Unmanned aerial vehicle (UAV) inspection ultraviolet leakage system based on TOA / TDOA positioning

Abstract

The invention discloses an unmanned aerial vehicle (UAV) inspection ultraviolet leakage system based on TOA / TDOA positioning, and belongs to the field of visible light positioning. A light-emitting diode is arranged at the top end of a high-voltage transmission line tower to emit a modulated light signal, the unmanned aerial vehicle carries a visible light photoelectric detector and an ultraviolet light photoelectric detector, and the visible light photoelectric detector receives the light signal of the light-emitting diode, positions the unmanned aerial vehicle and ensures the correctness of a flight route; the ultraviolet light photoelectric detector detects the ultraviolet light intensity, and judges whether electric wires near the flight route generate corona and electric arc to form ultraviolet radiation or not due to shell damage. An expensive ultraviolet imaging device does not need to be used, manual participation is not needed in the whole inspection process, satellite positioning assistance is not needed, the system immune electromagnetic interference is avoided, the system can be used for outdoor high-voltage wire inspection work, the damage condition of the high-voltage wire is recognized in time and reported to a central control system, and the safety and stability of the power transmission process are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of optical positioning technology, and in particular to a drone inspection ultraviolet leakage system based on TOA / TDOA positioning. Background Art

[0002] When a damaged high-voltage wire discharges or generates an arc, it will release a large amount of energy to generate ultraviolet radiation, accompanied by electromagnetic interference, and there are huge safety hazards. The use of inspection drones to determine whether the wire casing is damaged is highly flexible and can effectively improve the efficiency of power transmission line inspections. Global Positioning System (GPS) positioning is greatly affected by complex electromagnetic environments, and is prone to problems such as poor signal reception quality and reduced positioning accuracy. Existing power line ultraviolet inspection systems are usually based on ultraviolet imaging systems and satellite positioning systems, and are manually controlled using cameras and image transmission systems. However, ultraviolet imaging instruments are expensive; satellite positioning systems have poor signal stability and insufficient reliability; manual control is not only costly, but also has a limited number of drones that can be operated at the same time, and there are also risks of human-induced accidents. Therefore, it is necessary to seek a lower-cost, highly reliable power system troubleshooting solution. Summary of the invention

[0003] The present invention provides a UAV inspection ultraviolet leakage system based on TOA / TDOA positioning, which is not affected by complex electromagnetic environments, can realize timely monitoring of wire damage, improve the inspection efficiency and accuracy of high-voltage transmission lines, and ensure the stability of power transmission.

[0004] The embodiment of the present invention provides a drone inspection ultraviolet leakage system based on TOA / TDOA positioning, comprising:

[0005] Light-emitting diodes are installed on top of multiple high-voltage transmission line towers;

[0006] A visible light photoelectric detector is mounted on the drone body and is used to receive visible light and calculate the arrival time or arrival time difference of the visible light according to the current signal obtained after photoelectric conversion of the visible light, so as to continuously locate the drone and obtain the flight trajectory of the drone;

[0007] The ultraviolet photoelectric detector is mounted on the drone body and is used to receive ultraviolet light. It determines whether the current intensity is greater than a preset threshold value based on the current signal after the ultraviolet light is photoelectrically converted. When the current intensity is greater than the preset threshold value, it is determined that there is strong ultraviolet radiation in the flight area, and the ultraviolet leakage position is determined according to the positioning information of the drone.

[0008] Optionally, in one embodiment of the present invention, the system comprises at least three high-voltage transmission line towers, and each tower is equipped with at least one light emitting diode.

[0009] Optionally, in one embodiment of the present invention, the system further includes:

[0010] The synchronization module is used for time synchronization between the light emitting diode and the visible light photodetector and the ultraviolet light photodetector, and between the light emitting diodes.

