CN106341956A - Fixed camera calibration method - Google Patents

Abstract

The invention discloses a fixed camera correction method, belongs to the machine vision localization detection field and is applied to the high-accuracy correction process of a surface mounting machine. The main objective of the invention is to solve the problem that the location, scale and rotation angle of the fixed camera of an existing surface mounting machine cannot be accurately measured in an equipment coordinate system when the fixed camera of the surface mounting machine is mechanically installed. According to the method of the invention, the positional relationship of a surface mounting head in a fixed camera is determined according to a calibration suction nozzle; a conversion relation between two coordinate systems is calculated and derived; the scale of the fixed camera is calculated through the position coordinates of a center; and the rotation angle of the fixed camera in an equipment coordinate system is calculated according to the position coordinates of the surface mounting head and the value coordinates of the surface mounting head. The coordinates, the rotation angle and the scale of the fixed camera are corrected, so that deviation in a detection process caused by manual installation can be offset, the calibration point detection and positioning accuracy of the surface mounting machine can be improved, and the surface mounting effect of the surface mounting machine can be improved. The fixed camera correction method of the invention is suitable for the machine vision precision correction field.

Description

A kind of fixed camera bearing calibration

Technical field

The present invention relates to a kind of fixed camera bearing calibration, belong to machine vision detection and localization technical field.

Technical background

In smt chip mounter, fixed camera is fixedly mounted on immovable fixed frame.Produced carrying out paster Cheng Shi, first has to accurately obtain the position of fixed camera, scale and the isoparametric value of the anglec of rotation, so that subsequently can be accurate Really find the relevant informations such as the zero point of system, the origin system of benchmark camera.Fixed camera position, scale and anglec of rotation etc. The accurate measurement of parameter determines that can the coordinate system of whole picking machine system accurately build, and affects SMD chip and produces in attachment During positioning accuracy.The fixed camera of existing chip mounter is when armstrong's patent is installed it is impossible to avoid manually installed bringing Deviation, error is larger.

Content of the invention

In order to overcome the fixed camera of existing chip mounter when armstrong's patent is installed it is impossible to avoid manually installed bring inclined Difference, the larger technical deficiency of error, the invention provides a kind of school of the fixed camera based on machine learning detection and localization technology Correction method, comprising:

Step one: initialization chip mounter camera setting, the movable length a of setting fixed camera timing placement head, unit For mm, No. 1 placement head, after anc nozzle head groove is drawn and demarcated nozzle head, moves to directly over the fixed camera visual field, correction Object is to demarcate nozzle head；

Step 2: this moment No. 1 position in device coordinate system for the placement head is set to initial position, first by No. 1 placement head X-axis negative direction along device coordinate system moves a/2 length, recalls image detecting program, obtains demarcation nozzle head center and exists Position coordinateses in fixed camera, are designated as d1 (x₁,y₁)；Then No. 1 placement head is moved back to initial position, then by No. 1 placement head edge The x-axis positive direction device coordinate system moves a/2 length, calls image detecting program, obtains demarcation nozzle head center and is fixing Magazine position coordinateses, are designated as d2 (x2, y2)；No. 1 placement head is moved back to initial position, then by No. 1 placement head along equipment The y-axis negative direction of coordinate system moves a/2 length, calls image detecting program, obtains demarcating nozzle head center in fixed camera Position coordinateses, be designated as d3 (x3, y3)；Then No. 1 placement head is moved back to initial position, then No. 1 placement head is sat along equipment The y-axis positive direction of mark system moves a/2 length, calls image detecting program, obtains demarcating nozzle head center in fixed camera Position coordinateses, are designated as d4 (x₄,y₄), the unit of described position coordinateses is mm；

Step 3: No. 1 placement head is moved back to the initial position defined in step 2, No. 1 placement head is rotated respectively to institute State 0 °, 90 °, 180 ° and 270 ° of positions in device coordinate system, call image detecting program, according to described 4 angles of rotation, Obtain demarcating position coordinateses in fixed camera for the nozzle head centre dot, be designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀, y₁₈₀) and (x₂₇₀,y₂₇₀), unit is pixel；And record now No. 1 placement head position coordinateses in device coordinate system (x_Equipment,y_Equipment), unit is mm, and described No. 1 placement head is the initial point of placement head coordinate system；

