Method for dispensing spreading material by means of an agricultural spreader

Abstract

The invention relates to a method for dispensing spreading material by means of an agricultural spreader (1), which comprises at least one spreading element (2) for generating a spread fan (F) and at least one spread-fan sensor (3) for monitoring the distribution of spreading material within the spread fan (F), wherein the spread-fan sensor (3) is at least partially heated by a heating means (6) in order to ensure dirt- and / or deposit-independent sensor operation. The invention also relates to a spreader (1) and to a spread-fan sensor (3).

Description

[0001] Method for spreading grit with an agricultural

[0002] Spreader

[0003] The present invention relates to a method for spreading grit using an agricultural spreader, which has at least one spreading element for generating a spreading fan and at least one spreading fan sensor for monitoring the grit distribution within the spreading fan. Further subjects of the invention are an agricultural spreader and a spreading fan sensor.

[0004] In agriculture, various types of spreading materials are often spread on cultivated areas, such as fields or pastures. These can be granular, granular, or powdered materials, particularly fertilizer or lime, which are spread on the cultivated areas to influence plant growth.

[0005] Spreading material is typically achieved using spreaders that allow for an even and widespread distribution of the material. These spreaders typically have two spreading elements, often designed like rotating discs. The material to be spread is usually directed onto the rotating spreading elements, which are then distributed evenly using centrifugal forces. Typically, a rearward-facing spreading fan is formed on each spreading element, through which the material is applied to the working area.

[0006] To distribute the spreading material across the entire area, the spreaders are generally moved across the area along parallel paths spaced apart from one another according to the width of the resulting spreading fan. These spreaders can be either attached to or mounted on agricultural tractors or, alternatively, can be self-propelled. The local distribution of the spreading material within the spreading fan, particularly the so-called transverse distribution of the spreading material perpendicular to the direction of travel of the spreader, depends on numerous influencing factors, such as wind influences, the homogeneity of the spreading material, the wear and tear of the spreading elements, the possible slope of the area, or the acceleration and braking of the tractor.

[0007] To avoid unevenness in the distribution of the spreading material, modern spreaders usually have several spreading fan sensors with which the distribution of the spreading material and in particular the transverse distribution in the spreading fans can be monitored.

[0008] EP 2 777 376 B1, for example, discloses a spreader on which several contactless spreading fan sensors based on radar technology are arranged. Each individual spreading fan sensor monitors a sector-like section of the entire spreading fan. If faults and / or deviations in the spreading material distribution are detected, parameters of the spreader can be changed via a control unit in order to improve the spreading material distribution in the spreading fan overall by changing the spreading material distribution in the sector-like sections. These parameters can be, for example, the rotation speed or rpm of the spreading elements or the feed, in particular the drop point, of the spreading material onto the spreading elements.

[0009] Such spreaders with spreading fan sensors enable a more even distribution of the spreading material over the field and have generally proven themselves in agricultural practice. However, when such spreaders are used in the field under unfavorable spreading conditions, the problem arises that the sensor surfaces of the spreading fan sensors become dirty and thus produce incorrect measured values ​​for the spreading material or lateral distribution, or even become completely unusable. A major source of contamination is often the spreading material itself, in addition to particles stirred up by the field or present in the ambient air, whose components and dust can settle on the spreading fan sensors. Contamination from precipitation or dew on the sensor surfaces can also interfere with the reliable recording of the spreading material distribution. The sensor surfaces of the spreading fan sensors must therefore be cleaned regularly during field use.To clean the sensor surfaces, DE 10 2014 106 777 A1 proposes a cleaning unit arranged on the spreader, which has a brush, a wiper or a nozzle for removing the deposits.

[0010] Such spreaders with cleaning units for the spreading fan sensors have also generally proven to be effective. However, under unfavorable spreading conditions, the cleaning units themselves can become contaminated, which can limit their functionality. For example, heavy deposits of dirt can block the complex mechanical components of the wiper or brush, as well as clog the nozzle, which can only be removed by laborious manual cleaning.

[0011] Furthermore, under very unfavorable spreading conditions, soiling can become so heavy that the cleaning units can no longer remove it reliably.

[0012] Against this background, the invention sets itself the task of specifying a method for spreading spreading material in which the spreading material distribution can be reliably detected without the need for complex cleaning of the sensor surfaces of the spreading fan sensors or the cleaning units.

[0013] This object is achieved in a method of the type mentioned above by the features of claim 1. Advantageous further developments are specified in the dependent subclaims.

[0014] The spread fan sensor is at least partially heated with a heating medium to ensure sensor operation independent of contamination and / or deposits. This allows the spread fan sensor, which may be wet with water due to precipitation or dew, to be dried through the evaporation of the water deposits. Less dirt or other deposits can adhere to a dry spread fan sensor. Furthermore, the dirt or deposits can be dried. Dry dirt or deposits impede spread fan detection less than moist dirt or deposits. Heating and the resulting drying of the spread fan sensor ensures that the spreading material distribution is reliably detected. The operational readiness of the spread fan sensor can thus be increased without it having to be cleaned at regular intervals.

[0015] With regard to the design of the heating means, it is proposed that the spreading fan sensor is heated with the heating means for a heating period at a heating temperature during the spreading material application in order to dry a sensor surface. By heating the spreading fan sensor for a heating period at a heating temperature, any contamination caused by moisture that has occurred on the spreading fan sensor, in particular on its sensor surface, can be dried during the spreading material application. Such contamination caused by moisture or wetness can result, for example, from the formation of dew, precipitation or swirling water droplets. The sensor surface of the spreading fan sensor can be kept free in an advantageous manner by heating it during the spreading material application. Furthermore, drying the sensor surface can prove advantageous with regard to spreading fan sensors that work with radar technology, since radar radiation orRadar waves can be absorbed by moisture. Heating a radar-emitting fan-shaped sensor to dry the sensor surface can increase its operational readiness and functionality.

[0016] In this context, it is further proposed that the spreading fan sensor be heated with the heating medium for a preheating period at a preheating temperature before operation of the spreader in order to dry the sensor surface. This ensures that the spreading fan sensor is ready for use at the start of spreading material application. In particular, moisture or wetness resulting, for example, from precipitation or dew formation outside of spreading operation can be advantageously dried before spreading operation or spreading material application. Preheating the spreading fan sensor for a preheating period at a preheating temperature can thus advantageously ensure reliable sensor operation at the start of spreading material application.In this context, it has proven advantageous to heat the spreading fan sensor automatically, especially in a time-controlled manner, over a preheating period at a preheating temperature such that the spreading fan sensor is dry by the time spreading begins. For example, preheating can take place in the morning a certain amount of time before the start of the working day.

