Method for creating reference lanes for agricultural vehicles

p0001The invention relates to a method for generating at least one reference lane for the automatic routing of an agricultural vehicle.

p0002Automatic routing systems and methods are increasingly being used in agriculture in order to rationalize the tillage, either by a brief and fast route for the processing of an agricultural area is identified, or to operating parameters of vehicles, such as tank levels and locations of the vehicles is to different times during a labor input to predict and optimize the effectiveness of the cooperation of the vehicles themselves.

p0003A method according to the Oberbegriff of claim 1 is known from <patcit id="pcit0001" dnum="DE102006002567A1"><text>DE 10 2006 002 567 A1</text></patcit> known. In this method, a to be processed agricultural area is scanned with a vehicle, and thereby the distance traveled route is recorded. The recorded route is displayed on a screen, and a user is given an opportunity to select on the traveled route start and end points of a reference lane. The Referenzfahrspur can then used be to the array of other, in the course of further processing of the surface to fahrenden lanes automatically festzulegen. This does not relieve the driver of the vehicle from the task itself to determine an economically mobile route for processing the surface, and it opens the possibility to automate the surface treatment of at least partially, by the vehicle is guided by a steering machine on the planned route along.

p0004Alternatively, to select start and end points of the Referenzfahrspur on a displayed graph provides the methods known to the driver of the vehicle the ability to start and end point of a Referenzfahrspur to specify by a start or Stoppsignal in the Routenplanungssystem enters when it starts to drive a reference lane or has finished.

p0005Both approaches are not yet fully satisfactory. If the findings traveled route is fully displayed on a touch screen monitor, it is difficult, especially in the case of a large processing area, start and end point of a reference lane determine with the necessary accuracy. Although it would be conceivable to represent each part of the route on an enlarged scale, but it is difficult to make sense to set a start or end point of a reference lane when the respective other point is not visible simultaneously. Specifically, when the already traveled route several parallel, also in an enlarged view at the same time visible Wegstücke covers, is to select start and end points of the Referenzfahrspur very error prone. If the driver in and out points of Referenzfahrspur each set should, while this überfährt, is a high probability that he forgets time the start or Stoppsignal to produce, especially when bearing in mind just a Referenzfahrspur to drive, his entire focus has been placed to steer the vehicle as closely as possible along the intended course of the reference lane.

p0006Object of the present invention is therefore to provide a process for obtaining a reference lane that allows a user to completely removes the task of selecting from a driven output route a reference lane, or at least helps him.

p0007The object is solved by providing in a method for obtaining a Referenzfahrspur for automatic Routenplanung an agricultural vehicle having the steps:<ol><li>a) shut down an exit route on a to be processed agricultural area;</li><li>b) recording the output route in a data processing device;</li><li>c) selecting at least a portion of the recorded output route as a reference lane the Ausgangsroute over its entire length on Richtungsänderungen untersucht will and in step c) a portion only as Referenzfahrspur selected, when the entire length of the portion not a limit überschreitende Richtungsänderung is found. In this way, parts of the original route, for example, turning maneuvers between two parallel adjacent herlaufenden lanes, driven at corners of agricultural land curves maneuvers will include, for avoiding obstacles or the like, excluded from the selection as a reference lane.</li></ol>

p0008Selecting a single Referenzfahrspur among the thus obtained sections may preferably carried out also by the Datenverarbeitungseinrichtung be made; this the quality of the sections in particular can be assessed on the basis of at least one criterion and as a reference lane of the section selected with the highest quality. So will the generation of Referenzfahrspur the driver unbemerkt instead, and this can his attention other objects turn.

p0009Alternatively, the activity of the data processing device may also be limited to preselecting one or more reference lanes and offering this preselected reference lanes for final selection by a user. If only a reference lane is preselected, the Offer is reduced to select an Offer to confirm. The decision whether a preselected reference lane is actually used is up, regardless of the number of preselected reference lanes to the user. For Vorauswahl can dieselben criteria used are as for the above-mentioned Qualitätsbeurteilung.