Step 4: 360 ° of positions that No. 1 placement head is rotated to described device coordinate system, that is, first defined in step 2 Beginning position, repeat step two, obtain 4 groups of position coordinateses d '₁(x′₁,y′₁)、d′₂(x′₂,y′₂)、d′₃(x′₃,y′₃)、d′₄(x′₄, y′₄), unit is pixel；

Step 5: 8 shift position coordinates of the placement head being obtained according to step 2 and step 4, it is calculated 4 anglecs of rotation Degree θ₁、θ₂、θ′₁With θ '₂, the anglec of rotation under device coordinate system for the final fixed camera coordinate system is Detailed process is:

Step May Day: calculate 1,2 points and 3,4 points of groups are in line the angle in image coordinate system:

$\left\{\begin{array}{c}{\mathrm{\θ}}_1={\tan }^{-1}\frac{y_1-y_2}{x_2-x_1}\\ {\mathrm{\θ}}_2={\tan }^{-1}\frac{x_3-x_4}{y_3-y_4}\end{array}\right.$

Step 5 two: the angle in device coordinate system that calculating 1 ', 2 ' is put and 3 ', 4 ' point groups are in line:

$\left\{\begin{array}{c}{\mathrm{\θ}}_1^{\′}={\tan }^{-1}\frac{y_1^{\′}-y_2^{\′}}{x_2^{\′}-x_1^{\′}}\\ {\mathrm{\θ}}_2^{\′}={\tan }^{-1}\frac{x_3^{\′}-x_4^{\′}}{y_3^{\′}-y_4^{\′}}\end{array}\right.$

Step 5 three: θ₁, θ₂, θ '₁, θ '₂Should be roughly equal, the calculating anglec of rotation in device coordinate system for the fixed camera:

Step 6: 8 shift position coordinates according to obtaining No. 1 placement head in step 2 and step 4 calculate fixation The width of pixel on camera x and y direction, i.e. fixed camera scale in the x and y direction, it is designated as w respectively_{Fixed camera x}And w_{Fixed camera y}, single Position is mm/pix；

Step 7: in step 3, after 4 angles of rotation, demarcate position in fixed camera for the nozzle head centre dot Coordinate, is designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀), demarcation nozzle head is calculated according to this 4 class value Mean place coordinate in fixed camera coordinate system for the center

Step 8: by position coordinateses (x in device coordinate system for No. 1 placement head of record in step 3_Equipment,y_Equipment), step Rapid five and the parameter that obtains of step 6 and step 7 and coordinate figure bring equation below into:

It is calculated the photocentre of the fixed camera coordinate (x in device coordinate system_{Fixed camera},y_{Fixed camera}).

The solution have the advantages that, by correcting coordinate, the anglec of rotation and the scale of fixed camera, compensate manually installed The deviation brought to detection process, improves chip mounter to precision during fixed point detection positioning, improves the attachment effect of chip mounter.

Brief description:

Fig. 1 is the flow chart of the present invention；

Fig. 2 is the lower surface schematic diagram demarcating nozzle head；

Fig. 3 is the relative position relation in fixed camera coordinate system and device coordinate system；

When Fig. 4 is that No. 1 placement head does not install demarcation nozzle head, whether No. 1 flight camera calibration has the figure photographing during suction nozzle Picture；

Fig. 5 is that after No. 1 placement head installs demarcation nozzle head, whether No. 1 flight camera calibration has the image photographing during suction nozzle；

Fig. 6 is to demarcate nozzle head to move to directly over the fixed camera visual field, the picture that fixed camera photographed；

Fig. 7 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of x-axis negative direction Demarcate image in the fixed camera visual field for the nozzle head center；

Fig. 8 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of x-axis positive direction Demarcate image in the fixed camera visual field for the nozzle head center；

Fig. 9 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of y-axis negative direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 10 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of y-axis positive direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 11 is to demarcate the image that nozzle head rotates to during 0 ° of position in the fixed camera visual field, is also in Part II Initial position；

Figure 12 is to demarcate the image that nozzle head rotates to during 90 ° of positions in the fixed camera visual field；

