CN115167381A

CN115167381A - AGV cooperative work group implementation method based on temporary multi-group small wireless network

Info

Publication number: CN115167381A
Application number: CN202210487163.1A
Authority: CN
Inventors: 彭士伟; 梁炜; 李世明; 杨雨沱; 刘帅
Original assignee: Shenyang Institute of Automation of CAS
Current assignee: Shenyang Institute of Automation of CAS
Priority date: 2022-05-06
Filing date: 2022-05-06
Publication date: 2022-10-11

Abstract

The invention relates to a wireless network technology and a robot technology, in particular to an AGV cooperative work group implementation method based on temporary multiple groups of small wireless networks. The invention mainly solves two technical problems of wireless network resource allocation and stable steering of the cooperative work group vehicle body. The method comprises the following specific steps: when the single machine works, the main dispatching wireless module is communicated with the main dispatching server to complete control dispatching, and the cooperative interaction wireless module does not work. When a cooperative working group is formed, cooperative interaction wireless modules of four AGVs form a temporary small wireless local area network, one host machine is provided with three slave machines, only a main scheduling wireless module of the host machine is communicated with a main scheduling server to complete control scheduling, control instructions of the slave machines are transmitted and completed by the temporary small wireless local area network formed by the cooperative interaction wireless modules of the host machine, and the temporary small wireless local area network is disassembled to release wireless frequency point resources after tasks are completed. In addition, the four-vehicle annular steering method around the common geometric center can ensure that the steering is stable and the vibration is minimum.

Description

AGV cooperative work group implementation method based on temporary multi-group small wireless network

Technical Field

The invention relates to a wireless network technology and a robot technology, in particular to an AGV cooperative work group implementation method based on temporary multiple groups of small wireless networks.

Background

An AGV (Automated Guided Vehicles), also known as an Automated Guided vehicle, is provided with an automatic navigation system on a vehicle body, so that the vehicle can automatically run along a designed route without manual participation, and required materials are automatically conveyed to a destination from a starting point. At present, the AGVs are widely applied in various industries, especially the industries such as automobiles, tobacco, household appliances and the like are very mature, and with the trend of intelligent manufacturing becoming stronger, the demands of enterprise production on intelligent logistics and intelligent warehousing become stronger, and in recent years, the AGVs market keeps a higher growth rate.

The application of the current stage to the AGV is mainly still that single executive task is the main, but the demand that many AGV carry in coordination is also showing gradually, and many AGV cooperate the independent assortment can adapt to more loads that shape, kind, weight are different, accomplishes the transport task that the unit can not carry out to further provide single AGV's utilization ratio, bring considerable economic benefits. However, how to form a specific cooperative team and if it is guaranteed that the cooperative team can keep synchronization and stability during the traveling process, a series of technical problems need to be solved.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a method for implementing an AGV cooperative working group based on multiple temporary small wireless networks, which adopts two sets of wireless modules of a single AVG, and gives full play to resource advantages of respective frequency bands to the utmost extent, so as to form a set of large main dispatching wireless network and four-vehicle cooperative temporary small wireless local area network, and solve the technical problems of stable communication and synchronous working between cooperative working groups on the premise of not increasing the load of the large main dispatching wireless network. In addition, aiming at the problem of difficult steering of the cooperative working group, the invention provides a method for realizing annular steering of four vehicles around a common geometric center, so that the stable vibration in the steering process is ensured to be minimum to the maximum extent, the stress among the four vehicles is further minimum, and the bearing load is ensured to be influenced to the minimum.

In order to achieve the purpose, the invention adopts the following technical scheme:

the AGV comprises a temporary multi-group small wireless network-based AGV cooperative working group, wherein each AGV comprises a controller, and a main scheduling wireless module and a cooperative interaction wireless module which are respectively connected with the controller;

the controller is used for performing two-way communication with the main dispatching server through the main dispatching wireless module when the single machine works, and the cooperative interaction wireless module is in a closed state; during cooperative work, the AGV and controllers in the three other AGVs form a cooperative work group, wherein the current controller is used as a host or a slave, the host is in two-way communication with a master scheduling server through a master scheduling wireless module, the master scheduling wireless module of the slave is in a closed state, and the four AGVs in the cooperative work group are communicated through a cooperative interaction wireless module.

The main dispatching wireless module works by adopting a 2.4G single channel, and the cooperative interaction wireless module works by adopting double 5G channels.