[0017] In an advantageous embodiment, it is proposed that the preheating temperature be higher than the heating temperature. This enables rapid drying of the spreading fan sensor during the preheating period. In particular, heavy moisture contamination, which can result, for example, from increased nighttime dew formation, can be dried quickly and reliably before the spreading of the spreading material begins.

[0018] It is further proposed that the heating temperature and / or the preheating temperature be adjusted at intervals. This enables customized heating, in particular the heating temperature and / or the preheating temperature can be adapted to the respective prevailing ambient conditions. For example, at a low ambient temperature, the heating temperature and / or the preheating temperature can be increased to effectively dry the spreading fan sensor. If the ambient temperature rises, as is generally observed over the course of the day, the heating temperature can be reduced. Furthermore, the heating temperature and / or the preheating temperature can be adjusted to the degree of moisture formation on the spreading fan sensor. This reliably ensures that the spreading fan sensor dries even under different ambient conditions.Furthermore, such a design allows for energy-efficient heating of the spread fan sensor, as the heating temperature and / or preheating temperature can be reduced, for example, when moisture buildup is lower, thus saving energy. By adjusting the heating temperature and preheating temperature at intervals, the energy required to dry and keep the spread fan sensor clear can be varied.

[0019] It has proven particularly advantageous if the fan-shaped sensor is heated with the heating medium in such a way that the sensor temperature is always above the dew point temperature. This design reliably prevents contamination of the fan-shaped sensor by moisture or wetness due to dew formation. The sensor temperature used as a reference can either be a value set manually or automatically by the operating personnel, or it can be set via a temperature sensor located on the fan-shaped sensor.

[0020] It is further proposed that the dew point temperature be determined from one or more environmental parameters. This ensures that the current dew point temperature at the location where the grit is applied is always used. This allows for the sensor temperature to be adjusted as precisely as possible to the respective dew point temperature value. By determining the dew point temperature as accurately as possible, energy consumption for heating can be improved.

[0021] It has proven advantageous if the environmental parameters are recorded by an environmental sensor, in particular arranged on the spreader, and / or originate from an external data source. Such an environmental sensor arranged on the spreader enables particularly precise recording of the current environmental conditions at the respective location where the spreading material is being applied. Alternatively, however, the environmental sensor can also be arranged on the tractor or in a stationary location, for example at the edge of the usable area or centrally between several usable areas. The environmental sensor can in particular be designed as a weather station. Databases or internet-based data sources for environmental parameters can serve as external data sources for the environmental parameters. Alternatively or additionally, historical data on the environmental parameters can also be used.

[0022] In this context, it is proposed that the environmental parameters include weather parameters and / or position parameters. Such a configuration advantageously enables particularly accurate and reliable consideration of the weather during the spreading of grit and / or the location of the respective usable area.

[0023] It is further proposed that the weather parameters include temperature parameters, humidity parameters, and / or air pressure parameters. These parameters can enable a particularly precise determination of the dew point temperature. Furthermore, other weather parameters can be determined or recorded, which can be used to determine or estimate the dew point temperature. For example, wind parameters can also be taken into account, which can be used to determine the risk of dust formation or turbulence of the grit.

[0024] With regard to the position parameters, it is proposed that these include location parameters and / or time parameters. The location parameters can in particular include location information such as GPS data and / or altitude information of the respective usable area. The time parameters can include information on the time of day as well as information on the time of year and / or the position of the sun. Furthermore, information on the usable area, such as the condition of the ground, in particular its moisture and thus the risk of dust formation, can also be included. It has also proven advantageous if the sensor temperature is determined based on one or more environmental parameters. In particular, a target sensor temperature can be specified based on one or more environmental parameters. It has proven advantageous if the sensor temperature is determined as a function of the temperature parameters.In an alternative embodiment, the sensor temperature can be determined using a temperature sensor built into the fan-shaped sensor. Alternatively, the respective air temperature or another suitable temperature value can be used as a reference value for the sensor temperature.

[0025] With regard to the design of the heating means, it has proven advantageous if the heating means is designed as an electric heating means. This enables a structurally simple and easily controllable heating of the spreading fan sensor, which enables effective drying of the spreading fan sensor. In an advantageous embodiment, the heating means can be operatively connected to the electrical system of the agricultural tractor for power supply. Alternatively, a separate power supply can be provided.

[0026] With regard to the positioning of the heating means, it is proposed that the heating means be arranged outside the sensor surface of the spreading fan sensor. In this way, it can be avoided that the heating means impairs or obscures the field of view of the sensor. In particular, the heating means can be arranged at least partially on the outside on the circumference of the field of view of the spreading fan sensor. This can enable effective and efficient heat transfer to the sensor surface of the spreading fan sensor that is to be dried. In this context, it has proven particularly advantageous with regard to the most even heating of the spreading fan sensor if the heating means is arranged at least partially on the outside around the sensor surface. From a design point of view, it has proven advantageous if the heating means is arranged on a housing of the spreading fan sensor.Such an arrangement enables particularly rapid heating of the fan-shaped sensor in the immediate vicinity of the contamination site. In particular, the heating medium can be positioned as close as possible to the sensor surface by being arranged on a housing of the fan-shaped sensor. From a design perspective, it can be advantageous in this context if the heating medium is arranged as an insert in the housing of the fan-shaped sensor. This also enables easy replacement of the heating medium in the event of a defect. In a further advantageous embodiment, the heating medium can be arranged in the immediate vicinity of the fan-shaped sensor, in particular on a circuit board of the fan-shaped sensor. This allows the area surrounding the fan-shaped sensor to be heated.

