CN105388899A - An AGV navigation control method based on two-dimension code image tags - Google Patents

Abstract

The invention discloses an AGV navigation control method based on two-dimension code image tags. The AGV navigation control method comprises the following steps: 1) obtaining the range of each pixel point in scanned images of two-dimension code tag scanners; 2) obtaining corresponding IDs and positions of the two-dimension code image tags in a coordinate system of the images themselves according to the scanned images of the two-dimension code tag scanners; 3) an AGV receiving navigation path instructions sent by a scheduling center; 4) the AGV sequentially establishing local navigation coordinate systems according to the navigation path instructions and calculating initial positions of the AGV in the local navigation coordinate systems; 5) planning an arc track between two two-dimension code image tags of the AGV in sequence; and 6) calculating the control quantity of the AGV according to the planed arc radius to enable the AGV to drive to each two-dimension code image tag in a navigation path instruction sequence in sequence, and thus the navigation path instruction is finished. The method can reduce production cost, reduce on-site implementation difficulty and improve guiding flexibility.

Description

A kind of AGV navigation control method based on image in 2 D code label

Technical field

The invention belongs to automatic guided vehicle Navigation Control field, relate to a kind of AGV navigation control method based on image in 2 D code label that can travel along given path, realize autonomous location.

Background technology

Automatic guided vehicle (AGV) is a kind of is power with rechargeable battery, the unmanned automated vehicle of homing guidance, it can under the monitoring of computing machine, planning and job requirements by path, accurate walking is also accommodated to the place of specifying, and completes a series of job task as picking, deliver goods, charging etc.Along with the raising of industrial automatization and developing rapidly of computer technology, AGV uses more and more as the handbarrow between assembling line or implement.

Chinese patent application publication number CN201410767757 proposes a kind of AGV vision navigation control method.This vision navigation method comprises: the road Identification module of AGV, locating module, motion-control module and path planning module.AGV road Identification module obtains position deviation and the deviation of directivity of AGV and road mark line by Image Acquisition, Image semantic classification and information extraction; The RFID of locating module mainly by installing at path periphery, realizes AGV location in the work environment; Motion-control module is that the positional information that road Identification module obtained and the deviation of directivity carry out fuzzy control, thus controls the walking of dolly; Path planning module is the path between planning AGV and target.

The program at indoor laying colour band as road mark line, and using its deviation, directional information as the input of control module and then advancing of control AGV dolly; Use RFID label tag to detect the position residing for AGV.This method can make AGV travel along road mark line and can monitor AGV state in real time, but this method first needs lay colour band and install RFID, and site operation is complicated; Secondly colour band vulnerable to pollution, affects accuracy of identification; And AGV dolly can only travel along fixing colour band, inconvenience is alternative routing in the warehouse that shelf gather, flexible poor.

Summary of the invention

The present invention is the weak point overcoming prior art existence, a kind of AGV navigation control method based on image in 2 D code label is proposed, in warehouse, identify that the information of image in 2 D code label realizes the Navigation Control of AGV dolly to realizing by AGV dolly, thus complete the assignment instructions that dispatching center issues, reach and reduce production cost, reduce field conduct difficulty and improve the flexible object of guiding.

The present invention is that technical solution problem adopts following technical scheme:

A kind of AGV navigation control method based on image in 2 D code label of the present invention, be applied in the Automatic Warehouse that is made up of dispatching center, several movable goods shelfs and AGV dolly, be characterized in, in the traffic areas of described Automatic Warehouse, several image in 2 D code labels by the arrangement of same direction of equidistant stickup in the matrix form; Each image in 2 D code label comprises self ID number and adjacent No. ID; Described adjacent No. ID is formed by with No. ID that pastes 8 adjacent image in 2 D code labels that direction also arranges counterclockwise for starting point; Described AGV dolly is installed the two-dimension code label scanner that resolution is M × N; Described AGV navigation control method carries out as follows:

Step 1, according to the vertical range d between described two-dimension code label scanner and ground, determine that the sweep limit of described two-dimension code label scanner is Len × Wid; Formula (1) is utilized to obtain the range size Δ d of each pixel in the scan image of described two-dimension code label scanner:

$\mathrm{\Δ}d=\frac{Len\×Wid}{M\×N}---\left(1\right)$

Step 2, described two-dimension code label scanner is utilized to scan image in 2 D code label, form scan image, can obtain the angle Δ α of arbitrary coordinate axis in corresponding self ID number and adjacent No. ID and the position coordinates of central point in the local Coordinate System of described scan image of described image in 2 D code label, the label stickup direction of described image in 2 D code and scan image local Coordinate System according to described scan image; The self ID number that scanning obtains is sent to described dispatching center by described AGV dolly, makes described dispatching center know position residing for described AGV dolly;

Step 3, described AGV dolly receive the guidance path instruction that described dispatching center sends; Described guidance path instruction comprises the ID sequence of image in 2 D code label and corresponding waypoint sequence of attributes thereof; Described ID sequence is designated as { ID ₁, ID ₂..., ID _i..., ID _m; ID _ito represent in described ID sequence i-th No. ID; Described waypoint sequence of attributes is designated as { LD ₁, LD ₂..., LD _i..., LD _m; LD _irepresent i-th waypoint attribute in described waypoint sequence of attributes; Initial No. ID of described ID sequence is No. ID of the image in 2 D code label at described AGV dolly initial position place; 1≤i≤m;

Step 4, initialization i=1;

Step 5, ID ID according to i-th image in 2 D code label at described AGV dolly place _iand adjacent No. ID, obtain the i-th+1 ID ID in described ID sequence _i+1ranking n in adjacent No. ID of i-th image in 2 D code label _i; 1≤n _i≤ 8; Formula (2) is utilized to obtain described i-th ID ID _iimage in 2 D code label and described the i-th+1 ID ID _i+1image in 2 D code label line with paste the angle theta in direction _i+1:

θ _i+1＝45°×(n _i-1)(2)

Step 6, with the central point of described i-th image in 2 D code label for initial point O _i; With described the i-th+1 ID ID _i+1angle theta _i+1direction is X _idirection of principal axis; And with X _idirection of principal axis is rotated counterclockwise 90 ° for Y _idirection of principal axis, sets up i-th Local Navigation coordinate system X _io _iy _i;

Step 7, formula (3) and formula (4) is utilized to obtain described AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin initial position co-ordinates (A _i, B _i):

A _i＝(Wid/2-y _i)×Δd(3)

B _i＝(Len/2-x _i)×Δd(4)

In formula (3) and formula (4), x _iand y _irepresent the position coordinates of central point in the local Coordinate System of described scan image of i-th image in 2 D code label;

Step 8, formula (5) is utilized to obtain described AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin angle, initial heading Δ θ _i:

Δθ _i＝Δα-θ _i+1(5)

Step 9, with the barycenter of described AGV dolly for initial point O, with headstock direction for X-direction, and be rotated counterclockwise 90 ° for Y direction with X-direction, set up vehicle axis system XOY; Formula (6) is utilized to obtain the position (a of central point in vehicle axis system XOY of the i-th+1 image in 2 D code label _i, b _i):

$\left[\begin{array}{c}{a}_i\\ b_i\end{array}\right]=\left[\begin{array}{c}cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\\ -sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\end{array}\right]\left[\begin{array}{c}{P}_i-A_i\\ Q_i-B_i\end{array}\right]---\left(6\right)$

In formula (6), P _iand Q _irepresent that the central point of the i-th+1 image in 2 D code label is at i-th Local Navigation coordinate system X _io _iy _iin position coordinates;

Step 10, utilize formula (7) obtain with described i-th course angle Δ θ _itangent and cross the arc radius R of central point of the i-th+1 image in 2 D code label _i:

$R_i=\frac{a_i^2+b_i^2}{2\×b_i}---\left(7\right)$

Step 11, according to the structure of described AGV dolly and arc radius R _idetermine i-th controlled quentity controlled variable of described AGV dolly; Described AGV dolly is according to described i-th controlled quentity controlled variable and i-th waypoint attribute LD _itravel to the i-th+1 image in 2 D code label;

Step 12; By i+1 assignment to i, and judge whether i > m sets up, if set up, represent that described AGV dolly completes guidance path instruction; Otherwise, return step 5 order and perform.