Figure 13 is to demarcate the image that nozzle head rotates to during 180 ° of positions in the fixed camera visual field；

Figure 14 is to demarcate the image that nozzle head rotates to during 270 ° of positions in the fixed camera visual field；

Figure 15 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of x-axis negative direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 16 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of x-axis positive direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 17 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of y-axis negative direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 18 is to demarcate nozzle head in device coordinate system, with respect to initial position along after the mobile a/2 length of y-axis positive direction Demarcate image in the fixed camera visual field for the nozzle head center；

Figure 19 is the Comparative result of coordinate before and after fixed camera correction and the anglec of rotation.

Specific embodiment

Specific embodiment one:

A kind of bearing calibration of fixed camera of present embodiment, is realized by following steps:

Step one: initialization chip mounter camera setting, the movable length a of setting fixed camera timing placement head, unit For mm, No. 1 placement head, after anc nozzle head groove is drawn and demarcated nozzle head, moves to directly over the fixed camera visual field, correction Object is to demarcate nozzle head；What anc represented is nozzle head groove.

Step 2: this moment No. 1 position in device coordinate system for the placement head is set to initial position, first by No. 1 placement head X-axis negative direction along device coordinate system moves a/2 length, recalls image detecting program, obtains demarcation nozzle head center and exists Position coordinateses in fixed camera, are designated as d1 (x₁,y₁)；Then No. 1 placement head is moved back to initial position, then by No. 1 placement head edge The x-axis positive direction device coordinate system moves a/2 length, calls image detecting program, obtains demarcation nozzle head center and is fixing Magazine position coordinateses, are designated as d2 (x2, y2)；No. 1 placement head is moved back to initial position, then by No. 1 placement head along equipment The y-axis negative direction of coordinate system moves a/2 length, calls image detecting program, obtains demarcating nozzle head center in fixed camera Position coordinateses, be designated as d3 (x3, y3)；Then No. 1 placement head is moved back to initial position, then No. 1 placement head is sat along equipment The y-axis positive direction of mark system moves a/2 length, calls image detecting program, obtains demarcating nozzle head center in fixed camera Position coordinateses, are designated as d4 (x₄,y₄), the unit of described position coordinateses is mm.

Image detecting program of the present invention is to adopt machine learning algorithm, and for being known by the image of input Do not go out the program of the corresponding position coordinateses in nozzle head center of wherein appearance, because this kind of image detecting program is in prior art Conventional means, the training set for example consisting of picture adds parameter attribute to be trained, obtains a grader, this classification The input of device is picture, and output is position coordinateses.Because this is the conventional meanses in machine learning field, therefore the present invention is not to this figure As detection program is described extensively.

" calling image detecting program " of the present invention is it should be appreciated that by captured by the fixed camera under current state To image input to image detecting program, draw the position coordinateses being identified under current state." current state " refers mainly to Be current location.

Step 3: No. 1 placement head is moved back to the initial position defined in step 2, No. 1 placement head is rotated respectively to institute State 0 °, 90 °, 180 ° and 270 ° of positions in device coordinate system, call image detecting program, according to described 4 angles of rotation, Obtain demarcating position coordinateses in fixed camera for the nozzle head centre dot, be designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀, y₁₈₀) and (x₂₇₀,y₂₇₀), unit is pixel；And record now No. 1 placement head position coordinateses in device coordinate system (x_Equipment,y_Equipment), unit is mm, and described No. 1 placement head is the initial point of placement head coordinate system；Heretofore described rotation is inverse Hour hands rotate.

Step 4: 360 ° of positions that No. 1 placement head is rotated to described device coordinate system, that is, first defined in step 2 Beginning position, repeat step two, obtain 4 groups of position coordinateses d '₁(x′₁,y′₁)、d′₂(x′₂,y′₂)、d′₃(x′₃,y′₃)、d′₄(x′₄, y′₄), unit is pixel；

Step 5: 8 shift position coordinates of the placement head being obtained according to step 2 and step 4, it is calculated 4 anglecs of rotation Degree θ₁、θ₂、θ′₁With θ '₂, the anglec of rotation under device coordinate system for the final fixed camera coordinate system is Detailed process is:

Step May Day: calculate d₁、d₂Point and d₃、d₄Point group is in line the angle in image coordinate system:

$\left\{\begin{array}{c}{\mathrm{\θ}}_1=ta{n}^{-1}\frac{y_1-y_2}{x_2-x_1}\\ {\mathrm{\θ}}_2={\tan }^{-1}\frac{x_3-x_4}{y_3-y_4}\end{array}\right.$

Step 5 two: calculate d '₁、d′₂Point and d '₃、d′₄Point group is in line the angle in device coordinate system:

$\left\{\begin{array}{c}{\mathrm{\θ}}_1^{\′}={\tan }^{-1}\frac{y_1^{\′}-y_2^{\′}}{x_2^{\′}-x_1^{\′}}\\ {\mathrm{\θ}}_2^{\′}={\tan }^{-1}\frac{x_3^{\′}-x_4^{\′}}{y_3^{\′}-y_4^{\′}}\end{array}\right.$

Step 5 three: θ₁, θ₂, θ '₁, θ '₂Should be roughly equal, the calculating anglec of rotation in device coordinate system for the fixed camera:

Step 6: 8 shift position coordinates according to obtaining No. 1 placement head in step 2 and step 4 calculate fixation The width of pixel on camera x and y direction, i.e. fixed camera scale in the x and y direction, it is designated as w respectively_{Fixed camera x}And w_{Fixed camera y}, single Position is mm/pix；

Step 7: in step 3, after 4 angles of rotation, demarcate position in fixed camera for the nozzle head centre dot Coordinate, is designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀), demarcation nozzle head is calculated according to this 4 class value Mean place coordinate in fixed camera coordinate system for the center

Step 8: by position coordinateses (x in device coordinate system for No. 1 placement head of record in step 3_Equipment,y_Equipment), step Rapid five and the parameter that obtains of step 6 and step 7 and coordinate figure bring equation below into:

It is calculated the photocentre of the fixed camera coordinate (x in device coordinate system_{Fixed camera},y_{Fixed camera}).

Specific embodiment two:

From unlike specific embodiment one, step one particularly as follows:

Step is one by one: clicks on the functional keyss for paster fixed camera, fixing phase is read in the prompting according to graphic interface The movable length a of machine；

Step one two: all suction nozzles are placed in the prompting according to graphical interfaces；

Step one three: control hardware to obtain demarcation nozzle head from nozzle head lay down location, according to the graphical interfaces of chip mounter Prompting moves to No. 1 placement head directly over fixed camera central visual field position；

Step one four: control No. 1 placement head to move to above fixed camera center.

Present embodiment can be in concrete operations:

1) click on<the 5. fixed camera 1>button in chip mounter, point out to place suction nozzle.From " movable length " combo box Read the movable length of fixed camera in " fixed camera " control, be set to a (a > 0), unit mm.

2) click on next button, place all suction nozzles.No. 1 placement head of prompting is drawn from anc and is demarcated suction nozzle.

3) hardware is controlled to obtain calibration tool from anc, software interface display waits " acquisition calibration tool ", controls image Part shows the image of flight camera 1.Mobile No. 1 placement head of prompting is to directly over fixed camera central visual field position.

4) No. 1 placement head is controlled to move to above fixed camera center, image display window shows fixed camera Image, software interface display waits moving process.

Other structures and parameter are identical with specific embodiment one.

Specific embodiment three:

From unlike specific embodiment one or two, step 2 particularly as follows:

Step 2 one: No. 1 placement head is moved along the x-axis-a/2, if now No. 1 placement head is relatively fixed the seat of camera photocentre It is designated as d (x, y)=(- a/2,0), unit mm；

Step 2 two: the image that now fixed camera is photographed inputs to image detecting program, obtains demarcating nozzle head Position d in fixed camera for the centre dot₁(x₁,y₁), unit is pixel；

Step 2 three: No. 1 placement head is moved along the x-axis a, the coordinate that now No. 1 placement head is relatively fixed camera photocentre is (a/2,0), the image that now fixed camera is photographed inputs to image detecting program, obtains position in fixed camera for the center of circle Put d₂(x₂,y₂), unit pixel；

Step 2 four: No. 1 placement head is moved along the x-axis-a/2, and moves-a/2 along y-axis, now No. 1 placement head is relative The coordinate of fixed camera photocentre is that (0, a/2), the image that now fixed camera is photographed inputs to image detecting program, obtains Position in fixed camera for the center of circle, is designated as d₃(x₃,y₃), unit pixel；

Step 2 five: No. 1 placement head is moved a along y-axis, the coordinate that now No. 1 placement head is relatively fixed camera photocentre is (0, a/2), repeat step two or two, obtain position in fixed camera for the center of circle, be designated as d₄(x₄,y₄), unit pixel.

