CN115373356A - double-AGV cooperative transportation system and control method thereof - Google Patents

double-AGV cooperative transportation system and control method thereof Download PDF

Info

Publication number
CN115373356A
CN115373356A CN202211064229.2A CN202211064229A CN115373356A CN 115373356 A CN115373356 A CN 115373356A CN 202211064229 A CN202211064229 A CN 202211064229A CN 115373356 A CN115373356 A CN 115373356A
Authority
CN
China
Prior art keywords
agv
following
piloting
information
state information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211064229.2A
Other languages
Chinese (zh)
Inventor
鄢超波
付旭珂
胡建晨
卫军胡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sichuan Digital Economy Industry Development Research Institute
Xian Jiaotong University
Original Assignee
Sichuan Digital Economy Industry Development Research Institute
Xian Jiaotong University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sichuan Digital Economy Industry Development Research Institute, Xian Jiaotong University filed Critical Sichuan Digital Economy Industry Development Research Institute
Priority to CN202211064229.2A priority Critical patent/CN115373356A/en
Publication of CN115373356A publication Critical patent/CN115373356A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/418—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM]
    • G05B19/4189—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM] characterised by the transport system
    • G05B19/41895—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM] characterised by the transport system using automatic guided vehicles [AGV]
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/30—Nc systems
    • G05B2219/31—From computer integrated manufacturing till monitoring
    • G05B2219/31002—Computer controlled agv conveys workpieces between buffer and cell
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/60—Electric or hybrid propulsion means for production processes

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)

Abstract

The invention belongs to the field of intelligent manufacturing and flexible manufacturing, and discloses a double-AGV cooperative handling system and a control method thereof, wherein the double-AGV cooperative handling system comprises a navigation AGV, a following AGV and a goods shelf; the navigation AGV and the following AGV are respectively connected with two ends of the bottom of the goods shelf and are in communication connection; the method comprises the steps that a first state information acquisition device is arranged on a navigation AGV and used for acquiring state information of the navigation AGV and sending the state information to a following AGV through the navigation AGV; set up second state information acquisition device on following the AGV, second state information acquisition device is used for acquireing the state information who follows the AGV and sends to following the AGV, follows the AGV and is used for adjusting self position according to the state information of pilot AGV and the state information who follows the AGV. The double-AGV cooperative transportation system and the control method thereof realize better transportation processing aiming at the problem that a single AGV is difficult to effectively transport large parts.