[0011] Optionally, in one embodiment of the present invention, the arrival time or arrival time difference of the visible light is calculated according to the current signal obtained after the photoelectric conversion of the visible light to continuously locate the drone, including:

[0012] The arrival time or arrival time difference of visible light is calculated based on the current signal obtained after the photoelectric conversion of visible light. The distance or distance difference between the UAV and the LED is calculated by multiplying the speed of light by the arrival time or arrival time difference. Then, the UAV is continuously positioned based on the equations about the LED coordinates, UAV coordinates, and distance samples.

[0013] Optionally, in one embodiment of the present invention, the arrival time or arrival time difference of the visible light is calculated according to the current signal obtained after the photoelectric conversion of the visible light to continuously locate the drone, including:

[0014] Use visible light photodetectors to receive the light signals of the light emitting diodes at the top of each high-voltage transmission line tower, calculate the transmission time of the light signal from each light emitting diode to the visible light photodetector, and calculate the transmission distance based on the transmission time and the speed of light;

[0015] If the arrival time of visible light is measured, a circle is drawn with the coordinates of the light-emitting diode at the top of each high-voltage transmission line tower as the center and the transmission distance as the radius. The intersection of multiple circles is the current position of the drone.

[0016] If the arrival time difference of visible light is measured, a hyperbola is drawn with the light-emitting diode at the top of each high-voltage transmission line tower as the focus and the distance difference sample as the real semi-axis length. The intersection of multiple hyperbolas is the current position of the drone.

[0017] In the embodiment of the present invention, the unmanned aerial vehicle inspection ultraviolet leakage system based on TOA / TDOA positioning is characterized by placing a light emitting diode on the top of the high-voltage transmission line tower to emit a modulated light signal, and the unmanned aerial vehicle is equipped with two photoelectric detectors, one of which receives the light signal of the light emitting diode and is used to locate the unmanned aerial vehicle itself to ensure the correctness of the flight route; the other is used to detect the intensity of ultraviolet light, and is used to determine whether the wires near the flight route generate corona and arc due to the damage of the shell, forming ultraviolet radiation; finally, the coordinates of the abnormal area are uploaded to the server. The present invention does not need to use expensive ultraviolet imaging devices, and does not require manual participation in the entire inspection process. It does not require satellite positioning assistance, and the system is immune to electromagnetic interference. It can be used for outdoor high-voltage power line inspection work, and timely identify the damage of high-voltage power lines and report to the central control system to ensure the safety and stability of the power transmission process.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A schematic diagram of a drone inspection system for ultraviolet leakage based on TOA / TDOA positioning according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of a drone according to an embodiment of the present invention;

[0022] Figure 3 FIG. 4 is a schematic diagram of a typical TOA positioning algorithm according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] Visible light positioning (VLP) relies on visible light waves for signal transmission. However, there is a significant difference between the frequency range of visible light (390THz-790THz) and electromagnetic interference sources. Therefore, visible light is less sensitive to electromagnetic interference during propagation. This characteristic enables visible light positioning to achieve high-precision and reliable positioning even in complex electromagnetic environments. VLP based on arrival time or arrival time difference uses the propagation time of the signal from the transmitter to the receiver to calculate the link distance, thereby estimating the receiver's position.

[0025] Specifically, Figure 1 A schematic diagram of a UAV inspection system for ultraviolet leakage based on TOA / TDOA positioning provided according to an embodiment of the present invention.

[0026] like Figure 1 As shown, the drone inspection UV leakage system based on TOA / TDOA positioning includes:

[0027] A light emitting diode (LED) with a signal modulation function is arranged at the top of multiple high-voltage transmission line towers; a visible light photodetector (PD) is mounted on the drone body and is used to receive visible light, and calculate the arrival time or arrival time difference of the visible light based on the current signal obtained after the photoelectric conversion of the visible light, so as to continuously locate the drone and obtain the flight trajectory of the drone; an ultraviolet light photodetector is mounted on the drone body and is used to receive ultraviolet light, and determine whether the current intensity is greater than a preset threshold value based on the current signal after the photoelectric conversion of the ultraviolet light. When the current intensity is greater than the preset threshold value, it is determined that there is strong ultraviolet radiation in the flight area, and the ultraviolet leakage position is determined based on the positioning information of the drone.

