Autopilots have become mandatory for those who want profitability

Precision agriculture is an administration method, with the aim of optimizing costs, improving management practices and increasing crop productivity, based on different soil and crop conditions. Increasing crop productivity levels increasingly requires increased precision in sowing, cultural treatments and harvesting operations, a factor that has been favored by the use of guidance technologies, which help the operator to reduce errors during operations.

In Brazil, several techniques are used to control machine traffic in crops. Visual systems such as bars installed on the front of the tractor with ropes simulate the width of the implement or flag systems assist the farmer in driving the machine. The first systems that use embedded technology emerged as the light bar, a simple mechanism, where the operator marks a trajectory and the system, through light visual indicators, informs the operator of the route. What these techniques have in common is that traffic control is manual, that is, the quality of the work depends directly on the operator's attention, concentration and experience.

With the modernization and increase of the agricultural fleet, especially properties with large areas of area, manual techniques become obsolete and impractical, giving way to more modern systems such as autopilot. The use of automatic guidance based on satellite positioning systems can be embedded in agricultural machines such as tractors, harvesters, distributors and self-propelled sprayers and allows the machine to be automatically guided with precision and accuracy, with traffic lines with perfect parallelism, i.e. , without failures or overlapping in the crop.

There are two types of autopilot systems that are currently used in agriculture, which basically differ in the way they operate. They are the hydraulic pilot and the electric pilot. The electric pilot consists of electric motors that act on the steering wheel, allowing automatic steering of the machine according to the need to change displacement. The system basically consists of a receiving antenna, monitor, navigation module and electric motor. The hydraulic pilot acts directly on the machine's hydraulic system. This integration can be through a hydraulic valve coupled to the steering system or through an interface that communicates directly with the machine. The hydraulic pilot consists of a monitor, navigation module and angle and positioning sensors, hydraulic valve to drive the steering system.

For this correction to occur in the positioning of the machines, different levels of receiver precision and signal correction modes are available.

SUBMETRIC SIGNAL

A submetric signal is an open signal that is corrected by internal correction algorithms that provide accuracy greater than one meter between passes, and can be used in agricultural operations that have overlapping passes, such as soil preparation, spraying and distribution of inputs by broadcast. Regardless of the manufacturer, the internal correction algorithms behave similarly in all receivers, that is, they maintain accuracy from pass to pass, gradually losing this accuracy as time passes. The internal algorithms have no cost for their use and are available together with the purchase of the system.

Some manufacturers provide a differential submetric signal that uses satellite correction and guarantees accuracy of less than one meter between passes in operations such as soil preparation, spraying and distribution of inputs by broadcast. This correction system in some cases has an annual cost for its release.

DECIMETRIC SIGN

The decimeter signal, commonly known as paid signal, guarantees accuracy of around 10cm between passes, meeting the demand for precision for agricultural operations, such as soil preparation, spraying and planting. To use this correction there is an annual cost of subscribing to the signal.

CENTIMETRIC SIGN

Also known as RTK signal or real-time correction, it is the type of correction with the highest precision on the market, around 2,5cm between passes, and the only one that truly guarantees repeatability, that is, the vehicle's ability to travel in the same direction. same line, even after a long period. It is suitable for all operations, mainly planting in rows and creating rammed earth in rice cultivation. It is done using a station or reference base located at a georeferenced point transmitting correction signal via radio. This base can be fixed, normally mounted on a fixed metal structure, and has a greater range (a radius of approximately 20km), and the mobile base where it is mounted on a tripod and has a shorter range (approximately 3km to 4km radius) can be moved within the property.

There is also the possibility of purchasing different technology packages, such as tools that ensure that the machine continues working for a period of time, even after the loss of the transmitted signal, due to an obstacle or unfavorable weather condition for signal reception. .

Among the main advantages of using these systems are the reduction of machine downtime and greater compliance with the cultivation window, making it possible to work with the machines in periods when it would not be possible for the operator to direct the machine due to low visibility, such as example, at night. There is also a reduction in production costs, by avoiding overlapping in the application of products; reduction in fuel consumption, as well as necessary inputs such as fertilizers and pesticides. Furthermore, by avoiding overlapping passes, we increase the use of the total cultivation area and also avoid the occurrence of soil compaction, a factor that is unfavorable to the root development of crops.

The autopilot applies to all stages of crop production, from soil preparation to harvest. Added to the set of precision agriculture technologies, the automatic pilot contributes to ensuring that physical and chemical soil correction activities are carried out accurately, ensuring that input distribution maps are executed respecting soil variability, increasing the efficiency of time and use of inputs.

When applying phytosanitary products, the pilot contributes to greater efficiency of the applied product. By avoiding overlapping passes, it reduces syrup waste, as well as the occurrence of phytotoxicity due to excessive application. Furthermore, it allows application at alternative times, in which greater efficiency of the applied product can be achieved due to weather conditions such as temperature, wind and humidity being more suitable. It is estimated that there will be a cost reduction of approximately 15% with agricultural inputs, due to the adoption of technology resulting in a reduction in errors during operation.

During harvesting, there is also the possibility of applying the pilot, enabling the reduction of losses due to crushing of plants and also harvesting with precision in the platform passes, which increases efficiency with the total use of the platform.

With agriculture increasingly advancing in technology, the use of autopilot can no longer be considered just a technology to facilitate the operator's work. As mentioned previously, it considerably reduces spacing errors and overlaps in various applications, yet allows traffic control of agricultural machinery and better use of the area, which considerably improves the yield and management of field operations.

Gustavo dos Santos, Dauto Carpes, Juan Paulo Barbieri, Base Assessoria Agronomica

Read more in the October issue of Cultivar Máquinas.