[0027] With regard to the structural design of the heating means, it is further proposed that it be designed as a heating wire arranged at least partially around the sensor surface. This enables particularly uniform heating of the fan-shaped sensor and in particular of the sensor surface. Depending on the application, the heating wire can be arranged on the housing in a spiral, zigzag, or meandering manner, for example. The arrangement of the heating wire can be easily adapted to the sensor heating requirements and / or the available installation space. In an alternative design, the heating means can also be designed as a heating means integrated into the sensor surface - for example, as a thin heating wire similar to a vehicle window heater that does not interfere with sensor operation.Alternatively or in addition to an electric heating wire, inductive heating means or infrared heating means are also conceivable, which can be used to evaporate and / or vaporize moisture present on the fan-shaped sensor. Furthermore, to prevent contamination, the sensor surface can be at least partially coated with a moisture- or dirt-repellent material. In a further advantageous embodiment, it is proposed that the fan-shaped sensor be at least partially exposed to compressed air via a compressed air supply for cleaning the sensor surface. Applying compressed air can enable both additional drying of the sensor surface and the removal of deposits or contamination.

[0028] In this context, it has proven advantageous to apply compressed air to the fan-shaped sensor during the spreading material application to clean the sensor surface. The compressed air supply for a ventilation period allows, on the one hand, moisture contamination that has occurred on the fan-shaped sensor, particularly on its sensor surface, to be dried during the spreading material application, and, on the other hand, any deposits that have already adhered to it to be removed using the compressed air.

[0029] It is further proposed that a plurality of spreading fan sensors be provided, which are at least partially heated separately by the heating means and / or at least partially supplied with compressed air by the compressed air supply. A plurality of spreading fan sensors advantageously allows for more comprehensive detection of the spreading pattern in the spreading fan, in particular the transverse distribution of the spreading material within the spreading fan. A separate heating system and / or compressed air supply can ensure contamination- and / or deposit-independent sensor operation for each individual spreading fan sensor.

[0030] In this context, it has proven advantageous to heat the fan-shaped sensors for different heating periods and / or at different heating temperatures. In particular, the heating periods and / or temperatures can be adjusted to the degree of soiling or moisture wetting of the fan-shaped sensors. In the case of heavy soiling, a comparatively long heating period and / or a higher heating temperature can be selected. In the case of light soiling, lower heating temperatures and / or shorter heating periods can be selected.

[0031] In this context, it is further proposed that the spreading fan sensors be heated for different heating periods and / or preheating periods and / or at different heating temperatures and / or preheating temperatures, depending on their position relative to the spreading element and / or the spreading fan. Such a configuration makes it possible for each spreading fan sensor to be individually heated and / or preheated depending on its exposure to contamination. In particular, those spreading fan sensors that are exposed to a greater risk from contamination or wetting by moisture during spreading operation can be heated at higher heating temperatures and / or for longer heating periods in order to dry them.In addition, spread fan sensors that are less exposed to contamination due to their position relative to the spreading element and / or the spreading fan can be heated for shorter heating times and / or at lower heating temperatures. This ensures reliable sensor operation for all spread fan sensors, regardless of their position relative to the spreading element and / or the spreading fan.

[0032] Under particularly unfavorable application conditions, despite the heating medium, deposits may form on the spreading fan sensor, particularly on its sensor surface. These deposits can result in particular from the adhesion of particles of the spreading material, airborne dust, or soil particles. To still enable reliable detection of the spreading material distribution in the spreading fan, it is proposed that the spreading fan sensor be at least partially subjected to a vibration exciter to ensure sensor operation independent of contamination and / or deposits. The vibration excitation can reduce or remove contamination and / or deposits on the spreading fan sensor. In particular, stubborn incrustations on the spreading fan sensor can be quickly and reliably broken up and loosened.By subjecting the spreading fan sensor to vibration and cleaning it as a result, it can be ensured that the spreading material distribution is reliably detected. Alternatively or additionally, the vibration exciter can be configured to subject the spreading fan sensor to vibrations in such a way that contamination and / or deposits are avoided and / or reduced from the outset or during spreading operation. Furthermore, it can be provided that the spreading fan sensor is subjected to vibration by the vibration exciter before the start of spreading operation and / or at specific, in particular adjustable, intervals and / or time periods during spreading operation. The operational readiness of the spreading fan sensor can thus be increased without it having to be cleaned manually at regular intervals.

[0033] In an advantageous development of the invention, it is proposed that the spreading fan sensor, in order to clean a sensor surface, be subjected to vibration with the vibration exciter at an exposure frequency that differs from the natural frequency of the spreader for a specific exposure duration. Such a configuration enables particularly rapid and thorough cleaning of the sensor surface. In particular, an exposure frequency that differs from the natural frequency of the spreader increases the effectiveness of the vibration exposure and thus the cleaning or descaling of the spreading fan sensor. It is particularly advantageous if the exposure frequency and / or exposure duration can be adjusted, for example, to adapt to the degree of soiling of the spreading fan sensor.

[0034] In this context, it is proposed that the spreading fan sensor be subjected to multiple exposure frequencies, at least one of which corresponds to a natural frequency of the spreading fan sensor or part of the spreading fan sensor. This allows particularly thorough cleaning of the sensor surface. The exposure frequencies can also be advantageously adapted to the type and / or degree of contamination. From a control engineering perspective, it has proven advantageous if the monitoring of the spreading material distribution with the spreading fan sensor is interrupted during the exposure period. This ensures that the monitoring of the spreading material distribution in the spreading fan is not disturbed or distorted by the vibration exposure.In this context, it is particularly advantageous if the exposure time is chosen to be as short as possible in order to enable the shortest possible interruption in the monitoring of the spreading material distribution.

[0035] It is further proposed that the application frequency be selected and adjusted in such a way that the monitoring of the spreading material distribution is not disrupted. In particular, the application frequency or its spectrum can be selected and adjusted in such a way that it is filtered out by the evaluation electronics of the spreading fan sensor in such a way that it is not used for monitoring or evaluating the spreading material distribution.

[0036] This advantageously ensures that the vibration exposure does not disturb, hinder or distort the detection of the spreading material distribution in the spreading fan.

[0037] In this context, it has proven advantageous if the spreading fan sensor is at least partially subjected to a vibration exciter during an interruption in the spreading of spreading material. This ensures that the vibration is applied when no spreading material is taking place and therefore no spreading material distribution needs to be recorded. Such an interruption in the spreading material application can occur, for example, during the turning process. Furthermore, the spreading material application can also be interrupted for one of the spreading elements, for example at the edge of the usable area. A spreading fan sensor assigned to this spreading element can advantageously be actuated during the interruption in the spreading of spreading material. In this context, it has proven advantageous if the evaluation electronics of the spreading fan sensor are adapted to the application frequency.In particular, it can be advantageous if the evaluation electronics temporarily filter out the resulting interference signals during vibration excitation. This can improve the quality of detection of the lateral distribution of the spreading material.

