CN-116661431-B - Obstacle avoidance method and device for autonomous operation of agricultural machinery

CN116661431BCN 116661431 BCN116661431 BCN 116661431BCN-116661431-B

Abstract

The invention provides an obstacle avoidance method and device for autonomous operation of an agricultural machine, wherein the method comprises the steps of obtaining geometric characteristic information of an obstacle on a linear operation path of the agricultural machine and size parameters of the agricultural machine, determining an initial obstacle avoidance path for the obstacle based on the geometric characteristic information and the size parameters, wherein the initial obstacle avoidance path consists of a plurality of initial obstacle avoidance points, constructing an agricultural machine obstacle avoidance track function by taking the initial obstacle avoidance points as track nodes, constructing an objective function based on the agricultural machine obstacle avoidance track function by taking the minimum power change of the agricultural machine in the obstacle avoidance process as a target, determining constraint conditions required to be met in the obstacle avoidance process of the agricultural machine, and solving the objective function based on the constraint conditions to obtain an optimal obstacle avoidance path corresponding to the agricultural machine. According to the embodiment of the invention, aiming at the obstacles in the agricultural field, the optimal obstacle avoidance path meeting the tracking requirement of the agricultural machinery is generated, so that the agricultural machinery can safely avoid the obstacles on the linear operation path of the agricultural machinery.

Inventors

WU CAICONG
WANG KE
ZHAO XIN
WEN LONG
CHEN ZHIBO

Assignees

中国农业大学

Dates

Publication Date: 20260505
Application Date: 20220218

Claims (7)