Other structures and parameter are identical with specific embodiment one or two.

Specific embodiment four:

From unlike one of specific embodiment one to three, the step 3 of present embodiment particularly as follows:

Step 3 one: No. 1 placement head is moved back to the initial position defined in step 2, now fixed camera is photographed Image inputs to image detecting program, obtains demarcating position in fixed camera for the nozzle head center, is designated as d₀(x₀,y₀), unit Pixel；

Step 3 two: No. 1 placement head is rotated the figure photographing to fixed camera when 90 °, 180 ° and 270 ° of positions respectively As inputting to image detecting program, obtain demarcating correspondence position in fixed camera for the nozzle head center, be designated as (x₉₀,y₉₀)、 (x₁₈₀,y₁₈₀)、(x₂₇₀,y₂₇₀), unit is pixel, and records position coordinateses in device coordinate system for No. 1 placement head for (x_Equipment, y_Equipment), unit is mm.

One of other structures and parameter and specific embodiment one to three are identical.

Specific embodiment five:

From unlike one of specific embodiment one to four, the step 4 of present embodiment particularly as follows:

Step 4 one: No. 1 placement head is rotated to 360 ° of positions, i.e. initial position defined in step 2；

Step 4 two: No. 1 placement head is moved a/2 along x negative sense axle, if now No. 1 placement head is relatively fixed camera photocentre Coordinate be d ' (x ', y ')=(- a/2,0), unit be mm；

Step 4 three: the image that now fixed camera is photographed inputs to image detecting program, obtains demarcating nozzle head Position d ' in fixed camera for the centre dot₁(x′₁,y′₁), unit is pixel；

Step 4 four: by No. 1 placement head along the positive mobile a of x-axis, now No. 1 placement head is relatively fixed the seat of camera photocentre It is designated as (a/2,0), the image that now fixed camera is photographed inputs to image detecting program, obtain the center of circle in fixed camera Position, be designated as d '₂(x′₂,y′₂), unit pixel；

Step 4 five: No. 1 placement head is moved a/2 along x-axis negative sense, and moves a/2, now No. 1 paster along y-axis negative sense The coordinate that head is relatively fixed camera photocentre be d ' (x ', y ')=(0, a/2), image that now fixed camera is photographed input to Image detecting program, obtains position in fixed camera for the center of circle, is designated as d '₃(x′₃,y′₃), unit pixel；

Step 4 six: along the positive mobile a of y-axis, the coordinate that now No. 1 placement head is relatively fixed camera photocentre is d ' to placement head (x ', y ')=(0, a/2), the image that now fixed camera is photographed inputs to image detecting program, obtains the center of circle and is fixing Magazine position, is designated as d '₄(x′₄,y′₄), unit pixel.

Now, four positions are as shown in Figure 3.Wherein, position 1 ', 2 ' is parallel with y-axis, and position 3 ', 4 ' is parallel with x-axis. If coordinate in image coordinate system for the datum mark is (x ' on each position_i,y′_i), i=1,2,3,4.

One of other structures and parameter and specific embodiment one to four are identical.

Specific embodiment six:

From unlike one of specific embodiment one to five, the step 6 of present embodiment particularly as follows:

Step 2 is brought into following public affairs with 8 different shift position coordinates of No. 1 placement head of acquisition in step 4 Calculated in formula.

Step 6 one: on fixed camera x direction, the width of pixel is:

Step 6 two: on fixed camera y direction, the width of pixel is:

One of other structures and parameter and specific embodiment one to six are identical.

One of other structures and parameter and specific embodiment one to five are identical.

