CN112737662A - Unmanned aerial vehicle pipeline inspection system and multi-station relay method - Google Patents
Unmanned aerial vehicle pipeline inspection system and multi-station relay method Download PDFInfo
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- CN112737662A CN112737662A CN202011526163.5A CN202011526163A CN112737662A CN 112737662 A CN112737662 A CN 112737662A CN 202011526163 A CN202011526163 A CN 202011526163A CN 112737662 A CN112737662 A CN 112737662A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18502—Airborne stations
- H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2602—Signal structure
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0446—Resources in time domain, e.g. slots or frames
Abstract
The invention discloses an unmanned aerial vehicle pipeline inspection system and a multi-station relay method, and belongs to the technical field of pipeline inspection and unmanned aerial vehicle measurement and control. According to the invention, a distributed station arrangement mode is adopted according to the ground stations so as to realize the connection between the airplane and a plurality of ground stations; the ground station command control carries out power control and time slot resource adjustment on the airplanes through an uplink remote control frame according to the number of airplanes and track information of the current task, and further reduces self-interference of the system; and the ground control center comprehensively judges the uplink with the best link quality and awakens the corresponding ground station according to the airplane position information contained in the downlink telemetry frame, the AGC information contained in the ground station return link telemetry frame and the channel error code information. The invention has the characteristics of flexible time slot resource allocation and reliable ground station handover, is particularly suitable for long-distance routing inspection in petroleum pipeline routing inspection, has high routing inspection precision and is suitable for complex environment, and is an important improvement on the prior art.
Description
Technical Field
The invention relates to the technical field of pipeline inspection and unmanned aerial vehicle measurement and control, in particular to an unmanned aerial vehicle pipeline inspection system and a multi-station relay method.
Background
At present, with the wide development of the construction of basic facilities such as pipelines, lines and the like in China, the maintenance of the facilities is increasingly urgent. Traditional pipeline patrols line and generally adopts the manual work to patrol the line mode and realize, and the manual work is patrolled line mode work efficiency and is low, and the periodicity is long and is patrolled the line precision and low, receive external factor to influence big, is difficult to satisfy the pipeline that natural climate restricted, the landform is complicated and adverse circumstances under and patrols the line demand. For this reason, there are attempts in the prior art to apply unmanned aerial vehicles to pipeline patrols. However, the traditional unmanned aerial vehicle remote sensing technology is limited by the ground station and the airplane action distance, and the requirement of long-distance routing inspection is difficult to meet.
Disclosure of Invention
In view of the above, the invention provides an unmanned aerial vehicle pipeline inspection system and a multi-station relay method, which can meet the requirements of long inspection distance, short period, complex landform and high precision.
Based on the above purpose, the technical scheme provided by the invention is as follows:
a multi-station relay method for pipeline patrol of an unmanned aerial vehicle comprises the following steps:
(1) when the unmanned aerial vehicle executes a task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle;
(2) the command control center selects 3 ground stations with the optimal distance according to the position information of the unmanned aerial vehicle in the downlink information transmission frame, and the ground stations with the optimal distance are used as the ground stations with the optimal current distance;
(3) selecting a ground station with the best link quality according to AGC information and channel error code information contained in a ground return link telemetry frame of the current ground station with the best distance; the command control center wakes up the ground station with the best link quality through an uplink network protocol frame to complete the uplink remote control function of the ground station;
(4) when the unmanned aerial vehicle approaches another station in the current optimal distance ground stations, the command control center selects 3 new optimal distance ground stations according to the unmanned aerial vehicle position information in the downlink information transmission frame, and updates the current optimal distance ground stations to the 3 ground stations;
(5) and (4) repeating the steps (3) and (4) to finish the multi-station relay between the ground stations.
An unmanned aerial vehicle pipeline inspection system comprises a command control center, a plurality of ground stations and an unmanned aerial vehicle; when the unmanned aerial vehicle executes a task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle; the command control center realizes relay remote control on the unmanned aerial vehicle in the following way:
(1) the command control center selects 3 ground stations with the optimal distance according to the position information of the unmanned aerial vehicle in the downlink information transmission frame, and the ground stations with the optimal distance are used as the ground stations with the optimal current distance;
(2) selecting a ground station with the best link quality according to AGC information and channel error code information contained in a ground return link telemetry frame of the current ground station with the best distance; the command control center wakes up the ground station with the best link quality through an uplink network protocol frame to complete the uplink remote control function of the ground station;
(3) when the unmanned aerial vehicle approaches another station in the current optimal distance ground stations, the command control center selects 3 new optimal distance ground stations according to the unmanned aerial vehicle position information in the downlink information transmission frame, and updates the current optimal distance ground stations to the 3 ground stations;
(4) and (4) repeating the steps (2) and (3) to complete the multi-station relay between the ground stations.