Description

double-AGV cooperative transportation system and control method thereof
Technical Field
The invention belongs to the field of intelligent manufacturing and flexible manufacturing, and relates to a double-AGV cooperative carrying system and a control method thereof.
Background
In an actual manufacturing scenario, an AGV (Automated Guided Vehicle) is often used to replace manpower between several fixed stations for repeated transportation tasks, and is now widely used in production automation logistics systems in industries such as automobiles, aviation manufacturing plants, and warehouse logistics.
However, in some large and complex transportation scenarios, such as airplanes and high-speed rail assembly lines, the transportation process of large components still mainly depends on large equipment such as manually operated gantry cranes, and the like, so that the efficiency of the whole system is low. The maximum carrying capacity of the AGV-based carrying system depends on the maximum carrying capacity of a single AGV, and in the large-scale manufacturing scenario, the existing industrial AGV is slightly insufficient in function, efficiency, carrying capacity and stability. However, the AGVs with stronger development functions and carrying capabilities increase the manufacturing cost and the operation and maintenance cost, and meanwhile, the guidance control performance and the motion control capability of a single AGV are limited, and the whole system has high customization degree and poor universality and reusability.
Disclosure of Invention
The invention aims to overcome the defect of low conveying efficiency of large parts in the prior art and provides a double-AGV cooperative conveying system and a control method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
the invention provides a double-AGV cooperative handling system, which comprises a navigation AGV, a following AGV and a goods shelf, wherein the following AGV comprises a first AGV body and a second AGV body; the navigation AGV and the following AGV are respectively connected with two ends of the bottom of the goods shelf and are in communication connection; the navigation AGV comprises a following AGV body, wherein a first state information acquisition device is arranged on the navigation AGV body and used for acquiring state information of the navigation AGV body and sending the state information to the following AGV body through the navigation AGV body; set up second state information acquisition device on following the AGV, second state information acquisition device is used for acquireing the state information who follows the AGV and sends to following the AGV, follows the AGV and is used for adjusting self position according to the state information of pilot AGV and the state information who follows the AGV.
Optionally, the piloting AGV and the following AGV are in communication connection through WIFI, 5G or a wired manner; and the piloting AGV and the following AGV are the AGVs on the differential chassis.
Optionally, the navigation AGV and the following AGV are respectively connected with the two ends of the bottom of the goods shelf through bolts or connected with the two ends of the bottom of the goods shelf through bull eyes and balls.
Optionally, the first state information acquiring device includes a first visual recognition device, the second state information acquiring device includes a second visual recognition device, the state information of the piloting AGV includes position information of the piloting AGV, and the state information of the following AGV includes position information of the following AGV; the first visual recognition device is used for obtaining position information of the navigation AGV by obtaining position error information between the first preset positioning mark and the first visual recognition device, and the second visual recognition device is used for obtaining position information of the following AGV by obtaining position error information between the second preset positioning mark and the second visual recognition device; the first preset positioning mark and the second preset positioning mark are both marks preset on the goods shelf or goods on the goods shelf.
Optionally, the following AGV is further used for generating control information of the piloting AGV according to the state information of the piloting AGV and the state information of the following AGV and sending the control information to the piloting AGV, and the piloting AGV is used for controlling the running state of the AGV according to the control information of the piloting AGV.
In a second aspect of the present invention, a method for controlling the dual AGV cooperative transportation system includes:
acquiring operation constraint information of a piloting AGV and a following AGV;
the following AGV obtains target position information of the following AGV according to the state information of the piloting AGV, the state information of the following AGV and the operation constraint information of the piloting AGV and the following AGV;
and the following AGV obtains control information of the following AGV according to the target position information and the state information of the following AGV, and controls the running state of the following AGV according to the control information of the following AGV.
Optionally, the method for controlling the dual AGV cooperative transportation system further includes:
obtaining the distance between the navigation AGV and the following AGV according to the state information of the navigation AGV and the state information of the following AGV;
when the distance between the navigation AGV and the following AGV exceeds a preset safety threshold value, the following AGV generates a stopping instruction of the navigation AGV and sends the stopping instruction to the navigation AGV, and the navigation AGV responds to the stopping instruction of the navigation AGV and stops running;
when the piloting AGV is in a stop operation state and the piloting AGV and the following AGV are in a distance load preset safety threshold value, the following AGV generates a starting instruction of the piloting AGV and sends the starting instruction to the piloting AGV, and the piloting AGV responds to the starting instruction of the piloting AGV and starts to operate.
Optionally, the following AGVs obtain target position information of the following AGVs according to state information of the piloting AGVs, state information of the following AGVs and running constraint information of the piloting AGVs and the following AGVs, and the following AGVs include:
