Disclosure of Invention
The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.
The embodiment of the disclosure provides an AGV running speed control method, device and medium based on path curvature, which reasonably plans the running speed of an AGV along a planned path based on the path curvature and can ensure stable transportation of cargoes.
In a first aspect, an embodiment of the present disclosure provides a method for controlling a traveling speed of an AGV based on a path curvature, including:
acquiring curvature matrixes, minimum curvature threshold values and speed threshold values of all points in a planned path;
determining the maximum curvature in the planned path according to the curvature matrix;
determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold;
determining the theoretical speed of the AGV at each point in the planned path according to the speed threshold; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed;
determining the planned speed of the AGV at each point according to the maximum speed of each point in the planned path and the theoretical speed of the AGV at the point;
and controlling the AGV to travel along the planned path according to the planned speed.
In some embodiments, the determining the maximum speed for each point in the planned path according to the maximum curvature, minimum curvature threshold, and speed threshold comprises:
performing threshold processing on the curvature matrix to obtain the effective curvature of each point in the planned path;
and proportional conversion is carried out on the speed threshold according to the maximum curvature, the minimum curvature threshold and the effective curvature of each point in the planned path, so that the maximum speed of each point in the planned path is obtained.
In some embodiments, the formula for thresholding the curvature matrix is: k (K)s (i)=max(k(i),Kvalue ) Wherein K (i) represents the curvature of the ith point in the planned path, Kvalue Representing a minimum curvature threshold, K, of the planned paths (i) Representing an effective curvature of an i-th point in the planned path;
the calculation formula of the maximum speed of each point in the planned path is as follows:
wherein v ismax (i) To plan the maximum speed of the ith point in the path, vvalue_max Represents a maximum speed threshold, vvalue_min Representing a minimum speed threshold.
In some embodiments, the determining the theoretical speed of the AGV at each point in the planned path based on the speed threshold includes:
acquiring rated uniform acceleration of the AGV;
determining a displacement and speed relation when the AGV performs uniform acceleration linear motion;
determining the speed of the AGV at each point according to the relation;
and determining the theoretical speed of the AGV at each point according to the speed threshold and the speed of the AGV at each point.
In some embodiments, the determining the theoretical speed of the AGV at each point based on the speed threshold and the speed of the AGV at each point comprises:
the maximum theoretical speed of the AGV at the ith point is determined according to the following formula:
vH (i)=min(vi ,vvalue_max );
the minimum theoretical speed of the AGV at the ith point is determined according to the following equation:
vL (i)=max(vi vvalue_min );
wherein v isvalue_max Representing the mostHigh speed threshold, vvalue_min Represents a minimum speed threshold, a is the rated uniform acceleration of the AGV, ds is the travel distance of the AGV per unit time, vi For the speed of the AGV at the ith point, vi-1 The speed of the AGV at the i-1 th point;
the speed of AGV at the ith point is calculated as follows
In some embodiments, the determining the planned speed of the AGV at each point in the planned path according to the maximum speed of the AGV at the point and the theoretical speed of the AGV at the point includes:
comparing the maximum speed of each point in the planned path with the theoretical speed of the AGV at the point;
when the maximum speed of any point in the planned path is greater than the maximum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the maximum theoretical speed of the AGV at the point;
when the maximum speed of any point in the planned path is smaller than the minimum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the minimum theoretical speed of the AGV at the point;
and when the maximum speed of any point in the planned path is greater than or equal to the minimum theoretical speed of the AGV at the point and less than or equal to the maximum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the maximum speed of the point.
In some embodiments, the controlling the AGV to travel along the planned path according to the planned speed includes:
carrying out convolution smoothing filtering on the planning speed of the AGV at each point to obtain the running speed of the AGV;
and controlling the AGV to travel along the planned path according to the travel speed.
In a second aspect, an embodiment of the present disclosure further provides an AGV traveling vehicle speed control device based on a path curvature, including:
the acquisition module is used for acquiring curvature matrixes, minimum curvature threshold values and speed threshold values of all points in the planned path;
a maximum curvature determining module, configured to determine a maximum curvature in the planned path according to the curvature matrix;
the maximum speed determining module is used for determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold;
the theoretical speed determining module is used for determining the theoretical speed of each point in the planned path of the AGV according to the speed threshold value; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed;
the planning speed determining module is used for determining the planning speed of the AGV at each point according to the maximum speed of each point in the planning path and the theoretical speed of the AGV at the point;
and the running control module is used for controlling the AGV to run along the planned path according to the planned speed.
