WO2013076326A2

WO2013076326A2 - Device having an automatic gps-controlled lateral movement for controlling weeds in row crops

Info

Publication number: WO2013076326A2
Application number: PCT/ES2012/000289
Authority: WO
Inventors: Manuel PÉREZ RUIZ; Jacob CARBALLIDO DEL REY
Original assignee: Universidad De Sevilla
Priority date: 2011-11-24
Filing date: 2012-11-23
Publication date: 2013-05-30
Also published as: ES2423106B1; WO2013076326A3; ES2423106A1

Abstract

The present invention relates to a sustainable strategy for controlling weeds using an device having an automatic GPS-RTK-controlled lateral movement, with centimetre-level precision. This level of precision allows weeds to be removed mechanically from areas close to the crop and thus reduce the use of chemicals on row crops (cotton, beet, tomato, etc.). The invention falls within the fields of precision farming and natural-resources engineering.

Description

GPS-controlled automatic lateral displacement device for weed control in online crops

Object of the invention

This device allows to combine, in weed control, mechanical weeding (between crop line) and chemical weeding (in crop line) using the information received by an RTK-GPS equipment installed in the same implement. The device will move laterally through a hydraulic cylinder in real time allowing the approximation of mechanical weeding elements 5 cm from the crop or seed line and significantly reducing the chemical application. This localized operation can mean a maximum saving of 50% compared to the herbicide applications currently being made. To tow the device during application, a tractor or any other self-propelled vehicle suitable for floors not prepared for transit can be used.

State of the art

In the last decade, important advances have been made in computer instrumentation and sensors that have allowed the start of automation and incorporation of new technologies in many agricultural operations (Bak and Jocobsen, 2004; Griepentrog et al., 2004; Kise et al ., 2005). The use of these new technologies is fundamentally motivated by two factors: consumers and governments demand a reduction in the application of agrochemicals and achieve competitiveness in many crops reducing production costs.

Weed control in agricultural production in Spain is based on the use of soil disinfectants, cultivator passes between crop lines until vegetative development permits, and herbicide treatments (at least three, often one a week ). An adequate localized management of these operations will allow producers a reduction in the use of herbicides and an optimization in the use of mechanical operations, thus achieving sustainability and reducing the presence of residues in human food. Currently, the Spanish agricultural sector uses selective and non-selective herbicides and, although for many crops there are selective herbicides, there is still a great concern in society for the application of synthetic chemicals. Gerhards and Christensen (2006) indicate that mechanized weeding practices have been reduced in recent decades, however, the use of herbicide has not eliminated weed problems in agriculture. Using some areas of the automation and robotization disciplines, a greater reduction of inputs can be achieved and even in some cases herbicide treatments can be completely eliminated (Pérez and Agüera, 2009).

Mechanized weeding in general optimally eliminates weeds that grow between crop lines, but does not eliminate the weeds that grow within the crop line during the period when competition for nutrients, water and solar radiation is critical among weeds. and cultivation (Slaughter et al., 2008). This fact leads to the need to have to eliminate weeds from the cultivation line with manual weeding (Tillet, et al., 2008), application in herbicide bands in the cultivation line (Kaya and Buzluk, 2006) or, In the worst case, applications of uniform herbicides throughout the crop (usual way of operating from producers in Spain).

The reduction of the use of phytosanitary products and fertilizers is a concern of the different administrations. Currently the regulations and directives (Directive 91/141 / EEC) on marketing and use of plant protection products are under continuous review by the European Union and its objectives are mainly: to increase safety in human health and the environment and harmonize the authorization and marketing of phytosanitary products. Thus, the European Commission Communication "Towards a thematic strategy for the sustainable use of pesticides", lays the groundwork for a more sustainable use of pesticides, while ensuring the necessary protection of crops. On the other hand, Directive 91/676 / EEC of the European Council, aims to protect community waters against nitrates of agricultural origin, which are the main cause of pollution from diffuse sources. This Directive urges the governments of the different Member States to limit the application of nitrogen fertilizers. In this sense, current precision agriculture techniques allow the use of a set of tools with the double objective of achieving, on the one hand, a more precise knowledge of the conditions in which the crop is developed, thus allowing the taking of decisions with a better criterion, and on the other hand, the execution of said decisions. The achievement of these two objectives has as direct consequences a sustainable management of the system, more respectful with the environment, and a better economy, through the optimization of the different tasks (Berry et al., 2003; Kitchen et al., 2005).