1. An obstacle avoidance method for autonomous operation of an agricultural machine is characterized by comprising the following steps: obtaining geometrical characteristic information of an obstacle on a linear operation path of an agricultural machine and a size parameter of the agricultural machine; Determining an initial obstacle avoidance path for the obstacle based on the geometric feature information and the size parameter, wherein the initial obstacle avoidance path is composed of a plurality of initial obstacle avoidance points; constructing an agricultural machinery obstacle avoidance track function by taking the initial obstacle avoidance points as track nodes; The constructing the agricultural machinery obstacle avoidance track function by taking the initial obstacle avoidance point as a track node comprises the following steps: According to the distance between adjacent track nodes, performing time distribution on the agricultural machinery obstacle avoidance track according to uniform time distribution to obtain a time distribution result of the agricultural machinery obstacle avoidance track; Based on the agricultural machinery obstacle avoidance track function, taking the minimum power change of the agricultural machinery in the obstacle avoidance process as a target, finding the minimum value of the snap with the aim of minimizing the snap, constructing an objective function, and determining constraint conditions required to be met in the agricultural machinery obstacle avoidance process; The determining constraint conditions to be met in the obstacle avoidance process of the agricultural machinery comprises the following steps: Constructing an equality constraint condition based on the fact that the position, the speed and the acceleration of a first track node and a last track node on the initial obstacle avoidance path are preset values, and the position, the speed and the acceleration of an intermediate track node on the initial obstacle avoidance path are kept unchanged; solving the objective function based on the constraint condition to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery; based on the constraint condition, solving the objective function to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery, wherein the method comprises the following steps: and solving the objective function by adopting a QP (program guide) solver based on the constraint condition to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery.
2. The obstacle avoidance method for autonomous operation of an agricultural machine of claim 1, wherein the determining an initial obstacle avoidance path for the obstacle based on the geometric feature information and the dimensional parameter comprises: puffing the obstacle based on the geometric characteristic information and the size parameter to obtain an obstacle characteristic outline pattern corresponding to the obstacle; And determining an initial obstacle avoidance path aiming at the obstacle by adopting an improved shortest tangent method according to the obstacle characteristic outline pattern corresponding to the obstacle.
3. The obstacle avoidance method for autonomous operation of an agricultural machine according to claim 2, wherein, in the case that the obstacle feature profile is an obstacle feature circle, the determining, according to the obstacle feature profile corresponding to the obstacle, an initial obstacle avoidance path for the obstacle by using an improved shortest tangent method includes: Determining a second initial obstacle avoidance point and a sixth initial obstacle avoidance point on the linear operation path of the agricultural machine according to the intersection point of the obstacle characteristic circle and the linear operation path of the agricultural machine and the size parameter of the agricultural machine; determining tangents of the obstacle characteristic circles on the basis of the second initial obstacle avoidance point and the sixth initial obstacle avoidance point, wherein the tangents are a third initial obstacle avoidance point and a fifth initial obstacle avoidance point respectively; Determining a fourth initial obstacle avoidance point according to the intersection point of a first connecting line and a second connecting line, wherein the first connecting line is a connecting line between the second initial obstacle avoidance point and the third initial obstacle avoidance point, and the second connecting line is a connecting line between the sixth initial obstacle avoidance point and the fifth initial obstacle avoidance point; Taking the intersection point of a first parallel line and a second parallel line as the circle center, wherein the first parallel line is a parallel line with the distance from the straight line operation path of the agricultural machine equal to the minimum turning radius of the agricultural machine, the second parallel line is a parallel line with the distance from the connecting line of the second initial obstacle avoidance point and the fourth initial obstacle avoidance point equal to the minimum turning radius of the agricultural machine, a first agricultural machine minimum turning radius circle is determined, and a first initial obstacle avoidance point is determined according to the tangent point of the first agricultural machine minimum turning radius circle and the straight line operation path of the agricultural machine; taking the intersection point of the first parallel line and the third parallel line as the circle center, wherein the third parallel line is a parallel line with the distance equal to the minimum turning radius of the agricultural machinery from the connecting line of the sixth initial obstacle avoidance point and the fourth initial obstacle avoidance point, determining a second minimum turning radius circle of the agricultural machinery, and determining a seventh initial obstacle avoidance point according to the tangent point of the second minimum turning radius circle of the agricultural machinery and the linear operation path of the agricultural machinery; And determining an initial obstacle avoidance path aiming at the obstacle according to the first initial obstacle avoidance point, the second initial obstacle avoidance point, the third initial obstacle avoidance point, the fourth initial obstacle avoidance point, the fifth initial obstacle avoidance point, the sixth initial obstacle avoidance point and the seventh initial obstacle avoidance point.