obtaining the position information of the piloted AGV at the k +1 moment by the following formula:
Figure BDA0003827549380000031
Figure BDA0003827549380000032
wherein the content of the first and second substances,
Figure BDA0003827549380000033
to pilot the pose information of the AGV at time k,
Figure BDA0003827549380000034
for navigating the speed information of the AGV at the moment k, the delta T is a sampling interval,
Figure BDA0003827549380000035
the predicted position of the AGV at the time k + 1;
obtaining the advancing angle of the AGV from the k moment to the k +1 moment by the following formula
Figure BDA0003827549380000036
Figure BDA0003827549380000041
Wherein the content of the first and second substances,
Figure BDA0003827549380000042
position at time AGVk +1 by piloting
Figure BDA0003827549380000043
And position following AGVk time
Figure BDA0003827549380000044
Determining the position of (a);
the predicted position information of the following AGV at the time k +1 is obtained by the following formula:
Figure BDA0003827549380000045
Figure BDA0003827549380000046
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003827549380000047
to follow the position of the AGV at time k,
Figure BDA0003827549380000048
to follow the speed of the AGV at time k, Δ T is the sampling interval,
Figure BDA0003827549380000049
the direction of the linear velocity of the AGV at the moment k is followed;
correcting the predicted position information of the following AGV at the time k +1 by the following formula to obtain the target position information (x, y) of the following AGV at the time k + 1:
Figure BDA00038275493800000410
wherein dist ref To get a nominal distance between the piloting AGV and the following AGV,
Figure BDA00038275493800000411
to pilot the position of the AGV at time k +1,
Figure BDA00038275493800000412
to follow the position of the AGV at time k + 1.
Optionally, obtaining control information of the following AGV according to the target position information and the state information of the following AGV includes:
the tracking error of the following AGV at time k is obtained by the following formula:
Figure BDA00038275493800000413
wherein (x) e ,y e ,θ e ) To define the tracking error of the target position by the following AGV in the global coordinate system, (e) x ,e y ,e θ ) Defining the tracking error of a following AGV to the target position under a vehicle coordinate system, wherein theta is the angle of the following AGV;
according to the tracking error of the following AGV at the moment k, the tracking error elimination control information of the following AGV is obtained through the following formula:
Figure BDA0003827549380000051
wherein (v) r ,w r ) To follow reference and angular velocities on the AGV target trajectory, k 1 ,k 2 And k 3 Parameters in the control law are respectively non-0 positive numbers;
the reference velocity and the reference angular velocity of the following AGV are obtained by:
Figure BDA0003827549380000052
Figure BDA0003827549380000053
Figure BDA0003827549380000054
wherein the content of the first and second substances,
Figure BDA0003827549380000055
to follow the position of the AGV at time k,
Figure BDA0003827549380000056
to follow the position of the AGV at time k +1,
Figure BDA0003827549380000057
to follow the AGV linear velocity direction at time k, (v) r ,w r ) Delta T is a sampling interval for following the reference speed and the angular speed of the AGV at the target position at the moment k;
and eliminating the control information and the reference operation information according to the tracking error of the following AGV to obtain the control information of the following AGV.
Compared with the prior art, the invention has the following beneficial effects:
according to the double-AGV cooperative transportation system, the double AGVs are adopted for cooperative transportation, based on the arrangement of the first state information acquisition device and the second state information acquisition device, the state information of the navigation AGV and the state information of the following AGV can be acquired in real time, so that the following AGV can completely and dynamically follow the motion process of the navigation AGV, errors generated in the motion process can be effectively eliminated, in the motion process of the following AGV, the direction of the following AGV always faces the advancing direction of the navigation AGV, therefore, the paths of the following AGV at each sampling moment are straight tracks pointing to the navigation AGV, the distance between the two AGVs is ensured to be stable in the whole transportation process, the AGV and the goods carried on a goods shelf cannot receive stress between each other, and the stable operation of the double-AGV cooperative transportation system is ensured. Therefore, the double-AGV cooperative transportation system realizes better transportation processing aiming at the problem of transportation of a large part which is difficult to effectively carry out by a single AGV.
According to the control method of the double-AGV cooperative transportation system, the target position information of the following AGV and the generation of control information are realized on the basis of the state information of the piloting AGV and the state information of the following AGV in combination with the operation constraint information of the piloting AGV and the following AGV, so that the following AGV can completely and dynamically follow the movement process of the piloting AGV and can effectively eliminate errors generated in the movement process; in the process of following the AGV, the direction of the AGV always faces the advancing direction of the navigation AGV, so that the paths of the following AGV at each sampling moment are all a section of linear track pointing to the navigation AGV, and the distances of the following AGV are all the shortest distances meeting the constraint; the target position generation method of the following AGV is benefited, the speed of the following AGV is not larger than that of the piloting AGV, so that the speed of the whole cooperative handling system can be controlled by the movement speed of the piloting AGV, and the control is stable.
Drawings
FIG. 1 is a schematic diagram of a cooperative transporting system of two AGVs according to an embodiment of the present invention.
Fig. 2 is a flowchart of a method for controlling a cooperative transporting system of two AGVs according to an embodiment of the present invention.