[0038] From a design perspective, it is advantageous to provide multiple spreading fan sensors, each of which is at least partially exposed to a vibration exciter to clean the sensor surfaces. This type of design enables customized cleaning of the respective spreading fan sensors. In particular, the individual spreading fan sensors can be excited by vibration when they reach a critical level of contamination. The separate control of the vibration exciters of the individual spreading fan sensors also has the advantage that a brief interruption in the detection of the spreading material distribution associated with the vibration excitation is limited to only one spreading fan sensor. In this case, the corresponding spreading fan sensor can be excluded from the detection of the spreading material distribution of the spreading fan.Alternatively, several spreading fan sensors can be actuated simultaneously with the respective vibration exciter, whereby a short-term, simultaneous interruption of the detection of the spreading material distribution via these spreading fan sensors may occur, but this is accompanied by a simplified control.

[0039] In this context, it is proposed that the spread fan sensors be subjected to vibration for different exposure times. This advantageously allows for further adaptation of the vibration exposure to the conditions of the respective spread fan sensor, in particular its degree of contamination or deposits. The degree of contamination can be detected by sensors or specified as a fixed default value.

[0040] It is proposed that the spreading fan sensors be exposed to different exposure times depending on their position relative to the spreading element and / or the spreading fan. This makes it possible to react to the different environmental influences that affect the spreading fan sensors arranged at different positions. Since the dust and / or dirt load in particular can vary considerably depending on the position of the respective spreading fan sensors relative to the spreading element and / or the spreading fan, such a design enables the spreading fan sensors to be exposed to the system in a way that meets requirements. Furthermore, the energy required for descaling can be reduced by adapting the exposure time to the respective contamination situation.

[0041] To achieve the above-mentioned object, an agricultural spreader for spreading grit, comprising at least one spreading element for generating a spreading fan and at least one spreading fan sensor for monitoring the distribution of the grit within the spreading fan, which spreader comprises a heating means for at least partially heating the spreading fan sensor to ensure contamination- and / or deposit-independent sensor operation, is further proposed. This spreader offers the advantages explained above in connection with the method for spreading grit. Such a design, in particular, increases the operational readiness of the spreader, since any moisture and / or dirt deposits on the spreading fan sensor can be dried by the heating means.Dirt or deposits are less likely to adhere to a dry fan-shaped sensor, which is why the corresponding fan-shaped sensor needs to be cleaned less frequently.

[0042] In an advantageous embodiment, the at least one spreading fan sensor is arranged below or above the spreading device, with its field of view being oriented at an angle relative to a longitudinal axis of the spreader. Such an arrangement of the spreading fan sensor enables particularly precise and reliable detection of the spreading material distribution in the spreading fan, in particular the transverse distribution of the spreading material.

[0043] It is further proposed that the agricultural spreader have a plurality of spread fan sensors, each with a heating medium. The spread fan sensors are aligned at different detection angles relative to the longitudinal axis of the spreader to detect different viewing areas. Such a configuration enables the largest possible area of ​​the spread fan to be detected, thereby enabling the most accurate detection of the spreading material and its transverse distribution within the spread fan.

[0044] In this context, it is further proposed that the heating means of the individual spreading fan sensors be controllable separately. This makes it possible, in particular, for the heating means of the individual spreading fan sensors to be switched on and off independently of one another. This ensures that the individual spreading fan sensors are heated as required. For example, those spreading fan sensors that are more exposed to contamination can be heated for longer heating periods and / or at higher heating temperatures. Spreading fan sensors arranged in less exposed areas can be heated for shorter heating periods and / or at lower heating temperatures. This enables adapted heating of the individual spreading fan sensors, which also ensures efficient use of energy for drying.In an alternative design, the heating elements can only be controlled jointly or in groups. This results in less control effort.

[0045] In a particularly preferred embodiment, the heating means of the individual fan-shaped sensors can be controlled separately to set different heating times and / or heating temperatures and / or preheating times and / or preheating temperatures. Such a configuration enables precise adaptation of the heating times and / or heating temperatures and / or preheating times and / or preheating temperatures to the conditions and installation situations of the respective fan-shaped sensors.

[0046] In an advantageous development of the invention, it is proposed that the spreader has two spreading elements arranged symmetrically to a longitudinal axis of the spreader, each of which is assigned a plurality of spreading fan sensors arranged symmetrically to the longitudinal axis. Such a configuration enables uniform application of the spreading material on both sides of the longitudinal axis and reliable monitoring of the spreading material distribution in the two parts of the spreading fan formed to the left and right of the longitudinal axis of the spreader. Furthermore, such an arrangement enables comparatively simple control of the heating means. The control of the heating means of the spreading fan sensors of the left and right spreading elements can thus also take place symmetrically to the longitudinal axis.

[0047] Furthermore, an agricultural spreader for spreading grit is proposed, which has at least one spreading element for generating a spreading fan and at least one spreading fan sensor for monitoring the grit distribution within the spreading fan. A vibration exciter is provided for at least partially applying pressure to the spreading fan sensor to ensure sensor operation independent of contamination and / or deposits. This results in the advantages already explained in connection with the method for spreading grit.

[0048] It has proven advantageous to provide several spreading fan sensors, each with at least one vibration exciter. The spreading fan sensors are aligned at different detection angles relative to the longitudinal axis of the spreader to detect different viewing areas. Such a configuration enables large-area, fine-resolution detection of the spreading material distribution, which is reliable even in the event of the failure of individual spreading fan sensors. Furthermore, the fine-resolution detection of the spreading material distribution enables more precise adjustment of the spreading material distribution.

[0049] It is proposed that the vibration exciters of the individual spread fan sensors be controlled separately. This ensures that the individual spread fan sensors can be independently activated by a vibration exciter for cleaning in the event of contamination or deposits. Alternatively, the vibration exciters of the individual spread fan sensors can be controlled jointly, which is simpler from a control perspective.

[0050] An advantageous embodiment provides for the vibration exciters to be separately controlled to set different exposure times and / or frequencies. This allows for more precise adaptation to the respective contamination situation at the spreading fan sensors.

[0051] Furthermore, to solve the above-mentioned problem, a spreading fan sensor is proposed for monitoring the spreading material distribution in a spreading fan generated by a spreader for distributing spreading material over a usable area. The sensor has a heating means for at least partially heating the spreading fan sensor to ensure contamination- and / or deposit-independent sensor operation. Such a spreading fan sensor also offers the advantages mentioned above with regard to the method for spreading spreading material and the agricultural spreader.