Every AGV automobile body is the square, and four points of wheel installation constitute a square, and two wheels of arbitrary diagonal angle are for having concurrently to turn to and the rudderwheel of drive, and 2 remaining wheels are the universal wheel, and every AGV can advance in arbitrary direction, retreat, arbitrary angle turns to.

When the four AGVs cooperatively work, the four AGVs are arranged in a rectangular shape, the positions are sequentially marked as No. 1-4 clockwise, wherein the two AGVs at the No. 2 and 4 positions are clockwise twisted by 90 degrees relative to the two AGV bodies at the No. 1 and 3 positions, so that the wheels at the outermost sides of the four corner positions after cooperative team formation are ensured to be driving steering wheels.

The AGV cooperative work group realization method based on the temporary multi-group small wireless network comprises the following steps:

when the single machine works, each AGV is in two-way communication with the main dispatching server through the main dispatching wireless module, and the cooperative interaction wireless module is in a closed state;

when the cooperative work is finished, the cooperative interaction wireless module of each AGV is closed, the main dispatching wireless module is opened, and the cooperative work group is disassembled.

When the cooperative working group needs to turn, the cooperative working group stops, wheels of each AGV deflect as required and rotate in respective speed directions as required, the four AGVs rotate synchronously around a common geometric center as a whole, the deflection angle of the wheels is kept unchanged during rotation, the rotating speed ratio of the inner wheel to the outer wheel is kept unchanged, and the four AGVs are completely and relatively static in the whole steering process.

The wheel deflection angle calculation method comprises the following steps:

wherein alpha represents the angle of the outer driving steering wheel deviating from the side line of the vertical direction of the vehicle body, beta represents the angle of the inner driving steering wheel deviating from the side line of the vertical direction of the vehicle body, L represents the distance between the two AGV centers in the longitudinal direction of the cooperative work group, W represents the distance between the two AGV centers in the transverse direction of the cooperative work group, and S represents the side length of four wheel center points of the AGV arranged according to a square;

when four AGVs cooperatively work, the center points are arranged in a square shape, namely L = W, the calculation method is simplified as follows:

α＝45°，β＝45°。

the ratio of the rotating speed of the inner steering wheel to the rotating speed of the outer steering wheel of the AGV is as follows:

wherein, V _o Indicating outside drive steering wheel speed, V _i The inner side drives the rotation speed of a steering wheel;

when the center points are arranged in a square shape when four AGVs work cooperatively, namely L = W, the calculation method is simplified as follows:

the invention has the advantages and beneficial effects that: from the perspective of wireless network technology, the wireless resource allocation is reasonable, the natural advantages of respective frequency segments can be exerted, the original scheduling system is not required to be changed greatly, the load of wireless communication is not increased, the complexity of the scheduling system is not increased, and the problems and unnecessary investment are not introduced into the original single-machine working mode. From the viewpoint of smooth and continuous synchronization of steering, the invention provides an idea that under the condition that four wheels of each AGV touch the ground simultaneously, the unique solution that the four AGVs of the cooperative work group are completely static relatively to each other in the steering process can be ensured, if the idea is not followed, the wheels need to be lifted in the steering process to reduce the grounding supporting points, or certain position offset or angle offset must be allowed in the steering process, which has very adverse effect on heavy load or precision load which can be executed only by the AGV cooperative work group, and is easy to cause safety problem or damage to a carrying object.

Drawings

FIG. 1 is a schematic diagram of a wireless network architecture according to the present invention;

FIG. 2 is a schematic plan view of a cooperative team rear vehicle structure of the present invention;

FIG. 3 is a schematic diagram of calculation of steering parameters for the cooperative working group of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, in the whole system, a main dispatching server controls and dispatches a plurality of AGVs from an upper layer through a wireless network, each AGV completes a task issued by the main dispatching server when a single machine works, and the AGVs are not connected with each other, and a cooperative interaction wireless module installed inside the AGVs does not work. When the AGV needs to work cooperatively, the main dispatching server selects the idle AGV to a designated place to form a team, four selected AGVs travel to the designated place after receiving a team forming instruction, form a team shape with a longitudinal center distance L and a transverse center distance W according to technical parameter requirements issued by the main dispatching server, distribute channel frequency point resources of the cooperative interaction wireless module according to issued team numbers, the four AGVs have the same frequency point, form an efficient temporary wireless local area network according to a master-slave mode and a three-slave mode, the master sends a synchronous message, the slave responds, after all ready-to-work teams are completed, the three slave closes the main dispatching wireless module to stop working, and then the four AGVs are bound into a cooperative working group. Only the host computer in the No. 1 position can receive the control and dispatch command of the main dispatch server and issue the slave computer command to complete the given task.