FIG. 3 is a flowchart illustrating the details of a method for controlling a cooperative transporting system of two AGVs according to an embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating the concept of calculating the target position of the following AGVs based on the status information of the two AGVs according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating an exemplary AGV distance constraint pair F according to an embodiment of the present invention k+1|k Schematic diagram of the principle of correcting the position of (2).
FIG. 6 is a schematic diagram of the error between the position of a following AGV and a target position where X is F O F Y F In order to establish a vehicle body coordinate system on the following AGV, the origin of coordinates is the geometric center of the following AGV, and the X-axis direction is the speed direction of the following AGV.
Fig. 7 is a diagram of a real-world experiment track for two AGVs carrying cooperatively according to an embodiment of the present invention.
FIG. 8 is a schematic diagram of the distance fluctuation between two AGVs in an experimental process according to an embodiment of the present invention.
FIG. 9 is a graph of the linear velocity of two AGVs in an experimental process according to an embodiment of the present invention.
FIG. 10 is a graph of the angular velocity of two AGVs according to an embodiment of the present invention during an experiment.
Wherein: 1-piloting the AGV; 2-following the AGV; and 3-a shelf.
Detailed Description
In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Aiming at the problems in the background art, the inventor finds that two existing AGVs which are low in cost and easy to integrate and develop can be adopted for carrying in a coordinated mode in actual work, so that the manufacturing efficiency can be greatly improved, and the method has very important scientific value and practical significance.
Based on the above, the invention provides a double-AGV cooperative transportation system, which comprises a navigation AGV1, a following AGV2 and a goods shelf 3; the navigation AGV1 and the following AGV2 are respectively connected with two ends of the bottom of the goods shelf 3, and the navigation AGV1 and the following AGV2 are in communication connection; the navigation AGV1 is provided with a first state information acquisition device, and the first state information acquisition device is used for acquiring state information of the navigation AGV1 and sending the state information to the following AGV2 through the navigation AGV 1; set up second state information acquisition device on following AGV2, second state information acquisition device is used for acquireing and follows AGV 2's state information and send to following AGV2, follows AGV2 and is used for adjusting self position according to navigation AGV 1's state information and following AGV 2's state information. This two AGV transport system in coordination adopts two AGV to carry in coordination, to the transport problem of the big part that single AGV is difficult to effectively go on, has realized better transport and has handled.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, in an embodiment of the present invention, a dual AGV cooperative transportation system is provided, including a navigation AGV1, a following AGV2, and a rack 3; the piloting AGV1 and the following AGV2 are respectively connected with two ends of the bottom of the goods shelf 3, and the piloting AGV1 and the following AGV2 are in communication connection; the navigation AGV1 is provided with a first state information acquisition device, and the first state information acquisition device is used for acquiring state information of the navigation AGV1 and sending the state information to the following AGV2 through the navigation AGV 1; set up second state information acquisition device on following AGV2, second state information acquisition device is used for acquireing and follows AGV 2's state information and send to following AGV2, follows AGV2 and is used for adjusting self position according to navigation AGV 1's state information and following AGV 2's state information.
Wherein, navigation AGV1 with follow AGV2 and adopt the overall arrangement form of front and back connection, every AGV top has climbing mechanism, can hold up the transport with goods shelves 3, through rectangle goods shelves or leg joint between two AGV.
In conclusion, the double-AGV cooperative transportation system provided by the invention adopts double AGVs to cooperatively transport, based on the arrangement of the first state information acquisition device and the second state information acquisition device, the state information of the navigation AGV and the state information of the following AGV can be acquired in real time, so that the following AGV can completely and dynamically follow the motion process of the navigation AGV, and errors generated in the motion process can be effectively eliminated. Therefore, the double-AGV cooperative transportation system realizes better transportation processing aiming at the problem of transportation of a large part which is difficult to effectively carry out by a single AGV.
In a possible implementation, the navigation AGV1 and the following AGV2 are in communication connection through WIFI, 5G or a wired manner; and the piloting AGV1 and the following AGV2 are the AGVs on the differential chassis.
Optionally, the navigation AGV1 and the following AGV2 are respectively connected with the two ends of the bottom of the goods shelf 3 through bolts, or are connected with the two ends of the bottom of the goods shelf 3 through bull eyes and balls. When the connection is realized through the bull-eye ball, the tolerance range of the error can be ensured through the sliding of the bull-eye ball.
Optionally, the first state information acquiring device includes a first visual recognition device, the second state information acquiring device includes a second visual recognition device, the state information of the navigation AGV1 includes position information of the navigation AGV1, and the state information of the following AGV2 includes position information of the following AGV2; the first visual recognition device is used for obtaining position information of the navigation AGV1 by obtaining position error information between the first preset positioning mark and the first visual recognition device, and the second visual recognition device is used for obtaining position information of the following AGV2 by obtaining position error information between the second preset positioning mark and the second visual recognition device; the first preset positioning mark and the second preset positioning mark are both marks preset on the shelf 3 or goods on the shelf 3.