[0052] Furthermore, a spreading fan sensor is proposed for monitoring the spreading material distribution in a spreading fan generated by a spreader for distributing spreading material over a field. The sensor has a vibration exciter for at least partially applying vibration to the spreading fan sensor to ensure contamination- and / or deposit-independent sensor operation. This results in the advantages explained in connection with the method for spreading spreading material and the agricultural spreader.

[0053] Further details and advantages of the invention are explained below with the aid of the accompanying drawings according to Figs. 1 to 6b. Therein show:

[0054] Fig. 1 is a perspective view of an agricultural spreader attached to a tractor;

[0055] Fig. 2 is an enlarged detailed view of a section of the illustration according to Fig. 1;

[0056] Fig. 3-4 two enlarged detailed views of a section of the illustration according to Fig. 2;

[0057] Fig. 5a is a partially sectioned plan view of an agricultural spreader attached to a tractor as shown in Fig. 1;

[0058] Fig. 5b is an enlarged partial view of a section of the illustration according to Fig. 5a;

[0059] Fig. 6a shows a schematically illustrated exemplary course of the heating temperatures over time;

[0060] Fig. 6b shows a schematically illustrated exemplary curve of the dew point temperature and the sensor temperature based on the heating temperature curve according to Fig. 6a, and

[0061] Fig. 7-8 show two further enlarged detailed views of a section of the illustration in Fig. 2. The illustration in Fig. 1 shows, in perspective, a top view of an agricultural spreader 1 for spreading grit on agricultural land, for example, a grain field or a pasture. With the spreader 1, a wide variety of grit types can be spread on the land, in particular powdered or granular fertilizers and lime. The spreader 1 is mounted on an agricultural tractor 8, but can alternatively also be attached to the tractor 8 or be self-propelled.

[0062] For the even distribution of the spreading material over the usable area, the spreader 1 has two spreading elements 2. The spreading elements 2 are designed as plate-shaped spreading discs arranged next to one another on a plane, which rotate in opposite directions to distribute the spreading material. The spreading material is fed from above via a feed line and / or dosing device from a storage container arranged above the spreading elements 2 onto the rotating spreading elements 2, in particular to a respective drop point on the spreading elements 2. Due to the rotational speed or rotational speed of the spreading elements 2, the spreading material is hurled behind the spreader 1 against the direction of travel R using centrifugal forces.

[0063] The area behind and partly next to the spreader 1, in which the spreading material is distributed over the usable area, is referred to as the spreading fan F. The spreading fan F generally essentially comprises a circular sector, with each spreading element 2 only spreading in a partial area of ​​the spreading fan F. However, there is generally a transition area between the partial areas, in which spreading material is distributed by both spreading elements 2. The width of the spreading fan F transverse to the direction of travel R, which usually significantly exceeds the width of the spreader 1, can be adjusted using various parameters of the spreader 1. These include, for example, the rotation speed of the spreading elements 2, the point of impact of the spreading material on the spreading elements 2 or the nature of the spreading material.

[0064] For a uniform supply of spreading material to the plants grown on the cultivated area, a distribution of the spreading material as uniform as possible within the spreading fan F is generally desired. The distribution of the spreading material within the spreading fan F is referred to as spreading material distribution or also as transverse distribution. In order to detect and / or evaluate the spreading material distribution, the spreader 1 has several spreading fan sensors 3, see Fig. 1.

[0065] The spreading fan sensors 3 are designed as radar sensors and arranged above the spreading elements 2, whereby they are positioned comparatively close to the spreading elements 2 for reliable detection of the spreading material distribution. Alternatively, the spreading fan sensors 3 can also have a different operating principle and / or be arranged below the spreading elements 2 and / or on the storage container. Each spreading fan sensor 3 monitors a different segment- or sector-like section of the spreading fan F, which is why the individual spreading fan sensors 3 are arranged approximately semicircularly around the respective spreading element 2, see also Fig. 5a. The fields of view B of the spreading fan sensors 3 are directed radially outwards. The individual spreading fan sensors 3 are aligned at different detection angles a relative to the longitudinal axis A of the spreader 1 to cover or detect the entire spreading fan F.The two spreading elements 2 of the spreader 1 are arranged symmetrically on both sides of the longitudinal axis A, see Fig. 5a. The spreading fan sensors 3 assigned to the spreading elements 2 are also arranged symmetrically on both sides of the longitudinal axis A. However, alternative arrangements of the spreading elements 2 and / or the spreading fan sensors 3, for example asymmetrical ones, are also conceivable if this should prove advantageous in the respective application.

[0066] The spreading fan sensors 3 each have a sensor surface 3.1 (see Fig. 3), via which a sensor signal, in this case the radar signal, is transmitted and received to detect the spreading material distribution in the spreading fan F. For correct and reliable detection of the spreading material distribution, the sensor surface 3.1 must be as free as possible from dirt and deposits. For example, water droplets, such as deposits from precipitation, fog, or dew, can interfere with the radar signal. The sensor signal is evaluated using evaluation electronics.

[0067] Particularly with moist spreading fan sensors 3, there is the problem that fine-grained, powdery or dusty contaminants can adhere to them and / or grow into encrustations. This is particularly problematic if the sensor surface 3.1 becomes dirty, as this can disrupt the detection of the spreading material distribution. The contamination can, for example, result from the spreading material itself, which is often at least partially pulverized upon impact with the spreading elements 2 and during distribution or application via the spreading elements 2 and released into the ambient air as dust. From there, it can accumulate on the spreading fan sensors 3. Furthermore, particles already present in the ambient air or stirred up from the ground of the working area can adhere to the spreading fan sensors 3 as deposits, particularly if their surfaces are moist.

[0068] To ensure sensor operation independent of contamination and / or deposits, the fan-shaped sensor 3 is at least partially heated with a heating medium 6. This allows the fan-shaped sensor 3 to be dried by evaporation or vaporization of the water deposits. Less dirt or other deposits can adhere to a dry fan-shaped sensor 3, which at least reduces or even eliminates the need for cleaning and thus increases its operational readiness.

