CN108592910A - A kind of agricultural unmanned aerodynamic ship paths planning method based on wind direction - Google Patents

Abstract

The invention discloses a path planning method for agricultural unmanned aerodynamic boats based on wind direction, which comprises the steps of: obtaining position coordinate information of corner points on the edge of paddy fields; and setting the distance between the working area and the edge of paddy fields according to the turning radius of the aerodynamic boat and the planting conditions of rice use the wind direction sensor to monitor the wind direction information, and process the wind direction as a standard value; according to the wind direction information, set the initial path direction, initial steering and path line spacing of the aerodynamic ship in the operation area; find the closest path to the first path At the corner point of the paddy field edge, establish a straight line passing through the corner point and parallel to the initial path direction; according to the initial steering and path line spacing, plan n paths parallel to the above straight line in the operation area, when the path intersects with the boundary of the operation area When it is less than 2, the path planning in the operation area is completed. The invention can greatly reduce the interference of external wind on the course of the unmanned aerodynamic ship, and reduce the lateral drift during navigation.

Description

A path planning method for agricultural unmanned aerodynamic ships based on wind direction

technical field

The invention relates to the field of path planning, in particular to a path planning method for agricultural unmanned aerodynamic ships based on wind direction.

Background technique

In recent years, the aging population and the shortage of agricultural workers have seriously restricted the sustainable development of agriculture in my country. However, with the unprecedented development of computer technology and sensor technology, a series of automated agricultural machinery has been developed and even put on the market. The concept of smart agriculture has begun to become a reality. Among them, the path planning problem of unmanned agricultural machinery is one of the hot research fields.

At this stage, the field path planning schemes of agricultural machinery are mainly divided into regional path planning schemes and global path planning schemes. Regional path planning is to use the camera or laser, ultrasonic, radar and other sensors mounted on the agricultural machinery to detect the surrounding environment of the agricultural machinery, obtain the corresponding farmland environmental characteristic information, and plan the operation path of the agricultural machinery in real time. Global path planning is to use the global positioning system to geometrically divide the farmland, and plan the operation path according to the planting conditions of the crops. Considering the convenience of field management of crops, most of the current path planning specific solutions are to make agricultural machines work along the direction of crop rows.

The above-mentioned existing agricultural machinery path planning scheme meets the specific navigation operation requirements for traditional agricultural machinery such as tractors, rice transplanters, and harvesters. However, for agricultural unmanned aerodynamic ships used in shallow water environments such as paddy fields, it is difficult to meet the demand for high-precision navigation. The unmanned aerodynamic boat is a hard flat-bottomed boat that uses an internal combustion engine or an electric motor placed on the upper part of the hull to drive the air propeller to generate power. Because all of its power plants are above the water surface, the draft of the hull is very shallow, and its ability to resist external wind disturbance is poor. When planning according to the traditional path along the crop row, strong external wind acts on the hull of the aerodynamic boat, which can change the speed and course of the boat, and cause obvious lateral drift. This is extremely detrimental to the precise navigation of an aerodynamic boat.

Contents of the invention

When following the traditional path planning along the crop row, strong external wind acts on the hull of the aerodynamic boat, which can change the speed and course of the boat and cause obvious lateral drift. In view of this technical problem, the purpose of the present invention is to provide a path planning method for agricultural unmanned aerodynamic ships based on wind direction, so as to greatly reduce the interference of external wind on the course of unmanned aerodynamic ships and reduce the lateral drift during navigation .

To achieve the above object, the present invention adopts the following technical solutions:

A method for path planning of agricultural unmanned aerodynamic ships based on wind direction, comprising steps:

(1) Obtain the position coordinate information of the edge corner point of the paddy field;

(2) According to the turning radius of the aerodynamic ship and the rice planting conditions, set the safe distance between the operation area and the edge of the paddy field;

(3) Utilize the wind direction sensor to monitor the wind direction, and process the wind direction as a standard value;

(4) According to the standard value information of the wind direction, set the initial path direction θ _firstPath , initial steering and path line spacing d _space of the aerodynamic ship in the operation area;

(5) Determine the corner point p ₁ of the paddy field edge closest to the first path, and establish a straight line passing through the corner point p ₁ of the paddy field edge and parallel to the initial path direction θ _firstPath ;

(6) According to the initial steering and the path row spacing d _space , plan n paths parallel to the straight line in the operation area, and complete the path planning in the operation area when the intersection point between the path and the boundary of the operation area is less than 2.