p0010To facilitate the user the final selection among the pre-selected reference lanes, it can be displayed on a screen.

p0011Preferably, the user in the possibility offered a vorausgewählte Referenzfahrspur to shorten or lengthen when the of the Datenverarbeitungseinrichtung festgelegte length of Referenzfahrspur inexpedient recognizes.

p0012On a sufficiently straight piece of Ausgangsroute can always several together overlapping portions festgelegt be that over its entire length free from the limit überschreitenden Richtungsänderungen are. To keep the number of reference lanes in boundaries, each of the longest of these sections should be selected as the reference lane. This does not mean that the data processing device would identify the shorter sections in detail at all. So it is conceivable that the data processing device from the recorded output lane cuts out all those pieces whose direction change exceeds the limit, and the selection of the reference lane is made under the remaining portions. A quality criterion that can be used to increase the number of potential reference lanes is to reduce the speed of the work machine when exiting the output route. If this speed detected is, it is possible, for example, in step c), only those portions of Ausgangsroute as Referenzfahrspur select on which a Mindestgeschwindigkeit not unterschritten was. So be difficult to fahrende Routenabschnitte that a low speed call, automatically from the choice of Referenzfahrspur excluded since it is likely that the use of such a section as Referenzfahrspur a reference to the Referenzfahrspur planned route also difficult and therefore slow to fahrende sections contains.

p0013Another quality criterion is the strength of directional changes occur on a route section. For example, the number of pre-selected reference lanes can be reduced by under several sections of the exit route that are over their entire length free border of the threshold changes in direction, one or more will be discarded, which have the strongest change in direction in step c).

p0014Another quality criterion compliance of the direction of a route section comes with a preferential direction into consideration. Thus, under several sections, which are free border of the threshold changes in direction along its length, a preferred direction are determined, and one or more sections, the direction of which deviates most from the preferred direction will be excluded from the selection as a reference lane. Thus, when the initial route already contains several parallel running side by side lanes, a selected high probability of this as a reference lane. Furthermore, when the output directions rings includes a path of the vehicle to the surface to be worked around, a portion of this path, which runs on a longitudinal edge of the surface along, be selected with higher probability as a reference lane as a part of the way along a transverse edge.

p0015Also, the length can be used as a quality criterion. Thus, for example of several sections of the output directions that are free border of the threshold changes in direction along its length, each section will be discarded, the length of which is less than a predetermined minimum length. This minimum length may be fixed, or it may be proportional to the longest section, so as to automatically take into account the dimensions of the surface to be processed.

p0016The initial route may include reverse driven sections, for example, when the vehicle stops in front of an obstacle, and resets the driver acknowledges and further drives the obstacle aside. Since such sections are not desirable in a reference lane, it is expedient that such backward driven sections are hidden already in the recorded output route.

p0017To suppress random influences such as a rocking back and forth of the vehicle on uneven ground in defining the reference lane, it may be expedient to smooth a selected in step c) section. Since the driver usually knows if deviations from the straight line back to random influences or selective directing, it is advantageous if the step of smoothing is carried out at the request of the driver.

p0018Preferably, the inventive method in real time during the processing of an agricultural area to be used as long as the already driven output route covers only part of the processed agricultural area, to obtain a reference lane, the uncovered to plan a route to that of the original route part of the area used is.

p0019Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a generating of an agricultural vehicle driven on a field Ausgangsrou- te, at the root of the inventive method;</dd><dt>FIG. 2</dt><dd>a first stage of processing the Ausgangsroute; </dd><dt>Fig. 3</dt><dd>a second stage of processing;</dd><dt>Fig. 4</dt><dd>a third processing stage;</dd><dt>Fig. 5</dt><dd>the directional distribution of the processing in the beitungsstadium <figref idrefs="f0002">Fig. 4</figref> extracted Routenabschnitte;</dd><dt>Fig. 6</dt><dd>a representation on a display screen of the vehicle, by means of which a user cut off automatically extracted Routenab- can select a reference lane;</dd><dt>Fig. 7</dt><dd>a display image, the light allows a user to edit a selected route segment;</dd><dt>Fig. 8</dt><dd>an illustration of the display screen of the vehicle, in which a selected reference lanes specified planned lane is to be seen;</dd><dt>Fig. 9</dt><dd>an example of a piece of a driven path, a de- rived from the traversed distance reference lane and one based on the reference lane planned additional lane; and</dd><dt>Fig. 10</dt><dd>Examples of the determination of the change in direction of the driven path.</dd></dl>