[0069] The function and design of the heating means 6 are explained below with reference to the illustrations in Figs. 3 and 4. The heating means 6 is designed as an electric heating means which can be supplied with electrical power via the on-board electrical system of the tractor 8. Alternatively, the heating means 6 can be supplied with power via a separate power supply. As shown in Fig. 4, the heating means is designed as a heating wire 6.1 which is arranged on a housing 7 of the spreading fan sensor 3. The heating wire 6.1 is arranged outside the sensor surface 3.1 of the spreading fan sensor 3. The heating wire 6.1 is wound spirally around the sensor surface 3.1 of the spreading fan sensor 3. Alternatively, the heating wire 6.1 can also be arranged only in sections around the sensor surface 3.1 or can be laid in a different pattern.Depending on the application, a meandering, bifilar, modular, or other arrangement of the heating wire 6.1 is possible. Furthermore, the heating wire 6.1 can alternatively or additionally be integrated into the sensor surface 3.1, for which purpose it must be designed to be comparatively thin so as not to disturb or hinder the detection of the transverse distribution of the spreading material S. Furthermore, the heating wire 6.1 can also be arranged on the inside of the housing 7 of the spreading fan sensor 3.

[0070] Furthermore, with regard to a simple and quick exchangeability of the heating means 6, it can be advantageous if this is designed as an insert or exchange element detachably connected to the spreading fan sensor 3.

[0071] When the heating medium 6, designed as a heating wire 6.1, is subjected to electrical current, it releases heat and thereby heats the fan-shaped sensor 3. The arrangement of the heating wire 6.1 ensures that primarily the sensor surface 3.1 of the fan-shaped sensor 3 is heated. As a result of the heating, the water adhering to the fan-shaped sensor 3, and in particular to the sensor surface 3.1, evaporates. The fan-shaped sensor 3 and the sensor surface 3.1 are dried. The drying process can be controlled via the heating temperature TH and the heating duration DH, whereby different heating temperatures TH and heating durations DH can be set depending on the ambient conditions.

[0072] Alternatively or in addition to being designed as a heating wire 6.1 operating on the basis of resistance heating, the heating means 6 can also be designed in another way, for example as an inductive heating element or as a heating means 6 operating on the basis of infrared radiation or microwave radiation. In order to be able to ensure the operational readiness of the spreading fan sensor 3 immediately at the start of spreading material, for example at the start of work early in the morning, it is provided that the spreading fan sensor 3 can also be heated with a preheating temperature Tv for a preheating time Dv. By preheating, the water that forms on the spreading fan sensor 3 during an interruption in operation, for example during a night-time rest period, can be removed. Especially at night, dew often forms on the spreading fan sensors 3 due to condensation processes, which can be removed by preheating.Preferably, the heating means 6 is designed in the manner of a parking heater so that automated preheating takes place in such a way that the spreading fan sensor 3 is at least partially dry at the start of spreading material.

[0073] Since the most relevant source of moisture deposits on the spreading fan sensor 3 is dew formation, even during daytime spreading, the spreading fan sensor 3 is heated with the heating medium 6 to ensure contamination- and / or deposit-independent sensor operation such that a sensor temperature Ts is always above the dew point temperature TT during spreading operation. This ensures that the moisture present in the air cannot condense on the spreading fan sensor 3 and deposit as water deposits, for example, on the sensor surface 3.1.

[0074] As a prerequisite for such a procedure, the sensor temperature Ts must be measured or determined. The value of the sensor temperature Ts corresponds to a target or specified value, which - as explained - should be above the current dew point temperature TT. To determine the sensor temperature Ts, either a temperature sensor can be provided on the spreader 1 or on the spreading fan sensor 3, or the sensor temperature Ts can be determined using one or more environmental parameters. For this purpose, the sensor temperature Ts can be determined, for example, based on the current ambient air temperature or determined or specified based on any other variables.

[0075] The dew point temperature TT can also be determined from one or more environmental parameters. In particular, one or more environmental sensors 4 can be arranged on the spreader 1 to detect the environmental parameters. Alternatively or additionally, environmental sensors 4 can be provided on the tractor 8 and / or arranged remotely from the spreader 1, for example, at the edge of the working area. Furthermore, it is conceivable that the environmental parameters are retrieved from an external data source. This can be, for example, a database or an internet-based data source.

[0076] The environmental parameters include weather parameters and position parameters, with the weather parameters particularly including parameters that can be used to determine the dew point temperature TT. These can be, in particular, temperature parameters and / or humidity parameters and / or air pressure parameters. Further weather parameters are also conceivable.

[0077] The position parameters include location parameters and time parameters. The location parameters can be determined, in particular, using a satellite positioning system, such as GPS. Furthermore, the location parameters can also include information on the altitude above sea level and / or the condition of the soil in the cultivated area, particularly regarding its moisture content, and / or the plants grown on the cultivated area. Other location parameters influencing the formation of moisture and / or contamination on the spread fan sensor 3 are also conceivable here.

[0078] In addition to the time of day, the time parameters can also include information about the position of the sun or the time of year. Furthermore, other parameters are conceivable that can be used to determine or estimate the dew point temperature TT and / or the sensor temperature Ts.

[0079] In the following, using the illustrations in Fig. 6a and Fig. 6b, it is explained how an exemplary spreading fan sensor 3.1 is heated with the heating means 6 before and during spreading of the spreading material. The schematic diagram in Fig. 6a shows an exemplary sequence of heating intervals I over a working day, which begins with the start of work at 8:00 a.m. In order that the spreading fan sensor 3 is dried from nighttime dew formation or other wetting with moisture by the start of work, the preheating phase begins at 6:00 a.m. During this preheating phase, the heating means 6 is set to a preheating temperature Tv, which is maintained for the preheating period Dv. As can be seen from the diagram in Fig. 6b, which has the same time scale as the diagram in Fig. 6a, the sensor temperature Ts is at a comparatively low level at the beginning of the preheating period Dv due to the nighttime cooling.Since the sensor temperature Ts is also below the dew point temperature TT, dew formation is to be expected on the fan-shaped sensor 3. As a result of heating with the heating medium 6 from 6:00 a.m., the sensor temperature Ts rises and exceeds the dew point temperature TT, so that the fan-shaped sensor 3 dries. The hatched area in Fig. 6b symbolizes the drying of the fan-shaped sensor 3, since in this case the sensor temperature Ts is above the dew point temperature TT.

