Current acquisition board card based on CAN bus

Abstract

The utility model provides a current acquisition board card based on a CAN bus, which comprises a mainboard card provided with an analog-to-digital converter and a microcontroller and provided with a plurality of plug slots; the plurality of daughter boards are electrically connected with the main board card through the plug-in slots, the daughter boards are used for converting collected analog current into corresponding voltage, and the ranges of current collected by different daughter boards are different; the analog-to-digital converter converts a voltage signal output by the daughter board into a digital signal and sends the digital signal to the microcontroller through an SPI protocol, and the microcontroller converts the digital signal into an actual voltage value, converts the actual voltage value into a CAN signal and sends the CAN signal to a PC. According to the utility model, the collected current can be used as a CAN signal to be sent to the CAN bus, the current in different ranges can be collected through different sub-board cards, and the current in different collection ranges can be collected on the same current collection board card at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive testing, and particularly relates to a current acquisition board based on CAN bus. Background Art

[0002] The communication mode adopted by the current acquisition board under the NI architecture is PCI (Peripheral Component Interconnect), which cannot directly transmit CAN signals, that is, it cannot directly send the acquired current as a CAN signal to the CAN bus. For products based on CAN / CANFD communication, it is not convenient to use.

[0003] In addition, the current acquisition boards in the industry are universal for the whole vehicle, with too wide a collection range and no pertinence.

[0004] Therefore, how to send the acquired current as a CAN signal to the CAN bus is the focus of attention of those skilled in the art. Content of the Utility Model

[0005] The purpose of the utility model is to provide a current acquisition board based on CAN bus, which can send the acquired current as a CAN signal to the CAN bus.

[0006] To achieve the above purpose, the utility model provides a current acquisition board based on CAN bus, including:

[0007] A main board, on which an analog-to-digital converter and a microcontroller are installed, and the main board has a plurality of plug-in slots;

[0008] A plurality of daughter boards, which are electrically connected to the main board through the plug-in slots, and the daughter boards are used to convert the acquired analog current into corresponding voltages, and different daughter boards have different current acquisition ranges;

[0009] The analog-to-digital converter converts the voltage signal output by the daughter board into a digital signal and sends it to the microcontroller through the SPI protocol. The microcontroller converts the digital signal into an actual voltage value and converts it into a CAN signal and sends it to the PC.

[0010] In an optional solution, a signal conditioning circuit is integrated inside the analog-to-digital converter, which can simultaneously perform synchronous sampling on multiple channels.

[0011] In an optional solution, the current acquisition ranges of the plurality of daughter boards are: 4 - 20 mA, 0 - 5 A, 0 - 50 A.

[0012] In an optional solution, a 250-ohm resistor is installed on the daughter board, so as to convert the current range of 4 - 20 mA into a voltage range of 1 - 5 V.

[0013] In an alternative solution, different current transformers are installed on different sub-boards to convert large currents into small currents for measurement and then convert them into voltage outputs.

[0014] In an alternative solution, the microcontroller is STM32H750VBT6 and the analog-to-digital converter is AD7606.

[0015] The beneficial effects of the present utility model are as follows:

[0016] The present utility model can send the collected current as a CAN signal to the CAN bus, and through different sub-board cards, currents in different ranges can be collected, and currents in different collection ranges can be collected simultaneously on the same current collection board card. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By describing the exemplary embodiments of the present utility model in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present utility model will become more obvious. In the exemplary embodiments of the present utility model, the same reference numerals generally represent the same components.

[0018] Figure 1 FIG. is a schematic structural diagram of a current collection board card based on a CAN bus in an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following further describes the present utility model in detail with reference to the drawings and specific embodiments. According to the following description and drawings, the advantages and features of the present utility model will be clearer. However, it should be noted that the inventive concept of the technical solution of the present utility model can be implemented in many different forms and is not limited to the specific embodiments described herein. The drawings are all in very simplified forms and use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the purpose of the embodiments of the present utility model.

[0020] It should be understood that when an element or layer is referred to as "on", "adjacent to", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as "directly on", "directly adjacent to", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, without departing from the teachings of the present utility model, the first element, component, region, layer, or part discussed below may be denoted as the second element, component, region, layer, or part.

[0021] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. are used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are intended to include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "below" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "below" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0022] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present utility model. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0023] Embodiment 1

[0024] Referring to Figure 1 , this embodiment provides a current acquisition board based on the CAN bus, including:

[0025] Main board card, on which an analog-to-digital converter and a microcontroller are installed, and the main board card has a plurality of socket slots;

[0026] A plurality of daughter boards, which are electrically connected to the main board card through the socket slots. The daughter boards are used to convert the collected analog current into corresponding voltages, and the current ranges collected by different daughter boards are different;

[0027] The analog-to-digital converter converts the voltage signal output by the daughter board into a digital signal and sends it to the microcontroller through the SPI protocol. The microcontroller converts the digital signal into an actual voltage value and converts it into a CAN signal to be sent to the PC.

[0028] Specifically, in this embodiment, for the current acquisition board card commonly used in the current industry with a large acquisition range and poor pertinence, a current acquisition board card is developed. By matching different current sensors, different acquisition ranges can be quickly switched. The currently frequently used current acquisition ranges are as follows: sensor current 4 - 20 mA, solenoid valve current 0 - 5 A, caliper current 0 - 50 A.

[0029] For the above acquisition ranges, among them, for the sensor current acquisition range of 4 - 20 mA, by connecting a 250-ohm resistor, the acquisition voltage range is 1 - 5 V. For the acquisition of 0 - 5 A and 0 - 50 A currents, the large current is converted into a small current for measurement through the current transformer on the daughter board. The current measurement range can be changed by installing different daughter boards. Currents with different acquisition ranges can be simultaneously acquired on the same current acquisition board card.

[0030] Figure 1 Three daughter boards are shown, namely daughter board 1, daughter board 2, and daughter board 3. The current acquisition ranges of these three daughter boards are different. It can be understood that the number of daughter boards can also be 4 or 5, and the acquisition ranges of two daughter boards can also be the same. The purpose of designing multiple daughter boards in this embodiment is that by plugging in different daughter boards, currents in multiple ranges can be acquired.

[0031] The current acquisition board card in this embodiment is designed based on the H750 microcontroller (MCU). The working principles of the key components are as follows:

[0032] Current acquisition: When acquiring the sensor current (4 - 20 mA), plug in the daughter board installed with a 250-ohm resistor, and the acquired current can be converted into a voltage of 1 - 5 V; when acquiring the 0 - 5 A solenoid valve current or 0 - 50 A caliper current, by plugging in the daughter board with a Hall effect current transformer, the large current is converted into a small current for measurement, and the acquired current is converted into a voltage.

[0033] Data Acquisition (AD7606): The analog-to-digital converter (ADC) converts analog signals into digital signals for the microcontroller MCU to process. The AD7606 chip can receive analog input signals in the range of ±10V or ±5V. To ensure that the input signal is within this range, the AD7606 internally integrates a signal conditioning circuit that can perform synchronous sampling on multiple channels. After the AD7606 performs analog-to-digital conversion, the digital signal is further processed by the microcontroller and converted into an actual voltage value. The AD7606 supports an SPI-compatible interface and sends the signal via the SPI protocol.

[0034] Microcontroller (H750): As the core processing unit of the system, it is responsible for executing program code and processing various input and output signals. It has multiple communication interfaces (such as SPI, I2C, USART, CAN, etc.) for data exchange with other external devices or sensors. In this embodiment, the H750 microcontroller communicates with the AD7606 via SPI, reads the converted digital signal, converts the ADC reading into an actual voltage value, and sends it to the PC via the CAN interface.

[0035] This embodiment has the following technical effects:

[0036] Using the CAN bus as the communication protocol: In the design of the current acquisition board, using the CAN bus for data transmission is a key point. It can convert the collected voltage signal into a CAN signal and send it into the bus environment, ensuring the real-time and accuracy of the data.

[0037] Efficient data processing ability: The acquisition board efficiently acquires and processes analog signals, converts the analog signals into digital signals, and converts the SPI protocol signal into a CAN signal.

[0038] Expandability and compatibility: When designing, compatibility with other systems and the expandability of its own measurement range are considered. The measured current range supports 4 - 20mA, 0 - 5A, and 0 - 50A. This design scheme is not only applicable to chassis braking tests but also compatible with other automotive test environments that require current data acquisition.

[0039] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A current acquisition board based on CAN bus, characterized in that: include: A mainboard card, on which an analog-to-digital converter and a microcontroller are installed, and the mainboard card has a plurality of plug-in slots; A plurality of sub-boards, the plurality of sub-boards being electrically connected to the main board through the plug-in slots, the sub-boards being used to convert the collected analog current into a corresponding voltage, and different sub-boards collecting different current ranges; The analog-to-digital converter converts the voltage signal output by the daughter board into a digital signal and sends it to the microcontroller through the SPI protocol. The microcontroller converts the digital signal into an actual voltage value and converts it into a CAN signal and sends it to the PC.

2. The current acquisition board based on CAN bus as claimed in claim 1, characterized in that: The analog-to-digital converter has a signal conditioning circuit integrated therein, and can perform synchronous sampling on multiple channels at the same time.

3. The current acquisition board based on CAN bus as claimed in claim 1, characterized in that: The current collection ranges of the multiple sub-boards are: 4-20mA, 0-5A, 0-50A.

4. The current acquisition board based on CAN bus as claimed in claim 3, characterized in that: A 250 ohm resistor is installed on the daughter board to convert the current range of 4-20mA into the voltage range of 1-5V.

5. The current acquisition board based on CAN bus as claimed in claim 3, characterized in that: Different current transformers are installed on different sub-boards to convert large current into small current for measurement and then into voltage output.

6. The current acquisition board based on CAN bus as claimed in claim 1, characterized in that: The microcontroller is STM32H750VBT6, and the analog-to-digital converter is AD7606.

Images