Integrated coiled cable multi-parameter test system

Abstract

The utility model belongs to the technical field of cable detection, and aims to solve the problem that coiled wires and cables are difficult to detect and low in precision. The utility model provides an integrated coiled cable multi-parameter test system. A cable resistance measurement module comprises a high-precision programmable constant current source module, an AD acquisition module and a resistance measurement interface; the high-precision programmable constant current source module is connected with the main control module, the high-precision programmable constant current source module is connected with a measured cable through the resistance measurement interface, and the main control module is connected with the resistance measurement interface through the AD acquisition module; the cable length measuring module comprises a pulse transmitting and receiving module, a high-precision time measuring module and a length measuring interface; the pulse transmitting and receiving module is connected with the main control module, the high-precision time measuring module is connected with the pulse transmitting and receiving module, and the pulse transmitting and receiving module is connected with a measured cable through a length measuring interface. The system can complete the measurement of the resistance, the cross section area and the length of the coiled cable, and improves the detection efficiency of the parameters of the coiled cable.

Description

Technical Field

[0001] The utility model belongs to the technical field of cable detection, and particularly relates to a multi-parameter testing system for integrated coiled cables. Background Art

[0002] At the present stage, with the increasing application proportion of wire and cable in the urban power distribution network and information transmission system, the material inspection of power cable is more important for the safety of the power transmission and distribution system. Due to the difficulty in detecting coiled wire and cable, there are problems such as the actual length not matching the nominal length, the DC resistance not meeting the national standard requirements, and the effective cross-sectional area being too small.

[0003] Moreover, in the quality inspection of coiled cables, using the traditional meter-reading method to measure the length of the cable not only has large errors but also is difficult to operate.

[0004] In addition, the effective cross-sectional area of the cable is an important parameter for inspecting the cable quality. Most of the conductors in the cable core layer are made of multiple copper wires by die-casting, and it is inevitable to be bumped and squeezed during transportation, resulting in an irregular cross-sectional shape. Although the traditional weighing method has high precision and is applicable to most cables, for coiled cables with a large diameter, it is difficult to accurately quantify the length. When using this method, it is necessary to intercept several meters of cable, which is inconvenient to operate and affects sales and use. Summary of the Utility Model

[0005] The utility model provides a multi-parameter testing system for integrated coiled cables to solve at least one of the above technical problems existing in the prior art.

[0006] The utility model is realized by adopting the following technical solutions: an integrated multi-parameter testing system for a coiled cable, which includes a main control module, a cable resistance measurement module and a cable length measurement module; the cable resistance measurement module includes a high-precision programmable constant current source module, an AD acquisition module and a resistance measurement interface; among them, the high-precision programmable constant current source module is connected to the main control module and is used to receive a control signal and transmit a current control signal; the high-precision programmable constant current source module is connected to the cable under test through the resistance measurement interface and is used to send a constant current signal to the cable under test; the main control module and the resistance measurement interface are connected through the AD acquisition module, and the AD acquisition module is used to collect the voltage signals at both ends of the cable under test and send them to the main control module after analog-to-digital conversion; the cable length measurement module includes a pulse transmitting and receiving module, a high-precision time measurement module, a temperature measurement interface and a length measurement interface; among them, the pulse transmitting and receiving module is connected to the main control module and is used to receive and transmit pulse signals; the high-precision time measurement module is connected to the pulse transmitting and receiving module and is used to measure the time interval between the transmitted pulse signal and the reflected pulse signal; the high-precision time measurement module is connected to the external environment through the temperature measurement interface and is used to collect the ambient temperature; the pulse transmitting and receiving module is connected to the cable under test through the length measurement interface and is used to send a test pulse signal to the cable under test and receive the echo signal.

[0007] Preferably, it further includes an HMI touch display screen, which is connected to the main control module and is used for real-time system display and measurement operations.

[0008] Preferably, the high-precision programmable constant current source module includes a CPLD chip and a current emission circuit; among them, the CPLD chip is connected to the main control module through the RS485 bus and is used to receive the instructions of the main control module and control the current emission circuit to output a constant current of corresponding magnitude; the current emission circuit is connected to the cable under test through the resistance measurement interface and is used to complete the injection of the test current; the AD acquisition module is connected to the main control module through the SPI bus.