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, the present invention is by adopting the information of scanning image in 2 D code label, set up Local Navigation coordinate system successively, and obtain the position of AGV dolly in Local Navigation coordinate system, complete the location navigation of AGV dolly, and carry out local paths planning, thus complete the guidance path instruction that dispatching system issues, improve the flexibility of guidance path, reduce production cost.

2, the present invention sets up Local Navigation coordinate system by conversion, overall navigation task is resolved into each Local Navigation task, solves the problem of image in 2 D code label location difficulty in global coordinate system, thus reduce the difficulty of field conduct.

3, the present invention substitutes RFID label tag by using image in 2 D code label, be not only the position that dispatching center provides AGV dolly, and provide local location information for the Navigation Control of AGV dolly, solve the orientation problem of AGV dolly, thus decrease the use number of sensor, reduce production cost.

4, the present invention is by the stickup image in 2 D code label of matrix form, makes route diversion easy, solves shelf and to gather the problem of zone routing planning difficulty, improve guiding flexible.

Accompanying drawing explanation

Fig. 1 be the present invention in warehouse by the image in 2 D code label schematic diagram that matrix form is pasted with equidirectional;

Fig. 2 is that in the present invention, AGV current place path point is the Local Navigation coordinate system of i-th image in 2 D code label, the i-th+1 the image in 2 D code label foundation of next path point;

Fig. 3 is the structural representation of single steering wheel AGV in the embodiment of the present invention;

Fig. 4 is the path schematic diagram of the guidance path sequence instruction composition that dispatching center of the present invention issues;

Fig. 5 is the lateral deviation schematic diagram each image in 2 D code label being detected in the present invention in AGV dolly driving process;

Fig. 6 is that in the present invention, AGV adopts the present invention to carry out Navigation Control along the angular deviation schematic diagram each image in 2 D code label being detected in route process;

Fig. 7 is that in the present invention, AGV adopts the present invention to carry out the front wheel angle change curve of Navigation Control.

Embodiment

It in the present embodiment, for single steering wheel AGV, is realize the AGV Navigation Control based on image in 2 D code label according to the following procedure: the range size 1, obtaining each pixel in the scan image of two-dimension code label scanner; 2, corresponding No. ID and the pose of image in 2 D code label in image local Coordinate System is obtained according to the scan image of two-dimension code label scanner; 3, the guidance path instruction of AGV dolly receiving scheduling center transmission; 4, AGV dolly sets up Local Navigation coordinate system successively according to guidance path instruction, and calculates the initial pose of AGV dolly in Local Navigation coordinate system; 5, the arc track of AGV dolly between two image in 2 D code labels is planned successively; 6, calculate the controlled quentity controlled variable of AGV dolly according to the arc radius of planning, make AGV dolly travel to each image in 2 D code label in guidance path instruction sequence successively, to complete guidance path instruction.

Specifically, a kind of AGV navigation control method based on image in 2 D code label is applied in the Automatic Warehouse that is made up of dispatching center, several movable goods shelfs and AGV dolly; As shown in Figure 1, in the traffic areas of Automatic Warehouse, equidistant L=1m pastes several image in 2 D code labels arranged by same direction in the matrix form; Each image in 2 D code label comprises self ID number and adjacent No. ID; Adjacent No. ID is formed by with No. ID that pastes 8 adjacent image in 2 D code labels that direction also arranges counterclockwise for starting point; The name of product that single steering wheel AGV dolly is equipped with Datalogic company to be the resolution of Matrix-210-213-100 be 752 × 480 two-dimension code label scanner, position in scanner image of information and two-dimension code label central point that two-dimension code label itself comprises and misalignment angle can be obtained, positional precision is 0.2mm, and angle precision is 1 °; Image in 2 D code label adopts DataMatrix code, and tag size is 4cm × 4cm; AGV navigation control method carries out as follows:

Step 1, according to the vertical range d=18cm between two-dimension code label scanner and ground, determine that the sweep limit of two-dimension code label scanner is 132mm × 86mm; Formula (1) is utilized to obtain the range size Δ d of each pixel in the scan image of two-dimension code label scanner:

$\mathrm{\Δ}d=\frac{132mm\×86mm}{752\×480}---\left(1\right)$

Step 2, two-dimension code label scanner is utilized to scan image in 2 D code label, form scan image, the position coordinates x of central point in the local Coordinate System of scan image of corresponding self ID number and adjacent No. ID and image in 2 D code label can be obtained according to scan image _i, y _i, image in 2 D code label paste the angle Δ α of arbitrary coordinate axis in direction and scan image local Coordinate System; The self ID number that scanning obtains is sent to dispatching center of institute by AGV dolly, makes dispatching center know position residing for AGV dolly;

The guidance path instruction that step 3, AGV dolly receiving scheduling center send; Guidance path instruction comprises the ID sequence of image in 2 D code label and corresponding waypoint sequence of attributes thereof, and the array using 2 × n to tie up describes, No. ID, each path point on the first row delegated path, and the second row represents attribute corresponding to each path point; ID sequence is designated as { ID ₁, ID ₂..., ID _i..., ID _m; ID _ito represent in ID sequence i-th No. ID; Waypoint sequence of attributes is designated as { LD ₁, LD ₂..., LD _i..., LD _m; LD _irepresent i-th waypoint attribute in waypoint sequence of attributes; As: $\left[\begin{array}{c}1,2,3,9,14,19\\ 0,1,2,3,0,4\end{array}\right],$ 0 of second row represents at the uniform velocity, and 1 represents that deceleration, 2 represents that acceleration, 3 represents that parking picking, 4 represents parking unloading.Initial No. ID of ID sequence is No. ID of the image in 2 D code label at AGV dolly initial position place; 1≤i≤m;

Step 4, initialization i=1;

Step 5, ID ID according to i-th image in 2 D code label at AGV dolly place _iand adjacent No. ID, obtain the i-th+1 ID ID in ID sequence _i+1ranking n in adjacent No. ID of i-th image in 2 D code label _i; 1≤n _i≤ 8; Formula (2) is utilized to obtain the i-th+1 ID ID _i+1image in 2 D code label and i-th ID ID _iimage in 2 D code label line with paste the angle theta in direction _i+1:

θ _i+1＝45°×(n _i-1)(2)

Step 6, as shown in Figure 2, with the central point of i-th image in 2 D code label for initial point O _i; With the i-th+1 ID ID _i+1angle theta _i+1for X _idirection of principal axis; And with X _idirection of principal axis is rotated counterclockwise 90 ° for Y _idirection of principal axis, sets up i-th Local Navigation coordinate system X _io _iy _i;

Step 7, formula (3) and formula (4) is utilized to obtain AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin initial position co-ordinates (A _i, B _i):

A _i＝(Wid/2-y _i)×Δd(3)

B _i＝(Len/2-x _i)×Δd(4)

Step 8, formula (5) is utilized to obtain AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin course angle Δ θ _i:

Δθ _i＝Δα-θ _i+1(5)

Step 9, with the barycenter of AGV dolly for initial point O, with headstock direction for X-direction, and be rotated counterclockwise 90 ° for Y direction with X-direction, set up vehicle axis system XOY; Formula (6) is utilized to obtain the position (a of central point in vehicle axis system XOY of the i-th+1 image in 2 D code label _i, b _i):

$\left[\begin{array}{c}{a}_i\\ b_i\end{array}\right]=\left[\begin{array}{c}cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\\ -sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\end{array}\right]\left[\begin{array}{c}{P}_i-A_i\\ Q_i-B_i\end{array}\right]---\left(6\right)$