p0020The inventive method is applicable to any agricultural vehicle for processing of an agricultural area, such as a tractor, a forage harvester, a combine or the like, which is equipped with a system for automatic positioning such as a GPS receiver. The GPS receiver regularly calculates the position of the vehicle and transmits it to a computer. The computer is preferably a Bordcomputer the vehicle, but the method also on a stationary computer executable to the Ortsinformationen the GPS receiver fortlaufend, preferably via radio, be transferred.

p0021The computer reconstructs the distance traveled by the vehicle path based on the location information obtained in chronological order. Of the vehicle driven Ausgangsroute 1 is in<figref idrefs="f0001">Fig. 1</figref> Only the clearer representation because together with the outline of one of the vehicle to be processed field 2 illustrated. The computer requires a priori no information on the shape of the surface to be machined of the vehicle.

p0022As in <figref idrefs="f0001">Fig. 1</figref> to realize the vehicle is initially driven at the edge of the field 2 along expose headland areas.

p0023Although the edges of the field 2 are geradling, succeeds usually not to drive an exactly straight, parallel to the adjacent edge of way, because the vehicle must first also with an experienced driver some distance approaching the border or to him by remove before the driver can recognize that the distance of the vehicle requires the sidelines of the correction, and is able to steer. A rocking back and forth of the vehicle due to uneven ground may cause the detected path of the vehicle is not exactly straight runs, because a reference point of the vehicle, with respect to the vehicle position is determined, even when exact straight-ahead by a swaying of the vehicle can be deflected to the side.

p0024There are portions of the exit Route 1, in which the vehicle is reversing, such as sections 3 has at the corners of the field, resulting from the fact that the vehicle to fully edit the field surface, initially deep into the corner drives and then reset to a curve go to. But can even when driving along the field edges backwards driven sections 4 occur, for example when the driver encountered in the field working on an obstacle and must return to vacate it aside can, so it is not detected by a processing tool of the vehicle. It is assumed that reverse historical routes generally do not come as a reference lanes into consideration. You can therefore from the aufgezeichneten Ausgangsroute 1 deleted. So disintegrates the starting Route 1, as in<figref idrefs="f0001">FIG. 2</figref> shown, possibly in a plurality of separate sections 5-1, 5-2, 5-3, 6-1, 6-2, 6-3, each of which extends to an edge of the panel 2 along one corner to another, and short fragments 7, 8 at the corners.

p0025In the case of Section 4, in which the path of the vehicle is immediately before and after resetting substantially congruent, the parts of the route before and treated after resetting after deletion of section 4 as a contiguous section 5-3.

p0026For the remaining portions of the output Route 1 is through their entire length calculates the direction change and compared with a limit value. Path sections 9, in which the direction of change exceeds the limit, such as in particular the highly curved ends of the in<figref idrefs="f0001">FIG. 2</figref> shown sections 5-1, 5-2, 5-3, 6-1, 6-2, 6-3, 7, 8, is expected to come as a reference lanes not in question. These highly curved ends shortened sections 5-1, 5-2, 5-3, 6-1, 6-2, 6-3, 7, 8 are in<figref idrefs="f0001">Fig. 3</figref> shown.

p0027The computer calculates the length of the remaining route sections 5-1, 5-2, 5-3, 6-1, 6-2, 6-3, 7, 8, and compares it with a limit value. The limit can be fixed or dependent on the dimensions of the field. 2 In particular, as the limit value a predetermined Bruchteil the length of the longest among the sections 5-1, ... 6-3, 7, 8 to be adopted. The length of the fragments 7, 8 is below the limit, so that as a possible Referenzspuren in<figref idrefs="f0002">Fig. 4</figref> only the sections 5-1, 6-3 ... remain.