[0009] Preferably, the high-precision time measurement module includes an MS1022 chip and a temperature measurement module; among them, the MS1022 chip is connected to the main control module through the SPI bus and is used to receive control signals and send the ambient temperature and the time interval information of the transmitted pulse signal and the reflected pulse signal to the main control module; the MS1022 chip is connected to the temperature measurement interface through the temperature measurement module, and the temperature measurement module is used to measure the ambient temperature and send the temperature information to the MS1022 chip.

[0010] Preferably, the pulse transmitting and receiving module includes a pulse emission circuit, a pulse shaping circuit, a pulse amplification circuit and a pulse isolation detection circuit;

[0011] The pulse emission circuit is connected to the main control module and is used to receive and transmit pulse signals to the MS1022 chip and the pulse shaping circuit; the pulse shaping circuit is connected to the pulse emission circuit and is used to shape the pulse signals; the pulse amplification output circuit is connected to the pulse shaping circuit and is used to amplify the pulse signals; the pulse isolation detection circuit is connected to the pulse amplification output circuit, the MS1022 chip and the length measurement interface, and is used to transmit pulse test signals to the cable under test, receive echo signals and send the signals to the MS1022 chip.

[0012] Preferably, the core of the main control module is the STM32F407VET6 chip, the core of the AD acquisition module is the AD7606 chip, and the core of the high-precision time measurement module is the MS1022 chip.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0014] By using the integrated and automated cable parameter measurement system to complete the measurement of the resistance, cross-sectional area and length of the coiled cable, it can greatly improve the detection efficiency of the coiled cable parameters and reduce the errors and mistakes caused by manual detection. At the same time, it can also improve the system reliability and measurement range through high-precision circuits and chips.

[0015] This system has high integration, is easy to operate, and can measure multiple parameters. It can realize the measurement of the length of wire and cable through the time domain reflection principle, and realize the functions of measuring the DC resistance and effective cross-sectional area according to the four-wire method resistance measurement principle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is the schematic diagram of module connection in this embodiment;

[0018] Figure 2 is the circuit diagram of the RS485 bus interface in this embodiment;

[0019] Figure 3 is the connection relationship diagram of the high-precision acquisition circuit in this embodiment;

[0020] Figure 4 is the connection relationship diagram of the pulse transceiver circuit in this embodiment;

[0021] Figure 5 is the connection relationship diagram of the high-precision time measurement circuit in this embodiment. Detailed implementation manners

[0022] In combination with the accompanying drawings in the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other implementation manners obtained by those of ordinary skill in the art without making creative efforts fall within the scope protected by the present utility model.

[0023] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the limited conditions under which the present utility model can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should fall within the scope covered by the technical content disclosed in the present utility model. It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0024] The present utility model provides an embodiment:

[0025] As Figures 1 to 5 shown, the integrated multi-parameter test system for a coiled cable includes a main control module, a cable resistance measurement module, and a cable length measurement module; the cable resistance measurement module includes a high-precision programmable constant current source module, an AD acquisition module, and a resistance measurement interface; wherein the high-precision programmable constant current source module is connected to the main control module for receiving a control signal and transmitting a current control signal; the high-precision programmable constant current source module is connected to the cable under test through the resistance measurement interface for sending a constant current signal to the cable under test; the main control module is connected to the resistance measurement interface through the AD acquisition module, and the AD acquisition module is used for collecting the voltage signals at both ends of the cable under test and sending them to the main control module after analog-to-digital conversion;

[0026] The cable length measurement module includes a pulse transmitting and receiving module, a high-precision time measurement module, a temperature measurement interface, and a length measurement interface. Among them, the pulse transmitting and receiving module is connected to the main control module and is used to receive and transmit pulse signals. The high-precision time measurement module is connected to the pulse transmitting and receiving module and is used to measure the time interval between the transmitted pulse signal and the reflected pulse signal. The high-precision time measurement module is connected to the external environment through the temperature measurement interface and is used to collect the ambient temperature. The pulse transmitting and receiving module is connected to the cable under test through the length measurement interface and is used to send a test pulse signal to the cable under test and receive the echo signal. It also includes an HMI touch display screen, which is connected to the main control module and is used for real-time system display and measurement operations.

[0027] In this embodiment, the core of the main control module is the STM32F407VET6 chip, and the control and measurement functions of each module are realized through the corresponding bus interfaces.

