Versatile Camera Machine Vision Lab

Transcription

1 Versatile Camera Machine Vision Lab In-Sight Explorer

2 Table of Contents Pill Inspection... Error! Bookmark not defined. Get Connected... Error! Bookmark not defined. Set Up Image Location Tool... Error! Bookmark not defined. Inspection Tool... Error! Bookmark not defined. Vision Guided Robotics... Error! Bookmark not defined. Set Up Image... Error! Bookmark not defined. Calibration... Error! Bookmark not defined. Train Pattern... Error! Bookmark not defined. Communications... Error! Bookmark not defined. 2D Data Matrix & OCR... Error! Bookmark not defined. Light Change... Error! Bookmark not defined. Set Up Image... Error! Bookmark not defined. 2D Data Matrix... Error! Bookmark not defined. OCR... Error! Bookmark not defined. Logic... Error! Bookmark not defined. Reference Material... Error! Bookmark not defined

3 Pill Inspections 30 minutes Goal: The goal of this inspection is to properly identify and count the green and orange pills. This will be done with the use of red lighting and filtering to accentuate the difference between the pills. Tools Used: Edge Detect, Edge Intersect, Blob Getting Connected: The IP Address of the computer needs to match the IP Address of the camera. If the camera does not appear in the Get Connected box, go to page 39 and follow the steps to connect your camera. Connected cameras will appear here - 3 -

4 Setup Image: This is the most important part of any vision inspection. It is imperative that the lighting and lensing are optimized to show the greatest difference between a good and bad part. Prior to the software setup the camera needs to be located approx. 5.5 above the table surface with the light pointing directly downwards. After this the image set up is composed of 3 things: Light Intensity How much light is saturating the surface Exposure Time How long the chip is exposed to light Focus What area is the lens focusing on Select the Set Up Image tab on the left tool panel under Application Steps. The bottom of the page will populate with the editable settings for image set up. Verify all 4 lights are checked and Intensity is set to 100% 1. Scroll down and select Light Settings Select OK to save and close - 4 -

5 The exposure time must now be set to optimize the image for the best analysis. This is typically done with trial and error but for this analysis.03 ms is a good starting point. Start with exposure at.030 ms Next, use autofocus to sharpen image. First select the Focus Region and then position the focus region over the desired area. Then select Autofocus to allow the camera to optimize the focus position. Place Focus Region over area desired to be in focus Select Autofocus. The camera lights should flash during the autofocus process

6 Location Tool: Once the image is optimized a datum must be located for the inspection. This is done with a location tool. There are a variety of tools available to be used for location tools but for this inspection the Edge Intersect tool will be used. The edge intersect tool works by finding two edges and the calculated intersection point of these edges. Once the tool is added to the palette the program will automatically create two edge find tools as well as the intersection point to be used as the datum. Select Edge Intersection and the click Add Select Edges Shown - 6 -

7 This will create two edge find regions that are shown below with the green boxes, as long as the edge of the part falls within these boxes the system can locate the part. For this inspection it is best to open the tool region to account for larger positional variations. Simply click on the box areas and drag to desired size. Trigger the camera a few times and move the part to verify the location tool works properly

8 Inspection Tool: Now that the part has been located in the Field of View (FOV) it is time to inspect for the proper pills. This will be done with the use of the blob count tool, which looks for groups of pixels that have similar intensity. For this inspection the green pills will be considered good and the orange pills will be considered bad. The blob count tool will look for two large black blobs within the inspection region. There must be a minimum blob size used to verify the entire pill is in the capsule. Again, typically trial and error would be used to test for the appropriate blob specifications, for this inspection please use the settings below. Size and locate inspection region as shown - 8 -

9 Set the blob tool settings to the following. Note that the blob tool is automatically fixtured to the edge intersect locate tool

10 With these settings the blob tool will show a green border around the dark pills. This tool can the be copied and pasted in the tool palette to inspect the other three inspection points as seen below. The part can now be rotated and repositioned to pass and fail the pills in different areas. This concludes the Pill Inspection section of the lab. Note that the green pills appear much darker in the camera image than with the naked eye. This is due to the use of the red light, red and blue are opposite of each other on the color wheel which means that when a red light is shown on a blue object it appears very dark or black. Contrarily, if a red light is shown on a red object it will appear brighter or white. This is an example of how the proper lighting can be used to generate stark differences between good and bad parts. Once finished please go to File -> New Job to erase job

11 Vision Guided Robotics 20 minutes Goal: The goal of this lab is to demonstrate the camera calibration process and how PatMax Redline can be used for robotic guidance. Tools Used: Calibration Tool, PatMax Redline, Communications Getting Connected: The IP Address of the computer needs to match the IP Address of the camera. If the camera does not appear in the Get Connected box, go to page 39 to connect your camera. Setup Image: For this inspection place the camera approx. 12 above the ground with the camera light facing directly at the ground. Once this achieved set the Set Up Image settings to the following

12 With the light settings and exposure set, place a sample block in the FOV and run autofocus

13 Calibration: Once the image is focused and optimized the next step of the vision guided robotic process is to calibrate the image. This is what sets the user frame for the robot to be calibrated to. The image will be calibrated with the use of a calibration grid and it is necessary to align the calibration grid with the image in the desired direction and position. To locate the calibration grid in the FOV appropriately the center of the image must first be found. The IS7802 camera has a chip that contains 1600 pixels wide and 1200 pixels high. This means the center of the image is located at 800,600 pixels with 0,0 located in the top left corner of the image. A construction point will be plotted to locate the center of the image. Select Point from the Plot Tools. Click Add and set the X value to 800 and the Y value to

14 This will locate the center of the image as seen below

15 Y-Axis Now that the center of the image is located it will be easier to properly place the calibration grid. The calibration grid that will be used contains a fiducial which automatically locates the origin and XY axis. See image below for details. X-Axis Remove the sample part and place the calibration grid in the FOV of the camera. Take care to align the fiducial origin with the center of the image. When the system is calibrated the image coordinate system will base off the fiducial origin and XY Axis angles. The next step is to open the calibration wizard, to do this go to Set Up Image and select Calibrate from the tool settings area

16 Set the calibration wizard to match the setting of the calibration grid being used. Next, select the Pose option to the left. The pose is the image that will be used to calibrate the system. If a large FOV is required, multiple pose s can be used to calibrate the image if a single calibration grid is not large enough. For this inspection a single pose will suffice

17 Green X s should appear on the corners of the calibration boxes on the calibration grid. These points are generated by the software and used to calibrate the image. Once these appear select calibrate. A calibration result score is generated to provide a reference for the image calibration. For excellent calibration scores a laser etched grid or machined aluminum grid are recommended to provide the most precise and accurate calibration. The paper calibration grid can be distorted and provide inaccurate results

18 Now that the image is calibrated the construction point will need to be centered in the image as the origin has now been redefined. Set X&Y to 0,0 to move construction point to origin of calibrated image. Now that the image has been calibrated all measurements and position will be in mm with reference to the origin. A robot user frame can also set to match the layout of the image coordinate structure, but this process is beyond the scope of this lab

19 Training Pattern: After the image has been calibrated a part needs to be located within this image. Place the sample part near the middle of the image and add a PatMax RedLine Pattern 1-10 location tool. Train the pattern and set the tool parameters as follows

20 These settings will allow the PatMax Redline tool to find 2 patterns in any rotational position within the search region. After this tool is set up, place a few sample parts in various positions to make sure the tool is working properly. The tool palette contains a snap shot of the information provided by the PatMax Redline tool. The numbers next to the pattern name are the (X position, Y position) rotation and the score of the pattern match. In this example Pattern 1 is located at 46.6mm to the right of the origin, 32.9mm above the origin and rotated at 18.3 degrees. This information can now be exported through the communications tab

21 Communication: There are two ways to export the positional data from In-Sight Explorer. One is to send each coordinate for each pattern to the PLC. The second is to directly send the information to a robot in its native communication style. To send the information to the PLC go to the communications tab and select the following. Select Add Device and set the Device Setup menu to the following:

22 The next step is to select the information that is desired to go to the PLC. This is done by going to the Format Output Data tab and adding variables. Then select the variables to be added to the output data packet

23 This will then populate the Format Output Data table with the appropriate information. This data can then be formatted to fit the desired output for communication with the PLC. From this information it is shown that Pattern 0 has a position that is 46.5 mm above the origin and 32.9mm to the right of it with an angle of degrees

24 The second method for exporting the data is to talk directly with the Robot. In order to configure this communication method, the Ethernet/IP device must be removed. Then add the robot communication style that is desired, this data is preformatted to the preference of the robot selected. See images below for settings

25 The information is preformatted to communicate with the robot, however the same information that was provided to the PLC is shown below. This is the end of the vision guided robotics lab. It should be noted that while this initial set up of the image calibration tool is quite simple, great care should be taken during the calibration process to ensure the image and robot user frame are calibrated as accurately as possible. The success of the installation will depend on this. Please leave cameras powered on and connected and wait for next lab

26 2D Data Matrix & OCR - 20 minutes Goal: The goal of this lab is to demonstrate the barcode reading capabilities of the camera as well as the Optical Character Recognition (OCR) capabilities. This lab will also deal with changing hardware set ups and lighting solutions. Tools Used: Read 2D Code, OCRMax, Logic Getting Connected: The IP Address of the computer needs to match the IP Address of the camera. If the camera does not appear in the Get Connected box, go to page 39 to connect your camera. Light Change: For this inspection an external light and C-mount lens will be used. This will require the integrated light and autofocus module to be removed from the camera. The autofocus position must be set to 0 and the camera powered off before the autofocus module can be removed. Do not disassemble the camera before disconnecting power and setting autofocus to

27 Once the focus position is set to 0 and the camera is disconnected from power the lens cover, light and autofocus modules may be removed. This is by removing the screws shown in the images below. Lens Cover Removal 2mm Hex

28 Light Housing 2mm Hex

29 Autofocus Module 1.5mm Hex

30 Camera Ready for C-Mount Lens External light port

31 Set Up Image: For this image set up the lens will need to be manually focused and the aperture of the lens should be set on the darkest setting. The camera should be mounted approximately 12 from the surface with the external light positioned 45 degrees off axis 6 away from the part. This will provide even illumination of the angled face of the part. The exposure should start off around 1.00 ms. The light settings for the camera will need to be adjusted to have the external light trigger. This is done in the Setup Image tab with selecting the Light Settings option. Simply check External instead of Internal if the camera did not automatically switch. Once the image is set up properly it should look like the one below

32 2D Matrix Code: Cognex vision systems can read 2D and 1D barcodes as well as perform a variety of other inspections. All that is required to read a 2D barcode is to add the Read 2D Code tool to the palette. A location tool is not required for 2D barcodes as they contain a location feature as part of the 2D code. This can be used for locating other tools as well. Position the inspection region generously around the code/part. This is the area where the program will look to find a barcode

33 The system will find the barcode and display the results in the tool palette

34 OCR: The system is also able to read characters from a part. This is done with the OCRMax tool. This tool can be fixtured from the barcode tool and it also must be trained to find/decipher the appropriate characters. Place the search region around the text that is going to be inspected and the software will parse out the letters. These letters then need to be trained into a library which the OCRMax tool will reference every time it sees a character. These characters can be verified against a known string to make sure that the proper text is printed

35 Enter the text and select train all this will train all the characters to their appropriate alphanumeric symbol. After the text is trained it can be verified, this is done in the settings tab of the OCRMax tool, change the Inspection Mode to Read/Verify and enter the string of letters that the OCRMax tool needs to match with

36 Be sure to link the OCRMax tool to the IDCode in the Tool Fixture. Once these tools have been set up properly, try testing the system on the other test block labeled ABA122. The tools can find and decipher both the 2D data matrix code and read the text. However, the OCRMax tool fails because it cannot verify the string it reads matches the match string of ABC123 that was established

37 Logic: The system also has logic and data processing capabilities as well. If it was desired to have only one bit for a pass or fail of the entire job this can be accomplished with the logic tools. A logic tool will be set up to only pass if both the IDCode_1 tool and the Text_1 tool pass. See below: Use the operators on the right to build the desired logic function

38 This can then be output through the communications tab using the process discussed earlier so that a single bit will pass or fail the entire job. This is the end of the 2D Data Matrix & OCR lab section. Please remember that the OCRMax tools must be trained for every alphanumeric character that can be entered for the string. Meaning a sample of A-Z and 1-9 must be trained for each character in the string if completely random text must be read. Hopefully these labs were beneficial in showing the versatility of a single camera system and the variety of applications it can solve. Thank you for your time and effort!

39 Reference Material Getting Connected 1. Set a static IP address on your Computer NIC Open the Network and Sharing Center Select - Change a dapter s ettings Select the Ethernet adapter. Your screen may look different. Just don t pick the any VPNs (in my case below Pulse Secure ) or wireless

40 Right-Click - Select Properties Double Click Internet Protocol Version 4 (TCP/IPv4) to open the Properties window Apply the Static IP Settings shown below and click OK

41 2. Launch In-Sight Explorer. Go to Get Connected Click Add, if no cameras appear select Show all

42 3. Next set the camera IP address and subnet to match the computer