阅读说明：本技术 汽车结构应变数据测试系统 (Automobile structure strain data testing system ) 是由 王飞 宗志坚 熊新卫 鲁细晓 于 2021-09-13 设计创作，主要内容包括：本发明实施例提供一种汽车结构应变数据测试系统,包括依次连接的桥路模块、放大模块、滤波模块、A/D转换器以及控制器模块；所述桥路模块用于将应变片的电阻变化信号转换为电压变化信号；所述放大模块用于对所述电压变化信号进行放大；所述滤波模块用于对所述电压变化信号进行滤波处理；所述A/D转换器用于将模拟信号转换为数字信号；所述控制器模块用于控制采集电路、编写实时时钟、协议的转换以及编写定时器。本发明实施例能够针对汽车结构对应变花输出的应变同步进行调理、采集和发送,最大可对6个通道同步进行采集；且具有模块硬件简单、集成电路小和成本低的优点。(The embodiment of the invention provides an automobile structure strain data testing system, which comprises a bridge module, an amplifying module, a filtering module, an A/D converter and a controller module which are connected in sequence; the bridge module is used for converting the resistance change signal of the strain gauge into a voltage change signal; the amplifying module is used for amplifying the voltage change signal; the filtering module is used for filtering the voltage change signal; the A/D converter is used for converting the analog signal into a digital signal; the controller module is used for controlling the acquisition circuit, compiling the real-time clock, converting the protocol and compiling the timer. The embodiment of the invention can synchronously condition, collect and send the strain output by the strain rosette aiming at the automobile structure, and can synchronously collect 6 channels to the maximum extent; and has the advantages of simple module hardware, small integrated circuit and low cost.)

1. An automobile structure strain data testing system is characterized by comprising a bridge module, an amplifying module, a filtering module, an A/D converter and a controller module which are connected in sequence;

the bridge module is used for converting the resistance change signal of the strain gauge into a voltage change signal;

the amplifying module is used for amplifying the voltage change signal;

the filtering module is used for filtering the voltage change signal;

the A/D converter is used for converting the analog signal into a digital signal;

the controller module is used for controlling the acquisition circuit, compiling the real-time clock, converting the protocol and compiling the timer.

2. The system of claim 1, further comprising a CAN module connected to the controller module;

the CAN module is used for receiving and sending CAN data.

3. The system of claim 1 or 2, further comprising a power module;

the power supply module is used for supplying power to all modules included in the automobile structure strain data testing system.

4. The system as recited in claim 1, wherein the bridge modules are wheatstone bridges, and the strain gauges in the wheatstone bridges are connected using 1/4 bridges.

5. The system of claim 1, wherein the amplification module comprises:

one end of the resistor R65 is connected with one end of the resistor R66 through the capacitor C38; one end of the resistor R65 is grounded through a capacitor C33; one end of the resistor R65 is connected with one end of the amplifier through a resistor R44; one end of the resistor R44 is connected with the output end through a resistor R56 and a resistor R7; one end of the resistor R66 is grounded through a capacitor C34; one end of the resistor R66 is connected with the other end of the amplifier through a resistor R45; one end of the resistor R45 is grounded through a resistor R6; one end of the resistor R7 is grounded through a capacitor C11;

the resistor R44 is used for adjusting the amplification factor of the amplification module.

6. The system of claim 1, wherein the filtering module comprises an RFI filter and a low pass filter;

the RFI filter is used for attenuating noise signals and sending the attenuated signals to the amplifying module;

the low-pass filter is used for filtering the signal amplified by the amplifying module.

7. The system of claim 1, wherein the a/D converter is a 24-bit a/D converter comprising a plurality of channels that sample synchronously and a voltage divider circuit.

8. The system of claim 1, wherein the acquisition circuit comprises at least one collector node, and when the CAN data of the collector nodes are transmitted at the same time, the bus performs arbitration according to the CAN ID of the collector nodes to determine the data transmitted by the bus at the current time.

9. The system of claim 2, further comprising:

the DC-DC module is used for converting the 24V voltage into 6.5V voltage;

and the voltage reduction module is used for converting 6.5V voltage into analog power voltage 5V and digital power voltage 5V, and converting the digital power voltage 5V into digital power voltage 3.3V.

Technical Field

The invention relates to the technical field of automobiles, in particular to an automobile structure strain data testing system.

Background

At present, most of strain test systems in the market are centralized stress-strain test systems and distributed dynamic strain gauges. In a centralized stress-strain testing system, a plurality of channels of each instrument can be simultaneously collected, signals are transmitted to a computer in a wireless or wired mode, and the operation of signal collection, storage and analysis is performed at a client side. The distributed dynamic strain gauge has a large volume, a minimum number of 8 channels and high cost. Therefore, these two strain testing systems are not suitable for widespread use in automobiles.

Disclosure of Invention

To address the above problems, embodiments of the present invention provide an automotive structural strain data testing system that overcomes, or at least partially solves, the above problems.