[0080] At the start of work at 8:00 a.m., which marks the start of spreading material with spreader 1, the sensor temperature Ts is significantly above the dew point temperature TT due to the preheating. To enable comparatively energy-efficient heating, the heating temperature TH is then set to an average value TH2, which is below the preheating temperature Tv, and maintained for the heating period DH2, see Fig. 6a. Due to the lower heating temperature DH2, the sensor temperature Ts approaches the dew point temperature TT, which initially rises over the course of the day. To prevent the sensor temperature Ts from falling below the dew point temperature TT, the heating temperature is set to the value THS for a heating period DH3, whereby the heating temperature THS is greater than the heating temperature TH2. As a result, the sensor temperature Ts rises again and the difference to the dew point temperature TT increases during the heating period DH3.

[0081] Subsequently, heating can be carried out at a lower heating temperature THI for a heating period DHI, since there is no risk of the dew point temperature TT being exceeded by the sensor temperature Ts. As the day progresses, particularly at midday, when high ambient temperatures are recorded due to high solar radiation, the heating of the fan-shaped sensor 3 can even be switched off. The fan-shaped sensor 3 is not heated again until late in the afternoon, initially for a heating period DH3 at the heating temperature TH3 and subsequently for a heating period DHI at the heating temperature THI.

[0082] Based on the above-explained example of heating a spreading fan sensor 3 over the course of a day, it becomes clear how the sensor temperature Ts can be controlled using different heating periods DH and preheating periods Dv as well as heating temperatures TH and preheating temperatures Tv such that the sensor temperature Ts is always above the dew point temperature TT during spreading of the spreading material. This ensures that no dew can form on the spreading fan sensor 3. Since the spreading fan sensor 3 remains dry or is dried, particles of the spreading material and other contaminants cannot adhere to the spreading fan sensor 3 or can only adhere to a lesser extent and / or form an incrustation. Trouble-free sensor operation for recording or detecting the transverse distribution of the spreading material in the spreading fan F can be ensured in this way. Furthermore, the cleaning effort required to clean the spreading fan sensor 3 and in particular the sensor surface 3 is reduced.1 significantly reduced.

[0083] The temperature curves explained above, according to Figs. 6a and 6b, are to be understood as examples. In particular, the heating temperature curve according to Fig. 6a can be adapted as desired, both with regard to the heating and preheating temperatures TH, TV and the heating and preheating durations DH, DV. Furthermore, the number and length of the heating intervals I can be adapted as desired to the respective application. Furthermore, temperature values ​​other than the sensor temperature Ts and the dew point temperature TT can also be used as reference or comparison values.

[0084] The following explains, based on the illustrations in Fig. 5a and b, how the heating means 6 of the individual spreading fan sensors 3, which monitor different sections or sectors of the spreading fan F, can be controlled separately. Depending on the position of the spreading fan sensors 3 relative to the spreading elements 2 or to the longitudinal axis A, they are exposed to a greater or lesser risk of dew formation and deposits of water and moisture. For example, spreading fan sensors 3 positioned close to the longitudinal axis A can be somewhat better protected by elements of the spreader 1 than spreading fan sensors 3 arranged in outer areas of the spreader 1. On the other hand, the individual spreading fan sensors 3 can be exposed to different loads or exposures to dust or dirt particles. Therefore, the heating means 6 of the various spreading fan sensors 3 can be controlled separately, whereby their heating can be adapted to the respective installation situation.Spread fan sensors 3 arranged in particularly exposed positions can, for example, be heated for longer heating periods DH or preheating periods Dv or with higher heating temperatures TH or preheating temperatures Tv than spread fan sensors 3 that are not exposed to significant contamination by water or dust particles. Alternatively, however, it may also be advantageous to heat all spread fan sensors 3 simultaneously or synchronously for simplified control. Furthermore, it is conceivable to provide only some of the spread fan sensors 3 with heating means 6.

[0085] The fan-shaped sensors 3 can also be supplied with compressed air via a compressed air supply (not shown in the figures) for cleaning the sensor surfaces 3.1. In this case, a compressed air supply can be assigned to each fan-shaped sensor 3. Alternatively, only a portion of the fan-shaped sensors 3 can be assigned a compressed air supply. The compressed air supply can be directed, in particular, to the respective sensor surface 3.1 for cleaning and / or drying. Analogous to the intermittent heating by means of the heating means 6, the fan-shaped sensors 3 can be supplied with compressed air for different ventilation periods. Furthermore, different compressed air pressure levels can also be set. The ventilation periods and / or the compressed air pressure levels can be adjusted intermittently. In particular, the ventilation periods and / or the compressed air pressure levels can be adapted to the respective contamination and / or deposits.

[0086] The fan-shaped sensors 3 and in particular their sensor surfaces 3.1 can also be provided with a water- and / or dirt-repellent coating, which can reduce the adhesion of moisture and / or dirt.

[0087] Particularly with moist spreading fan sensors 3, there is the problem that fine-grained, powdery or dust-like contaminants can adhere to them and grow into stubborn incrustations. This is particularly problematic when the sensor surface 3.1 becomes incrusted, as this can disrupt the detection of the spreading material distribution. The incrustations formed as incrustations can, for example, result from the spreading material itself, which is often at least partially pulverized upon impact with the spreading elements 2 and during distribution or application via the spreading elements 2 and released into the ambient air as dust. From there, it can accumulate on the spreading fan sensors 3. Furthermore, particles already present in the ambient air or stirred up from the ground of the working area can adhere to the spreading fan sensors 3 as deposits.To ensure sensor operation independent of contamination and / or deposits, the spreading fan sensor 3 is at least partially exposed to a vibration exciter 9. This prevents, reduces, breaks up, and / or removes contamination, particularly incrustations, on the spreading fan sensor 3. Manual cleaning requirements can be reduced, and the operational readiness of the spreading fan sensor 3 can be increased.

[0088] The following explains the functionality and design of the vibration exciter 9 using the illustrations in Figs. 7 and 8. The vibration exciter 9 is arranged on a housing 7 of the spreading fan sensor 3, so that the sensor surface 3.1 of the spreading fan sensor 3 can be excited to vibrate, at least partially or in sections. To supply electrical voltage, the spreading fan sensor 3 is connected to the on-board electrical system of the tractor 8.

[0089] The vibration exciter 9 can be operated at a certain frequency, which differs from the natural frequency of the spreader 1, thereby enabling effective vibration application and thus effective removal of deposits on the spreading fan sensor 3. The duration of the vibration application to the spreading fan sensor 3 can be adapted, in particular, to the degree of contamination. However, the duration of the application is generally only a short period of time.