The mark preset on the shelf 3 or the goods on the shelf 3 may be a label or a two-dimensional code. First visual identification device and second visual identification device for align with label or two-dimensional code on goods shelves or the goods, with correct navigation AGV1 and follow AGV 2's position, the distance between navigation AGV1 and the following AGV2 can be adjusted according to the actual handling condition.
Referring to fig. 2, in another embodiment of the present invention, a method for controlling a dual AGV cooperative transport system as described above is provided, including the steps of:
s1: and acquiring the operation constraint information of the piloting AGV1 and the following AGV 2.
S2: and the following AGV2 obtains target position information of the following AGV2 according to the state information of the piloting AGV1, the state information of the following AGV2 and the running constraint information of the piloting AGV1 and the following AGV 2.
S3: and the following AGV2 obtains control information of the following AGV2 according to the target position information and the state information of the following AGV2, and controls the self running state according to the control information of the following AGV 2.
In conclusion, the control method of the double-AGV cooperative transportation system is based on the state information of the navigation AGV1 and the state information of the following AGV2, combines the running constraint information of the navigation AGV1 and the following AGV2, realizes the acquisition of the target position information of the following AGV2 and the generation of the control information, enables the following AGV2 to completely and dynamically follow the movement process of the navigation AGV1, and can effectively eliminate errors generated in the movement process; in the process of following the AGV2, the direction of the AGV always faces the advancing direction of the navigation AGV1, so that the paths of the following AGV2 at each sampling moment are all a section of straight line track pointing to the navigation AGV1, and the distances of the following AGV2 are all the shortest distances meeting the constraint; thanks to the target position generation method of the following AGV2, the speed of the following AGV2 is not greater than that of the piloting AGV1, so that the speed of the whole cooperative handling system can be controlled by the movement speed of the piloting AGV1, and the control is stable.
In a possible real-time manner, the method for controlling the AGV cooperative transport system further includes: obtaining the distance between the navigation AGV1 and the following AGV2 according to the state information of the navigation AGV1 and the state information of the following AGV2; when the distance between the navigation AGV1 and the following AGV2 exceeds a preset safety threshold value, the following AGV2 generates a stopping instruction of the navigation AGV1 and sends the stopping instruction to the navigation AGV1, and the navigation AGV1 responds to the stopping instruction of the navigation AGV1 and stops running; when the piloting AGV1 is in a stop operation state and the distance between the piloting AGV1 and the following AGV2 is loaded with a preset safety threshold value, the following AGV2 generates a starting instruction of the piloting AGV1 and sends the starting instruction to the piloting AGV1, and the piloting AGV1 responds to the starting instruction of the piloting AGV1 and starts to operate.
In a possible real-time mode, the control method of the double-AGV cooperative transportation system is composed of the front and back arrangement of the AGVs of the two differential chassis, combines the characteristics of the cooperative transportation problem, adopts a Leader-Follower method to calculate a target track in real time for following the AGV2, combines the control laws of track tracking and deviation rectification, constructs a system model of the double-AGV cooperative transportation, and realizes the stable and reliable cooperative operation of the double-AGV cooperative transportation system by taking the distance between the two AGVs as a judgment condition to always meet the limit.
Referring to fig. 3, the method for controlling the dual AGV cooperative transport system according to the embodiment includes the following steps:
step 1: adjusting the initial positions of the two AGVs according to the size of the part to be transported or the length of the goods shelf, so that the distance between the two AGVs is in accordance with the size of the goods to be transported; meanwhile, a communication environment is set, modes such as WIFI, 5G or wired communication can be selected, two AGVs start to communicate with each other, and information needing interaction comprises state information such as pose speed and the like and an obstacle avoidance start-stop control instruction.
Step 2: and the navigation AGV1 sends self state information to the following AGV2, and the following AGV2 combines the navigation AGV1 and the self state information to calculate the target position information at each moment in real time.
And step 3: and the following AGV2 calculates the control quantity required by reaching the target position at each moment according to the deviation between the position of the following AGV and the target position, and continuously issues the calculated control quantity to the chassis until the transportation task is finished.
And 4, step 4: navigating the AGV1 according to the path of the carrying task, and tracking the navigating AGV1 along with the AGV2 according to the control quantity in the step 3; and simultaneously following the AGV2 to monitor the fluctuation of the distance between the two AGVs, when the distance exceeds a safety threshold value, following the AGV2 to send a stop instruction to the navigation AGV1, simultaneously following the AGV2 to adjust the position of the AGV according to the control quantity in the step 3 so as to eliminate the distance deviation between the two AGVs, and when the distance meets the safety threshold value, continuing the forward movement of the navigation AGV1 until the transfer task is finished.
Optionally, referring to fig. 4, in step 2, a Leader-Follower idea is adopted, and the pose information of two AGVs is combined to calculate the target position for following the AGV2, which specifically includes:
step 2.1: gather position appearance and the speed information of piloting AGV1 and following AGV2 at k moment:
Figure BDA0003827549380000121
correspondingly, the position information of the piloted AGV1 at the time k +1 is calculated as:
Figure BDA0003827549380000122
Figure BDA0003827549380000123
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003827549380000124
and
Figure BDA0003827549380000125
respectively the pose information and the speed information of the piloting AGV1 at the moment k, delta T is a sampling interval,
Figure BDA0003827549380000126
the position of the piloted AGV1 at time k +1 predicted for time k.
Step 2.2: defining an angle
Figure BDA0003827549380000127
I.e. following the angle of advance of the AGV2 at each moment:
Figure BDA0003827549380000128
wherein the content of the first and second substances,
Figure BDA0003827549380000129
position by piloting AGVk +1 moment
Figure BDA00038275493800001210
And position following AGVk time
Figure BDA00038275493800001211
Determining the position of (a);
angle of rotation
Figure BDA00038275493800001212
Is the X axis and L axis of the inertial coordinate system k+1|k And F k The angle of the connecting line, the predicted position information at the time k +1 following the AGV2, is calculated as:
Figure BDA0003827549380000131
Figure BDA0003827549380000132
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003827549380000133
and
Figure BDA0003827549380000134
respectively, the position and linear velocity of the following AGV2 at time k, Δ T is the sampling interval,
Figure BDA0003827549380000135
to follow the linear speed direction of the AGV2 at time k.
Step 2.3: referring to fig. 5, according to the operation restriction information of the navigation AGV1 and the following AGV2, that is, the distance restriction of the navigation AGV1 and the following AGV2, the predicted position information is corrected:
Figure BDA0003827549380000136
wherein, dist ref To navigate the nominal distance between the AGV1 and the following AGV2,
Figure BDA0003827549380000137
and
Figure BDA0003827549380000138
the positions of the piloting AGV1 and the following AGV2 at the moment k +1 are respectively, and the calculated (x, y) is the accurate predicted position of the following AGV2 at the moment k + 1.
Thus, the target position information to be reached at each time following the AGV2 can be obtained.
Optionally, referring to fig. 6, in step 3, the following AGV2 needs to calculate a control amount for tracking the target position according to a deviation between the position at each time and the target position, and the specific steps include:
step 3.1: at the moment k, the positioning pose following the AGV2 is [ x, y, theta ]]With object pose [ x ] r ,y r ,θ r ]Then, the tracking error at each moment is converted into the following AGV2 in the vehicle coordinate system, and the following calculation may be performed as:
Figure BDA0003827549380000139
wherein (x) e ,y e ,θ e ) And (e) x ,e y ,e θ ) The following AGV2 is defined as the tracking error of the target position in the global coordinate system and the vehicle coordinate system, and θ is the angle of the following AGV 2.
Step 3.2: on the basis of the tracking error of step 3.1, the control quantity following the AGV2 at each moment is:
Figure BDA0003827549380000141
wherein (v) r ,w r ) To follow reference and angular velocities on the AGV2 target trajectory, k 1 ,k 2 And k 3 The parameters are parameters in the control law, and are all non-0 positive numbers.
Step 3.3: meanwhile, the reference velocity and the reference angular velocity following the target trajectory of the AGV2 are calculated as follows:
Figure BDA0003827549380000142
Figure BDA0003827549380000143
Figure BDA0003827549380000144
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003827549380000145
and
Figure BDA0003827549380000146
respectively following the position of the AGV2 at time k and at time k +1,
Figure BDA0003827549380000147
to follow the linear velocity direction of AGV2 at time k, (v) r ,w r ) To follow the reference velocity and angular velocity of the AGV2 at the target position at time k, Δ T is the sampling interval.
After the calculation and the release of the speed and the angular speed of the following AGV2 are completed at the moment k, the positions of the two AGVs move to the moment k +1, and the step 2 and the step 3 are repeated.
Referring to fig. 7, a diagram of a material object experiment track of the collaborative handling of the piloting AGV1 and the following AGV2 is shown, wherein the track of the piloting AGV1 is a rounded rectangle, the track of the following AGV2 in a straight line stage approaches to the piloting AGV1, and the turning radius in a turning stage is smaller than that of the piloting AGV1, so that the track of the dual-AGV collaborative handling system can be completely determined by the motion track of the piloting AGV1, and meanwhile, the speed of the following AGV can not exceed that of the piloting AGV1, and the safety in the handling process of the dual-machine collaborative handling system is ensured; meanwhile, 8 points on the track are marked in the figure, so that the position of the shelf 3 in the process of transportation can be determined.
Referring to fig. 8 to 10, specific data during a physical experiment for piloting the AGV1 and following the AGV2 to move cooperatively are shown.
Fig. 8 is a distance curve between the navigation AGV1 and the following AGV2, and the distance between the navigation AGV1 and the following AGV2 is always kept within ± 3cm compared with the rated distance of 3.28 m; fig. 9 and 10 are linear velocities and linear velocity curves of the leading AGV1 and the following AGV2, respectively, and the velocity of the following AGV2 is always less than or equal to the velocity of the leading AGV1 during the transportation process, which is benefited from the target trajectory designed for the following AGV2; meanwhile, the speed curve is smooth and has no sudden change, and the stability of the motion process is also reflected.
Therefore, the control method of the double-AGV cooperative transportation system can ensure that the following AGV can completely and dynamically follow the movement process of the pilot AGV, and can effectively eliminate errors generated in the transportation process, so that the deviation between the distance between the two AGVs and the rated distance is kept within a minimum range.
The above description is only a preferred embodiment of the present invention, and it should be noted that the scope of the present invention is not limited thereto, and any person skilled in the art can make several modifications and substitutions within the technical scope of the present invention, and these modifications and substitutions should also be regarded as the scope of the present invention.