[0028] The cable resistance measurement module consists of a high-precision programmable constant current source module, an AD acquisition module, and a resistance measurement interface. Among them, the high-precision programmable constant current source module is connected to the single-chip microcomputer core main control STM32F407VET6 chip through the RS485 bus. Please refer to Figure 2 , the RS485 bus consists of a transceiver SP3485 and its external circuit. The main control chip receives and sends signals through pins 1 and 4, controls the transceiver mode through pins 2 and 3, and transceives data through pins 6 and 7. At the same time, bias resistors R11 and R15 are connected to pins 6 and 7 to avoid an uncertain state when the bus is idle;

[0029] Among them, the high-precision programmable constant current source module includes a CPLD chip and a current emission circuit. The CPLD chip is connected to the main control module through the RS485 bus, and receives the instructions of the main control module through the Modbus communication protocol and controls the current emission circuit to output a constant current of the corresponding magnitude. The current emission circuit is connected to the cable under test through the resistance measurement interface and is used to complete the injection of the test current. The AD acquisition module is connected to the main control module through the SPI bus. The core of the AD acquisition module is the AD7606 chip. The AD7606 chip is connected to the single-chip microcomputer core main control STM32F407VET6 chip through the SPI bus, collects the voltages at both ends of the cable, shuts off the current output after the collection, calculates the resistance value of the cable according to Ohm's law, and calculates the nominal resistance value at 20°C according to the temperature value.

[0030] Please refer to Figure 3, the AD acquisition module consists of an AD7606 chip and peripheral circuits. The AD7606 chip is connected to the STM32F407VET6 chip, the core master control of the single-chip microcomputer, through the SPI bus, and is used to receive control signals and send acquired data. The AD acquisition module is connected to the cable under test through a resistance measurement interface, and is used to receive the signal to be measured and complete AD conversion. The AD7606 chip has a 16-bit high resolution and a sampling rate of 200KSPS, can process a true bipolar signal input of up to ±10V at most, and has a filter and input high impedance characteristics inside the chip, which reduces the complexity of the designed circuit while ensuring the system performance.

[0031] The high-precision time measurement module includes an MS1022 chip and a temperature measurement module. Among them, the MS1022 chip is connected to the main control module through the SPI bus, and is used to receive control signals, send ambient temperature, and transmit the time interval information of the transmitted pulse signal and the reflected pulse signal to the main control module. The MS1022 chip is connected to the temperature measurement interface through the temperature measurement module, and the temperature measurement module is used to measure the ambient temperature and send the temperature information to the MS1022 chip.

[0032] The pulse transmitting and receiving module includes a pulse transmitting circuit, a pulse shaping circuit, a pulse amplifying circuit, and a pulse isolation detection circuit;

[0033] The pulse transmitting circuit is connected to the main control module and is used to receive and transfer pulse signals to the MS1022 chip and the pulse shaping circuit; the pulse shaping circuit is connected to the pulse transmitting circuit and is used to shape the pulse signal; the pulse amplifying output circuit is connected to the pulse shaping circuit and is used to amplify the pulse signal; the pulse isolation detection circuit is connected to the pulse amplifying output circuit, the MS1022 chip, and the length measurement interface, and the pulse isolation detection circuit is used to transmit a pulse test signal to the cable under test, receive the echo signal, and send the signal to the MS1022 chip.

[0034] Please refer to Figure 4 , the pulse transmitting and receiving module consists of a first-stage shaping and amplifying circuit, a second-stage shaping and amplifying circuit, and an integrated transmitting and receiving circuit. The first-stage amplifying circuit uses a high-speed comparator TLV3501 to perform first-stage amplification and shaping on the pulse signal. The TLV3501 has a push-pull output design, with a rise time or fall time of only 1.5ns and a device delay time of only 4.5ns, and can amplify the amplitude of the pulse signal input by the single-chip microcomputer to 5V. The second-stage amplifying circuit uses a high-speed analog switch DG201HS and an inverter SN74LVC1G240 to perform secondary amplification on the pulse signal. The integrated transmitting and receiving circuit uses an HR610660 transformer to isolate the signal, performs shaping and limiting through the TLV3501, and finally receives the pulse signal and sends it to the time measurement chip through STOP.

[0035] Please refer toFigure 5 The high-precision time measurement module uses the high-precision time measurement chip MS1022 to measure the time interval between the transmitted pulse and the cable terminal reflected pulse and temperature measurement. It has two measurement ranges corresponding to short-distance and long-distance measurements respectively. The measurement range 1 is from 3.5 ns to 2.5 μs, and the resolution is 37 ps; the measurement range 2 is from 500 ns to 4 ms, and the resolution is 75 ps. The single-chip microcomputer configures and reads data from the MS1022 through the SPI bus interface, and the interrupt pin MS_INTN is used to trigger the single-chip microcomputer to read the time data.

