In the previous lesson, we discussed the CCD parameter settings on the user interface, how to calculate the offset between the camera center and the electric screwdriver center, and the camera calibration function.
Today, Zhengdong Assistant will share with you the steps for setting up the visual correction and hole finding teaching operation of the overall machine vision locking solution.
01▶Visual Correction Settings◀
● Visual correction is added because samples are prone to positional shifts during visual locking. Therefore, an automatic correction system was developed by combining forward motion technology with machine vision technology. This system can locate the sample in real time when it shifts position during locking and can promptly feed the deviation signal back to the actuator, thereby improving locking accuracy and work efficiency.
1. On the main user interface, click the formula management button to enter the formula management interface, then click MARK point settings to enter the visual correction settings interface.
Main interface
Recipe Management Interface
Visual correction interface
【Workpiece Positioning Method】: Click to switch to visual correction mode.
[Manual]: Click to bring up the manual operation interface of the machine.
[Return]: Click to return to the previous page.
[Correction Photo Position]: When there are multiple different workpieces on the current fixture, you can click to switch which workpiece in the currently created template, i.e., the correction photo position. Multiple correction photo positions need to be set. (For example: If there are two different samples on the current fixture and locking is required, click correction photo position 1 to create the first sample template. After creation, click correction photo position 2 to create the second template. A single mark point can create 4 different workpiece shape templates, and two mark points can create 8 different workpiece shape templates.)
【Number of Screw Holes for Correction at Photo Positions】: Enter the number of screw holes on the currently created workpiece template that require screw fastening.
2. Introduction to visual correction mode and explanation of setup steps.
(1) Dual Mark Point Positioning and Correction Definition: This function is used when the sample size is large and the field of view cannot accommodate all the screw holes that need to be fastened on the entire workpiece. (The camera needs to be moved to two different shooting positions to capture images.)
Dual Mark Point Correction Settings Interface
Setup steps:
A. First, click the [Manual] button, move the camera to the position of [Mark1 Photo Position] (the goal is to capture a clear image of Mark 1 at this position), and then click [Acquire] to get a photo.
B. Click the "Show ROI" button at the Mark1 camera position. A green rectangular ROI box will pop up. Drag the rectangle to select the shape template you want to create.
C. Click "Create Template" on the Mark1 camera position to create a shape template for Mark1.
D. The green area displayed at this point is the outline of the template. If you need to make changes, click "Show Eraser" to modify the template. After making changes, click "Confirm Changes" to save, and then click "Return to Previous Level". If you don't need to make any changes, simply click "Return to Previous Level". The template creation for template correction and photo position 1 is now complete.
E. Click the [Manual] button to move the machine to the [Mark2 Image Position] location (the goal is to capture a clear image of Mark point 2, i.e., the second shape template, at this location), and then click [Acquire] to obtain a photo. Next, set the shape template for the Mark2 image position; the subsequent steps can be referred to steps B, C, and D above. The dual Mark point positioning and correction setup is now complete.
F. Video demonstration.
(2) Single Mark point positioning and correction.
Setup steps:
A. First, manually move the machine to the position of the Mark photo location (the goal is to capture a clear image of the Mark point at that location), then click "Acquire" to get a photo.
B. Click the "Show ROI" button to bring up a green rectangular ROI box. Drag the rectangle to select the shape template you want to create.
C. Click "Create Template" to create a shape template for the Mark point.
D. The green area displayed at this time is the outline of the template. If you need to make changes, you can click "Show Eraser" to modify the template. After making changes, click "Confirm Changes" to save, and then click "Return to Previous Level".
E. If you don't want to make any changes, simply click "Return to Previous Level". The single-point positioning correction method is now set up.
F. Video demonstration.
02▶Visual Hole Finding Teaching Operation◀
●The purpose of visual hole finding teaching is to locate the screw holes on the sample that need to be screwed in.
Visual hole finding interface
[Grayscale range]: Based on the extracted grayscale values of the screw holes, set the upper and lower limits of the grayscale values of the acquired image to filter out screw holes that meet the conditions.
[Hole Area Range]: Based on the obtained hole area of the screw hole, the upper and lower limits of the hole area range are set to filter out screw holes that meet the conditions.
【Screw hole roundness】: Set the roundness of the screw hole. The setting range is 1~100%. The larger the value, the closer the roundness is to a circle.
【Contrast】: Sets the contrast of the image.
[Manual]: Click to bring up the manual operation interface of the machine.
[Return]: Click to return to the previous page.
Visual hole finding steps:
1. Click the "Manual" button to move the machine to a suitable position (where you can capture images of screw holes). Then click "1. Record Image Position," and according to the current image position number, click the "Take Point" button for the corresponding image position to record it. After recording, click "Return" to go back to the previous level. (The number of points recorded corresponds to the number of image positions on the machine.)
2. Then click on [2. Get Image] to update the image information at the current shooting location.
3. Set the grayscale value range. First, determine the grayscale value range inside the screw hole: Click the [Grayscale Extractor] icon on the right, set it to extraction mode, and then click on the location on the image with the mouse. The grayscale value of the corresponding pixel will be returned. Next, take several points to determine the grayscale value range inside and outside the screw hole. Finally, fill in the [Grayscale Value Range] in the [Hole Finding Parameters] section.
4. Set the hole area range: Click "Show ROI" to bring up a green rectangle. Move the selection box to a specific screw hole, then click the "Hole Area" button to calculate a reference area. Finally, based on the reference area value, fill in the "Hole Area Range" in the "Find Hole Parameters" section to find screw holes with the corresponding area.
5. Set screw hole roundness and contrast: Fill in the parameters such as "Screw Hole Roundness" and "Contrast" in the "Hole Finding Parameters" according to the actual hole finding situation. "Screw Hole Roundness" is one of the filtering conditions for screw holes; only screw holes with a roundness greater than this value will be retained. "Contrast" is the absolute value of the difference in grayscale values between the inside and outside of the screw hole at its boundary; only those with a difference greater than this value are considered to be at the boundary of the screw hole.
6. Click the "Show ROI" button, drag the green rectangular ROI frame to select all the screw holes that need to be fastened, and finally click the "3. Region of Interest" button. Now we can visually locate the holes within the rectangular ROI frame.
7. Click on [4. Visual Hole Finding] to perform visual hole finding based on the hole finding parameters.
8. Click on [5. Point Record] to bring up the hole position sorting interface. Here you can sort and delete screw holes. In the "Locking Point Sort" column, enter 0-10 to sort the holes. During locking, holes with smaller values will be locked first, and if the sort value for a hole is set to 0, that hole will not be locked. Then click [OK] to update the hole positions and sorting data in the relevant recipe file. The visual hole finding operation is now complete.
Hole Position Sorting Interface
9. Video demonstration.
That concludes our presentation on the visual correction and hole finding teaching operations for ZhengMotion Technology's [Machine Vision Locking Overall Solution].
For more exciting content, please follow the "Zheng Motion Assistant" WeChat official account. To obtain a complete machine vision locking solution, please consult Zheng Motion's technical sales engineer: 400-089-8936.
This article is original content from Zheng Motion Technology. We welcome everyone to reprint it for mutual learning and to jointly improve China's intelligent manufacturing level. Copyright belongs to Zheng Motion Technology. Please indicate the source if you reprint this article.