According to an embodiment of the present invention, there is provided an automobile structure strain data testing system, including: the bridge module, the amplifying module, the filtering module, the A/D converter and the controller module are connected in sequence;

the bridge module is used for converting the resistance change signal of the strain gauge into a voltage change signal;

the amplifying module is used for amplifying the voltage change signal;

the filtering module is used for filtering the voltage change signal;

the A/D converter is used for converting the analog signal into a digital signal;

the controller module is used for controlling the acquisition circuit, compiling the real-time clock, converting the protocol and compiling the timer.

Preferably, the system further comprises a CAN module connected to the controller module;

the CAN module is used for receiving and sending CAN data.

Preferably, the system further comprises a power module;

the power supply module is used for supplying power to all modules included in the automobile structure strain data testing system.

Preferably, the bridge modules are wheatstone bridges, and the strain gauges in the wheatstone bridges are connected by 1/4 bridges.

Preferably, the amplifying module includes:

one end of the resistor R65 is connected with one end of the resistor R66 through the capacitor C38; one end of the resistor R65 is grounded through a capacitor C33; one end of the resistor R65 is connected with one end of the amplifier through a resistor R44; one end of the resistor R44 is connected with the output end through a resistor R56 and a resistor R7; one end of the resistor R66 is grounded through a capacitor C34; one end of the resistor R66 is connected with the other end of the amplifier through a resistor R45; one end of the resistor R45 is grounded through a resistor R6; one end of the resistor R7 is grounded through a capacitor C11;

the resistor R44 is used for adjusting the amplification factor of the amplification module.

Preferably, the filtering module comprises an RFI filter and a low pass filter;

the RFI filter is used for attenuating noise signals and sending the attenuated signals to the amplifying module;

the low-pass filter is used for filtering the signal amplified by the amplifying module.

Preferably, the a/D converter is a 24-bit a/D converter, and includes a plurality of channels for synchronous sampling and a voltage dividing circuit.

Preferably, the acquisition circuit includes at least one collector node, and when the CAN data of the collector node are transmitted at the same time, the bus performs arbitration according to the CAN ID of the collector node to determine the data transmitted by the bus at the current time.

Preferably, the system further comprises:

the DC-DC module is used for converting the 24V voltage into 6.5V voltage;

and the voltage reduction module is used for converting 6.5V voltage into analog power voltage 5V and digital power voltage 5V, and converting the digital power voltage 5V into digital power voltage 3.3V.

The automobile structure strain data testing system provided by the embodiment of the invention can synchronously condition, collect and send strain output by strain roses aiming at an automobile structure, and can synchronously collect 6 channels to the maximum extent; and has the advantages of simple module hardware, small integrated circuit and low cost.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from these without inventive effort.

FIG. 1 is a schematic structural diagram of a system for testing structural strain data of an automobile according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a system for testing structural strain data of an automobile according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of a Wheatstone bridge according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a strain conditioning circuit according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a circuit for converting 6.5V to digital voltages of 5V and 3.3V according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a circuit for converting 24V into 6.5V according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a circuit for converting 6.5V to analog voltage 5V according to an embodiment of the present invention;

fig. 8 is a schematic diagram of each bit design of a CAN standard frame according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In view of the technical problems of dispersion of strain at a key structure of an automobile, unknown direction of principal stress at a position, cost reduction and volume reduction in the prior art, an embodiment of the present invention provides an automobile structure strain data testing system, and fig. 1 is a schematic structural diagram of the automobile structure strain data testing system provided by the embodiment of the present invention, and the system includes a bridge module 101, an amplifying module 102, a filtering module 103, an a/D converter 104 and a controller module 105, which are connected in sequence. The bridge module 101 is used for converting the resistance change signal of the strain gauge into a voltage change signal; the amplifying module 102 is configured to amplify the voltage variation signal; the filtering module 103 is configured to perform filtering processing on the voltage variation signal; the a/D converter 104 is used for converting an analog signal into a digital signal; the controller module 105 is used to control the acquisition circuit, program the real-time clock, convert the protocol, and program the timer.

Wherein, the filter circuit filters the voltage signal of gathering, and the purpose is to reduce the interference of noise. The A/D converter converts the collected analog signals into digital signals, and the collection precision and the sampling frequency of the A/D converter are related to the module. Aiming at the microcontroller module MCU, the microcontroller module needs to communicate with the A/D converter through the SPI and receive signals of the temperature sensor, the number of used IO ports is large, the storage space is large, and CAN communication is supported.

The automobile structure strain data testing system provided by the embodiment of the invention can synchronously condition, collect and send strain output by strain roses aiming at an automobile structure, and can synchronously collect 6 channels to the maximum extent; and has the advantages of simple module hardware, small integrated circuit and low cost.

Based on the content of the foregoing embodiment, as an alternative embodiment, fig. 2 is a schematic structural diagram of an automobile structural strain data testing system according to another embodiment of the present invention, referring to fig. 2, where the system further includes a CAN module connected to the controller module; the CAN module is used for receiving and sending CAN data.

Based on the content of the above embodiment, as an alternative embodiment, referring to fig. 2, the system further includes a power module; the power supply module is used for supplying power to all modules included in the automobile structure strain data testing system.