Preferably, in step (1), use the GPS receiver to locate the latitude and longitude coordinate information of the edge corners of the paddy field. In order to achieve accurate path planning, the latitude and longitude coordinates need to be converted to the universal Transverse Mercator coordinate system.

As preferably, in step (3), use the geomagnetic azimuth sensor to find the geographical true north direction, place the north of the wind direction sensor in the geographical true north direction, record the wind direction sample information for a period of time, and use the following formula to make a standard value for the wind direction Processing to obtain the standard value information of the wind direction. Since this standard value can well represent the overall situation of the wind direction during this period.

Among them, n is the number of wind direction samples recorded, and x _i is the wind direction sample value at time i.

Preferably, in step (5), the direction of the vectors from each edge corner point of the paddy field to the other edge corner points is calculated sequentially, if the directions of the three vectors starting from a certain edge corner point are all on the same side of the initial path direction θ _firstPath , the edge corner point is the edge corner point p ₁ of the paddy field closest to the first path.

Further, the straight line passing through the corner point p1 _of the paddy field edge is:

y=a _path1 x+b _point

Among them: a _path1 is the slope of the straight line, b _point is the intercept of the straight line;

Then, according to the line spacing d _space information and steering information, the straight line where the nth path is planned is:

y=a _path x+b _move

in:

The slope of the line: a _path = a _path1 ,

Straight line intercept:

or

In the formula, n is the nth path planned.

Description of drawings

Figure 1 is the real-time wind direction within 1 hour;

Figure 2 is an example diagram of path planning;

Figure 3 is an example diagram of path planning.

Detailed ways

The present invention will be described in detail below in conjunction with the embodiments and accompanying drawings, but the present invention is not limited thereto.

Due to the shallow draft of the aerodynamic boat, it can completely float above the water surface in shallow water environments such as paddy fields. Driving in any direction will not affect the normal growth of rice seedlings. The wind direction of natural wind is relatively stable. For example, China has a subtropical monsoon climate, with east and southeast winds prevailing in spring and summer, and westerly and northwest winds prevailing in autumn and winter. Figure 1 is the real-time wind direction of the wind recorded by the wind sensor within one hour. It can be seen that within one hour, the wind direction basically falls in an acute angle of 60° within the range of 240°-300°.

The agricultural unmanned aerodynamic ship path planning method in the present embodiment utilizes C language to design and develop an agricultural unmanned aerodynamic ship path planning software platform based on the wind direction under the Visual Studio programming environment of Microsoft Corporation of the United States. The unmanned aerodynamic ship performs navigation operations according to the route planned by the software platform. The specific path planning implementation process is as follows:

(1) Obtain the position coordinate information of the edge corner point of the paddy field

The acquisition of the position coordinate information of the edge corners of the paddy field is the basic work of the present invention. It is to determine the edge, size and shape of the paddy fields. The invention utilizes a high-precision GPS receiver to manually collect position coordinate information of paddy field edge corner points. Transform the obtained original coordinate information (longitude and latitude information) of the corner points of the edge of the paddy field into the Universal Transverse Mercator (UTM) coordinate system, as shown in p1-p4 in Figure 2.

(2) Setting the safe operating area

According to the turning radius of the aerodynamic ship and the rice planting conditions, the safe operation area is set. As shown in Figure 2, if the safety distance is d _safe meters, the safe operation area is the actual operation area [p ₁ '～p' ₄ ] after the edge of the original paddy field shrinks inward by d _safe meters.

(3) Record and calculate the wind direction

Use the geomagnetic azimuth sensor to find the geographic true north, and place the north of the wind sensor in the geographic true north. After recording the wind direction sample information for 30 seconds, refer to the formula (1) to find the standard value of the wind direction sample as the reference wind direction value for this route planning.

Among them, n is the number of wind direction samples recorded, and x _i is the wind direction sample value at time i.