Specific embodiment seven:

From unlike one of specific embodiment one to six, the step 7 of present embodiment particularly as follows:

4 groups of position of rotation coordinate (x in fixed camera for the placement head center will be demarcated in step 3₀,y₀)、(x₉₀,y₉₀)、 (x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀) be brought in formula to carry out being calculated and demarcate placement head center in fixed camera coordinate system Mean place coordinateSpecific formula for calculation is as follows:

$\stackrel{\&overbar;}{x}=\underset{i=0,90,180,270}{\&sigma;}{x}_i/4$

$\stackrel{\&overbar;}{y}=\underset{i=0,90,180,270}{\&sigma;}{y}_i/4$

One of other structures and parameter and specific embodiment one to six are identical.

Specific embodiment eight:

From unlike one of specific embodiment one to seven, the step 8 of present embodiment particularly as follows:

By position coordinateses (x in device coordinate system for No. 1 placement head of record in step 3_Equipment,y_Equipment), step 5 and step Rapid six and step 7 in the rotation angle value that calculates, scale value and coordinate figure substitute into equation below:

It is calculated the photocentre of the fixed camera coordinate (x in device coordinate system_{Fixed camera},y_{Fixed camera}).

One of other structures and parameter and specific embodiment one to seven are identical.

Specific embodiment nine:

From unlike one of specific embodiment one to eight, the moving long of fixed camera timing placement head in step one Degree a is 5mm.

Claims (9)

1. a kind of fixed camera bearing calibration is it is characterised in that realize according to the following steps:

Step one: initialization chip mounter camera setting, the movable length a of setting fixed camera timing placement head, unit is mm, No. 1 placement head, after anc nozzle head groove is drawn and demarcated nozzle head, moves to directly over the fixed camera visual field, described demarcation is inhaled Mouth is the object of correction；

Step 2: this moment No. 1 position in device coordinate system for the placement head is set to initial position, first by No. 1 placement head along The x-axis negative direction of device coordinate system moves a/2 length, recalls image detecting program, obtains demarcation nozzle head center and is fixing Magazine position coordinateses, are designated as d1 (x₁,y₁)；Then No. 1 placement head is moved back to initial position, then by No. 1 placement head along setting The x-axis positive direction of standby coordinate system moves a/2 length, calls image detecting program, obtains demarcating nozzle head center in fixed camera In position coordinateses, be designated as d2 (x2, y2)；No. 1 placement head is moved back to initial position, then by No. 1 placement head along device coordinate The y-axis negative direction of system moves a/2 length, calls image detecting program, obtains demarcating position in fixed camera for the nozzle head center Put coordinate, be designated as d3 (x3, y3)；Then No. 1 placement head is moved back to initial position, then by No. 1 placement head along device coordinate system Y-axis positive direction move a/2 length, call image detecting program, obtain demarcate position in fixed camera for the nozzle head center Coordinate, is designated as d4 (x₄,y₄), the unit of described position coordinateses is mm；

Step 3: No. 1 placement head is moved back to the initial position defined in step 2, No. 1 placement head is rotated respectively and sets to described 0 °, 90 °, 180 ° and 270 ° of positions in standby coordinate system, call image detecting program, according to described 4 angles of rotation, obtain Demarcate position coordinateses in fixed camera for the nozzle head centre dot, be designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀), unit is pixel；And record now No. 1 placement head position coordinateses (x in device coordinate system_Equipment, y_Equipment), unit is mm, and described No. 1 placement head is the initial point of placement head coordinate system；

Step 4: 360 ° of positions that No. 1 placement head is rotated to described device coordinate system, i.e. initial bit defined in step 2 Put, repeat step two, obtain 4 groups of position coordinateses d '₁(x′₁,y′₁)、d′₂(x′₂,y′₂)、d′₃(x′₃,y′₃)、d′₄(x′₄,y′₄), Unit is pixel；

Step 5: 8 shift position coordinates of the placement head being obtained according to step 2 and step 4, it is calculated 4 anglecs of rotation θ₁、θ₂、θ′₁With θ '₂, the anglec of rotation under device coordinate system for the final fixed camera coordinate system is Detailed process is:

Step May Day: calculate d₁、d₂Point and d₃、d₄Point group is in line the angle in image coordinate system:

$\left\{\begin{array}{c}{\mathrm{\&theta;}}_1={\tan }^{-1}\frac{y_1-y_2}{x_2-x_1}\\ {\mathrm{\&theta;}}_2={\tan }^{-1}\frac{x_3-x_4}{y_3-y_4}\end{array}\right.$

Step 5 two: calculate d '₁、d′₂Point and d '₃、d′₄Point group is in line the angle in device coordinate system:

$\left\{\begin{array}{c}{\mathrm{\&theta;}}_1^{\&prime;}={\tan }^{-1}\frac{y_1^{\&prime;}-y_2^{\&prime;}}{x_2^{\&prime;}-x_1^{\&prime;}}\\ {\mathrm{\&theta;}}_2^{\&prime;}={\tan }^{-1}\frac{x_3^{\&prime;}-x_4^{\&prime;}}{y_3^{\&prime;}-y_4^{\&prime;}}\end{array}\right.$

Step 5 three: θ₁, θ₂, θ '₁, θ '₂Should be roughly equal, the calculating anglec of rotation in device coordinate system for the fixed camera:

Step 6: 8 shift position coordinates according to obtaining No. 1 placement head in step 2 and step 4 calculate fixed camera The width of pixel on x and y direction, i.e. fixed camera scale in the x and y direction, it is designated as w respectively_{Fixed camera x}And w_{Fixed camera y}, unit is mm/pix；

Step 7: in step 3, after 4 angles of rotation, demarcate position coordinateses in fixed camera for the nozzle head centre dot, It is designated as (x respectively₀,y₀)、(x₉₀,y₉₀)、(x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀), demarcation nozzle head center is calculated according to this 4 class value Mean place coordinate in fixed camera coordinate system

Step 8: by position coordinateses (x in device coordinate system for No. 1 placement head of record in step 3_Equipment,y_Equipment), step 5 The parameter obtaining with step 6 and step 7 and coordinate figure bring equation below into:

It is calculated the photocentre of the fixed camera coordinate (x in device coordinate system_{Fixed camera},y_{Fixed camera}).

2. fixed camera bearing calibration according to claim 1 it is characterised in that step one particularly as follows:

Step is one by one: clicks on the functional keyss for paster fixed camera, fixed camera is read in the prompting according to graphic interface Movable length a；

Step one two: all suction nozzles are placed in the prompting according to graphical interfaces；

Step one three: control hardware to obtain demarcation nozzle head from nozzle head lay down location, according to the graphical interfaces prompting of chip mounter No. 1 placement head is moved to directly over fixed camera central visual field position；

Step one four: control No. 1 placement head to move to above fixed camera center.

3. fixed camera bearing calibration according to claim 1 it is characterised in that step 2 particularly as follows:

Step 2 one: No. 1 placement head is moved along the x-axis-a/2, if the coordinate that now No. 1 placement head is relatively fixed camera photocentre is D (x, y)=(- a/2,0), unit mm；

Step 2 two: the image that now fixed camera is photographed inputs to image detecting program, obtains demarcating nozzle head center Position d in fixed camera for the round dot₁(x₁,y₁), unit is pixel；

Step 2 three: No. 1 placement head is moved along the x-axis a, the coordinate that now No. 1 placement head is relatively fixed camera photocentre be (a/2, 0) image, now fixed camera being photographed inputs to image detecting program, obtains position d in fixed camera for the center of circle₂ (x₂,y₂), unit is pixel；

Step 2 four: No. 1 placement head is moved along the x-axis-a/2, and moves-a/2 along y-axis, now No. 1 placement head is relatively fixed The coordinate of camera photocentre is that (0, a/2), the image that now fixed camera is photographed inputs to image detecting program, obtains the center of circle Position in fixed camera, is designated as d₃(x₃,y₃), unit is pixel；

Step 2 five: No. 1 placement head is moved a along y-axis, the coordinate that now No. 1 placement head is relatively fixed camera photocentre is (0, a/ 2), repeat step two or two, obtain position in fixed camera for the center of circle, are designated as d₄(x₄,y₄), unit is pixel.