p0028In a next step, the preferred direction of the remaining sections is determined. <figref idrefs="f0002">Fig. 5</figref> qualitatively shows a graph of the directional distribution as the for the route sections <figref idrefs="f0002">Fig. 4</figref> could be obtained. A maximum 10 at 0 ° or 180 ° opening onto the two sections 5-1, 5-2 back to the straight right Feldrand entlanglaufen. Two smaller side lobes 11, 12 correspond to the section 5-3, which runs along the left edge of the field and how this is slightly bent. Another maximum 13 at 90 ° is due to the running along the narrow sides of the panel 2, sections 6-1, ... 6-3. The computer recognizes the highest maximum at 0 ° as the Vorzugsrichtung the field 2. Thus only come in Längsrichtung verlaufenden sections 5-1, ... 5-3 as Referenzfahrspuren into consideration.

p0029These are a user of the computer, preferably so the driver of the vehicle, for selection and editing. For this purpose, the vehicle has a touch-sensitive display screen or touch screen, on which, as in<figref idrefs="f0003">Fig. 6</figref> represented, in a central field the next reference lanes in question route sections 5-1, 5-2, 5-3 are shown cards excessively. As discussed above, data for shape of the field 2 for the process are not required; when present, may, however, be provided that the outline of the field 2 together with the computer vorausgewählten Routenabschnitten 5-1, 5-2, 5-3 on the Anzeigeschirm represented is.

p0030The user can select from among the displayed route sections 5-1, ... 5-3 one by on its representation, he taps his finger on the screen, or by by tapping shown next to the central field of the screen selection icons 14, 15 the route sections shown an activated after another. A user currently activated route section, here the section 5-3 is highlighted on the display screen, for example, by bold presentation.

p0031Another tool for selecting a route section under the displayed sections 5-1, ..., 5-3 can the driver a key 32 provided, through which he can instruct the computer to select the section with the greatest change in direction and of exclude further processing. Among the in<figref idrefs="f0003">Fig. 6</figref> Sections shown, the portion 5-3 the strongest change in direction, and if this change of direction would be due to inaccurate driving, it would be appropriate to exclude the section 5-3 of the selection as a reference lane. In this hypothetical situation is the Richtungsänderung of section 5-3, however, the non-linear course of Feldrandes due, and in the knowledge is the driver, the key 32 can not use.

p0032After activating a Routenabschnitts the user has the opportunity to touch one Auswahlsymbols 16 capitalized Routenabschnitt as a Referenzfahrspur select while in an editing mode to change from the typical Anzeigebild in <figref idrefs="f0003">Fig. 7</figref> is shown. On the now bisected the central field of the display screen beginning and end of the selected route section 5-3 are shown in an enlarged scale. Using the GPS Epmfängers recorded coordinate points 17 of the route section 5-3 are highlighted here in the form of small black circles. A stretch at the beginning of Section 5-3, on the not yet match the actually traveled route due to the previously traveled turning maneuver with the desired accuracy with the driver actually intended straight path is clearly visible in the enlarged view, and the driver can help of cursor keys 18, setting 19, at which the various recorded during running the output route 1 coordinate points 17 of the section is 5-3 actually begin. The currently selected as the start point of the reference lane coordinate point 17 is in the representation of<figref idrefs="f0003">Fig. 7</figref> indicated by a surrounding circle and by the fact that the reference lane as a bold line and adjacent thereto parts of the outgoing route are 1 as lean lines. Corresponding cursor keys 20, 21 to move the end point of the route section 5-3 are at the opposite edge of the screen, adjacent to the representation of the end of the route section 5-3, appears.