In formula (6), P _iand Q _irepresent that the central point of the i-th+1 image in 2 D code label is at i-th Local Navigation coordinate system X _io _iy _iin position coordinates; The P when AGV dolly is kept straight on _i=L=1m, Q _i=0; When AGV dolly is turned q _i=0;

Step 10, utilize formula (7) obtain with i-th course angle Δ θ _itangent and cross the arc radius R of central point of the i-th+1 image in 2 D code label _i:

$R_i=\frac{a_i^2+b_i^2}{2\×b_i}---\left(7\right)$

Step 11, as shown in Figure 3, utilizes formula (8) according to the arc radius R of planning _icalculate the front wheel angle β of single steering wheel AGV _iwith travel speed V _i, between two image in 2 D code labels, AGV is with fixing front wheel angle β _iwith travel speed V _iadvance.

β _i＝arctan(b/R _i)(8)

In formula (8), b is the distance of front-wheel central point to two trailing wheel lines, b=1.64m in the present embodiment.AGV dolly travel speed V in the present embodiment _iaccording to the setting of waypoint attribute, wherein at the uniform velocity keep straight on as 0.5m/s, slow down as 0.2m/s, turn as 0.1m/s.AGV dolly is according to i-th controlled quentity controlled variable β _i, V _iwith i-th waypoint attribute LD _itravel to the i-th+1 image in 2 D code label;

Step 12; By i+1 assignment to i, and judge whether i > m sets up, if set up, represent that AGV dolly completes guidance path instruction; Otherwise, return step 5 order and perform.

Method of the present invention is used to carry out the Navigation Control of AGV, edge route as shown in Figure 4, A is starting point, and travel direction is A->B->C->D-Gre atT.GreaT.GTA, wherein AB, CD are straight line, and BC, DA are circular arc line.At the uniform velocity keep straight on as 0.5m/s, slow down as 0.2m/s, turn as 0.1m/s.As shown in Figure 5 and Figure 6, maximum lateral deviation is 4cm to effect, and maximum angle deviation is 3 °, and visible employing navigation control method of the present invention can complete the guidance path instruction that dispatching center issues reliably.As can be seen from Figure 7, during straight-line travelling, front wheel angle is within ± 5 °, and during negotiation of bends, front wheel angle is within 40 ° ± 5 °, and the amplitude of variation of AGV front wheel angle is in the process of moving less as can be seen here, and it is comparatively steady that AGV travels.The Navigation Control that visible employing this method carries out AGV can ensure that AGV reliably completes the actions such as craspedodrome, turning stably.

Claims (1)

1. the AGV navigation control method based on image in 2 D code label, be applied in the Automatic Warehouse that is made up of dispatching center, several movable goods shelfs and AGV dolly, it is characterized in that, in the traffic areas of described Automatic Warehouse, several image in 2 D code labels by the arrangement of same direction of equidistant stickup in the matrix form; Each image in 2 D code label comprises self ID number and adjacent No. ID; Described adjacent No. ID is formed by with No. ID that pastes 8 adjacent image in 2 D code labels that direction also arranges counterclockwise for starting point; Described AGV dolly is installed the two-dimension code label scanner that resolution is M × N; Described AGV navigation control method carries out as follows:

Step 1, according to the vertical range d between described two-dimension code label scanner and ground, determine that the sweep limit of described two-dimension code label scanner is Len × Wid; Formula (1) is utilized to obtain the range size Δ d of each pixel in the scan image of described two-dimension code label scanner:

$\mathrm{\Δ}d=\frac{Len\×Wid}{M\×N}---\left(1\right)$

Step 2, described two-dimension code label scanner is utilized to scan image in 2 D code label, form scan image, can obtain the angle Δ α of arbitrary coordinate axis in corresponding self ID number and adjacent No. ID and the position coordinates of central point in the local Coordinate System of described scan image of described image in 2 D code label, the label stickup direction of described image in 2 D code and scan image local Coordinate System according to described scan image; The self ID number that scanning obtains is sent to described dispatching center by described AGV dolly, makes described dispatching center know position residing for described AGV dolly;