(4) Set path planning parameters

According to the standard value of the wind direction sample, set the initial path direction θ _firstPath , the initial turning direction and the path row spacing d _space . The default setting is that the initial path direction is consistent with the standard value of the wind direction sample θ _firstPath = θ _wind ; the initial steering is right steering, and the row spacing is five meters.

(5) Determine the position of the waypoint

Taking the initial turning to the right as an example, calculate the direction of the vectors from each edge corner point of the paddy field to the other edge corner points in turn, for example and and many more. When the directions of the three vectors starting from a certain edge corner point are all to the right of the initial path direction θ _firstPath , the edge corner point is the corner point closest to the first path, such as the edge corner point p in Figure 2 ₁ .

y=a _path1 x+b _point

Among them: a _path1 is the slope of the straight line, b _point is the intercept of the straight line;

Then, according to the line spacing d _space information and steering information, the straight line where the nth path is planned is:

y=a _path x+b _move

in:

The slope of the line: a _path = a _path1 ,

Straight line intercept:

or

In the formula, n is the nth path planned.

Then the two intersection points of the straight line and the safe operation area [p ₁ '～p' ₄ ] are the path point positions. When the new intersection point is less than 2 after a certain n+1, it means that the safe operation area is exceeded, that is, the path planning is completed. Figure 3 is an example of a paddy field path planning done on Google Maps. Among them, the corner coordinates of the paddy field edge (43°4'29.15"N, 141°20'16.35"E), (43°4'29.85"N, 141°20'17.83"E), (43°4'30.54"N , 141°20'17.23"E) and (43°4'29.84"N, 141°20'15.76"E), the standard value of the wind direction is 163.2°, the path line spacing is 4 meters, and the safety distance is 3 meters.

The above is only an example of the implementation of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included within the protection scope of the present invention .

Claims (5)

1. a kind of agricultural unmanned aerodynamic ship paths planning method based on wind direction, which is characterized in that including step：

(1) location coordinate information of the edge angle point in paddy field is obtained；

(2) according to the turning radius of aerodynamic ship and Rice Cropping situation, safety of the setting operating area apart from paddy field edge Distance；

(3) it utilizes wind transducer to monitor wind direction, and standard value processing is made to wind direction；

(4) according to the standard value information of wind direction, initial path direction θ of the setting air Power Vessel in operating area_firstPath、 Initial steer and path line space d_space；

(5) the nearest paddy field edge angle point p of the first paths of distance is determined₁, established paddy field edge angle point p₁And with initial path side To θ_firstPathParallel straight line；

(6) according to initial steer and path line space d_space, the road of n items and the straight line parallel is planned in the operating area Diameter, when the boundary intersection of path and operating area is less than 2, the path planning that fulfils assignment in region.

2. agricultural unmanned aerodynamic ship paths planning method as described in claim 1, which is characterized in that in step (1), The original coordinates information of paddy field edge angle point is positioned using GPS receiver, and is transformed into conduct under Universal Trans Meridian coordinate system The location coordinate information.

3. agricultural unmanned aerodynamic ship paths planning method as described in claim 1, which is characterized in that in step (3), Geographical direct north is found using magnetic field orientation sensor, the north of wind transducer is placed in geographical direct north, records one section After the wind direction sample information of time, standard value processing is made to wind direction using following formula, obtains the standard value information of wind direction；

Wherein, n is the wind direction sample number of record, x_iFor the wind direction sample value at i moment.

4. agricultural unmanned aerodynamic ship paths planning method as described in claim 1, which is characterized in that in step (5), Each edge angle point in paddy field is calculated successively to the direction of remaining edge angle point vector, if a certain edge angle point set out 3 are vectorial Direction is in initial path direction θ_firstPathHomonymy when, and combine initial steer information, determine near first paths water Field edge angle point p₁。

5. agricultural unmanned aerodynamic ship paths planning method as claimed in claim 4, which is characterized in that set paddy field edge Angle point p₁Straight line be：

Y=a_path1x+b_point

Wherein：a_path1For the slope of the straight line, b_pointFor the intercept of the straight line；

Then according to line space d_spaceInformation and direction information, straight line where the nth bar path cooked up are：

Y=a_pathx+b_move

Wherein：

Straight slope：a_path=a_path1

Linear intercept：

Or

N is the nth bar path of planning in formula.