Furthermore, the ground stations adopt a distributed station arrangement mode, self-interference of the system is eliminated in a geographical isolation mode, the ground control center sets the n continuous ground stations as 1 group, n is more than or equal to 2 and less than or equal to 16, and the ground stations with the distance of n times of the station distance between different groups use the same time slot to send data.
Furthermore, the link design of the system adopts a TDMA time division multiple access system, and the channel transmission adopts an OFDM modulation system.
Furthermore, the ground station dynamically refreshes the downlink time slot of each unmanned aerial vehicle through resource time slot adjustment of the uplink remote control frame, so that one ground station can simultaneously control a plurality of unmanned aerial vehicles.
As can be seen from the above description, the technical scheme of the invention has the beneficial effects that:
1. the invention can realize the connection between the ground station and the ground station, thereby achieving the function of long-distance pipeline inspection.
2. Furthermore, the system adopts a geographical isolation mode to set the ground station, so that the self-interference of the system can be physically eliminated.
3. Furthermore, the invention can dynamically refresh the downlink time slot by adjusting the resource time slot of the uplink remote control frame, and can achieve the effect of simultaneously controlling a plurality of airplanes by one station, thereby greatly reducing the design cost and shortening the research and development period.
Drawings
Fig. 1 is a schematic structural diagram of a pipeline patrol system in an embodiment of the present invention.
Fig. 2 is a schematic diagram of a time frame structure in the embodiment of the invention.
Detailed Description
In order to facilitate understanding of the technical solutions of the present patent by those skilled in the art, and to make the technical objects, technical solutions and advantages of the present patent more apparent and fully support the scope of the claims, the technical solutions of the present patent are described in detail in the following embodiments.
As shown in fig. 1, an unmanned aerial vehicle pipeline patrol system includes a command control center, a plurality of ground stations, and an unmanned aerial vehicle; when the unmanned aerial vehicle executes the task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle.
When the ground station adopts distributed station distribution, the ground control center sets continuous n (n is 16 at most) stations as 1 group, and the stations with the distance of n times of the station distance between different groups use the same time slot to transmit data. Assuming that n is 5, stations numbered 1 to 5 are group 1, stations numbered 6 to 10 are group 2, station 1 and station 6 can transmit data using the same time slot 1, station 2 and station 7 can transmit data using the same time slot 2, station 3 and station 8 can transmit data using the same time slot 3, station 4 and station 9 can transmit data using the same time slot 4, and station 5 and station 10 can transmit data using the same time slot 5. In the specific station distribution process, the MAC _ IDs of the ground stations are arranged consecutively, and the slot number transmitted by the ground station can be determined by the remainder of dividing the MAC _ ID by n.
The time frame structure of the system is shown in fig. 2, downlink time slots 1-8 are time slots occupied by 2 unmanned aerial vehicle nodes, and 4 time slots can be randomly distributed to two airplanes respectively. The uplink time slots 9-12 occupy time slots for the ground station nodes, and can simultaneously allocate time slots to 4 different ground stations. The time slots 57, 58, 59 are used for aircraft node random occupancy for broadcasting local position information for the ground control center to calculate and display the aircraft position in the overlapping airspace. The onboard terminal uses a locally generated random number t as a basis (the random number seed is the starting time of the onboard terminal) at the starting time of each time frame to select one of the time slots 57, 58 and 59 to transmit data (if t =1, the time slot 57 is selected to transmit, if t =2, the time slot 58 is selected to transmit, if t =3, the time slot 59 is selected to transmit, and if t =0, the data is not transmitted). Specifically, the time frame structure parameters are shown in the following table:
| time slot | OFDM symbol | Remarks for note | Time slot | OFDM symbol | Remarks for note |
| 1~8 | 66 | Ground station designated aircraft occupancy | 49~56 | 66 | Ground station designated aircraft occupancy |
| 9~12 | 12 | Ground station | 57 | 12 | Aircraft random occupancy |
| 13~20 | 66 | Ground station designated aircraft occupancy | 58 | 12 | Aircraft random occupancy |
| 21~24 | 12 | Ground station | 59 | 12 | Aircraft random occupancy |
| 25~32 | 66 | Ground station designated aircraft occupancy | 60 | 12 | Reserved spectrum sensing |
| 33~36 | 12 | Ground station | |||
| 37~44 | 66 | Ground station designated aircraft occupancy | |||
| 45~48 | 12 | Ground station |
The link design of the system adopts a TDMA time division multiple access system, the airplane nodes are network nodes, and at most 16 ground station nodes and 2 unmanned aerial vehicle nodes work simultaneously in the same network. Considering the influence of multipath channel, the channel transmission modulation system adopts OFDM technique.
In addition, the ground command control center can perform power control and time slot resource adjustment on the airplanes through the uplink remote control frame according to the number of airplanes of the current task and the flight path information of the airplanes, and further reduces self-interference of the system.