4. The obstacle avoidance method for autonomous operation of an agricultural machine according to claim 2, wherein, in the case that the obstacle feature profile is an obstacle feature rectangle, the determining, according to the obstacle feature profile corresponding to the obstacle, an initial obstacle avoidance path for the obstacle by using an improved shortest tangent method includes: Determining a ninth initial obstacle avoidance point and a thirteenth initial obstacle avoidance point on the linear operation path of the agricultural machinery according to the intersection point of the obstacle characteristic rectangle and the linear operation path of the agricultural machinery and the size parameter of the agricultural machinery; On the basis of the ninth initial obstacle avoidance point and the thirteenth initial obstacle avoidance point, respectively making a connection line between the geometric center of the obstacle characteristic rectangle and a first vertex and a perpendicular line between the geometric center of the obstacle characteristic rectangle and a connection line of a second vertex, determining a first foot drop and a second foot drop, taking the geometric center of the obstacle characteristic rectangle as a circle center, and taking the distance between the geometric center of the obstacle characteristic rectangle and the first foot drop as a radius to obtain the excircle of the obstacle characteristic rectangle, wherein a line segment formed by connecting the first vertex and the second vertex of the obstacle characteristic rectangle is not intersected with the linear operation path of the agricultural machine; selecting a tangential point on an arc with an included angle smaller than 180 degrees, which is formed by the geometric centers of the first vertical leg, the second vertical leg and the obstacle characteristic rectangle, as an eleventh initial obstacle avoidance point according to the tangential point of the outer circle of the obstacle characteristic rectangle and the parallel line of the agricultural machinery linear operation path; Determining a tenth initial obstacle avoidance point according to the intersection point of a fourth parallel line and a third connecting line, wherein the fourth parallel line is a parallel line of the agricultural machinery straight line operation path passing through the eleventh initial obstacle avoidance point, the third connecting line is a connecting line of the ninth initial obstacle avoidance point and the first vertical foot, the tenth initial obstacle avoidance point is determined, and the twelfth initial obstacle avoidance point is determined according to the intersection point of a fifth parallel line and the fourth connecting line, wherein the fifth parallel line is a parallel line of the agricultural machinery straight line operation path passing through the eleventh initial obstacle avoidance point, and the fourth connecting line is a connecting line of the thirteenth initial obstacle avoidance point and the second vertical foot; taking the intersection point of a sixth parallel line and a seventh parallel line as the circle center, wherein the sixth parallel line is a parallel line with the distance from the linear operation path of the agricultural machine equal to the minimum turning radius of the agricultural machine, the seventh parallel line is a parallel line with the distance from the connecting line of a ninth initial obstacle avoidance point and a tenth initial obstacle avoidance point equal to the minimum turning radius of the agricultural machine, determining a third minimum turning radius circle, and determining an eighth initial obstacle avoidance point according to the tangent point of the third minimum turning radius circle and the linear operation path of the agricultural machine; Taking the intersection point of the sixth parallel line and the eighth parallel line as the circle center, wherein the eighth parallel line is a parallel line with the distance equal to the minimum turning radius of the agricultural machinery from the connecting line of the thirteenth initial obstacle avoidance point and the twelfth initial obstacle avoidance point, determining a fourth agricultural machinery minimum turning radius circle, and determining a fourteenth initial obstacle avoidance point according to the tangent point of the fourth agricultural machinery minimum turning radius circle and the agricultural machinery linear operation path; and determining an initial obstacle avoidance path aiming at the obstacle according to the eighth initial obstacle avoidance point, the ninth initial obstacle avoidance point, the tenth initial obstacle avoidance point, the eleventh initial obstacle avoidance point, the twelfth initial obstacle avoidance point, the thirteenth initial obstacle avoidance point and the fourteenth initial obstacle avoidance point.
5. An obstacle avoidance device for autonomous operation of an agricultural machine, comprising: The acquisition module is used for acquiring geometric characteristic information of an obstacle on a linear operation path of the agricultural machine and size parameters of the agricultural machine; the first processing module is used for determining an initial obstacle avoidance path aiming at the obstacle based on the geometric characteristic information and the size parameter, wherein the initial obstacle avoidance path is composed of a plurality of initial obstacle avoidance points; The second processing module is used for constructing an agricultural machinery obstacle avoidance track function by taking the initial obstacle avoidance points as track nodes; The constructing the agricultural machinery obstacle avoidance track function by taking the initial obstacle avoidance point as a track node comprises the following steps: According to the distance between adjacent track nodes, performing time distribution on the agricultural machinery obstacle avoidance track according to uniform time distribution to obtain a time distribution result of the agricultural machinery obstacle avoidance track; the third processing module is used for finding out the minimum value of the snap with the aim of minimizing the snap based on the agricultural machinery obstacle avoidance track function and taking the minimum power change of the agricultural machinery in the obstacle avoidance process as the aim, constructing an objective function, and determining constraint conditions to be met in the agricultural machinery obstacle avoidance process; The determining constraint conditions to be met in the obstacle avoidance process of the agricultural machinery comprises the following steps: Constructing an equality constraint condition based on the fact that the position, the speed and the acceleration of a first track node and a last track node on the initial obstacle avoidance path are preset values, and the position, the speed and the acceleration of an intermediate track node on the initial obstacle avoidance path are kept unchanged; the solving module is used for solving the objective function based on the constraint condition to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery; based on the constraint condition, solving the objective function to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery, wherein the method comprises the following steps: and solving the objective function by adopting a QP (program guide) solver based on the constraint condition to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery.
6. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the obstacle avoidance method of any one of claims 1 to 4 when the program is executed.
7. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the obstacle avoidance method of autonomous agricultural oriented operation of any one of claims 1 to 4.