There is currently a wide variety of devices on the market that allow precision farming techniques and procedures to be put into practice, however its dissemination among our farmers and service companies is not yet at the level of other European countries such as Germany, France, United Kingdom or Denmark. On the other hand, the adoption of these techniques requires previous tests and adaptations to our forms of work, machinery and crops that make their adoption even more difficult, also taking into account their still high cost.

Lee et al. (1999) designed a weed control team based on selective application through very precise vision systems. With the vision system, we can differentiate between weeds and growing areas, eliminating only weeds. The team manages to take an image every 0.34 seconds, which it subsequently processed representing a region of a cultivation line of 11, 43 cm x 10.16 cm, thus allowing to reach a working speed of 1.20 km / h. Image processing algorithms were correctly identified in real time in terms of 73.1% in tomatoes and 68.8% of weeds respectively.

Norremark et al (2003) developed a team for the generation of a crop location map, derived from geo-referenced data recorded during the planting operation. For this, the sugar beet culture was chosen, using a precision sowing machine, adapted with optical sensors to detect the dispersion of the seeds in the furrow. In addition, they used a system (RTK-GPS) and a double indication axis tilt sensor: global position and magnitude of seeder angles. For all this they worked with a data acquisition system that was configured for the recording and storage of global planting positions and the actual position of these seeds when sown. The validation showed that 95% of the sugar beet in sown plants appeared in the positions of the elaborated geo-spatial map. In general, the overall accuracy of the estimate in terms of geo-referencing of the plants was satisfactory.

Sun et al (2010) studied the feasibility of using the RTK-GPS for the generation of position maps of tomato plants, at the time of transplantation. For this, a planter machine was used with a RTK-GPS receiver, and a real-time controller on board the machine. The errors obtained in the generation of the crop map were 0.8 to 2.1cm in the North direction and 1, 6 to 3.8 cm in the East direction. The results suggest the positive viability of creating a plant location map using an RTK-GPS planting equipment. This map can be used as a prescription map for weed control.

Currently there are several patents that present methodologies and / or procedures based on the use of real-time positioning systems applied to the agricultural sector (US 2003187560 and WO 9837977) and remote sensing (P200503103). There are also some patents for weed removal equipment in an optimized manner, but in no case achieve the accuracy and cost reduction of the present invention, which by way of example we can mention patents U200602565, P0509571 and E99119492.

In this list of devices that we have found in the literature, the following drawbacks can be noted:

1 .- Those who carry vision devices for the application need more time for image processing, so the speed of work achieved is not very high. In addition, the success of vision devices to recognize weeds is affected by uncontrolled environmental factors (natural light, wind, etc.), image acquisition (moving or stationary) and the level of statistical validation.

2. - Obtaining a location map of each of the plants or crop seed to be used in the control of weeds, has the disadvantage of generating the map in an operation prior to the application of weed removal (not in real time). Although, this way of working is a management Very precise localization and allows producers to completely eliminate herbicides, it is not a competitive option currently in agriculture.

Based on the previous approaches, we consider that it is necessary to develop a combined lateral displacement equipment for the control of weeds in crops in line with an assumable cost that allows to respond to the points indicated above, reducing the cost and achieving the required competitiveness in this agricultural operation.

Description of the figures

To complete and complement the description of the present invention and to make its characteristics more understandable, a series of figures are attached which, with illustrative and non-limiting character, represent the following:

- Figure 1 is a front perspective view of the lateral displacer in the foreground and the rest of the equipment, with the extension frames open, with the pressure elements and the application modules necessary to perform a 6-line field work of cultivation

- Figure 2, is a rear perspective view, shows in detail the beveled blades for precision mechanical treatment together with the chemical application equipment in bands.