[0028] The visible light photodetector converts the visible light received by the LED into electric current and is also used to receive visible light communication signals.

[0029] In one embodiment of the present invention, the system further comprises: a synchronization module for performing time synchronization between the light emitting diode and the visible light photodetector and the ultraviolet light photodetector, and between the light emitting diodes.

[0030] Specifically, synchronization has been completed between the LED and the photodetector for time of arrival (TOA) positioning; or synchronization has been completed between the LEDs for time difference of arrival (TDOA) positioning.

[0031] The LED lamp beads on the top of the high-voltage transmission line tower light up, and the LED circuit at the transmitting end needs to be synchronized with the PD mounted on the receiving end drone. The local clocks of the transmitting end and the receiving end are synchronized. The optical signal emitted by the transmitting end is attached with the timestamp of the current moment. The receiving end demodulates and decodes the sending time of the optical signal, and subtracts it from the local time to obtain the signal transmission time.

[0032] like Figure 2 As shown, in an embodiment of the present invention, the drone body includes the following parts: a fuselage frame, which is generally made of lightweight materials; a power system, in which a power module supplies energy to the motor, and an electric controller controls the motor to drive the blades to rotate; a flight control system, which has built-in sensors such as gyroscopes and accelerometers to control the balance, speed, altitude, route, etc. of the drone flying in the air.

[0033] The drone is equipped with two photodetectors at the bottom. One photodetector is used to receive LED light and calculate its arrival time to locate itself. The other photodetector is used to determine whether the current intensity of ultraviolet light conversion exceeds the acceptable threshold. If it exceeds, there is strong ultraviolet radiation in the flight area, and there may be damage to the wire casing, or corona or arc discharge. The drone flies slightly higher than the high-voltage transmission line, and the fuselage remains basically horizontal during flight, so the two photodetectors also remain horizontal.

[0034] In one embodiment of the present invention, there are at least three high-voltage transmission line towers in the system, and at least one LED is installed on each high-voltage transmission line tower.

[0035] In one embodiment of the present invention, the light emitted by the high-power LED installed on the top of the high-voltage transmission line tower is modulated.

[0036] In one embodiment of the present invention, the coordinates of the LEDs on the high-voltage transmission line tower are known to the drone end.

[0037] In one embodiment of the present invention, the positioning algorithm uses the TOA / TDOA positioning algorithm of triangulation. The positioning will not be affected by whether the external environment is day or night. The external natural light is a DC component, and the LED light is an AC component, which will not interfere with the PD receiving end to collect the signal emitted by the LED on the high-voltage transmission line tower.

[0038] In one embodiment of the present invention, the arrival time or arrival time difference of the visible light is calculated according to the current signal obtained after the photoelectric conversion of the visible light to continuously locate the drone, including:

[0039] The arrival time or arrival time difference of visible light is calculated based on the current signal obtained after the photoelectric conversion of visible light. The distance or distance difference between the UAV and the LED is calculated by multiplying the speed of light by the arrival time or arrival time difference. Then, the UAV is continuously positioned based on the equations about the LED coordinates, UAV coordinates, and distance samples.

[0040] Specifically, a visible light photodetector is used to receive the light signal of the light emitting diode at the top of each high-voltage transmission line tower, and the transmission time of the light signal emitted by each light emitting diode to reach the visible light photodetector is calculated, and the transmission distance is calculated according to the transmission time and the speed of light;

[0041] If the arrival time of visible light is measured, a circle is drawn with the coordinates of the light-emitting diode at the top of each high-voltage transmission line tower as the center and the transmission distance as the radius. The intersection of multiple circles is the current position of the drone.

[0042] If the arrival time difference of visible light is measured, a hyperbola is drawn with the light-emitting diode at the top of each high-voltage transmission line tower as the focus and the distance difference sample as the real semi-axis length. The intersection of multiple hyperbolas is the current position of the drone.

