CN102435914B - Portable aircraft wire comprehensive performance tester - Google Patents

Abstract

A portable aircraft wire comprehensive performance tester, including: electrical parameter measurement circuit, high-speed A/D acquisition circuit, pulse transmission circuit, overvoltage protection circuit, interface conversion circuit, impedance matching circuit, DSP control unit, power supply, man-machine Interactive interface; wherein: the pulse emission circuit, impedance matching circuit, interface conversion circuit, measured wire, overvoltage protection circuit and high-speed A/D acquisition circuit are sequentially connected in series, and the output of the high-speed A/D acquisition circuit The terminal is connected to the DSP control unit, the pulse emission circuit is also connected to the DSP control unit, the measured wire is also connected to the high-speed A/D acquisition circuit through the electrical parameter measurement circuit, and the described power supply and the man-machine interface are respectively connected to the DSP control unit. The invention can measure parameters such as AC and DC voltage, current, resistance, capacitance and the like of the wire to be tested, and can also diagnose the fault of the aircraft wire and determine the fault location.

Description

Portable aircraft wire comprehensive performance tester

technical field

The invention relates to an aircraft conductor comprehensive performance tester. In particular, it relates to a portable aircraft wire comprehensive performance tester which can diagnose aircraft wire faults and determine fault locations.

Background technique

Aircraft wire failure is one of the common faults in the aircraft electrical system, which will lead to instability of indicating instruments, malfunction of control machinery, abnormal signals, short circuit of wires and fires, etc., which are directly related to aircraft safety. In order to shorten the troubleshooting time of the aircraft and save maintenance costs, a comprehensive performance tester for aircraft wires is needed to comprehensively test the performance of the aircraft wires, correctly diagnose the faults of the aircraft wires, and accurately determine the location of the faults of the aircraft wires. At present, although there are aircraft wire fault locators, they have the disadvantages of large size, large power consumption, need for external power supply, and low intelligence, which are not suitable for widespread use in the aircraft maintenance industry. Therefore, a portable Aircraft wire comprehensive performance tester.

Contents of the invention

The technical problem to be solved by the present invention is to provide a portable aircraft conductor comprehensive performance tester that can measure parameters such as AC and DC voltage, current, resistance, capacitance, etc. of the conductor to be tested, and can also diagnose the fault of the conductor of the aircraft and determine the location of the fault.

The technical solution adopted in the present invention is: a portable aircraft wire comprehensive performance tester, including: electrical parameter measurement circuit, high-speed A/D acquisition circuit, pulse transmission circuit, overvoltage protection circuit, interface conversion circuit, impedance matching circuit, DSP control unit, power supply, human-computer interaction interface; wherein: the pulse emission circuit, impedance matching circuit, interface conversion circuit, tested wire, overvoltage protection circuit and high-speed A/D acquisition circuit are sequentially connected in series, and the The output end of the high-speed A/D acquisition circuit is connected with the DSP control unit, and the pulse emission circuit is also connected with the DSP control unit, and the described measured wire is also connected with the high-speed A/D acquisition circuit through the electrical parameter measurement circuit, and the described The power supply and the man-machine interface are respectively connected to the DSP control unit.

The DSP control unit includes a DSP controller and a FLASH memory chip and an ARM memory chip connected to the DSP controller respectively, and the high-speed A/D acquisition circuit, the pulse emission circuit, the power supply and the man-machine interface are respectively connected DSP controller in DSP control unit.

The interface conversion circuit includes: a 4N26 photocoupler connected in series, an adjustable resistor, a 74HC14 chip and a 555 time base circuit, wherein the input end of the 4N26 photocoupler is connected to an impedance matching circuit, and the The output of the 555 time base circuit is connected to the wire under test.

The portable aircraft conductor comprehensive performance tester of the present invention can measure parameters such as AC and DC voltage, current, resistance, capacitance and the like of the conductor to be tested, and can also diagnose faults of the conductors of the aircraft and determine the location of the fault. Has the following characteristics:

1. Propose the system hardware based on DSP control core, pulse generating circuit and small-size LCD screen, etc., to provide the equipment hardware basis for the portable aircraft wire comprehensive performance tester;

2. Propose the system software modularization processing, enhance the expansion ability and portability of the system;

3. A reflection signal processing method based on the wavelet analysis method is proposed to reduce the influence of interference signals on the measurement results;

4. Using the least squares method to judge the location of the launch point and the fault point, the location of the fault point can be accurately located;

Description of drawings

Fig. 1 is the overall structure schematic diagram of portable aircraft wire comprehensive performance tester of the present invention;

Fig. 2 is the constitution block diagram of interface conversion circuit of the present invention;

Fig. 3 is a control flow chart of the portable aircraft wire comprehensive performance tester of the present invention.

in:

1: Electrical parameter measurement circuit 2: High-speed A/D acquisition circuit

3: Low voltage narrow pulse transmitting circuit 4: Overvoltage protection circuit

5: Interface conversion circuit 6: Impedance matching circuit

7: DSP control unit 8: Power supply

9: Human-computer interaction interface 10: FLASH memory chip

11: ARM memory chip 12: Tested wire

13: DSP controller

Detailed ways

The portable aircraft wire comprehensive performance tester of the present invention will be described in detail below in conjunction with the embodiments and accompanying drawings.

As shown in Figure 1, the portable aircraft lead comprehensive performance tester of the present invention comprises: electrical parameter measurement circuit 1, high-speed A/D acquisition circuit 2, low voltage narrow pulse transmission circuit 3, overvoltage protection circuit 4, interface conversion circuit 5 , impedance matching circuit 6, DSP control unit 7, power supply 8, man-machine interface 9; wherein: the low-voltage narrow pulse transmitting circuit 3, impedance matching circuit 6, interface conversion circuit 5, measured wire 12, overvoltage The protection circuit 4 and the high-speed A/D acquisition circuit 2 are sequentially connected in series, the output end of the high-speed A/D acquisition circuit 2 is connected to the DSP control unit 7, and the described low-voltage narrow pulse transmitting circuit 3 is also connected to the DSP control unit 7, The measured wire 12 is also connected to the high-speed A/D acquisition circuit 2 through the electrical parameter measurement circuit 1, and the power supply 8 and the man-machine interface 9 are respectively connected to the DSP control unit 7. Described DSP control unit 7 comprises DSP controller 13 and the FLASH memory chip 10 that is connected with DSP controller 13 respectively, ARM memory chip 11, described high-speed A/D acquisition circuit 2, low voltage narrow pulse emission circuit 3, The power supply 8 and the man-machine interface 9 are respectively connected to the DSP controller 13 in the DSP control unit 7 .

In the portable aircraft wire comprehensive performance tester of the present invention:

The electrical parameter measurement circuit 1 uses a chip of the type ICL7139 to extract the parameters of the AC and DC voltage, current, impedance, and capacitance of the measured wire 12, and then connects with the high-speed A/D acquisition circuit 2 to convert the analog signal into a digital signal. Signal;

The high-speed A/D acquisition circuit 2 adopts the chip of ADS7844 model, which is connected with the DSP controller 13 in the DSP control unit 7 and the overvoltage protection circuit 4, completes the analog/digital conversion, and collects the transmitted signal and reflected signal Send it to the DSP control unit 7 for subsequent processing.

The low-voltage narrow pulse transmitting circuit 3 adopts the chip of model MAX038, which provides the signal basis for the whole portable aircraft wire comprehensive performance tester, and is connected with the DSP controller 13 in the impedance matching circuit 6 and the DSP control unit 7 respectively, and is used to generate the cycle Narrow-edge high-speed pulse signal with adjustable amplitude and variable width;

The overvoltage protection circuit 4 is respectively connected with the high-speed A/D acquisition circuit 2 and the measured wire 12, thereby ensuring the safety performance of the system;

Interface conversion circuit 5 adopts current loop circuit, including 555 time base circuit 54, 4N26 photocoupler 51 and 74HC14 chip 53, adjustable resistor 52, as shown in Figure 2, 4N26 photocoupler 51, adjustable resistor 52, The 74HC14 chip 53 and the 555 time base circuit 54 are sequentially connected in series, wherein the input end of the 4N26 photocoupler 51 is connected to the impedance matching circuit 6, and the output of the 555 time base circuit 54 is connected to the wire 12 under test. The interface conversion circuit 5 is respectively connected with the impedance matching circuit 6 and the measured wire 12, and completes the switching between the impedance matching circuit 6 and the measured wire 12;

Impedance matching circuit 6 adopts adjustable resistors, which are respectively connected with low-voltage narrow pulse transmitting circuit 3 and interface conversion circuit 5. Using the principle of resistance-capacitance coupling, the output impedance of the system is adjusted according to the characteristic impedance of the wire 12 to be tested, so as to ensure that the signal is transmitted during transmission. without distortion;

The DSP controller 13 in the DSP control unit 7 is connected with the low-voltage narrow pulse transmitting circuit 3, the high-speed A/D acquisition circuit 2, the power supply 8, and the man-machine interface 9 respectively, and its input information control at the man-machine interface 9 Next, use the signal processing method to analyze the collected data, judge the type and location of the fault by looking for the singular point of the data, and display the waveform. In addition, the electrical parameters can also be obtained after processing;

The power supply 8 is connected with the DSP control unit 7 as the power supply of the equipment;

The human-computer interaction interface 9 is connected with the DSP controller 13 in the DSP control unit 7, and is used to display fault types, location information and electrical parameters, and realize information input to the entire system;

FLASH memory chip 10, is connected with DSP controller 13, is used for storing program and partial data information;

The RAM storage chip 11 is connected with the DSP controller 13 and is used to expand the storage space outside the DSP chip.

As shown in Figure 3, when the portable aircraft wire comprehensive performance tester of the present invention is working, at first each functional module of this tester is initialized, then the program judgment is carried out, and the judgment condition is whether it is an electrical parameter measurement, if it is an electrical parameter measurement , the A/D acquisition circuit collects the signal transmitted by the electrical parameter measurement circuit, the collected signal is then sent to the DSP control core, and performs filtering processing and corresponding mathematical operations to obtain the corresponding results of the measured electrical parameters, and finally in the small It is displayed on the LCD screen; if it is judged that it is not the measurement of electrical parameters, the DSP trigger pulse generating circuit transmits the required low-voltage narrow pulse signal, the pulse signal is transmitted to the fault point through the wire and reflected, the reflected signal is collected by the A/D acquisition circuit, and then Send it to the DSP control core for corresponding filtering and wavelet noise reduction processing to obtain an ideal reflection waveform. According to the reflection waveform, the fault type can be obtained, and the reflection waveform can be subjected to least square method and related processing to obtain the location of the fault point. , and finally display the result on the small LCD screen. Next, the program further judges whether to stop the current operation, and if so, ends the operation; if not, returns to the electrical parameter measurement and judgment unit for the next program cycle.

Claims (3)

1. portable aircraft lead general performance test, it is characterized in that, comprising: electric parameter measurement circuit (1), high-speed a/d Acquisition Circuit (2), pulse radiating circuit (3), overvoltage crowbar (4), interface conversion circuit (5), impedance matching circuit (6), DSP control module (7), power supply (8), human-computer interaction interface (9); Wherein: described pulse radiating circuit (3); impedance matching circuit (6); interface conversion circuit (5); tested lead (12); overvoltage crowbar (4) and high-speed a/d Acquisition Circuit (2) are connected in series successively; the output terminal of described high-speed a/d Acquisition Circuit (2) connects DSP control module (7); described pulse radiating circuit (3) also connects DSP control module (7); described tested lead (12) also connects high-speed a/d Acquisition Circuit (2) by electric parameter measurement circuit (1); described power supply (8) is connected DSP control module (7) respectively with human-computer interaction interface (9); described electric parameter measurement circuit (1) is that the employing model is the chip of ICL7139; combined-voltage with tested lead (12); electric current; impedance; the parameter extraction of electric capacity comes out; link to each other with high-speed a/d Acquisition Circuit (2) again, analog signal conversion is become digital signal.

2. portable aircraft lead general performance test according to claim 1, it is characterized in that, described DSP control module (7) includes dsp controller (13) and the FLASH storage chip (10) that links to each other with dsp controller (13) respectively, ARM storage chip (11), and described high-speed a/d Acquisition Circuit (2), pulse radiating circuit (3), power supply (8) and human-computer interaction interface (9) are connected the dsp controller (13) in the DSP control module (7) respectively.

3. portable aircraft lead general performance test according to claim 1, it is characterized in that, described interface conversion circuit (5) includes: Chuan Jie 4N26 photoelectrical coupler (51), adjustable resistance (52), 74HC14 chip (53) and 555 time base circuits (54) successively, wherein, the input end of described 4N26 photoelectrical coupler (51) connects impedance matching circuit (6), and the output of described 555 time base circuits (54) connects tested lead (12).

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