Step 3, described AGV dolly receive the guidance path instruction that described dispatching center sends; Described guidance path instruction comprises the ID sequence of image in 2 D code label and corresponding waypoint sequence of attributes thereof; Described ID sequence is designated as { ID ₁, ID ₂..., ID _i..., ID _m; ID _ito represent in described ID sequence i-th No. ID; Described waypoint sequence of attributes is designated as { LD ₁, LD ₂..., LD _i..., LD _m; LD _irepresent i-th waypoint attribute in described waypoint sequence of attributes; Initial No. ID of described ID sequence is No. ID of the image in 2 D code label at described AGV dolly initial position place; 1≤i≤m;

Step 4, initialization i=1;

Step 5, ID ID according to i-th image in 2 D code label at described AGV dolly place _iand adjacent No. ID, obtain the i-th+1 ID ID in described ID sequence _i+1ranking n in adjacent No. ID of i-th image in 2 D code label _i; 1≤n _i≤ 8; Formula (2) is utilized to obtain described i-th ID ID _iimage in 2 D code label and described the i-th+1 ID ID _i+1image in 2 D code label line with paste the angle theta in direction _i+1:

θ _i+1＝45°×(n _i-1)(2)

Step 6, with the central point of described i-th image in 2 D code label for initial point O _i; With described the i-th+1 ID ID _i+1angle theta _i+1direction is X _idirection of principal axis; And with X _idirection of principal axis is rotated counterclockwise 90 ° for Y _idirection of principal axis, sets up i-th Local Navigation coordinate system X _io _iy _i;

Step 7, formula (3) and formula (4) is utilized to obtain described AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin initial position co-ordinates (A _i, B _i):

A _i＝(Wid/2-y _i)×Δd(3)

B _i＝(Len/2-x _i)×Δd(4)

In formula (3) and formula (4), x _iand y _irepresent the position coordinates of central point in the local Coordinate System of described scan image of i-th image in 2 D code label;

Step 8, formula (5) is utilized to obtain described AGV dolly at i-th Local Navigation coordinate system X _io _iy _iin angle, initial heading Δ θ _i:

Δθ _i＝Δα-θ _i+1(5)

Step 9, with the barycenter of described AGV dolly for initial point O, with headstock direction for X-direction, and be rotated counterclockwise 90 ° for Y direction with X-direction, set up vehicle axis system XOY; Formula (6) is utilized to obtain the position (a of central point in vehicle axis system XOY of the i-th+1 image in 2 D code label _i, b _i):

$\left[\begin{array}{c}{a}_i\\ b_i\end{array}\right]=\left[\begin{array}{c}cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\\ -sin\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right),cos\left(\mathrm{\Δ}{\mathrm{\θ}}_i\right)\end{array}\right]\left[\begin{array}{c}{P}_i-A_i\\ Q_i-B_i\end{array}\right]---\left(6\right)$

In formula (6), P _iand Q _irepresent that the central point of the i-th+1 image in 2 D code label is at i-th Local Navigation coordinate system X _io _iy _iin position coordinates;

Step 10, utilize formula (7) obtain with described i-th course angle Δ θ _itangent and cross the arc radius R of central point of the i-th+1 image in 2 D code label _i:

$R_i=\frac{a_i^2+b_i^2}{2\×b_i}---\left(7\right)$

Step 11, according to the structure of described AGV dolly and arc radius R _idetermine i-th controlled quentity controlled variable of described AGV dolly; Described AGV dolly is according to described i-th controlled quentity controlled variable and i-th waypoint attribute LD _itravel to the i-th+1 image in 2 D code label;

Step 12; By i+1 assignment to i, and judge whether i > m sets up, if set up, represent that described AGV dolly completes guidance path instruction; Otherwise, return step 5 order and perform.