[0043] like Figure 3 As shown, a schematic diagram of the triangulation TOA positioning algorithm is provided.

[0044] In one embodiment of the present invention, the triangulation TOA positioning algorithm is as follows: the PD on the drone receives the light signal of each tower top LED respectively, and calculates the transmission time t of the light signal emitted by each LED to reach the PD respectively. TOA,i , respectively calculate the transmission distance:

[0045] d i =c·t TOA,i ,i=1,2,…,N

[0046] Among them, c is the speed of light 299792458m / s. From this, draw a circle with all the tower top LEDs as the center, corresponding to d i A circle with a radius of Figure 3 As shown. Find the intersection of the N circles, which is the estimated position of the drone.

[0047] The drone inspection UV leakage system based on TOA / TDOA positioning proposed in the embodiment of the present invention uses visible light positioning and visible light communication technology to ensure the stable flight of the drone on a specific route. That is, the expected flight trajectory of the drone is sent to the drone in real time through the visible light communication module, and the deviation of the drone from the expected trajectory at any time is evaluated through visible light positioning technology, so as to make real-time adjustments. At the same time, an ultraviolet photosensitive diode is used to monitor the ultraviolet intensity of the wire part, and the coordinates of the strong ultraviolet area are recorded, which provides a new solution for real-time detection of damage to the casing of high-voltage transmission lines.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A drone inspection UV leakage system based on TOA / TDOA positioning, characterized in that: include: Light-emitting diodes are installed on top of multiple high-voltage transmission line towers; A visible light photoelectric detector is mounted on the drone body and is used to receive visible light and calculate the arrival time or arrival time difference of the visible light according to the current signal obtained after photoelectric conversion of the visible light, so as to continuously locate the drone and obtain the flight trajectory of the drone; The ultraviolet photoelectric detector is mounted on the drone body and is used to receive ultraviolet light. It determines whether the current intensity is greater than a preset threshold value based on the current signal after the ultraviolet light is photoelectrically converted. When the current intensity is greater than the preset threshold value, it is determined that there is strong ultraviolet radiation in the flight area, and the ultraviolet leakage position is determined according to the positioning information of the drone.

2. The system according to claim 1, characterized in that The system comprises at least three high-voltage transmission line towers, and each tower is equipped with at least one light-emitting diode.

3. The system according to claim 1, characterized in that The system further comprises: The synchronization module is used for time synchronization between the light emitting diode and the visible light photodetector and the ultraviolet light photodetector, and between the light emitting diodes.

4. The system according to claim 1, characterized in that The arrival time or arrival time difference of visible light is calculated based on the current signal obtained after the photoelectric conversion of visible light to continuously locate the UAV, including: The arrival time or arrival time difference of visible light is calculated based on the current signal obtained after the photoelectric conversion of visible light. The distance or distance difference between the UAV and the LED is calculated by multiplying the speed of light by the arrival time or arrival time difference. Then, the UAV is continuously positioned based on the equations about the LED coordinates, UAV coordinates, and distance samples.

5. The system according to claim 4, characterized in that The arrival time or arrival time difference of visible light is calculated based on the current signal obtained after photoelectric conversion of visible light to continuously locate the drone: Use visible light photodetectors to receive the light signals of the light emitting diodes at the top of each high-voltage transmission line tower, calculate the transmission time of the light signal from each light emitting diode to the visible light photodetector, and calculate the transmission distance based on the transmission time and the speed of light; If the arrival time of visible light is measured, a circle is drawn with the coordinates of the light-emitting diode at the top of each high-voltage transmission line tower as the center and the transmission distance as the radius. The intersection of multiple circles is the current position of the drone. If the arrival time difference of visible light is measured, a hyperbola is drawn with the light-emitting diode at the top of each high-voltage transmission line tower as the focus and the distance difference sample as the real semi-axis length. The intersection of multiple hyperbolas is the current position of the drone.

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