Cognex Machine Vision & Mitsubishi Robot Interface/Setup Tutorial Nicholas Bozzelli & Quentin Kilgore Millersville University October 2017

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1 Cognex Machine Vision & Mitsubishi Robot Interface/Setup Tutorial Nicholas Bozzelli & Quentin Kilgore Millersville University October 2017 Part I: Cognex Set-Up Overview: Using the Cognex vision system, you will be setting up the camera to read a contrast between a dark shade on a wooden block and a white piece of paper. You will learn how to send that output signal to a Mitsubishi Robotic arm. 1. Verify that the Cognex power supply is plugged in. 2. Open up Insight Explorer 5.4.1, which is located on the desktop. 3. Located on the Cognex camera is a nameplate that shows the camera number. Take note as to what number it is. 4. Once the software is opened up you will see a couple main features. You have the toolbar across the top, an Application Steps project tree on the left with 9 options, a camera window in the middle, a palette project tree on the right, and some windows and general information on the bottom. 5. First step is to connect to your camera. Click on the Get Connected button on the left, and in the bottom left-hand corner will be a window that displays the cameras that you can connect to. In this window, you will be able to see all the cameras that are currently online, so you need to make sure that you are connecting to the correct camera. They will be labeled Millersville, then the camera number. This needs to match with what is labeled on your camera. 6. Click Connect. 7. Next click on Set Up Image in the Application Steps project tree. 8. At the bottom of the screen will be an Edit Acquisition Settings window, and the first option is Trigger. You want to change that option to Continuous for this labs purpose. This makes it so that the camera is constantly capturing images when you go live. 1

2 9. On the left-hand side under Acquire/Load Image is a Live Video button. You want to click on that and wave something under the camera just to verify that your camera is connected and working properly. If it is not, repeat the previous steps to ensure that you properly connected the camera. Once you confirm your camera is working, grab a white piece of computer paper (it must be completely white with no lines) and a wooden block from the lab that has a dark letter and border on one side. Place the paper under the view of the camera, and place the wooden block directly under the camera in its field of view. Once this is complete, click Live Video again to end the feed. 10. Back under the application steps tree you want to click on Locate Part. This step will tell the camera the general location to look for an object. 11. In the bottom, left-hand portion of the screen is an Add Tool window. This is where you can specify how the camera looks for a part. For this lab, we are just going to look at a general pattern. Under that window you want to select Pattern and click Add. 12. In the camera window, you will see a large green box and a smaller pink box. The green box is the cameras search image. Decrease the size of this box to fit loosely around the block shown in the picture below. The pink box is the pattern window. This is going to tell the camera what pattern to look for. You want to take that window and position it over your object. 2

3 Once you are happy with the location click OK. On the right-hand side in the palette tree you will be able to see the tool that you just added. 13. Once you position the pink box and click OK, at the bottom of the screen an edit tool window will appear. In this window, you can rename your tool (i.e. pattern_1) if desired. This can be helpful when you have multiple tools being used. In that window, you have a General and Settings tab. Click on the Settings tab, and change the rotation tolerance to 180. This makes it so the camera will recognize your object within a wide tolerance range. If this is left at a lower tolerance, the camera will only be able to recognize your object from a very specific angle (i.e. only one position of the wooden blocks letter). 14. Next you want to go to Inspect Part, and again you are going to add a tool. For this lab we are going to look at contrast. 15. Click on the Presence/Absence tools drop down menu. 3

4 Click on Contrast and click Add. 16. You will see a directions window appear with a shape drop down menu. Your options will be rectangle, circle, annulus, and polygon. You want to pick the option that will best fit your shape. For this lab you are going to want to pick rectangle. 17. Click OK 18. You will see a small green rectangle. Again, you want to take that and drag it over your object, but this time you want that box to be slightly inside your objects border (i.e. slightly inside the wooden blocks dark border). If it is not positioned properly, your readings will not be accurate because it will not be reading a proper contrast between white and black. 19. At the bottom of the screen there is an Edit Tool window. Just like the pattern tool you can rename your tool where it shows Tool Name. In that window this time, you will have a General and Range Limits tab. Click on the Range Limits, and hit the Set Limits button. This button will tell the camera the maximum and minimum limits for which to read the contrast. You can verify that this worked when the numbers in the Maximum and Minimum windows change, and you can drag the box around and see the box change from green, meaning it is a pass, and red, meaning it is a fail. 20. Skip the Inputs/Outputs button in the application steps tree. 4

5 21. Click on the Communication tab. This is where you will connect the Cognex camera to the Mitsubishi Robot. 22. Click on Add Device in the bottom left-hand side of the screen. Under Device it should say None. Click on the box and select Robot. Under Manufacturer, click the white box and select Mitsubishi. Under Protocol, click the white box and select Ethernet Native String, since we are using Ethernet to connect the system together. Click OK. 23. Once you click OK, a screen labeled Format Output String appears at the bottom of the screen. The Format Output String is where you choose which output(s) the robot is going to read from the Cognex. This will later be referenced in the Mitsubishi code. 24. Under the Format Output String, click on Add. A pop-up screen with multiple drop-down menus will appear based on which Locate and Inspect tools you previously set up. Click on the drop-down menu for whatever you named your Locate Part tool (i.e. Pattern_1). Find the name that states if there is a Pass (i.e. Pattern_1.Pass). Click OK. You should now see the name you selected on the bottom window of the screen. 25. Repeat step 24 to add your Inspect Part tool (i.e. Contrast_1.Pass). 26. Both the Pattern and Contrast tools should now be in the Format Output String window. 5

6 27. Skip the Filmstrip tab and click on the Save Job tab. 28. Click on Save As and make sure that you are saving your project under the In-Sight Sensors location. Double click on the camera name (i.e. Millersville_12) and save your file here. This ensures that you are saving your file directly to the camera itself. If this is saved in a different location, the robot will not be able to receive the file from the Cognex. Also, make sure that the name you are saving as is under 15 characters. If it is not under 15 characters, when you go to run the experiment you will receive an error code from the robot controller. 29. Click the Run Job tab. 30. Confirm that you see your Pattern and Contrast tools at the bottom window on the screen. 31. Click the Online tab, and when the pop-up appears to ask if you want to go online click Yes. 32. You will now see your camera running the jobs you created. Move the wooden block around the table and orient it in different positions to see what passes and what fails based on what you set up. Your results are seen at the bottom of the screen in real-time. 33. If the contrast is not working and you are receiving fails every time, or your results are varying a lot, click the Offline tab. Click on the Inspect Part tab back in the Application Steps tree. On the right is your Palette with your tools. Click on the Contrast name under the Results tab and edit your box size so that you read a better contrast. Then run the job again and confirm the systems reliability. 6

7 Part II: Robot Set-Up Overview: Melfa Basic uses specific coding instructions for use with vision systems. Provided to you are three coding instructions that include their descriptions and sample codes. Write a program that opens the robot hand when a Pass is detected and closes the robot hand when a Fail is detected. The code must include the three vision system code instructions (yes, you will need all three). Note: Remember how the robot reads through the code. Which instructions need to come first, and which can come last? Note: The sample codes will be useful here, but not everything in the sample codes necessarily need to be used. 1. Open RT ToolBox2 located on the computers desktop. 2. On the top of the screen is your toolbar. Select WorkSpace and click New. This WorkSpace will be used anytime you are logged in on the computer under your personal desktop. 3. Under Workspace name create a name. 4. An Edit Project screen appears. Rename the Project name. 5. Under Method, select the drop down menu and click TCP/IP, since we are connecting via Ethernet. 7

8 6. Click on the Detail button next to Method. A pop-up screen appears. Change the IP Address to the IP Address located on the robot controller that is on the lab bench. 7. Where is says Robot Model, click on the select button and scroll through until you see the option RH-6FH3520-D. Click OK. Change the language to MELFA-BASIC V. Click OK at the bottom of the pop-up screen. 8

9 8. If your workspace is set up correctly, your workspace tree should look similar to what is pictured below. 9. In the workspace tree, under your project name, click the plus icon, then click the plus icon next to Offline, and then right click on Program and click new. 10. Name your robot program. Your program name MUST NOT EXCEED FOUR CHARACTERS. The display on the robot controllers can only handle four characters. Click OK. 11. A program window will appear, and this is where you will write your program. Attached to this tutorial are three codes specifically designed for a vision system. Using these three coding instructions, write a program that opens the robot hand when a Pass is detected and closes the robot hand when a Fail is detected. The code must include the three vision system code instructions (yes, you will need all three). 9

10 Part III: Running the Program Overview: In this portion of the lab, you will run the whole program that integrates the Cognex vision system with the Mitsubishi Robotic arm. 1. Switch on the power on the black voltage regulator sitting on top of the Mitsubishi controller box. 2. Switch on the power on the Mitsubishi controller box. 3. On the Mitsubishi controller box, click the button that says CHNG DISP, and use the Down and Up arrows to scroll through and find your program name (ex: TAPE). 4. Click the CHNG DISP button again until you see the speed appear. It will look something like what is pictures below. Change the speed to be By clicking CHNG DISP again, change the display back to the original display it was showing. (i.e ) 10

11 6. Back in Insight Explorer, Click the Run Job tab. Confirm that you see your Pattern and Contrast tools at the bottom window on the screen. 7. Click the Online tab, and when the pop-up appears to ask if you want to go online click Yes. Your camera is now running. 8. In RT Toolbox, click on the Online tab, and select Online 9. In the Workspace Tree on the left, select Online à Program à click on your program name. 10. In RT Toolbox, click on File located on the top toolbar. 11. Click on Save As -> Robot Name your program and keep the name up to 4 characters. Your program is now saved to the controller. 12. On the Mitsubishi controller, press the SVO ON button to turn the servos on. Make sure your robot is clear of any obstructions. Press START. Your program should now be running. 11