Claims (9)

1. The double-AGV cooperative carrying system is characterized by comprising a piloting AGV (1), a following AGV (2) and a goods shelf (3);
the navigation AGV (1) and the following AGV (2) are respectively connected with two ends of the bottom of the goods shelf (3), and the navigation AGV (1) and the following AGV (2) are in communication connection;
the navigation AGV (1) is provided with a first state information acquisition device, and the first state information acquisition device is used for acquiring state information of the navigation AGV (1) and sending the state information to the following AGV (2) through the navigation AGV (1); set up second state information acquisition device on following AGV (2), second state information acquisition device is used for acquireing the state information who follows AGV (2) and sends to following AGV (2), follows AGV (2) and is used for adjusting self position according to the state information of pilot AGV (1) and the state information who follows AGV (2).
2. The system of claim 1, wherein the lead AGV (1) and the following AGV (2) are communicatively connected via WIFI, 5G or wired means; and the piloting AGV (1) and the following AGV (2) are the AGVs on the differential chassis.
3. Double AGV cooperative handling system according to claim 1, characterised in that the piloting AGV (1) and the following AGV (2) are connected to both ends of the bottom of the rack (3) through pins, or to both ends of the bottom of the rack (3) through bull's eye balls, respectively.
4. The system of claim 1, wherein the first status information acquiring device comprises a first visual recognition device, the second status information acquiring device comprises a second visual recognition device, the status information of the piloting AGV (1) comprises position information of the piloting AGV (1), and the status information of the following AGV (2) comprises position information of the following AGV (2); the first visual recognition device is used for obtaining the position information of the piloting AGV (1) by obtaining the position error information between the first preset positioning mark and the first visual recognition device, and the second visual recognition device is used for obtaining the position information of the following AGV (2) by obtaining the position error information between the second preset positioning mark and the second visual recognition device; the first preset positioning mark and the second preset positioning mark are both marks preset on the goods shelf (3) or goods on the goods shelf (3).
5. The double-AGV cooperative handling system according to claim 1, wherein the following AGV (2) is further configured to generate control information of the piloting AGV (1) according to the state information of the piloting AGV (1) and the state information of the following AGV (2) and send the control information to the piloting AGV (1), and the piloting AGV (1) is configured to control the running state of the AGV (1) according to the control information.
6. A method of controlling a dual AGV cooperative transport system according to any one of claims 1 to 5, comprising:
acquiring operation constraint information of a piloting AGV (1) and a following AGV (2);
the following AGV (2) obtains target position information of the following AGV (2) according to the state information of the piloting AGV (1), the state information of the following AGV (2) and the operation constraint information of the piloting AGV (1) and the following AGV (2);
and the following AGV (2) obtains the control information of the following AGV (2) according to the target position information and the state information of the following AGV (2), and controls the running state of the following AGV (2) according to the control information of the following AGV (2).
7. The method of claim 6, further comprising:
obtaining the distance between the navigation AGV (1) and the following AGV (2) according to the state information of the navigation AGV (1) and the state information of the following AGV (2);
when the distance between the navigation AGV (1) and the following AGV (2) exceeds a preset safety threshold value, the following AGV (2) generates a stopping instruction of the navigation AGV (1) and sends the stopping instruction to the navigation AGV (1), and the navigation AGV (1) responds to the stopping instruction of the navigation AGV (1) and stops running;
when the piloting AGV (1) is in a stop operation state, and the piloting AGV (1) and the following AGV (2) generate a starting instruction of the piloting AGV (1) and send the starting instruction to the piloting AGV (1), and the piloting AGV (1) responds to the starting instruction of the piloting AGV (1) to start operation when a preset safety threshold value of distance load is loaded.
8. The method for controlling a system according to claim 6, wherein the following AGV (2) obtains the target position information of the following AGV (2) according to the state information of the piloting AGV (1), the state information of the following AGV (2), and the operation constraint information of the piloting AGV (1) and the following AGV (2), and comprises:
obtaining the position information of the piloted AGV (1) at the k +1 moment by the following formula:
Figure FDA0003827549370000031
Figure FDA0003827549370000032
wherein the content of the first and second substances,
Figure FDA0003827549370000033
in order to pilot the pose information of the AGV (1) at the moment k,
Figure FDA0003827549370000034
for piloting the speed information of the AGV (1) at the time k, delta T is the sampling interval,
Figure FDA0003827549370000035
a position of the piloting AGV (1) at a time k +1 predicted for the time k;
obtaining the advancing angle of the following AGV (2) from the time k to the time k +1 through the following formula
Figure FDA0003827549370000036
Figure FDA0003827549370000037
Wherein the content of the first and second substances,
Figure FDA0003827549370000038
by piloting the position of AGV (1) at time k +1
Figure FDA0003827549370000039
And following the AGV (2) k time position
Figure FDA00038275493700000310
Determining the position of (a);
the predicted position information of the following AGV (2) at the time k +1 is obtained by the following formula:
Figure FDA00038275493700000311
Figure FDA00038275493700000312
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA00038275493700000313
to follow the position of the AGV (2) at time k,
Figure FDA00038275493700000314
Δ T is the sampling interval in order to follow the speed of the AGV (2) at time k,
Figure FDA00038275493700000315
the linear velocity direction of the AGV (2) at the moment k is followed;
correcting the predicted position information of the following AGV (2) at the time k +1 by the following formula to obtain the target position information (x, y) of the following AGV (2) at the time k + 1:
Figure FDA0003827549370000041
wherein, dist ref For the nominal distance between the piloting AGV (1) and the following AGV (2),
Figure FDA0003827549370000042
to pilot the position of the AGV (1) at time k +1,
Figure FDA0003827549370000043
to follow the position of the AGV (2) at time k + 1.
9. The method of claim 6, wherein the following AGV (2) obtains the control information of the following AGV (2) according to the target position information and the status information of the following AGV (2) comprises:
the tracking error of the following AGV (2) at the time k is obtained by the following formula:
Figure FDA0003827549370000044
wherein (x) e ,y e ,θ e ) To define the tracking error of the target position by the following AGV (2) in the global coordinate system, (e) x ,e y ,e θ ) In order to define the tracking error of the following AGV (2) to the target position under the vehicle coordinate system, theta is the angle of the following AGV (2);
according to the tracking error of the following AGV (2) at the moment k, the tracking error elimination control information of the following AGV (2) is obtained through the following formula:
Figure FDA0003827549370000045
wherein (v) r ,w r ) K for following reference and angular velocities on the AGV (2) target trajectory 1 ,k 2 And k 3 Parameters in the control law are respectively non-0 positive numbers;
the reference speed and the reference angular speed of the following AGV (2) are obtained by:
Figure FDA0003827549370000051
Figure FDA0003827549370000052
Figure FDA0003827549370000053
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003827549370000054
to follow the position of the AGV (2) at time k,
Figure FDA0003827549370000055
to follow the position of the AGV (2) at time k +1,
Figure FDA0003827549370000056
to follow the linear velocity direction of the AGV (2) at time k, (v) r ,w r ) Delta T is a sampling interval for following the reference speed and the angular speed of the AGV (2) at the target position at the moment k;
and eliminating the control information and the reference operation information according to the tracking error of the following AGV (2) to obtain the control information of the following AGV (2).
CN202211064229.2A 2022-08-31 2022-08-31 double-AGV cooperative transportation system and control method thereof Pending CN115373356A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211064229.2A CN115373356A (en) 2022-08-31 2022-08-31 double-AGV cooperative transportation system and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211064229.2A CN115373356A (en) 2022-08-31 2022-08-31 double-AGV cooperative transportation system and control method thereof