[0090] Alternatively or additionally, the vibration exciter 9 can be designed to apply vibration to the one or more spreading fan sensors 3 in such a way that deposits and / or contamination are avoided from the outset or during the spreading operation or at least reduced as far as possible. Furthermore, it can be provided that the one or more spreading fan sensors 3 are applied by means of the vibration exciter 9 before the start of the spreading operation and / or at certain, in particular adjustable, intervals and / or time periods during the spreading operation. In order to avoid distortion or disruption of the detection of the spreading material distribution in the spreading fan F via the spreading fan sensor 3 during the vibration application, the detection or evaluation of the spreading material distribution is briefly suspended during the vibration application. After the vibration application has been completed, the detection or evaluationEvaluation of the spreading material distribution is continued via the then cleaned or de-crusted spreading fan sensor 3.

[0091] Additionally or alternatively, the evaluation electronics for evaluating the spreading material distribution can be designed such that the useful signal of the spreading fan sensor 3 is filtered out of its entire signal spectrum. The bandwidth or spectrum of the applied frequency is selected such that it is also filtered out of the signal spectrum via the corresponding filters. In this way, interference with the detection or evaluation of the spreading material distribution by the spreading fan sensor 3, which is equipped with a vibration exciter 9, can be avoided or even prevented.

[0092] Additionally or alternatively, the evaluation electronics can be designed so that the algorithm for evaluating the spreading material distribution is adjusted during the vibration exposure. In particular, corresponding filters can be activated only during vibration exposure and deactivated otherwise.

[0093] As explained above, a plurality of spreading fan sensors 3 are generally arranged on a spreader 1, see Fig. 5a. In this case, either each spreading fan sensor 3 can have a vibration exciter 9 or only selected spreading fan sensors 3 have a vibration exciter 9. For example, a vibration exciter 9 can be dispensed with for spreading fan sensors 3 which, due to installation space or position, are exposed to no or only minimal exposure to contamination. If each spreading fan sensor 3 is equipped with a vibration exciter 9, they can be actuated separately by the respective vibration exciter 9. In particular, the control of the vibration exciters 9 can be designed such that they are only excited when necessary, i.e. when the spreading fan sensor 3 is dirty. The exposure duration and / or the exposure frequency can also be set separately.Alternatively, all or some of the spread fan sensors 3 can be actuated simultaneously by the respective vibration exciter 9, which reduces the control effort. Furthermore, a configuration is conceivable in which one vibration exciter 9 is responsible for several spread fan sensors 3 and can act on them sequentially.

[0094] Depending on the position of the respective spreading fan sensors 3 relative to the spreading elements 2 and / or the spreading fan F, they can be exposed to different exposure times. This allows for further adaptation to the respective soiling situation. Spreading fan sensors 3 that become heavily soiled can be exposed to a longer exposure time.

[0095] The method for spreading grit described above, the spreader 1 for spreading grit and the spreading fan sensor 3 are characterized in that the spreading material distribution can be reliably detected without the need for complex cleaning, in particular of the sensor surfaces 3.1 of the spreading fan sensors 3.

[0096] Reference symbol

[0097] 1 spreader

[0098] 2 scattering organ

[0099] 3 Spread fan sensor

[0100] 3.1 Sensor area

[0101] 4 Environmental sensor

[0102] 6 Heating agents

[0103] 6.1 Heating wire

[0104] 7 housings

[0105] 8 tractor

[0106] 9 Vibration exciters

[0107] A Longitudinal axis

[0108] B Field of view

[0109] DH Heating timeDv Preheating time

[0110] F Spreading fan

[0111] I Heating interval

[0112] R Direction of travel t Time

[0113] T Temperature

[0114] TH heating temperature

[0115] Ts sensor temperature

[0116] TT dew point temperature

[0117] Tv preheating temperature a detection angle

Claims

Patent claims 1. Method for spreading grit using an agricultural spreader (1) which has at least one spreading element (2) for generating a spreading fan (F) and at least one spreading fan sensor (3) for monitoring the distribution of the grit within the spreading fan (F), characterized in that the spreading fan sensor (3) is at least partially heated with a heating means (6) to ensure contamination- and / or deposit-independent sensor operation.

2. Method according to claim 1, characterized in that the spreading fan sensor (3) is heated with the heating means (6) for a heating period (DH) at a heating temperature (TH) during the spreading of the spreading material in order to dry a sensor surface (3.1).

3. Method according to one of claims 1 or 2, characterized in that the spreading fan sensor (3) is heated with the heating means (6) for a preheating period (Dv) at a preheating temperature (Tv) before the operation of the spreading device (1) for drying the sensor surface (3.1).

4. Method according to one of the preceding claims, characterized in that the scattering fan sensor (3) is heated with the heating means (6) in such a way that a sensor temperature (Ts) is always above a dew point temperature (TT).

5. Method according to claim 4, characterized in that the dew point temperature (TT) is determined from one or more environmental parameters.

6. Method according to claim 5, characterized in that the environmental parameters are detected by an environmental sensor (4) arranged in particular on the spreader (1) and / or originate from an external data source.

7. Method according to claim 4, characterized in that the sensor temperature (Ts) is determined based on one or more environmental parameters.

8. Method according to one of the preceding claims, characterized in that the spreading fan sensor (3) is at least partially supplied with compressed air by a compressed air supply for cleaning the sensor surface (3.1).

9. Method according to claim 8, during the spreading of the grit for cleaning the sensor surface (3.1) with the compressed air supply for a ventilation period.

10. Method according to one of the preceding claims, characterized by a plurality of scatter fan sensors (3) which are separately heated at least partially by the heating means (6) and / or at least partially supplied with compressed air by the compressed air supply.

11. Agricultural spreader (1) for spreading grit, with at least one spreading element (2) for generating a spreading fan (F) and at least one spreading fan sensor (3) for monitoring the distribution of the grit within the spreading fan (F), characterized by a heating means (6) for at least partially heating the spreading fan sensor (3) to ensure contamination- and / or deposit-independent sensor operation.

12. Spreading fan sensor for monitoring the spreading of grit in a spreading fan (F) generated by a spreading device (1) for distributing grit on a usable area, characterized by a heating means (6) for at least partially heating the spreading fan sensor (3) to ensure contamination and / or deposit-independent sensor operation.

Images