Description of the invention

The electrical system of the lateral displacement equipment connects the electronic devices of the positioning system (GPS equipment and inertial box) to an automatism and a printed circuit board used to produce the movement of the lateral correction hydraulic system. The lateral correction system is controlled by the GPS receiver and the inertial box of gyroscopes. From the inertial box there is a cable hose of which four have the function of operating two solenoid valves responsible for directing in one direction or another the double-acting hydraulic cylinder in charge of moving the equipment. These four cables do not go directly to the solenoid valves, but are connected to independent 12 V relays (two circuit switched relays) that are responsible for operating the solenoid valves. These relays They allow the introduction of an external control to control the lateral movement of the equipment manually.

The automatic displacement of the hydraulic cylinder in a horizontal position is limited by two rod ends at the same height.

The double acting hydraulic cylinder was mounted on a frame or supporting structure of the assembly formed by at least one rectangular section tube with the length and consistency necessary to support the number of mechanical and chemical weeding elements required. This frame has in its central part the coupling elements for its coupling to the vehicle that must drag it, also ensuring its perfect horizontality during the operation.

On said frame the different metal arms are fixed with their respective grille at the end in two different work planes. The length of the arms must be identical so that the work is done in the ground at the same depth and the separation between them the same so that the work between crop lines or seeds is precise. Also on the frame is mounted a height adjustable equipment for the distribution of agrochemicals in bands.

The thickness and width of the bars, for mechanical weeding, will be the smallest possible to ensure the mechanical strength of the element, but will be dependent on the separation between crop lines or seeds. The bars can take different geometric shapes but in any case they will have a beveled leading edge to facilitate the cutting of the ground. The bars fixed to the tool-holder arm will cut to the ground, eliminating the weeds present between the crop line, at a first level of depth so that all of its leading edge located below the ground level will be cut.

Embodiment of the invention

Figures 1 and 2 show a possible embodiment of the weed locator control device, equipped in this case with 12 beveled blades (mechanical application) and 6 spray modules (chemical application). It consists of a frame (1) formed by two horizontal parallel bars joined at their right and left ends to two clamping bars (2) and (3). The frame in its clamping bars (2) and (3), joined by hinges, has a folding right (4) and left (5) parallelepiped that allows to achieve a greater working width and greater security in the transport configuration . Attached to the frame, on the back, it carries an anchor plate that allows the frame to be attached to the displacer (6) and this in turn has another anchor plate that joins the displacer to the vehicle that will be used to drag it (position of work) or suspend it (transport position) which in turn must carry the necessary adaptation elements (7). The bevelled blades mounted on spiral arms are connected to the frame by means of an angular plate (90 °) that allows the regulation in the depth levels necessary for each type of floor.

The displacer unit is formed by a double acting hydraulic cylinder mounted on a support structure formed by a rectangular section tube with a length of 60 cm (8) and the necessary consistency. The navigation box (9) (gyros box) of the guidance equipment is placed on the displacer and at its highest part, to avoid the GPS multipath error, the GPS signal reception antenna (10) is placed. Also on the displacer is the actuators (11) (solenoid valves) that allow the movement of the hydraulic cylinder to the left and right (12).

On the two horizontal bars of the frame there is a tank (14), in this case 500 liters, with the necessary regulation and distribution elements to achieve a selective pressure and distribution of the agrochemical product (15). The 12 beveled blades (16) attached to the frame are 35 cm apart from each other, centering 2 in each between crop lines. The 6 spray modules are separated 50 cm (17) and each of them consists of a spray nozzle with an opening angle of 80 ° providing 0.8 l / min in each crop line.

Claims

1. - GPS-controlled lateral displacement device, attachable to self-propelled vehicles, with weed control capability in line crops, characterized in that it comprises

a) a positioning system that allows an adjustment of mechanical and chemical weeding elements.

b) a combined weed removal system that allows a mechanical treatment between lines and a chemical treatment on the crop line to be carried out separately.

2. - Device of lateral displacement controlled by GPS for the control of weeds in crops in lines, according to claim 1, characterized in that the adjustment of the positioning system is 3 cm, preferably.

3. - Device of lateral displacement controlled by GPS for the control of weeds in crops in lines, according to claim 1, characterized in that the mechanical treatment is carried out with a working depth of 2-3 cm and the chemical treatment with a wet surface 10 cm, preferably.