When a task is executed, the line-of-sight communication condition is provided between each aircraft and a plurality of ground stations, and the ground control center comprehensively judges the uplink with the best link quality and awakens the corresponding ground station according to aircraft position information contained in the aircraft downlink telemetering frame, AGC information contained in the ground station return link telemetering frame and channel error code information, so as to complete the unicast/broadcast function of the uplink remote control instruction. For downlink information transmission, the airplane adopts a broadcast mode for transmission: all the ground stations receive the information of the downlink broadcast and transmit the information to the command control center through the optical fiber or the 4G network, and the command control center distinguishes different service types according to the frame type and realizes service data sequencing and recovery according to the frame counter.
Specifically, the unmanned aerial vehicle pipeline patrol multi-station relay method comprises the following steps:
(1) when the unmanned aerial vehicle executes a task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle;
(2) the command control center selects 3 ground stations with the optimal distance according to the position information of the unmanned aerial vehicle in the downlink information transmission frame, and the ground stations with the optimal distance are used as the ground stations with the optimal current distance;
(3) selecting a ground station with the best link quality according to AGC information and channel error code information contained in a ground return link telemetry frame of the current ground station with the best distance; the command control center wakes up the ground station with the best link quality through an uplink network protocol frame to complete the uplink remote control function of the ground station;
(4) when the unmanned aerial vehicle approaches another station in the current optimal distance ground stations, the command control center selects 3 new optimal distance ground stations according to the unmanned aerial vehicle position information in the downlink information transmission frame, and updates the current optimal distance ground stations to the 3 ground stations;
(5) and (4) repeating the steps (3) and (4) to finish the multi-station relay between the ground stations.
In a word, the invention has the characteristics of flexible time slot resource allocation and reliable ground station handover, is particularly suitable for long-distance routing inspection in petroleum pipeline routing inspection, has high routing inspection precision and is suitable for complex environment, and is an important improvement on the prior art.
Claims (5)
1. The utility model provides an unmanned aerial vehicle pipeline inspection multi-station relay method which is characterized by comprising the following steps:
(1) when the unmanned aerial vehicle executes a task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle;
(2) the command control center selects 3 ground stations with the optimal distance according to the position information of the unmanned aerial vehicle in the downlink information transmission frame, and the ground stations with the optimal distance are used as the ground stations with the optimal current distance;
(3) selecting a ground station with the best link quality according to AGC information and channel error code information contained in a ground return link telemetry frame of the current ground station with the best distance; the command control center wakes up the ground station with the best link quality through an uplink network protocol frame to complete the uplink remote control function of the ground station;
(4) when the unmanned aerial vehicle approaches another station in the current optimal distance ground stations, the command control center selects 3 new optimal distance ground stations according to the unmanned aerial vehicle position information in the downlink information transmission frame, and updates the current optimal distance ground stations to the 3 ground stations;
(5) and (4) repeating the steps (3) and (4) to finish the multi-station relay between the ground stations.
2. An unmanned aerial vehicle pipeline inspection system is characterized by comprising a command control center, a plurality of ground stations and an unmanned aerial vehicle; when the unmanned aerial vehicle executes a task, downlink information is transmitted in a broadcasting mode, and at least 3 ground stations receive downlink information transmission frames of the unmanned aerial vehicle within the line-of-sight communication range of the unmanned aerial vehicle; the command control center realizes relay remote control on the unmanned aerial vehicle in the following way:
(1) the command control center selects 3 ground stations with the optimal distance according to the position information of the unmanned aerial vehicle in the downlink information transmission frame, and the ground stations with the optimal distance are used as the ground stations with the optimal current distance;
(2) selecting a ground station with the best link quality according to AGC information and channel error code information contained in a ground return link telemetry frame of the current ground station with the best distance; the command control center wakes up the ground station with the best link quality through an uplink network protocol frame to complete the uplink remote control function of the ground station;
(3) when the unmanned aerial vehicle approaches another station in the current optimal distance ground stations, the command control center selects 3 new optimal distance ground stations according to the unmanned aerial vehicle position information in the downlink information transmission frame, and updates the current optimal distance ground stations to the 3 ground stations;
(4) and (4) repeating the steps (2) and (3) to complete the multi-station relay between the ground stations.
3. The unmanned aerial vehicle pipeline patrol system of claim 2, wherein the ground stations adopt a distributed station arrangement manner, self-interference of the system is eliminated through a geographic isolation manner, the ground control center sets n continuous ground stations into 1 group, n is greater than or equal to 2 and less than or equal to 16, and the ground stations with a distance of n times of station distance between different groups use the same time slot to transmit data.
4. An unmanned aerial vehicle pipeline patrol system according to claim 2, wherein the link design of the system employs a TDMA time division multiple access scheme, and the channel transmission employs an OFDM modulation scheme.
5. The unmanned aerial vehicle pipeline patrol system of claim 2, wherein the ground station dynamically refreshes downlink timeslots of each unmanned aerial vehicle through resource timeslot adjustment of an uplink remote control frame, thereby enabling one ground station to control multiple unmanned aerial vehicles simultaneously.
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