Based on the content of the foregoing embodiments, as an alternative embodiment, fig. 3 is a schematic structural diagram of a wheatstone bridge provided by an embodiment of the present invention, and as shown in fig. 3, the bridge modules are wheatstone bridges, and the strain gauges in the wheatstone bridges are connected by 1/4 bridges.

Specifically, referring to FIG. 3, the bridge module is of the type employing a Wheatstone bridge signal conditioning circuit in which R of the strain gage is removed₁Resistance, remaining R₂、R₃、R₄Are all equal in resistance to the strain gage, which is connected using an 1/4 bridge.

Based on the content of the foregoing embodiment, as an alternative embodiment, fig. 4 is a schematic structural diagram of a strain conditioning circuit provided in an embodiment of the present invention, and referring to fig. 4, the amplifying module includes: one end of the resistor R65 is connected with one end of the resistor R66 through the capacitor C38; one end of the resistor R65 is grounded through a capacitor C33; one end of the resistor R65 is connected with one end of the amplifier through a resistor R44; one end of the resistor R44 is connected with the output end through a resistor R56 and a resistor R7; one end of the resistor R66 is grounded through a capacitor C34; one end of the resistor R66 is connected with the other end of the amplifier through a resistor R45; one end of the resistor R45 is grounded through a resistor R6; one end of the resistor R7 is grounded through a capacitor C11; the resistor R44 is used for adjusting the amplification factor of the amplification module.

Based on the content of the foregoing embodiment, as an alternative embodiment, the filtering module includes an RFI filter and a low-pass filter; the RFI filter is used for attenuating noise signals and sending the attenuated signals to the amplifying module; the low-pass filter is used for filtering the signal amplified by the amplifying module.

Specifically, an RFI filter is designed to attenuate the noise signal before the amplifier, and a low-pass filter is designed to filter after the amplifier.

Based on the content of the above embodiments, as an alternative embodiment, the a/D converter is a 24-bit a/D converter, and includes a plurality of channels for synchronous sampling and a voltage dividing circuit.

Specifically, after signals of resistance changes of the strain gauge metal wires of the A/D converter are processed by the signal conditioning circuit, the obtained voltage change range is 0-5V, the signals are analog signals, the voltage analog signals need to be converted into digital signals through the A/D converter, 24-bit A/D converters are selected, 8 channels are used for synchronous sampling, and a voltage division circuit is designed.

Based on the content of the foregoing embodiment, as an optional embodiment, the acquisition circuit includes at least one collector node, and when the CAN data of the collector nodes are transmitted at the same time, the bus performs arbitration according to the CAN ID of the collector nodes to determine the data transmitted by the bus at the current time.

Specifically, each collector node adopts the design of CAN ID. When CAN data of multiple nodes are transmitted at the same time, the bus CAN arbitrate according to the CAN ID and determine the data transmitted by the bus at the current time. Because the CAN data of the data gateway adopts the standard frame, each sensor node is selected as the standard frame. For example, the strain flowers have 20 pieces, so the ID thereof can be designed to be 0x00 to 0x13, 8 bits are allocated, in order to ensure the data synchronization of the three axis channels of the strain flowers, 21 bits are allocated to the first axis and the second axis respectively, and 22 bits are allocated to the data of the third axis.

In addition, the CAN transceiver is compatible with the ISO 11898 standard, the baud rate is high, the anti-interference performance is strong, the non-electrified nodes cannot interfere with the bus line, the number of the nodes is large, and the anti-transient protection CAN be provided for the bus pins in the automobile environment. Fig. 8 is a schematic diagram of each bit design of a CAN standard frame according to an embodiment of the present invention.

Based on the content of the foregoing embodiment, as an alternative embodiment, the system further includes: the DC-DC module is used for converting the 24V voltage into 6.5V voltage; fig. 6 is a schematic structural diagram of a circuit for converting 24V into 6.5V according to an embodiment of the present invention. And the voltage reduction module is used for converting 6.5V voltage into analog power voltage 5V and digital power voltage 5V, and converting the digital power voltage 5V into digital power voltage 3.3V. Fig. 5 is a schematic structural diagram of a circuit for converting 6.5V into digital voltages 5V and 3.3V according to an embodiment of the present invention. Fig. 7 is a schematic structural diagram of a circuit for converting 6.5V into 5V analog voltage according to an embodiment of the present invention.

Specifically, for the power circuit, the power supply digital voltages of the acquisition circuit are 3.3V and 5V, the analog voltage is 5V, the voltage on the all-aluminum bus is 24V, and the power of the voltage reduced from 24V to 5V or 3.3V is larger, a DC-DC module is needed to be adopted to avoid burning out the acquisition circuit, and a proper DC-DC module is preferably selected to convert the 24V power supply into 6.5V voltage; further considering the higher requirement of the analog voltage, a voltage reduction module is selected to convert the 6.5V voltage into the analog power supply voltage 5V with higher precision; the voltage of 6.5V is converted into digital power voltage of 5V by the selective voltage reduction module, and then the voltage of 3.3V is converted into the digital power voltage by the selective voltage reduction module.

It should be noted that, in the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to relevant descriptions of other embodiments for parts that are not described in detail in a certain embodiment.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.