4. fixed camera bearing calibration according to claim 1 it is characterised in that step 3 particularly as follows:

Step 3 one: No. 1 placement head is moved back to the initial position defined in step 2, the image that now fixed camera is photographed Input to image detecting program, obtain demarcating position in fixed camera for the nozzle head center, be designated as d₀(x₀,y₀), unit is picture Element；

Step 3 two: No. 1 placement head is rotated respectively to fixed camera when 90 °, 180 ° and 270 ° of positions the image photographing defeated Enter to image detecting program, obtain demarcating correspondence position in fixed camera for the nozzle head center, be designated as (x₉₀,y₉₀)、(x₁₈₀, y₁₈₀)、(x₂₇₀,y₂₇₀), unit is pixel, and records position coordinateses in device coordinate system for No. 1 placement head for (x_Equipment,y_Equipment), Unit is mm.

5. fixed camera bearing calibration according to claim 1 it is characterised in that step 4 particularly as follows:

Step 4 one: No. 1 placement head is rotated to 360 ° of positions, i.e. initial position defined in step 2；

Step 4 two: No. 1 placement head is moved a/2 along x negative sense axle, if now No. 1 placement head is relatively fixed the seat of camera photocentre It is designated as d ' (x ', y ')=(- a/2,0), unit is mm；

Step 4 three: the image that now fixed camera is photographed inputs to image detecting program, obtains demarcating nozzle head center Position d ' in fixed camera for the round dot₁(x′₁,y′₁), unit is pixel；

Step 4 four: by No. 1 placement head along the positive mobile a of x-axis, the coordinate that now No. 1 placement head is relatively fixed camera photocentre is (a/2,0), the image that now fixed camera is photographed inputs to image detecting program, obtains position in fixed camera for the center of circle Put, be designated as d '₂(x′₂,y′₂), unit is pixel；

Step 4 five: No. 1 placement head is moved a/2 along x-axis negative sense, and moves a/2, now No. 1 placement head phase along y-axis negative sense Coordinate to fixed camera photocentre is that d ' (x ', y ')=(0, a/2), the image that now fixed camera is photographed inputs to image Detection program, obtains position in fixed camera for the center of circle, is designated as d '₃(x′₃,y′₃), unit is pixel；

Step 4 six: placement head along the positive mobile a of y-axis, coordinate that now No. 1 placement head is relatively fixed camera photocentre be d ' (x ', Y ')=(0, a/2), the image that now fixed camera is photographed inputs to image detecting program, obtains the center of circle in fixed camera In position, be designated as d '₄(x′₄,y′₄), unit is pixel.

6. fixed camera bearing calibration according to claim 1 it is characterised in that step 6 particularly as follows:

Step 2 is brought in formula below with 8 different shift position coordinates of No. 1 placement head of acquisition in step 4 Calculated；

Step 6 one: on fixed camera x direction, the width of pixel is:

Step 6 two: on fixed camera y direction, the width of pixel is:

7. fixed camera bearing calibration according to claim 1 it is characterised in that step 7 particularly as follows:

4 groups of position of rotation coordinate (x in fixed camera for the placement head center will be demarcated in step 3₀,y₀)、(x₉₀,y₉₀)、 (x₁₈₀,y₁₈₀) and (x₂₇₀,y₂₇₀) be brought in formula to carry out being calculated and demarcate placement head center in fixed camera coordinate system Mean place coordinateSpecific formula for calculation is as follows:

$\stackrel{\&overbar;}{x}=\underset{i=0,90,180,270}{\&sigma;}{x}_i/4$

$\stackrel{\&overbar;}{y}=\underset{i=0,90,180,270}{\&sigma;}{y}_i/4.$

8. fixed camera bearing calibration according to claim 1 it is characterised in that step 8 particularly as follows:

By position coordinateses (x in device coordinate system for No. 1 placement head of record in step 3_Equipment,y_Equipment), step 5 and step 6 And rotation angle value, scale value and the coordinate figure substitution equation below calculating in step 7:

It is calculated the photocentre of the fixed camera coordinate (x in device coordinate system_{Fixed camera},y_{Fixed camera}).

9. fixed camera bearing calibration according to claim 1 is it is characterised in that described fixed camera timing placement head Movable length a be 5mm.