Publications (1)

Publication Number Publication Date
CN115373356A true CN115373356A (en) 2022-11-22

Family

ID=84069406

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211064229.2A Pending CN115373356A (en) 2022-08-31 2022-08-31 double-AGV cooperative transportation system and control method thereof

Country Status (1)

Country Link
CN (1) CN115373356A (en)

Similar Documents

Publication Publication Date Title
CN111399509B (en) Multi-mobile-robot cooperative transfer control method and system
Morales et al. Pure-pursuit reactive path tracking for nonholonomic mobile robots with a 2D laser scanner
US9870002B1 (en) Velocity control of position-controlled motor controllers
CN107943020B (en) Automatic deviation rectifying method for tire crane cart
CN111158355A (en) Automatic navigation cloud server and automatic navigation control method
Wang et al. Autonomous target docking of nonholonomic mobile robots using relative pose measurements
CN103048996A (en) Automatic guided vehicle based on laser scanning distance meter, and system and navigation method of automatic guided vehicle
CN102145808A (en) Industrial laser guidance AGV double-closed-loop control system and control method thereof
CN111039231B (en) Intelligent forklift turning path planning method
Wu et al. Coordinated path tracking of two vision-guided tractors for heavy-duty robotic vehicles
CN103760908A (en) Inspecting device closed loop tracking control method
CN113625702B (en) Unmanned vehicle simultaneous path tracking and obstacle avoidance method based on quadratic programming
Aref et al. A macro-micro controller for pallet picking by an articulated-frame-steering hydraulic mobile machine
Lin et al. An automated guided logistics robot for pallet transportation
Xu et al. Design and implementation of differential drive AGV based on laser guidance
Chen et al. Real-time predictive sliding mode control method for AGV with actuator delay
CN106909160B (en) SD-type AGV reversing attitude angle control device based on double-closed-loop PID control
CN115373356A (en) double-AGV cooperative transportation system and control method thereof
CN112666934A (en) Control system, scheduling system and control method for automobile carrying AGV
Juntao et al. Research of AGV positioning based on the two-dimensional Code Recognition Method
CN116859917A (en) Master-slave linkage control method for double-vehicle of mobile robot for carrying ultra-long cargoes
Yuan et al. AGV system based on multi-sensor information fusion
TWI770966B (en) Guidance control method of unmanned self-propelled vehicle
CN111830980B (en) Laser navigation path following method
CN209225929U (en) Shuttle vehicle type warehousing system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination