1. The utility model provides a cable fault is harmless positioner fast based on chaos is synchronous which characterized in that: the method comprises the following steps:

the microwave chaotic signal source circuit is used for outputting a broadband chaotic time domain test signal;

the power divider is used for dividing the broadband chaotic time domain test signal into a chaotic reference signal and a chaotic test signal, wherein the chaotic reference signal is input into the fast correlation measurement unit, and the chaotic test signal is input into the power amplifier;

the power amplifier is used for amplifying the chaotic test signal;

the connector is used for inputting the amplified chaotic test signal into a cable to be tested and transmitting a chaotic echo signal reflected from a fault position on the cable to be tested to the low-noise amplifier;

the low-noise amplifier is used for amplifying the chaotic echo signal and inputting the chaotic echo signal into the chaotic synchronization circuit;

the chaotic synchronization circuit is used for filtering the amplified chaotic echo signal and inputting the filtered chaotic echo signal into the fast correlation measurement unit;

the data processing and control unit is used for calculating the distance from the cable fault point to the cable test end and positioning the fault point in the cable;

the microwave chaotic signal source circuit is sequentially connected with the power distributor, the power amplifier and the connector, the connector is also connected with the low-noise amplifier, the low-noise amplifier is connected with the fast related measuring unit through the chaotic synchronization circuit, and the fast related measuring unit is also respectively connected with the power distributor and the data processing and controlling unit.

2. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 1, characterized in that: the microwave chaotic signal source circuit adopts an improved microwave Colpitts chaotic circuit, and generates an amplitude chaotic signal based on the nonlinear characteristic of a triode in the improved microwave Colpitts chaotic circuit.

3. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 1, characterized in that: the connector is a T-shaped connector and comprises a first port, a second port and a third port, wherein the first port is used for receiving the amplified chaotic test signal, the second port is used for transmitting the amplified chaotic test signal to a cable to be tested, and the third port is used for transmitting the chaotic echo signal of a fault position on the cable to be tested to a low-noise amplifier.

4. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 1, characterized in that: the fast correlation measurement unit is used for obtaining the delay time of the filtered chaotic echo signal relative to the chaotic reference signal, and comprises a first input channel, a second input channel, a variable electric delay line, a combiner, a rectifier and an integrator module;

the first input channel is used for receiving the chaotic reference signal, the second input channel is used for receiving the filtered chaotic echo signal, the chaotic reference signal firstly passes through the variable electrical delay line to realize time delay, and the chaotic reference signal after time delay and the chaotic echo signal input from the second input channel are input into the combiner together.

5. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 4, characterized in that: and the signal output from the combiner sequentially passes through the rectifier and the integrator module, an output value is compared with a preset threshold value, and if the output value is greater than the preset threshold value, the delay time of the chaotic reference signal at the moment is the round-trip time of the chaotic echo signal from the test end of the cable to be tested to a fault point.

6. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 4, characterized in that: the variable electrical delay line comprises an ADC (analog-to-digital converter) conversion module, a storage/delay module, a DAC (digital-to-analog converter) conversion module, a clock module and a delay control circuit, and the delay method of the chaotic reference signal comprises the following steps: the ADC conversion module converts the input chaotic reference signal into a digital signal, the converted digital signal enters the storage/delay module, time delay is realized in a data storage mode, the digital signal is converted into an analog signal through the DAC conversion module, and the delay time is adjusted and controlled through the clock module and the delay control circuit.

7. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 1, characterized in that: the cable fault rapid nondestructive positioning device based on chaotic synchronization further comprises a data display unit connected with the data processing and control unit and used for displaying cable fault position information obtained by the data processing and control unit.

8. The chaotic synchronization-based cable fault rapid nondestructive positioning device according to claim 1, characterized in that: the cable fault rapid nondestructive positioning device based on chaotic synchronization further comprises a power supply unit which is used for supplying power to the microwave chaotic signal source circuit, the rapid correlation measurement unit, the data processing and control unit and the data display unit.

