Why do farmers need an RTK drone?

From August 11 to 14, NK "Expocentr Ukrainy" held the 32nd International Agricultural Exhibition in Kyiv. Corona virus measures undoubtedly affected the holding of theexhibition, but it is very gratifying to note thatunmanned aerial vehicles began to return to the agenda of farmers. If in 2019 drones were presented in a couple of pavilions, then, more often than not, in the form of booklets. In 2020, various companies presented quite a lot of interesting devices and sensor equipment of both domestic and foreign production. Traditionally, solutions for spectral monitoring were presented for the compilation of maps of vegetation indices of fields, as well as the treatment of crops with various chemicals and the introduction of a trichogram. Separately, the Drone.ua company presented an RTK complex based on the DJI Phantom 4 RTK drone, quite unusual for an agriculturist.

RTK complex based on the DJI Phantom 4 RTK drone

The device is not cheap and the possibility of accurate positioning has increased its price several times, if for a normal device they ask for 60-70 thousand UAH, then with RTK the price increases by 3 times. And in a set with a ground station with a D-RTK 2 base station, the price increases already by 5-6 times. It is also not worth waiting for a drastic reduction in the price of this product, such accuracy is possible only with precision optics, which are not cheap at all. In order to ensure an acceptable price for the consumer, the manufacturer introduced an innovation - the software and hardware complex of the RTK device is adjusted to the individual features of a specific optical system. It is still difficult to put such products on the conveyor - hence the cost.

Traditionally, such devices are used in mining to estimate the volume of materials, where they have already earned recognition for their high accuracy and efficiency. In land management, such devices allow you to determine the boundaries of fields with an accuracy of up to 2 cm, but the contours of the field are generally stable and the service is one-time, so it makes sense to purchase such equipment and hire a specialized company once. We will try to answer this question.

Оборудование для сельского хозяйства относительно новое и возникла дискуссия зачем оно вовсе нужно для агрария на постоянной основе? Попробуем ответить на этот вопрос.

The first point is accounting and control...

Unfortunately, questions about the honesty of employees are still relevant. Various organizational measures and technical means are being implemented to combat theft, but as they say, whoever seeks will find an opportunity. At the same time, several groups can steal at the same time, it is extremely difficult to trace them, and the management may not really control the situation.

In agriculture, there is also something that is measured by volume, starting with the harvest, which is transported by electricity. Definitely a modernharvester can do a lot, including taking into account the volume of the harvest. But everything is not so clear and simple. When creating a methodology for forecasting the amount of harvest based on maps of the distribution of vegetation indices, the authors used data from the on-board PC of a very "advanced" combine as initial data. About such people prepare that for the money paid for him, he himself brews coffee and brings the debt. Although he did not make coffee, he warmed it up properly - in addition to the standard air conditioner, there was also a special thermal mug connected to the combine's network in the cabin. It lacked specialized sensors, and we received an Excel file with a variety of data, some of which are presented in the table

Example of data series obtained from combine sensors and transferred to a spreadsheet for analysis. Below are the types of data.

Harvest data was recorded every second, dry, wet and total harvest were recorded separately. When the data began to be compared, it became clear that it was premature to speak about the precise accuracy of harvest accounting. 3% of the data had to be simply weeded out. For example, the system showed a huge yield when using less than half of the harvester, etc. There were also questions about humidity fixation, when clearly erroneous results were revealed when comparing data from different sensors (picture below).

The graph shows that most of the results are described by a linear relationship, as it should be, but there are some clearly erroneous results

That is, there is room for maneuver for crooks. Naturally, if we estimate not only the mass, but also the volume of the grain, the task of "redistribution of values" becomes more complicated. The RTK drone is capable of regularly evaluating volumes without any particular problems - a familiar task for it. In addition, other loose materials, traditionally measured by heaps in households, are usually in abundance.

The second point is the organization of work directly in the field.

The work of a mechanic is rather complicated and tiring. Engineers made serious efforts to make the mechanic's work comfortable. Yes, already in the standard configuration, modern combines have salons like those of executive-class cars with climate control, etc. The physical aspect has undoubtedly been solved and a strong man is no longer needed to control the unit, but the requirements for constant vigilance remained relevant. Thus, when working, one must strictly adhere to the technological ruts and maintain attentiveness throughout the day, which is not easy at all.

Driving systems developed for RTK systems, which are already on the Ukrainian market, can serve as an alternative. An accuracy of 2 cm is more than sufficient for observing the technological track on the field. But changes can occur on the field from year to year, new or old puddles and other obstacles will appear. This is precisely where a UAV with an RTK module is able to accurately assess the real state of the field and refine it as necessary. This will allow you to calculate optimal routes and save engine resources and fuel. The mechanic will still not be left without work, but it is possible to use not so high-class specialists, i.e. the personnel problem is partially solved.

The optical or forward-looking radar system installed on the equipment is relatively little dependent on the support of third-party organizations, as opposed to precise positioning systems. But RTK services can be provided not only by commercial structures, but also by state companies, for example, this is one of the activities of the National Center for Control and Testing of Spacecraft of Ukraine (https://spacecenter.gov.ua/sknzu). Over the past years, they managed to create a system of accurate positioning for most of Ukraine. That is, for RTK systems there is no rigid binding of the user to a specific service provider company.

Under such conditions, this small RTK drone has every chance of becoming indispensable equipment for agricultural enterprises in general and for plant growing in particular.

DJI Phantom 4 RTK drone: quite small, especially "compared" to the price of the RTK complex and the capabilities it provides.