RTK Technology in UAV substation inspection

In the era of "climbing pole", inspectors can only complete 3-5 tower tasks every day, and the whole line inspection may take one month. In the era of "UAV" with 5g technology, it takes only 3 hours to patrol a 60 km line, which can not only establish a three-dimensional model of the line in time, but also realize intelligent processing, automatic identification, equipment status verification, fault warning and other processes according to the preset program.
5g UAV patrol inspection is just a miniature of realizing ubiquitous power Internet of things in the power industry. 5g technology, which can run 200000 sets of data in one second, is an important communication carrier for building ubiquitous power Internet of things.
In recent years, as a new inspection tool
UAV has become flexible and low-cost
Low environmental requirements, easy to carry and transport without terrain restrictions
And so on
It is widely used in patrol inspection
With the rapid development of call network in recent years
Inspection of substation equipment with multi rotor UAV
It also effectively improves the quality of inspection work
So, how does UAV overcome strong electromagnetic interference
How about the inspection of high voltage lines and substations?
This has to mention today's protagonist -- RTK Positioning Technology
Before understanding RTK Positioning Technology
We need to understand satellite positioning technology first
Also known as GNSS Technology
By measuring the distance between a known satellite and a user's receiver, the technology synthesizes the data of multiple satellites and calculates the specific position of the receiver. Because of the need to calculate the three-dimensional position and deviation, at least four satellites are needed.
The advantages of GNSS technology are: short observation time, three-dimensional coordinates, easy operation, all-weather work, multiple functions and low cost.
At present, the mainstream GNSS systems include Beidou satellite navigation system (China), GPS (America), GLonASS (Russia), Galileo (Europe), etc.
But GNSS technology also has its disadvantages
It may produce positioning error for various reasons
For example, the clock on satellite and the clock on receiver can't keep synchronization all the time, which will cause time deviation signal; if it is reflected by atmosphere and various obstacles in the process of propagation, the signal propagation path may be longer, resulting in ranging error, etc.
This kind of positioning error can reach meter level, or even more than 10 meters. Such errors make GNSS system unable to meet the requirements of industries and scenarios with high positioning accuracy.
However, according to the characteristics of GNSS positioning technology, smart scientists have developed RTK Positioning Technology.
What is RTK Positioning Technology?
RTK is the abbreviation of real-time kinematic, that is, real-time dynamic, also known as carrier phase difference technology. RTK is a technology that can improve the positioning accuracy of GNSS system. It can reduce the positioning error of GNSS system to centimeter level.
RTK Positioning Technology is applied to UAV, which makes UAV have high precision positioning and anti-magnetic interference ability.
When the UAV enters the flight area with strong interference such as substation, even if the UAV uses RTK Positioning Technology, the strong magnetic field will still interfere with the electronic compass of the UAV, making it unable to accurately determine the course, causing the hovering position to shift, increasing the flight risk.
In view of this situation, the dual antenna direction finding technology is applied to the UAV RTK Positioning Technology.
The original UAV RTK Positioning Technology only has one antenna, which can only obtain the precise position relationship between the mobile station and the reference station, and can not provide accurate mobile station heading information.
The dual antenna direction finding technology adds another antenna on the basis of one antenna in the mobile station. After the mobile station receives and solves the two signals respectively, it uses the data of one receiving antenna as the reference to send the solution correction information to the other receiving antenna to complete the relative precise positioning of antenna 2 and antenna 1, so as to obtain the relative vector between the two antennas.
After the data processing, the vector can provide the UAV with the heading information, so that the UAV can obtain high-precision two-dimensional information, that is, the position and heading information. The farther the relative distance between antennas is, the higher the orientation accuracy is.
UAV inspection process
Take infrared and visible light photos of UAV airborne equipment, carry out infrared survey of the whole substation and fine inspection of electrical equipment and connecting parts of high-altitude framework,
Take advantage of the unique high altitude angle advantage of UAV, carry out all-round inspection on the equipment at different positions, especially the hidden dangers hard to be found in the ground patrol inspection such as high altitude hardware cracks and missing pins, eliminate the defects in time, and ensure the safe and stable operation of the equipment.
The application of RTK Technology in substation patrol inspection has brought more powerful anti-magnetic interference ability and precise positioning ability for UAV. Even in areas with strong magnetic interference, such as substations, it can still be close to power facilities. After the electronic compass is disturbed, it can provide precise heading information, ensure positioning accuracy, reduce flight risk, improve operation efficiency, and effectively solve the problem of UAV in power transformation The reliability of station patrol inspection can make limited supplement to substation manual and robot patrol inspection.
In addition, the operator does not need to climb any more, and the UAV can be found when operating on the ground. It reduces the labor intensity of personnel, improves the intrinsic safety, and creates a new inspection mode of "manual inspection + robot inspection + UAV inspection".