[0036] This system can realize the measurement of the length of wire and cable through the time domain reflection principle, and realize the functions of measuring the DC resistance and effective cross-sectional area according to the four-wire method resistance measurement principle. The above methods of measuring the length by the time domain reflection principle and the method of measuring the resistance by the four-wire method are both existing technologies. After obtaining the cable length and resistance value, according to the resistance calculation formula: R = ρl / S, where R is the resistance value, l is the cable length, S is the cross-sectional area, and ρ is the resistivity and depends on the temperature and material of the cable. According to the above formula, the effective cross-sectional area of the cable can be solved, and the above calculation formula is also an existing technology.

[0037] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An integrated cable reel multi-parameter testing system, characterized by: It includes a main control module, a cable resistance measurement module and a cable length measurement module; The cable resistance measurement module includes a high-precision programmable constant current source module, an AD acquisition module and a resistance measurement interface; wherein the high-precision programmable constant current source module is connected to the main control module, and is used to receive a control signal and transmit a current control signal; the high-precision programmable constant current source module is connected to the measured cable via the resistance measurement interface, and is used to send a constant current signal to the measured cable; the main control module is connected to the resistance measurement interface via the AD acquisition module, and the AD acquisition module is used to collect voltage signals at both ends of the measured cable and send them to the main control module after analog-to-digital conversion; The cable length measurement module includes a pulse transmitting and receiving module, a high-precision time measurement module, a temperature measurement interface and a length measurement interface; wherein the pulse transmitting and receiving module is connected to the main control module for receiving and transmitting pulse signals; the high-precision time measurement module is connected to the pulse transmitting and receiving module for measuring the time interval between the transmitted pulse signal and the reflected pulse signal; The high-precision time measurement module is connected to the external environment via the temperature measurement interface to collect the ambient temperature; The pulse transmitting and receiving module is connected to the cable under test via the length measurement interface, and is used for sending a test pulse signal to the cable under test and receiving an echo signal.

2. The integrated cable reel multi-parameter testing system according to claim 1 is characterized in that: It also includes an HMI touch display screen, which is connected to the main control module and is used for real-time system display and measurement operations.

3. The integrated cable reel multi-parameter testing system according to claim 1 is characterized in that: The high-precision programmable constant current source module includes a CPLD chip and a current transmitting circuit; wherein the CPLD chip is connected to the main control module via the RS485 bus, and is used to receive the instructions of the main control module and control the current transmitting circuit to output a constant current of corresponding magnitude; the current transmitting circuit is connected to the cable under test via the resistance measurement interface, and is used to complete the injection of the test current; the AD acquisition module is connected to the main control module via the SPI bus.

4. The integrated cable reel multi-parameter testing system according to claim 1 is characterized in that: The high-precision time measurement module includes an MS1022 chip and a temperature measurement module; wherein the MS1022 chip is connected to the main control module via the SPI bus, and is used to control the reception of signals and the sending of ambient temperature and time interval information of the transmitted pulse signal and the reflected pulse signal to the main control module; the MS1022 chip is connected to the temperature measurement interface via the temperature measurement module, and the temperature measurement module is used to measure the ambient temperature and send the temperature information to the MS1022 chip.

5. The integrated cable reel multi-parameter testing system according to claim 4 is characterized in that: The pulse transmitting and receiving module includes a pulse transmitting circuit, a pulse shaping circuit, a pulse amplifying circuit and a pulse isolating and detecting circuit; The pulse transmitting circuit is connected to the main control module and is used to receive and transmit the pulse signal to the MS1022 chip and the pulse shaping circuit; The pulse shaping circuit is connected to the pulse transmitting circuit and is used for shaping the pulse signal; The pulse amplification output circuit is connected to the pulse shaping circuit and is used to amplify the pulse signal; The pulse isolation detection circuit is connected to the pulse amplification output circuit, the MS1022 chip and the length measurement interface. The pulse isolation detection circuit is used to transmit a pulse test signal to the cable under test, receive an echo signal and send the signal to the MS1022 chip.

6. The integrated cable reel multi-parameter testing system according to claim 1 is characterized in that: The core of the main control module is the STM32F407VET6 chip, the core of the AD acquisition module is the AD7606 chip, and the core of the high-precision time measurement module is the MS1022 chip.

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