In a third aspect, embodiments of the present disclosure also provide an AGV, comprising: the AGV traveling vehicle speed control method based on the path curvature according to the first aspect is realized by a memory, a processor and a computer program stored on the memory and capable of running on the processor when the processor executes the computer program.
In a fourth aspect, the disclosed embodiments also provide a computer readable storage medium storing computer executable instructions for performing the path curvature-based AGV travel vehicle speed control method according to the first aspect.
The disclosed embodiments include: acquiring curvature matrixes, minimum curvature threshold values and speed threshold values of all points in a planned path; determining the maximum curvature in the planned path according to the curvature matrix; determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed; determining the planned speed of the AGV at each point according to the maximum speed of each point in the planned path and the theoretical speed of the AGV at the point; and controlling the AGV to travel along the planned path according to the planned speed.
Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Detailed Description
In order to make the objects, technical solutions and advantages of the present disclosure more apparent, the present disclosure will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present disclosure.
It should be noted that although functional block division is performed in a device diagram and a logic sequence is shown in a flowchart, in some cases, the steps shown or described may be performed in a different order than the block division in the device, or in the flowchart. The terms first, second and the like in the description, in the claims and in the above-described figures, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.
The disclosure provides a method, a device and a medium for controlling an AGV running speed based on a path curvature, wherein the method comprises the following steps: acquiring curvature matrixes, minimum curvature threshold values and speed threshold values of all points in a planned path; determining the maximum curvature in the planned path according to the curvature matrix; determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed; determining the planned speed of the AGV at each point according to the maximum speed of each point in the planned path and the theoretical speed of the AGV at the point; and controlling the AGV to travel along the planned path according to the planned speed.
The inventor aims at solving the technical problems in the background art, and researches find that as the curvature and the turning radius are reciprocal, and the larger the turning radius (i.e. the smaller the curvature), the more straight the path, the larger the allowable running speed, the smaller the turning radius (i.e. the larger the curvature), the more curved the path, and the smaller the allowable running speed, based on the fact, the invention provides an AGV running speed control method, device and medium based on the path curvature, which performs speed planning on each point in a planned path based on the path curvature characteristic, and the obtained planned speed can ensure stable transportation of goods when the AGV runs.
As shown in fig. 1, fig. 1 is a flowchart of a method for controlling a traveling speed of an AGV based on a curvature of a path according to an embodiment of the present disclosure, including, but not limited to, the following steps:
step S100, a curvature matrix, a minimum curvature threshold value and a speed threshold value of all points in a planned path are obtained;
step S200, determining the maximum curvature in the planned path according to the curvature matrix;
step S300, determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold;
step S400, determining the theoretical speed of the AGV at each point in the planned path according to the speed threshold; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed;
step S500, determining the planning speed of the AGV at each point according to the maximum speed of each point in the planning path and the theoretical speed of the AGV at the point;
and step S600, controlling the AGV to travel along the planned path according to the planned speed.
It should be noted that, the curvature matrix in this embodiment includes curvatures of all points in the planned path, the minimum curvature threshold and the speed threshold are calibrated in advance, and the calibration basis is to ensure a value interval of stable running of the AGV, which can be determined according to multiple tests.
In a modified embodiment, in step S300, the determining the maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold and the speed threshold includes:
performing threshold processing on the curvature matrix to obtain the effective curvature of each point in the planned path;
the formula for thresholding the curvature matrix is as follows: k (K)s (i)=max(k(i),Kvalue ) Wherein K (i) represents the curvature of the ith point in the planned path, Kvalue Representing a minimum curvature threshold, K, of the planned paths (i) Representing an effective curvature of an i-th point in the planned path;
proportional conversion is carried out on the speed threshold according to the maximum curvature, the minimum curvature threshold and the effective curvature of each point in the planned path, and the maximum speed of each point in the planned path is obtained:
the calculation formula of the maximum speed of each point in the planned path is as follows:
wherein v ismax (i) To plan a pathMaximum speed of the ith point in (v)value_max Represents a maximum speed threshold, vvalue_min Representing a minimum speed threshold.
In an improved embodiment, said determining the theoretical speed of the AGV at each point in the planned path based on said speed threshold comprises:
acquiring rated uniform acceleration of the AGV;
determining a displacement and speed relation when the AGV performs uniform acceleration linear motion;
determining the speed of the AGV at each point according to the relation;
and determining the theoretical speed of the AGV at each point according to the speed threshold and the speed of the AGV at each point.