Description

Obstacle avoidance method and device for autonomous operation of agricultural machinery Technical Field The invention relates to the technical field of automatic navigation of agricultural machinery, in particular to an obstacle avoidance method and device for autonomous operation of agricultural machinery. Background In recent years, with the rapid increase of the economy in China, the quantity and proportion of non-agriculture employment are continuously increased, the labor force of the young and young villages is accelerated to flow from agriculture to non-agriculture, the quantity of the agricultural labor force is continuously reduced, and the aging trend is increasingly promoted. Correspondingly, the labor cost of China is continuously increased, the production cost is increased, the international market competitiveness of agricultural products is weakened, the labor input quantity is reduced by improving the labor productivity, the main way for reducing the agricultural production cost is realized, and the market demand derived from the increase of the labor cost inevitably leads to innovation and application of labor substitution technology. The agricultural machinery automatic navigation technology is an unmanned agricultural critical control technology and is also the foundation of unmanned agricultural development. With the popularization and application of satellite systems in agriculture, the development of automatic navigation technology based on the global navigation satellite system is mature, and the practical application is the most extensive, so that the satellite system is a representative product of the current agricultural automatic navigation system. However, the current popular automatic driving technology of agricultural machinery is not enough, when an automatic driving system works, a digital boundary of a field is usually generated based on the boundary of the field to carry out path planning, but an operator is still required to drive the agricultural machinery to carry out obstacle avoidance and turning around, and at present, although part of agricultural machinery can realize unmanned operation, no consideration is given to the obstacles in the field of the field, so that an obstacle avoidance algorithm becomes a key technology for improving the usability of the automatic driving system of the agricultural machinery. Disclosure of Invention The invention provides an obstacle avoidance method and device for autonomous operation of an agricultural machine, which are used for solving the problem of how to generate an obstacle avoidance curve aiming at farmland obstacles in the field of automatic navigation of the agricultural machine. The invention provides an obstacle avoidance method for autonomous operation of an agricultural machine, which comprises the following steps: obtaining geometrical characteristic information of an obstacle on a linear operation path of an agricultural machine and a size parameter of the agricultural machine; Determining an initial obstacle avoidance path for the obstacle based on the geometric feature information and the size parameter, wherein the initial obstacle avoidance path is composed of a plurality of initial obstacle avoidance points; constructing an agricultural machinery obstacle avoidance track function by taking the initial obstacle avoidance points as track nodes; based on the agricultural machinery obstacle avoidance track function, constructing an objective function by taking the minimum power change of the agricultural machinery in the obstacle avoidance process as a target, and determining constraint conditions to be met in the agricultural machinery obstacle avoidance process; And solving the objective function based on the constraint condition to obtain an optimal obstacle avoidance path corresponding to the agricultural machinery. Optionally, the determining an initial obstacle avoidance path for the obstacle based on the geometric feature information and the size parameter includes: puffing the obstacle based on the geometric characteristic information and the size parameter to obtain an obstacle characteristic outline pattern corresponding to the obstacle; And determining an initial obstacle avoidance path aiming at the obstacle by adopting an improved shortest tangent method according to the obstacle characteristic outline pattern corresponding to the obstacle. Optionally, when the obstacle feature profile is an obstacle feature circle, determining, according to the obstacle feature profile corresponding to the obstacle, an initial obstacle avoidance path for the obstacle by using an improved shortest tangent method includes: Determining a second initial obstacle avoidance point and a sixth initial obstacle avoidance point on the linear operation path of the agricultural machine according to the intersection point of the obstacle characteristic circle and the linear operation path of the agricultural machine and the size pa