p0033In practice, the coordinate points are 17 that make up the section composed 5-3, never exactly on a straight line. Even with an ideally straight steered vehicle captured coordinate points have a random lateral offset relative to the direction of travel. Such random Seitwärtsversätze are not desired in a reference lane, since they would require constant steering corrections when following a balanced planned on such a reference lane lane. To avoid this, it is expedient to reduce Seitwärtsversätze in the recorded when driving the output Route 1 coordinate points by calculating for the successively recorded coordinate points 17 each their lateral offset with respect to the current direction of travel and suppresses random interference on the sideways offset by low-pass filtering or at least be reduced. It is also conceivable, the selected Routenabschnitt 5-3 to straighten out by the user individual among Koordinatenpunkten 17 of Routenabschnitts selects and the computer aufgezeichneten arc between the selected Koordinatenpunkten 17 by a straight line between the selected points replaced, or that the computer beispielsweise according to the known method of least Fehlerquadrate, a Ausgleichsgerade by Koordinatenpunkte 17 of the Referenzfahrspur selected section 5-3 calculates. Such straightening can trigger the display screen of the user, for example by pressing a corresponding button 22nd

p0034While such a straightening readily useful is when one of the straight right edge of the panel 2 along verlaufenden sections 5-1, 5-2 as Referenzfahrspur is selected, it is in the case of the section 5-3 problematic, since the left Feldrand, where the 5-3 entlangläuft, itself not a straight line is. Namely, when the Seitwärtsabweichung between actually been run way and straightened way greater than the Arbeitsbreite of the vehicle, then would use the straightened path instead of actually driven Routenabschnitts 5-3 as Referenzfahrspur cause parts of Feldfläche twice or not be processed. In order to avoid this problem, a key 23 can be provided, which enables the user to the section 5-3 in two Unterabschnitte 24-1, 24-2 (see<figref idrefs="f0003">Fig. 7</figref>) disassemble. The demarcation of the border between the two subsections 24-1, 24-2 can be effected purely manually by the driver by means of cursor keys one of the coordinate points 17 selects, on which the subdivision is to take place; Preferably, they can be supported by the computer, the calculated coordinate point to those 25 on the 5-3 section at which the latter has the greatest change in direction (see<figref idrefs="f0003">Fig. 6</figref>), And this point 25 as the boundary between the two parts suggests.

p0035The thus obtained from the 5-3 section portions 24-1, 24-2 each extend on a straight piece of the window perimeters and therefore can be smoothed appropriately or replaced by a best-fit line. An accurate determination of the beginning and end of the two sections thus obtained may again in the in<figref idrefs="f0003">Fig. 7</figref> Display mode illustrated done.

p0036A still further simplification may be that the computer before it will respond to a command from the user to straighten a selected route segment, which occur on this route section sideways deviations compared with the working width of the vehicle and propose to the section in several individually straightening sections disassemble when the maximum Seitwärtsabweichung a predetermined Bruchteil the Arbeitsbreite exceeds.

p0037As a result of straightening, as shown in <figref idrefs="f0003">Fig. 8</figref> shown in Sections 24-1, 24-2 two straight Referenzfahrspuren 26-1, 26-2 received, and based on these Referenzfahrspuren parallel to these planned lane 27 includes corresponding to the profile of the left Feldrandes a kink.

p0038<figref idrefs="f0004">Fig. 9</figref> illustrates how using a straightened Referenzfahrspur subsequently be traversed lanes planned be. A portion of the actual from the vehicle driven path with 28 designated, beiderseits the path 28 extends a hatched area 29 of the vehicle when traveling along the path 28 has been processed. The machined surface 29 is here, although at the same width on both sides of the path 28, but this is not a requirement. When the vehicle is an asymmetric Bearbeitungswerkzeug used or the Bezugspunkt on the vehicle to which the path 28 relative, is outside the Mittelebene of the vehicle is located, can be different widths of surface 29 beiderseits the path 28 resulting.

p0039One by straightening the driven path 28 obtained Referenzfahrspur is designated 30. If a next from the vehicle to be traversed track 31 parallel to Referenzfahrspur 30 extend to, then you have their distance from the distance traveled 28 less than the Arbeitsbreite B of the vehicle to be to the deviations between the path 28 and the Referenzfahrspur 30 to consider and a lückenlose Flächenbearbeitung to guarantee. The maximum deviation, by which the path 28 to 31 facing away from the to schedule lane side deviates from the reference lane 30, is denoted by d. one for reference lane 30 parallel track as new lane 31 therefore planned, their distance from the reference lane 30 is less by d than the working width B of the vehicle.

p0040The deviation d may be greater than the working width B, which has the consequence may find that the order d decreased distance between the reference lane 30 and the to schedule lane 31 is negative. In such a case, the next to be traversed track 31 is planned at the end remote from the area still to be processed side of the reference lane 30, and are following the track 31 to be traversed tracks on the surface to be machined side facing the track 31 at a distance B this planned.

p0041While in the above-described Vorgehensweise the based on the Referenzfahrspur 30 planned lanes all untereinander the distance B and have only the distance between the Referenzfahrspur 30 and the first planned lane 31 is less than B be can, alternatively, also the Referenzfahrspur so festgelegt be that also it has 31 the distance B from the first planned lane. For this purpose, it is sufficient that by straightening the driven path 28 obtained Referenzfahrspur by the distance d to the to planenden lanes opposite side to move, whereby in<figref idrefs="f0004">Fig. 9</figref> 30 'designated reference lane is obtained.

p0042To estimate the change in direction on the distance traveled 28, various methods are conceivable. One possibility is for example, that on board the vehicle together with the Ortsinformationen a Lenkradeinschlag monitored and the computer communicated is, and that the computer a threshold value of the Richtungsänderung than exceeded viewing, if a significant distance, for example several meters away the turning angle of the steering wheel exceeds a predetermined limit.

p0043Alternatively, gain information about the change in direction of the path 28 of the computer and from the transmitted location information itself. When the vehicle, for example, in each case after traveling a predetermined path location information such as in<figref idrefs="f0004">Fig. 10</figref> boldface Koordinatenpunkte 33-1, 33-2, 33-3 to the computer CONFERS, then on the central Koordinatenpunkt 33-2 aufgespannte angle α a useful measure of the Richtungsänderung at this point, and as the limit of Richtungsänderung can for the angle be predetermined α with a maximum deviation of 180 °. Alternatively, comes as a measure of the change in direction of the radius of a circular arc in consideration of connecting the points 33-1, 33-2, 33-3. The center of this arc is the intersection of the two bisectors on the lines (33-1, 33-2) and

p0044(33-2, 33-3). The smaller this radius is, the greater the change in direction.

p0045It may also be expedient, more than three Koordinatenpunkte for an estimate of the Richtungsänderung heranzuziehen. Thus, if between the points 33-1, 33-2, 33-3 further coordinate points are detected in 34, possibly also sudden steering maneuvers are detected over a short distance, which are hidden by a coarse grid of coordinate points. Since with increasing density of the coordinate points converge the three consecutive coordinate points spanned angle to 180 ° and calculating the radius of the connecting three points arc is always uncertain, it may be expedient to determine the angle between not immediately contiguous routes, such as between which, each in<figref idrefs="f0004">Fig. 10</figref> the points 33-1, 33-2 connected to a neighboring point 34th

numeral

p0046<dl id="dl0002" compact="compact"><dt>1</dt><dd>output route</dd><dt>2</dt><dd>field</dd><dt>3-6</dt><dd>section</dd><dt>7, 8</dt><dd>fragment</dd><dt>9</dt><dd>stretch</dd><dt>10-13</dt><dd>maximum</dd><dt>14-16</dt><dd>selection icon</dd><dt>17</dt><dd>coordinate point</dd><dt>18-21</dt><dd>cursor</dd><dt>22, 23</dt><dd>button</dd><dt>24</dt><dd>subsection</dd><dt>25</dt><dd>coordinate point</dd><dt>26</dt><dd>reference lane</dd><dt>27</dt><dd>lane</dd><dt>28</dt><dd>section</dd><dt>29</dt><dd>area</dd><dt>30</dt><dd>reference lane</dd><dt>31</dt><dd>lane</dd><dt>32</dt><dd>button</dd></dl>