As shown in fig. 2, it is particularly described that the main scheduling wireless module adopts a 2.4GHz band channel, and this band is characterized by strong diffraction capability and large coverage area, and is particularly suitable for a scenario where the wireless message load is not large and the bandwidth requirement is not high. The cooperative interaction wireless module adopts double 5G frequency band channels, one channel works at 5.2GHz, the other channel works at 5.8GHz, and the 5G frequency band has the characteristics of high bandwidth and high real-time performance, and the double channels further ensure the reliability. A plurality of AGV in the same place can form a plurality of cooperative work groups, and each cooperative work group monopolizes channel frequency point resources, so that a plurality of cooperative work groups can form a plurality of temporary small-sized wireless local area networks with different frequency points and irrelevant to each other. When the cooperative task is completed, the cooperative work group is dismissed to the appointed place, the host machine transmits a dismissal command to the slave machine after receiving the dismissal command, the slave machine controller starts the master scheduling wireless module, closes the cooperative interaction wireless module, dismisses the cooperative interaction temporary wireless local area network and releases wireless channel frequency point resources. For each AGV, at least one wireless module works, can receive and send instructions, and can ensure that each AGV can receive the instructions at any time to complete a given task.

According to the design requirements of the invention, each AGV body is square, wheel mounting points also form a square, two diagonal positions are provided with steering wheels which can be steered and driven, and the remaining 2 positions are provided with universal wheels, so that each AGV can advance and retreat in any direction and can steer at any angle. The AGV completing the cooperative work can be designed into only one specification, so that the two AGV bodies located at the

positions

2 and 4 need to be clockwise twisted by 90 degrees relative to the two AGV bodies located at the

positions

1 and 3 during the cooperative work, and four wheels located at the outermost sides of the four corners after the cooperative team formation are ensured to be driving steering wheels.

When the cooperative work team finishes executing the task and normally runs, the host receives an instruction of the upper-layer main scheduling server to run according to a route in a set direction and reports the state in time, the three slave machines receive the instruction sent by the host and run according to the set direction and the route requirement, because the cooperative work must ensure that the four AGV are relatively static, the cooperative interaction wireless module is required to have extremely high real-time performance and reliability, the host needs to give the instruction corresponding to the slave machine every time the host executes a small-step action and can start the next action after the three slave machines return correct responses, and the host machine and the slave machines need a large amount of data interaction in the whole running process. According to the design requirement of the invention, four AGVs stop when a cooperative group is formed to work and need to turn, wheels of each AGV deflect according to the requirement, then the AGV rotates according to the respective speed and direction according to the control requirement, the four AGVs synchronously rotate around the geometric center Q of the whole as a whole, and the deflection angle is calculated according to the following method:

wherein alpha represents the angle of the sideline of the outer driving steering wheel deviating from the vertical direction of the vehicle body, beta represents the angle of the sideline of the inner driving steering wheel deviating from the vertical direction of the vehicle body, L represents the center distance of two AGVs in the longitudinal direction of the cooperative group, W represents the center distance of two AGVs in the transverse direction of the cooperative group, and S represents the side length of four wheel center points of the AGVs arranged according to a square. The rotating speed ratio of the inner steering wheel and the outer steering wheel is calculated as follows:

wherein V _o Indicating outside drive steering wheel speed, V _i The inner side drives the rotation speed of the steering wheel. If the center points are arranged in a square shape when the four AGVs cooperate, the calculation method can be simplified as follows:

α＝45° β＝45°

as shown in fig. 3, α represents an angle of an outer driving steering wheel deviating from a vertical sideline of a vehicle body, β represents an angle of an inner driving steering wheel deviating from the vertical sideline of the vehicle body, L represents a distance between two AGVs in a longitudinal direction of a cooperative group, W represents a distance between two AGVs in a transverse direction of the cooperative group, S represents a side length of four wheel center points of the AGVs arranged in a square, Q represents a geometric center of rotation of the vehicle body when turning, C1 represents a track traveled by the outer driving steering wheel when turning, C2 represents a track traveled by the center of the AGV vehicle body when turning, and C3 represents a track traveled by the inner driving steering wheel when turning. According to the calculation method, when the AGV of the cooperative working group needs to turn, the position host machine 1 and the position slave machine 3 drive the steering wheel to deflect clockwise, the

