's original CAN bus system, connecting the nitrogen oxide sensor under test to the vehicle network and directly connecting the tester to the CAN bus for data exchange. While this traditional testing method can meet benchmarking testing requirements to some extent, it suffers from the following difficulties or shortcomings in practical applications:

[0003] (1) Lack of independent data recording function: Traditional nitrogen oxide sensor benchmarking test equipment usually relies on the host computer in the computer to connect and interact with the vehicle's CAN network in real time, and lacks the ability to record data independently without external connection. In offline state, the benchmarking test equipment cannot record CAN bus data in real time, and all data must rely on the real-time connection of the vehicle system or computer for storage, which limits the independence of the equipment.

[0004] (2) Lack of data playback function: Traditional nitrogen and oxygen sensor benchmark testers usually do not have offline playback function, that is, they cannot save data after disconnecting from the computer. This makes it impossible to effectively record the complete data of the CAN bus during the test, and it is impossible to perform offline playback or subsequent data analysis.

[0005] (3) Lack of message relay function: Traditional benchmarking test equipment only connects to the vehicle's CAN network and sends CAN bus data to the host computer for processing, and cannot forward data between multiple CAN interfaces. When there are many sensors to be tested, traditional equipment needs to install each sensor on the vehicle for testing, which is cumbersome and time-consuming. This method not only reduces testing efficiency, but also increases operational complexity.

[0006] (4) Sensor ID conflict issue: Traditional benchmarking test equipment requires the nitrogen oxide sensor to be directly connected to the vehicle's CAN network during use. However, when multiple sensors are connected to the vehicle network system for testing simultaneously, ID conflicts are prone to occur, which may lead to inaccurate test data or test failure. To solve this problem, it is usually necessary to modify the device ID of each conflicting sensor individually. However, when there are a large number of sensors to be tested, this process becomes too cumbersome and time-consuming, increasing operational complexity.

[0007] To address this, a multi-channel benchmarking tester for vehicle-mounted nitrogen and oxygen sensors is proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, this utility model provides the following technical solution: a multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors, comprising:

[0010] The MCU control module serves as the core control unit of the tester.

[0011] The CAN data communication module is connected to the MCU control module and is used to connect to the vehicle's CAN bus to receive real-time data, forward the data to the nitrogen oxide sensor under test, and send the data stored in the SD storage module through the CAN bus to realize data playback.

[0012] An SD storage module, connected to the MCU control module, is used to independently store CAN bus data and realize offline data recording function;

[0013] A real-time clock module, connected to the MCU control module, is used to add timestamps to the stored CAN data packets;

[0014] The power control module is used to provide a stable power supply to each module.

[0015] Preferably, the CAN data communication module includes a multi-channel CAN controller MCP2515 and a high-speed CAN transceiver TJA1042, used to receive, forward, and play back CAN data.

[0016] Preferably, the MCU control module adopts an STM series 32-bit microcontroller with a built-in CAN controller, which is used to control the parsing and forwarding of CAN data and the coordinated operation of various modules.

[0017] Preferably, the SD storage module adopts a standard SD card interface, supports the FAT32 file system, supports a maximum storage capacity of 32GB, and integrates a data compression algorithm.

[0018] Preferably, the real-time clock module uses a high-precision RTC chip DS3231, which is connected to the MCU control module via an I2C interface and is equipped with a backup battery CR2032.

[0019] Preferably, the power control module supports a wide voltage input of 9V to 36V, which is converted to a 3.3V or 5V operating voltage through the DC-DC step-down module LM2596. The power control module also integrates a power management chip TPS5430, which has overvoltage, overcurrent and short-circuit protection functions.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] 1. Data Recording Function: The tester designed in this invention directly records all data on the CAN bus via an SD card, without needing to connect to a computer or vehicle system. Data recording begins automatically upon power-on. This function improves the convenience and flexibility of testing, especially in situations where a real-time computer connection is not possible, allowing for independent data storage.

[0022] 2. Offline playback and real-time display: The CAN bus data stored in the tester of this invention can be directly sent back to the CAN bus for offline playback, or it can be connected to a computer via the bus for real-time display. This function allows testers to review and analyze test data at any time, improving the accuracy and reliability of the test.

[0023] 3. Avoid sensor ID conflicts: This invention avoids ID conflicts through the CAN message forwarding mechanism, ensuring that multiple sensors can work stably and correctly in the same test process, avoiding common communication problems in traditional testers.

[0024] 4. Message relay function to simplify the testing process: The message relay function of this tester can directly forward CAN messages on the vehicle bus to other CAN interfaces of the instrument in offline mode, so that the sensor under test does not need to be directly connected to the vehicle network to complete the test, avoiding repeated disassembly and installation of the sensor and improving the convenience of operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the present invention;

[0026] Figure 2 This is a schematic diagram of the front surface structure of the testing instrument device of this utility model;

[0027] Figure 3 This is a schematic diagram of the rear surface structure of the testing instrument device of this utility model;

[0028] Figure 4 This is a schematic diagram of the internal structure of the testing instrument device of this utility model. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0030] Please see Figure 1-4 This utility model provides a technical solution:

[0031] MCU Control Module: The MCU control module uses a high-performance 32-bit STM series microcontroller, which realizes the reception, parsing, and forwarding of multi-channel CAN data through a built-in CAN controller. The module schedules tasks through a real-time operating system to ensure efficient parallel execution of data reception, storage, and forwarding. The MCU is also responsible for controlling the device's operating status according to user instructions and intelligently forwarding received CAN messages to other CAN interfaces through message relay function to avoid sensor ID conflicts. The module connects to the CAN communication module, SD storage module, etc. through interfaces such as SPI and I2C to ensure efficient communication and data exchange between modules.

[0032] The MCU control module is the core component of this tester, responsible for coordinating the operation of all modules. Its main functions include data processing, task scheduling, issuing control commands, and forwarding CAN data, ensuring the normal operation of the equipment.

[0033] CAN Data Communication Module: The CAN communication module consists of a multi-channel CAN controller MCP2515 and a high-speed CAN transceiver TJA1042, supporting real-time reception and forwarding of vehicle CAN bus data. The module employs differential signal transmission and electromagnetic compatibility design to ensure stable operation in complex automotive environments. Under the control of the MCU, the module can forward received data to other CAN interfaces, implementing message relay functionality. It also supports retransmitting data stored on an SD card to the CAN bus for offline playback and testing.

[0034] This module is primarily responsible for connecting to the vehicle's CAN bus network. Its function is to receive real-time data from the vehicle's CAN bus and transmit the received data to the MCU for further processing. For offline playback, the CAN data communication module can also send data stored on the SD card via the CAN bus, enabling data playback. The module's role is to ensure that the tester can flexibly interact with the vehicle network and perform data playback and transmission in offline mode.

[0035] SD Storage Module: Utilizing a standard SD card interface, it supports up to 32GB of storage and uses the FAT32 file system for fast data storage and retrieval. During testing, the module records CAN bus data in real time and adds a timestamp to each data packet to ensure data integrity and timeliness. After testing, users can read the data via the SD card or transfer it to a host computer for analysis via USB. The module also supports data compression algorithms to reduce storage space usage and extend data recording time. It is used to store received CAN bus data. The device can record all data in real time during operation and save it to the SD card. The SD storage module provides ample storage space and supports later data viewing and offline playback.

[0036] Real-time clock module: The real-time clock module uses the high-precision RTC chip DS3231, which connects to the MCU via an I2C interface to generate millisecond-accurate timestamps for each CAN data packet. The module is equipped with a backup battery CR2032, ensuring time information is maintained even when the device is powered off. The module supports time calibration via a host computer or GPS module to ensure accuracy. When the device is in standby mode, the module operates in low-power mode to ensure continuity and traceability of time information.

[0037] Power Control Module: The power control module is responsible for providing the tester with a stable power supply required for operation. Through this module, the device can be directly connected to the vehicle's power system, ensuring automatic power supply during vehicle operation without the need for an external power source. This module features power management and protection functions, ensuring stable operation of the device under various working environments.

[0038] The structure of the tester is designed based on the above functional modules, such as... Figures 2 to 4 As shown. The tester structure includes a housing, inside which are installed the tester-sensor connection port 1, terminating resistor 2, status indicator 3, USB interface 4, SD card slot 5, power indicator 6, power management module 7, MCU chip 8, and real-time clock module 9.

[0039] Working principle:

[0040] Equipment startup: Connect the tester to the vehicle's CAN bus and power system. After power is connected, the power control module starts the equipment, the MCU control module initializes all hardware modules, and the equipment enters the working state.

[0041] Connecting to the vehicle's CAN bus: The device connects to the vehicle's CAN bus via the CAN data communication module and begins receiving real-time data from the vehicle's CAN bus, mainly including vehicle sensor information and control commands.

[0042] Intelligent data forwarding: The tester intelligently determines the type of the received CAN data packet through the MCU control module. If the data needs to be forwarded to the nitrogen and oxygen sensor under test, the MCU forwards the data to the appropriate CAN interface, thus realizing intelligent offline data relay.

[0043] Data logging and timestamps: During testing, all received CAN data is transmitted to the SD storage module for recording via the CAN data communication module. The real-time clock module attaches an accurate timestamp to each data packet, ensuring that the recorded data can be traced back to a precise point in time.

[0044] Data storage: All received data will be stored on an SD card for subsequent analysis and playback. Users can read the stored data from the SD card or export it for further analysis after the test is completed.

[0045] Real-time data monitoring and display: During testing, users can monitor the tester's data in real time by connecting to a host computer or PC. Through a data visualization interface, users can dynamically view the CAN data during the testing process, as well as the test progress and status.

[0046] Test Completion and Data Saving: After the test is completed, the device will save all test data to the SD card and can connect to the host computer via bus or other means for data download and analysis. The device can automatically shut down or enter standby mode without external device intervention.

[0047] Offline playback function: After the test is completed, the user can choose to play back the data stored on the SD card to the vehicle's CAN bus via the CAN data communication module. This allows the test data to be retransmitted back to the original vehicle network for verification or for other testing purposes.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors, characterized in that, include: The MCU control module serves as the core control unit of the tester. The CAN data communication module is connected to the MCU control module and is used to connect to the vehicle's CAN bus to receive real-time data, forward the data to the nitrogen oxide sensor under test, and send the data stored in the SD storage module through the CAN bus to realize data playback. An SD storage module, connected to the MCU control module, is used to independently store CAN bus data and realize offline data recording function; A real-time clock module, connected to the MCU control module, is used to add timestamps to the stored CAN data packets; The power control module is used to provide a stable power supply to each module.

2. The multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors according to claim 1, characterized in that: The CAN data communication module includes a multi-channel CAN controller MCP2515 and a high-speed CAN transceiver TJA1042, which are used to receive, forward and play back CAN data.

3. A multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors according to claim 1, characterized in that: The MCU control module uses an STM series 32-bit microcontroller with a built-in CAN controller, which is used to control the parsing and forwarding of CAN data and the coordinated operation of various modules.

4. A multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors according to claim 1, characterized in that: The SD storage module uses a standard SD card interface, supports the FAT32 file system, supports a maximum storage capacity of 32GB, and integrates a data compression algorithm.

5. A multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors according to claim 1, characterized in that: The real-time clock module uses a high-precision RTC chip DS3231, which is connected to the MCU control module via an I2C interface and is equipped with a backup battery CR2032.

6. A multi-channel calibration tester for vehicle-mounted nitrogen and oxygen sensors according to claim 1, characterized in that: The power control module supports a wide voltage input of 9V to 36V, which is converted to a 3.3V or 5V operating voltage through the DC-DC step-down module LM2596. The power control module also integrates a power management chip TPS5430, which has overvoltage, overcurrent and short circuit protection functions.

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