Background

With the continuous improvement of the industrial automation level, various large-scale complex systems and equipment, such as various low-voltage power lines, radio frequency lines, data lines and the like in nuclear power plants, intelligent buildings, aerospace vehicles, ships, warships, trains, subways and the like, form a cable network with complex connection relations and are responsible for transmitting power energy and transmitting control signals and data information. Cable networks in large complex systems operate in complex electrical environments for a long time, and faults such as short circuit, disconnection, insulation abrasion, poor contact between cables and connectors and the like are easily caused by factors such as humidity, corrosion, high and low temperatures, vibration friction, external force, pollution, radiation and the like. If the line fault is not repaired and maintained in time, the transmission signal is lost, the subsystem is out of order, and even major accidents and disasters are caused.

The traditional cable fault detection method is not suitable for detecting and positioning the fault of the complex cable network line in the large complex system. For example, visual inspection and various radiographic-based methods require close contact with the cable to be tested, do not reach deep inside the wire harness and the partition, and may cause secondary damage to the cable. The conventional method for testing the on-off, capacitance and resistance of the cable is used for carrying out point-to-point detection on the cable one by one, and is low in reliability and extremely high in workload.

The time domain reflectometry method is a single-end input detection method, and can transmit a high-frequency test signal to one end of a cable under the condition of not disassembling barriers such as a clapboard, a metal member and the like, detect a fault reflection signal in the cable at a signal input end, and realize nondestructive detection and positioning of a fault point according to the time difference between the reflection signal and the transmission signal.

If a proper test signal is selected, the interference with an online transmission signal in the cable can be avoided, and the online detection of the cable fault is realized. In the prior art, the high-resolution online detection of the cable fault can be realized by combining the broadband and noise-like characteristics of the chaotic signal with the time domain reflection measurement, but the following defects still exist:

1. although the orthogonality of the chaotic signal can be utilized to suppress the noise and the online transmission signal existing in the chaotic echo signal to a certain extent, the weak reflection signal can still be submerged in the noise base of a relevant curve and cannot be identified, and a plurality of complex and time-consuming subsequent processing methods are further required to realize the positioning of the weak reflection fault;

2. on-line detection requires a fast related measurement unit designed on hardware to realize real-time measurement of cable faults, and further improves the related operation speed.

There is a need in the art for a solution to the problems of the prior art.

Disclosure of Invention

The invention aims to provide a chaos synchronization-based cable fault rapid nondestructive positioning device, which solves the problems of chaos echo signal distortion and deformation and slow measurement speed caused by mixed noise interference when a chaos time domain reflectometry method is used for cable fault online detection.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a cable fault rapid nondestructive positioning device based on chaotic synchronization, which comprises:

the microwave chaotic signal source circuit is used for outputting a broadband chaotic time domain test signal;

the power divider is used for dividing the broadband chaotic time domain test signal into a chaotic reference signal and a chaotic test signal, wherein the chaotic reference signal is input into the fast correlation measurement unit, and the chaotic test signal is input into the power amplifier;

the power amplifier is used for amplifying the chaotic test signal;

the connector is used for inputting the amplified chaotic test signal into a cable to be tested and transmitting a chaotic echo signal reflected from a fault position on the cable to be tested to the low-noise amplifier;

the low-noise amplifier is used for amplifying the chaotic echo signal and inputting the chaotic echo signal into the chaotic synchronization circuit;

the chaotic synchronization circuit is used for filtering the amplified chaotic echo signal and inputting the filtered chaotic echo signal into the fast correlation measurement unit;

the data processing and control unit is used for calculating the distance from the cable fault point to the cable test end and positioning the fault point in the cable;

the microwave chaotic signal source circuit is sequentially connected with the power distributor, the power amplifier and the connector, the connector is also connected with the low-noise amplifier, the low-noise amplifier is connected with the fast related measuring unit through the chaotic synchronization circuit, and the fast related measuring unit is also respectively connected with the power distributor and the data processing and controlling unit.

Furthermore, the microwave chaotic signal source circuit adopts an improved microwave Colpitts chaotic circuit, and generates an amplitude chaotic signal based on the nonlinear characteristic of a triode in the improved microwave Colpitts chaotic circuit.

Further, the connector is a T-type connector and includes a first port, a second port and a third port, where the first port is configured to receive the amplified chaotic test signal, the second port is configured to transmit the amplified chaotic test signal to a cable to be tested, and the third port is configured to transmit a chaotic echo signal at a fault location on the cable to be tested to a low-noise amplifier.

Further, the fast correlation measurement unit is configured to obtain a delay time of the filtered chaotic echo signal relative to the chaotic reference signal, and the fast correlation measurement unit includes a first input channel, a second input channel, a variable electrical delay line, a combiner, a rectifier, and an integrator module;

the first input channel is used for receiving the chaotic reference signal, the second input channel is used for receiving the filtered chaotic echo signal, the chaotic reference signal firstly passes through the variable electrical delay line to realize time delay, and the chaotic reference signal after time delay and the chaotic echo signal input from the second input channel are input into the combiner together.

Further, the signal output from the combiner sequentially passes through the rectifier and the integrator module, an output value is compared with a preset threshold value, and if the output value is greater than the preset threshold value, the delay time of the chaotic reference signal at this time is the round-trip time of the chaotic echo signal from the test end of the cable to be tested to a fault point.

Further, the variable electrical delay line comprises an ADC conversion module, a storage/delay module, a DAC conversion module, a clock module, and a delay control circuit, and the delay method of the chaotic reference signal is as follows: the ADC conversion module converts the input chaotic reference signal into a digital signal, the converted digital signal enters the storage/delay module, time delay is realized in a data storage mode, the digital signal is converted into an analog signal through the DAC conversion module, and the delay time is adjusted and controlled through the clock module and the delay control circuit.

Furthermore, the cable fault rapid nondestructive positioning device based on chaotic synchronization further comprises a data display unit connected with the data processing and control unit and used for displaying the cable fault position information obtained by the data processing and control unit.

Furthermore, the cable fault rapid nondestructive positioning device based on chaotic synchronization further comprises a power supply unit for supplying power to the microwave chaotic signal source circuit, the rapid correlation measurement unit, the data processing and control unit and the data display unit.

The invention discloses the following technical effects:

1. the microwave chaotic signal circuit is used as a test signal source, and high-resolution online detection of cable faults can be realized based on the broadband characteristic and the orthogonal characteristic of the chaotic signal;

2. the chaotic synchronization processing is carried out on the chaotic echo signal, so that the noise in the received echo chaotic signal can be suppressed, the correlation between the chaotic echo signal and a chaotic reference signal is greatly improved, the workload complexity of back-end data processing is reduced, the data processing speed is improved, and the overall performance is improved;

3. by adopting the specially designed quick related measurement unit, the delay time measurement speed of the chaotic echo signal is improved, and the cable fault can be positioned in real time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a block diagram of the structure of the cable fault location device of the present invention;

FIG. 2 is a schematic circuit diagram of an improved Colpitts chaotic signal source in an embodiment of the invention;

FIG. 3 is a diagram of waveforms, power spectra and autocorrelation function of a Colpitts chaotic signal in an embodiment of the present invention;

FIG. 4 is a schematic diagram of a chaotic synchronization circuit in an embodiment of the present invention;

fig. 5 is a structural diagram of a fast correlation measurement unit in an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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 order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Fig. 1 is a block diagram of a cable fault location device according to the present invention, the internal structure of the device includes: the device comprises a microwave chaotic signal source circuit, a power divider, a power amplifier, a T-shaped connector, a low-noise amplifier, a chaotic synchronization circuit, a quick correlation measurement unit, a signal processing and control unit, a result display unit and a power supply unit.

The microwave chaotic signal source circuit emits broadband chaotic signals and is divided into two paths of signals through a power divider: one path is used as a reference signal and is directly input into a first input channel of the fast correlation measurement unit; the other path of the test signal is used as a test signal, is amplified by a power amplifier and then is input into a T-shaped connector, and is input into a cable to be tested through an output port of the T-shaped connector;

the chaotic test signal transmitted by the T-shaped connector is transmitted in the cable to be tested, and after a fault point is met, part of signal energy is reflected due to impedance mismatching at the fault position. The T-shaped connector controls the transmission direction of the chaotic echo signal, so that the echo reflection chaotic signal is transmitted to the low-noise amplifier through the other port of the T-shaped connector;

the low-noise amplifier accesses the amplified echo signal into the chaotic synchronization circuit. The chaotic synchronization circuit has the capability of filtering noise in chaotic signals, and chaotic echo signals containing noise can be filtered to a great extent after being processed by the chaotic synchronization circuit, so that effective chaotic test signals are extracted. And the output signal of the chaotic synchronization circuit is accessed to a second input channel of the fast correlation measurement unit.

The fast correlation measurement unit carries out correlation processing on the input reference signal and the echo signal, determines the delay time delta t of the echo signal relative to the reference signal, and the output of the fast correlation measurement unit is accessed to the signal processing and control unit;

and the signal processing and control unit determines the transmission speed v of the electromagnetic waves in the cable according to the type of the test cable, measures the distance from a fault point to a test end according to the R ═ v · Delta t/2, realizes cable fault positioning, and inputs the result to the result display unit.

The power supply unit is used for supplying power to the microwave chaotic signal source, the chaotic synchronization circuit, the two-channel fast correlation measurement unit, the data processing and control unit, the data display unit and the like.

Fig. 2 shows an implementation of the microwave chaotic signal source circuit selected in this embodiment, in which an improved microwave Colpitts chaotic circuit is used and the nonlinear characteristic of a triode is used to generate amplitude chaos. Inductor L₀And a capacitor C₀Forming an oscillating circuit, the generated oscillating signal passing through a coupling capacitor C₃And a triode Q₂The emitter follower composed of equal elements is connected with each other via a capacitor C₄And (6) outputting. In circuit Q₁And Q₂A BFG520XR type triode with the cut-off frequency of 9GHz, a resistor R, an inductor L and a capacitor C are adopted₁And C₂The value of (A) determines the fundamental frequency of the output chaotic signal, and the voltage source V₁And V₂Determines the operating state of the circuit. Fig. 3 shows the waveform, power spectrum and autocorrelation characteristics of the chaotic signal generated when the fundamental frequency is 1.5 GHz.

The power divider adopts a power divider with single-path input and double-path output, and a plurality of selectable products are available on the market. The working frequency range of the power divider needs to be larger than the bandwidth of the chaotic signal circuit. The operating frequency range of the amplifier also needs to match the bandwidth of the chaotic signal.

The implementation manner of the chaotic synchronization circuit is still an improved Colpitts chaotic circuit with the same parameters as the microwave chaotic signal source circuit, as shown in fig. 4. Signal from V_inIs connected in via a capacitor C_cCoupled to chaotic circuit, and synchronized to slave V_outAnd (6) outputting. The output synchronous chaotic signal is accessed into a fast correlation measurement unit.

A specific implementation of the fast correlation measurement unit is shown in fig. 5. The reference signal input from the first input port of the associated measurement unit is first subjected to a time delay through the variable electrical delay line structure. The time-delayed reference signal is input to the combiner together with the echo signal input from the second input port. Here the delay time of the reference signal can be adjusted as desired.

The variable electrical delay line structure is shown in fig. 5 as a dashed box. Firstly, an ADC conversion module converts an input analog reference signal into a digital signal, the converted digital signal enters a storage/delay module, time delay is realized through a data storage mode, and the digital signal is converted into an analog signal through an analog-digital conversion module. The delay time is adjusted and controlled by a clock module and a delay control circuit.

And the signal output from the combiner sequentially passes through the rectifier and the integrator module, the output value is compared with a preset threshold value, and if the output value is greater than the preset threshold value, the delay time of the reference signal at the moment is the round-trip time of the echo signal from the test end to the fault point.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.