position slave machines

2 and 4 deflect anticlockwise, all the AGV drive wheels to advance when the AGV needs to turn right, so that the whole cooperative working group rotates around the geometric center Q in the clockwise direction, and all the AGV drive wheels rotate around the geometric center Q in the anticlockwise direction when the AGV needs to turn left. The deflection angle of the wheels is kept unchanged all the time during rotation, the rotating speed ratio of the inner wheels and the outer wheels is kept unchanged all the time, the four AGVs can be guaranteed to be completely static in the whole process, C1 in the figure represents the track traveled by the outside driving steering wheel during turning, C2 represents the track traveled by the center of the AGV body during turning, and C3 represents the track traveled by the inside driving steering wheel during turning. From the aspect of stable and continuous steering synchronization, the invention provides a unique solution which can ensure that four AGVs of the cooperative working group are completely static relative to each other in the steering process under the condition that each AGV has four wheels which land simultaneously. If the concept is not followed, partial wheels need to be lifted during the steering process to reduce the number of the landing support points, but the load of the remaining landing wheels is increased, the structural strength of the vehicle body is not good, safety problems such as vehicle rollover are easily caused, the requirement for position deviation or angle deviation during the steering process can be lowered, however, the requirement for heavy load or precision load which can be executed by the AGV cooperative work team has a very bad influence, and the damage to the carrying object is easily caused. Thus, the solution proposed by the present invention can be considered to be the most reasonably optimized result. Not adopting such design considerations sacrifices performance at great expense.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, extension, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. The AGV cooperative work group based on the temporary multiple groups of small wireless networks is characterized in that each AGV comprises a controller, and a main dispatching wireless module and a cooperative interaction wireless module which are respectively connected with the controller;

the controller is used for performing two-way communication with the main scheduling server through the main scheduling wireless module when the single machine works, and the cooperative interaction wireless module is in a closed state; when the cooperative working is carried out, the cooperative working group is formed by the cooperative working group and controllers in the other three AGVs, wherein the current controller is used as a host or a slave, the host is in two-way communication with a master scheduling server through a master scheduling wireless module, the master scheduling wireless module of the slave is in a closed state, and the four AGVs in one cooperative working group are communicated through a cooperative interaction wireless module.

2. The AGV cooperative work group based on the temporal multi-group small wireless network of claim 1, wherein the main dispatch wireless module operates with 2.4G single channel and the cooperative interaction wireless module operates with dual 5G channels.

3. The AGV cooperative work group based on the temporary multi-group small wireless network according to claim 1, wherein each AGV body is square, four points of wheel installation form a square, two wheels at any opposite angle are steering wheels for steering and driving, the remaining 2 wheels are universal wheels, and each AGV can go forward and backward in any direction and steer at any angle.

4. The AGV cooperative work group based on the temporary multi-group small wireless network according to claim 1, wherein four AGVs are arranged in a rectangular shape and are sequentially marked as 1-4 in the clockwise direction during cooperative work, wherein two AGVs at the 2 and 4 positions are clockwise twisted by 90 degrees relative to two AGV bodies at the 1 and 3 positions to ensure that wheels at the outermost sides of four corner positions after the cooperative work group is completed are driving steering wheels.

5. The AGV cooperative work group implementation method based on the temporary multi-group small wireless network is characterized by comprising the following steps of:

when the cooperative work is finished, the cooperative interaction wireless module of each AGV is closed, the main dispatching wireless module is started, and the cooperative work group is disassembled.

6. The AGV cooperative work group implementation method based on the temporary multi-group small wireless network as claimed in claim 5, wherein when the cooperative work group needs to turn, the cooperative work group stops, wheels of each AGV deflect as required and rotate in respective speed directions as required, the four AGVs synchronously rotate around a common geometric center as a whole, the deflection angle of the wheels is kept constant all the time during rotation, the rotating speed ratio of the inner wheels and the outer wheels is kept constant all the time, and the four AGVs are completely and relatively static in the whole steering process.

7. The AGV cooperative work group implementation method based on temporary multi-group small wireless network of claim 6, wherein the wheel deflection angle calculation method comprises:

α＝45°，β＝45°。

8. the AGV cooperative work group implementation method based on the temporary multi-group small wireless network according to claim 6, wherein a rotating speed ratio of the inside and outside steering wheels of the AGV is as follows: