Cable test system

Abstract

The invention discloses a cable test system, which comprises a main control unit, a driving unit, an on-off test unit, an insulation test unit, a keyboard unit and a power supply unit, the keyboard unit sets the core number and test items of a cable to be tested, and sends the core number and test items as instructions to the main control unit; the main control unit sends the instruction to the driving unit, acquires signals output by the insulation test unit and the on-off test unit, and performs operational analysis and result processing on the signals; the driving unit controls the relay matrix according to the instruction, connects a to-be-tested cable to a test system, and connects the on-off test unit and the insulation test unit to a cable loop; the on-off test unit and the insulation test unit collect signals of a cable to be tested and send the signals to the main control unit; the power supply unit supplies power to the insulation test unit and the on-off test unit. In the process of realizing the test function, the system has the advantages of high test speed and flexible control, and can adapt to a cable with at most 128 cores.

Description

Technical Field

[0001] This application relates to the field of rockets, and specifically, to a cable testing system. Background Art

[0002] In the aviation and aerospace industries, cable detection is a basic detection during the assembly and fault repair of electrical equipment. For launch vehicles, the number of single - cable is huge, and most of them are multi - core cables. Facing a huge number and various types of detection items, the method of manually holding the equipment to detect each cable one by one is inefficient and has a high labor cost. This requires an organic integration of general detection equipment to complete the detection items on one device. In view of the problems existing in the cable detection process, a test platform with cable continuity and insulation detection functions is proposed and the system is designed. Currently, the commonly used detection equipment is mostly general equipment with a single function, and each time it can only detect one or a limited number of core wires. This method has low detection efficiency and high labor and time costs.

[0003] Therefore, how to provide a cable testing system that integrates the functions of general detection equipment and completes the detection items on one device has become an urgent problem to be solved in this field. Summary of the Invention

[0004] This application proposes a cable testing system, including: a main control unit, a driving unit, a continuity testing unit, an insulation testing unit, a keyboard unit, and a power supply unit; wherein the keyboard unit sets the number of cores and test items of the cable to be tested, and the number of cores and test items of the test cable are sent to the main control unit as instructions; the main control unit receives the instructions for cable testing, sends the instructions to the driving unit, and at the same time collects the signals output by the insulation testing unit and the continuity testing unit, and performs arithmetic analysis and result processing on the signals; after receiving the instructions, the driving unit controls the relay matrix, connects the cable to be tested to the testing system, and controls the switch of the relay to connect the continuity testing unit and the insulation testing unit to the cable loop; after being connected to the cable loop, the continuity testing unit and the insulation testing unit collect signals from the cable to be tested and send them to the main control unit; the power supply unit supplies power to the insulation testing unit and the continuity testing unit.

[0005] The cable testing system as described above, wherein the driving unit is an FPGA matrix driving module, and the FPGA matrix driving module consists of an FPGA and its peripheral circuits, a relay driving matrix circuit, and a relay matrix.

[0006] The cable testing system as described above, wherein the driving unit receives the commands sent by the main control unit, generates the "row" and "column" address decoding and latching signals for controlling the relays according to the test items, the decoding circuit corresponds to the row and column matrix in the relay matrix, and the decoded signals are sent to the I / O ports of the FPGA via the latching circuit, and the relays are turned on via the driving circuit to connect the continuity test unit and the insulation test unit into the cable loop respectively.

[0007] The cable testing system as described above, wherein the continuity test unit includes a first to third resistor, a first relay, a second relay, and a first operational amplifier.

[0008] The cable testing system as described above, wherein one end of the first resistor is connected to the power supply unit, the other end of the first resistor is connected to the positive input terminal of the first operational amplifier, the other end of the other end of the first resistor is also connected to one end of the second resistor, and the other end of the second resistor is grounded; the other end of the first resistor is connected to the first relay, the second relay is connected to one end of the third resistor, and the other end of the third resistor is grounded; the second relay is also connected to the negative input terminal of the first operational amplifier; the output terminal of the first operational amplifier is connected to the main control unit.

[0009] The cable testing system as described above, which further includes the equivalent resistance of the cable. When the cable under test is connected to the circuit, the equivalent resistance is respectively connected to relay S3 and relay Q1;

[0010] The cable testing system as described above, wherein the power supply unit connected to the first resistor is set as a +5VDC power supply.

[0011] The cable testing system as described above, wherein during the test, relay S3 and relay Q1 are closed. If the cable under test is conducting normally and the equivalent resistance of the cable is less than the specified threshold, the output value of the first operational amplifier is 0 and it outputs "0" externally; if the cable has an open circuit fault, the negative terminal of the first operational amplifier is grounded, the positive input potential is about 5V DC, and its output value is 5VDC, and it outputs "1" externally; the main control unit determines whether the cable is conducting by judging the level.

[0012] The cable testing system as described above, wherein the insulation test unit includes a fourth to seventh resistor, a third relay, a fourth relay, and a second operational amplifier.

[0013] The cable testing system described above, wherein one end of the fourth resistor is connected to the power supply unit, the other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the input terminal of the second operational amplifier; the other end of the fifth resistor is also connected to one end of the sixth resistor, and the other end of the sixth resistor is grounded; the third relay is connected to one end of the fifth resistor; the fourth relay is connected to the input terminal of the second operational amplifier, and the fourth relay is also connected to one end of the seventh resistor, and the other end of the seventh resistor is grounded; the output terminal of the second operational amplifier is connected to the A / D chip, and the A / D chip is connected to the main control unit.

[0014] The present application has the following beneficial effects:

[0015] The cable testing system proposed in the present application has the advantages of fast testing speed and flexible control in the process of realizing the testing function, and can adapt to cables with up to 128 cores at the same time. And the present application adopts the DC inverse transformation method, generates an alternating current signal by pulse width modulation of a DC low-voltage power supply, and generates a DC high-voltage through amplification, rectification, filtering, voltage stabilization and other links to meet the requirements of the power supply for insulation resistance testing. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0017] Figure 1 is a flowchart of the cable testing system provided according to an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of the circuit structure of the continuity test unit provided according to an embodiment of the present application;

[0019] Figure 3 is a schematic diagram of the circuit structure of the insulation test provided according to an embodiment of the present application; Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0021] The cable testing system proposed in the present application can integrate the functions of general detection equipment, centralize the detection items on one device to complete, improve work efficiency and reduce labor costs.

[0022] Example 1

[0023] As Figure 1 shown, the cable testing system provided by the embodiment of the present application, where the cable testing system may be in the form of a cable tester, specifically including: a main control unit 110, a driving unit 120, a continuity testing unit 130, an insulation testing unit 140, a keyboard unit 150, and a power supply unit 160.

[0024] Among them, the keyboard unit 150 is used to set the number of cores and test items of the cable to be tested, and send the number of cores and test items of the tested cable as instructions to the main control unit 110.

[0025] The main control unit 110 is respectively connected to the driving unit 120, the insulation testing unit 130, and the continuity testing unit 140. As the upper computer of the testing system, it is used to receive instructions for cable testing and send the instructions to the driving unit to control the configuration and working process of the driving unit. At the same time, it collects the signals output by the insulation testing unit 130 and the continuity testing unit 140 for arithmetic analysis and result processing.

[0026] After receiving the instruction, the driving unit 120 is used to control the relay matrix, connect the cable to be tested to the testing system, and control the switch of the relay to connect the continuity testing unit 130 and the insulation testing unit 140 to the cable loop to test the cable to be tested.

[0027] Among them, the driving unit 120 may be an FPGA matrix driving module, and the main circuit structure can refer to the existing technology and will not be elaborated here. The main function is to realize the switch control of the relay according to the testing requirements of the main control unit. The driving unit mainly consists of an FPGA and its peripheral circuits, a relay driving matrix circuit, and a relay matrix.

[0028] After receiving the instruction as the upper computer, the main control unit 110 sends it to the FPGA matrix driving module as the lower computer. The FPGA matrix driving module is the matrix switch of the relay matrix, and the control of the relay matrix is realized through the FPGA matrix driving module to connect the cable under test to the testing system.

[0029] Among them, an efficient and reliable matrix switch module is the key to realizing the detection work, and an FPGA is used as the core component of the control logic of the lower computer. Compared with the main control unit, the FPGA has rich I / O interfaces, does not require interface expansion, can meet the testing requirements of the project, has flexible configuration, reduces the system volume, and is convenient for function expansion.

[0030] Specifically, the drive unit 120 receives the commands sent by the main control unit 110, generates the "row" and "column" address decoding and latching signals for controlling the relays according to the test items. The decoding circuit corresponds to the row and column matrix in the relay matrix. The decoded signals are sent to the I / O ports of the FPGA after passing through the latching circuit, and the relays are turned on through the drive circuit to connect the continuity test unit 130 and the insulation test unit 140 into the cable loop respectively.

[0031] The continuity test unit 130 is connected to the main control unit 110 and is used to collect signals from the cable under test after being connected to the cable loop through the relay, convert the collected signals into digital signals and send them to the main control unit.

[0032] The insulation test circuit 140 is connected to the main control unit 110 and is used to collect signals after being connected to the cable loop through the relay, convert the collected signals into digital signals and send them to the main control unit.

[0033] The main control unit 110 collects, calculates, and analyzes the received signals to obtain whether the cable under test is conductive and the insulation resistance result of the cable under test, and displays them in real time through the display.

[0034] The following are the specific

[0035] working principles of the continuity test unit 130, the insulation test circuit 140, and the main control unit 110:

[0036] As shown in Figure 2 below, it is the circuit structure diagram of the continuity test unit 130. One end of a resistor R1 (the first resistor) is connected to the power supply unit 160 (at this time, it is a +5VDC power supply), and the other end of the resistor R1 is connected to the positive input terminal of the first operational amplifier. The other end of the resistor R1 is also connected to one end of a resistor R3 (the second resistor), and the other end of the resistor R3 is grounded. The other end of the resistor R1 is connected to a relay S3 (the first relay), and a relay Q1 (the second relay) is connected to one end of a resistor R4 (the third resistor), and the other end of the resistor R4 is grounded. The relay Q1 is also connected to the negative input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the main control unit. Specifically, the output terminal is connected to the INT1 pin of the main control module.

[0037] As shown in Figure 2 below, when the cable under test is connected to the circuit, there is an equivalent resistance Rx of the cable. The equivalent resistance Rx is set between the relay S3 and the relay Q1 and is connected to the relay S3 and the relay Q1 respectively.

[0038] Specifically, the test power supply is a +5VDC power supply, Rx is the equivalent resistance of the cable under test. When testing, the relay S3 and the relay Q1 are closed. If the cable under test is conducting normally, the equivalent resistance Rx of the cable is very small, and the potentials of the two input stages of the operational amplifier are almost equal, and its output value is close to 0 (considered as 0). If the cable has an open circuit fault, the negative terminal of the operational amplifier is grounded, and the positive input potential is about 5V DC, and its output value will also be about 5V DC.

[0039] Since the output signal of the operational amplifier conforms to the TTL level, when the cable is conducting normally, it is equivalent to outputting "0" externally, and when the cable is open-circuited, it is equivalent to outputting "1" externally. The output terminal is connected to the INT1 pin of the main control module, and the main control unit determines whether the cable is conducting by judging the level.

[0040] As Figure 3 shown, it is the circuit structure diagram of the insulation test unit 140. One end of the resistor R5 (the fourth resistor) is connected to the power supply unit 160, the other end of the resistor R5 is connected to one end of the resistor R6 (the fifth resistor), and the other end of the resistor R6 is connected to the input terminal of the second operational amplifier. The other end of the resistor R6 is also connected to one end of the resistor R8 (the sixth resistor), and the other end of the resistor R8 is grounded. The relay S1 (the third relay) is connected to one end of the resistor R6. The relay S2 (the fourth relay) is connected to the input terminal of the second operational amplifier, and the relay S2 is also connected to one end of the resistor R7 (the seventh resistor), and the other end of the resistor R7 is grounded. The output terminal of the second operational amplifier is connected to the A / D chip, and the A / D chip is connected to the main control unit.

[0041] Among them, referring to Figure 3 shown, when the cable under test is connected to the circuit, there is a resistor Ry set between the relay S1 and the relay S2.

[0042] Among them, the national standard equal-voltage method is adopted to measure the insulation resistance. Figure 3 The power supply unit 160 in

[0043] generates a 500V DC voltage as the voltage source for the resistance test by the high-voltage circuit.

[0044] U1 = R8 * U / (R6 + R8);

[0045] U2 = R7 * U / (Ry + R7);

[0046] Therefore, the equivalent insulation resistance Ry=(((R6+R8) / R8)*(U1 / U2)-1)*R7

[0047] Wherein R6 represents the voltage value collected by the resistor R6, R7 represents the voltage value collected by the resistor R7, and R8 represents the voltage value collected by the resistor R8.

[0048] When the principle shown in the figure is adopted, the insulation resistance Ry has nothing to do with the power supply voltage U, which can minimize the system's requirements for power supply. As long as U1 and U2 are sampled at the same time, and the insulation resistance is calculated in combination with the standard resistors R6-R8, and finally the error is corrected by software, high-precision insulation resistance measurement can be achieved, and the results can be displayed in real time on the display.

[0049] The power supply unit 160 can provide power for the entire test system in addition to providing test power. Specifically, the power supply unit inputs 27V DC and outputs DC 5V, DC 3.3V, DC 1.8V, DC 1.2V and 500V DC test high voltage.

[0050] The 500V DC power supply required for the measurement of cable insulation resistance is designed using the DC inverter method. The DC low-voltage power supply is pulse-width modulated to generate an AC signal, and then the AC signal is amplified, rectified, filtered, and stabilized to generate a 500V DC voltage to meet the power supply requirements of the insulation resistance test.

[0051] The cable testing system further includes a cable transfer interface 170 .

[0052] The cable transfer interface 170 provides an operation and aviation plug-in interface to realize the operation and access functions of the cable under test.

[0053] Due to the various types and specifications of cables under test, they are connected to the 9-core, 85-core or 128-core aviation plug on the tester through adapters as needed during testing, so as to reduce the number of tester interfaces and the size of the tester.

[0054] This application has the following beneficial effects:

[0055] The cable testing system proposed in this application has the advantages of fast testing rate and flexible control in the process of realizing the testing function, and can adapt to cables with a maximum of 128 cores. In addition, this application adopts the DC inverter method to generate an AC signal from a DC low-voltage power supply through pulse width modulation, and generates a DC high-voltage voltage through amplification, rectification, filtering, voltage stabilization and other links to meet the power supply requirements of the insulation resistance test.

[0056] Although the examples referred to in the present application are described, they are for illustrative purposes only and not a limitation of the present application. Changes, additions, and / or deletions to the embodiments can be made without departing from the scope of the present application.

[0057] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A cable testing system, characterized in that: include: Main control unit, drive unit, continuity test unit, insulation test unit, keyboard unit and power supply unit; The keyboard unit sets the number of cores and test items of the cable to be tested, and the number of cores and test items of the tested cable are sent to the main control unit as instructions; The main control unit receives the instruction to perform cable testing and sends the instruction to the drive unit, and at the same time collects the signals output by the insulation test unit and the continuity test unit, and performs calculation analysis and result processing on the signals; After receiving the instruction, the drive unit controls the relay matrix, connects the cable to be tested to the test system, and controls the switch of the relay to connect the continuity test unit and the insulation test unit to the cable loop; After being connected to the cable loop, the continuity test unit and the insulation test unit collect signals from the cable to be tested and send them to the main control unit; The power supply unit supplies power to the insulation test unit and the continuity test unit.

2. The cable testing system according to claim 1, characterized in that: The driving unit is an FPGA matrix driving module, which is composed of an FPGA and its peripheral circuits, a relay driving matrix circuit, and a relay matrix.

3. The cable testing system according to claim 1, characterized in that: The drive unit receives the command sent by the main control unit, and generates the "row" and "column" address decoding and latching signals of the control relay according to the test items. The decoding circuit corresponds to the row and column matrix in the relay matrix. The decoded signal is sent to the I / O port of the FPGA after the latch circuit. The drive circuit turns on the relay to connect the on-off test unit and the insulation test unit to the cable loop respectively.

4. The cable testing system according to claim 1, characterized in that: The on-off test unit includes first to third resistors, a first relay, a second relay, and a first operational amplifier.

5. The cable testing system according to claim 4, characterized in that: One end of the first resistor is connected to the power supply unit, the other end of the first resistor is connected to the positive input end of the first operational amplifier, the other end of the other end of the first resistor is also connected to one end of the second resistor, and the other end of the second resistor is grounded; the other end of the first resistor is connected to the first relay, the second relay is connected to one end of the third resistor, and the other end of the third resistor is grounded; the second relay is also connected to the reverse input end of the first operational amplifier; the output end of the first operational amplifier is connected to the main control unit.

6. The cable testing system according to claim 5, characterized in that: It also includes the equivalent resistance of the cable, which is connected to relay S3 and relay Q1 respectively when the cable under test is connected to the circuit.

7. The cable testing system according to claim 5, characterized in that: The power supply unit connected to the first resistor is set to a +5VDC power supply.

8. The cable testing system according to any one of claims 5 to 7, characterized in that: During the test, the relay S3 and the relay Q1 are closed. If the tested cable is normally conductive and the equivalent resistance of the cable is less than the specified threshold, the output value of the first operational amplifier is 0, and "0" is output externally. If the cable is broken, the negative pole of the first operational amplifier is grounded, the positive input potential is about 5VDC, and its output value is 5V DC, and it outputs "1" to the outside; The main control unit determines whether the cable is conductive by judging the level.

9. The cable testing system according to claim 1, characterized in that: The insulation test unit includes fourth to seventh resistors, a third relay, a fourth relay, and a second operational amplifier.

10. The cable testing system according to claim 9, characterized in that: One end of the fourth resistor is connected to the power supply unit, the other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the input end of the second operational amplifier; the other end of the fifth resistor is also connected to one end of the sixth resistor, and the other end of the sixth resistor is grounded; the third relay is connected to one end of the fifth resistor; the fourth relay is connected to the input end of the second operational amplifier, the fourth relay is also connected to one end of the seventh resistor, and the other end of the seventh resistor is grounded; the output end of the second operational amplifier is connected to the A / D chip, and the A / D chip is connected to the main control unit.

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