The displacement and speed relation formula when the AGV carries out uniform acceleration linear motion is as follows:wherein a is the rated uniform acceleration of the AGV, ds is the travel distance of the AGV in each unit time, vi For the speed of the AGV at the ith point, vi-1 The speed of the AGV at the i-1 th point; the speed of the AGV at the ith point can be expressed as
The maximum theoretical speed of the AGV at the ith point is
The minimum theoretical speed of the AGV at the ith point is
The rated uniform acceleration a of the AGV is obtained from the characteristics of the motor driver, ifNamely, the deceleration and the uniform acceleration a are reversed.
In an improved embodiment, the determining the planned speed of the AGV at each point in the planned path according to the maximum speed of the AGV at the point and the theoretical speed of the AGV at the point comprises:
comparing the maximum speed of each point in the planned path with the theoretical speed of the AGV at the point;
when the maximum speed of any point in the planned path is greater than the maximum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the maximum theoretical speed of the AGV at the point;
when the maximum speed of any point in the planned path is smaller than the minimum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the minimum theoretical speed of the AGV at the point;
and when the maximum speed of any point in the planned path is greater than or equal to the minimum theoretical speed of the AGV at the point and less than or equal to the maximum theoretical speed of the AGV at the point, setting the planned speed of the AGV at the point as the maximum speed of the point.
In some embodiments, the planned speed v of the AGV at this point is outputplan (i) The pseudo code of (2) is:
step 1: if vmax (i)>vH (i) Output vplan (i)=vH (i);
Step 2: elseif vmax (i) < L (i), then output vplan (i)=vL (i);
Step 3: else vplan (i)=vmax (i)。
In some embodiments, a maximum speed threshold v is setvalue_max =1m/s,vvalue_min The planned speed is shown in fig. 2, with the abscissa in fig. 2 representing the number of points in the planned path, =0.7m/s.
In addition, in an embodiment, the step S600 further includes, but is not limited to, the following steps:
the planned speed v of the AGV at the ith pointplan (i) Performing convolution smoothing filtering to obtain the running speed of the AGV;
and controlling the AGV to travel along the planned path according to the travel speed.
In this embodiment, in order to make the speed change smoother to improve the smoothness during running, the planned speed is convolved and smoothed, and the filtered result is shown in fig. 3, where the abscissa in fig. 3 represents the number of the midpoints of the planned path:
in addition, referring to fig. 4, in an embodiment, there is also provided an AGV traveling vehicle speed control device based on a path curvature, the AGV traveling vehicle speed control device based on a path curvature including;
an acquisition module 100, configured to acquire a curvature matrix, a minimum curvature threshold, and a speed threshold of all points in the planned path;
a maximum curvature determination module 200, configured to determine a maximum curvature in the planned path according to the curvature matrix;
a maximum speed determining module 300, configured to determine a maximum speed of each point in the planned path according to the maximum curvature, the minimum curvature threshold, and the speed threshold; wherein the speed threshold comprises a maximum speed threshold and a minimum speed threshold;
a theoretical speed determining module 400, configured to determine a theoretical speed of the AGV at each point in the planned path according to the speed threshold; wherein the theoretical speed comprises a maximum theoretical speed and a minimum theoretical speed;
the planned speed determining module 500 is configured to determine a planned speed of the AGV at each point in the planned path according to the maximum speed of the AGV at the point and the theoretical speed of the AGV at the point;
and the running control module 600 is used for controlling the AGV to run along the planned path according to the planned speed.
The above described apparatus embodiments are merely illustrative, wherein the units illustrated as separate components may or may not be physically separate, i.e. may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
Additionally, referring to FIG. 5, one embodiment of the present disclosure also provides an AGV10, the AGV10 comprising: memory 11, processor 12, and a computer program stored on memory 11 and executable on processor 12.
The processor 12 and the memory 11 may be connected by a bus or other means.
The non-transitory software program and instructions required to implement the path curvature based AGV travel speed control method of the above embodiment are stored in the memory 11, which when executed by the processor 12, performs the path curvature based AGV travel speed control method of the above embodiment.
In addition, an embodiment of the present disclosure further provides a computer readable storage medium storing computer executable instructions that are executed by a processor or a controller, for example, by one of the above-described electronic device embodiments, and cause the above-described processor to execute the path curvature-based AGV travel vehicle speed control method in the above-described embodiment.
Those of ordinary skill in the art will appreciate that all or some of the steps, systems, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.
While the preferred embodiments of the present disclosure have been illustrated and described, the present disclosure is not limited to the above-described embodiments, and various equivalent modifications and substitutions can be made by those skilled in the art without departing from the spirit of the present disclosure, and these equivalent modifications and substitutions are intended to be included in the scope of the present disclosure as defined in the appended claims.