Risk Assessment and Fixes

Risk: When the length of the shaft is beyond the field of view of the camera, the camera can only identify one end or the center of the shaft and cannot obtain the point cloud of the complete shaft. Under this circumstance, it is difficult to accurately obtain the center position of the shaft in the axial direction.

Fix: For scenarios where the placement accuracy in the length direction is high, auxiliary devices such as cylinders can be used to make the ends of the shafts aligned.

Risk: The incoming workpieces have significant oil stains and iron filings on the surface, making it easy for the magnetic gripper to lose grip.

Fix:

Risk: The shafts with reflective surfaces are more susceptible to the influence of external light, resulting in the partial loss of the obtained shaft point cloud, which affects the success rate of vision recognition and locating accuracy.

Fix: Build a shading or take other shading measures, such as applying shading film, to provide a stable lighting environment for the camera, so as to improve the quality of the point cloud obtained. For detailed instructions, refer to Shading Solution.

Risk: The partitions are made of highly transparent material, allowing the camera to easily recognize the lower-level workpieces through the partitions.

Fix: Use non-transparent or frosted partitions.

Risk: The low rigidity of partitions leads to the following problems during actual usage.

Fix: Use partitions of high-strength materials or add reinforcement bars to the partition to enhance the strength of the partitions.

Risk: The inner walls of the bin are reflective, showing the reflection of the shafts, which will cause more noise in the shaft point cloud and misidentifications by deep learning.

Fix: It is recommended to replace the bin or make the inner walls of the bin non-reflective.

Risk: The bin walls are welded by iron mesh, and the following problems are encountered in actual use.

Fix: The bin walls should be made of square steel or other high-strength materials, and should be constantly checked and maintained during later use.

Risk: The spaces in the bin wall are larger than the cross-sectional area of the shaft, and the shaft can easily stick out of the bin and cannot be picked.

Fix: Use a bin with sealed bin walls.

Risk: The bottom surface of the bin is smooth and flat, and the shafts are prone to roll through the bin. After the camera captures the images and the shaft poses are calculated, the actual positions of the shafts may change due to rolling, making it difficult for the robot to pick accurately.

Fix: Place high-friction pads or other materials that can serve the same function on the bottom surface of the bin.

Risk: When there is film attached to the inner walls of the bin, the film may obscure the shaft, resulting in the shaft not being recognized, or the clamp collides with the film during robot picking, so that the shaft cannot be picked accurately.

Fix: Remove the film, and change to other packaging forms or unify the conditions of incoming workpieces to ensure that the film in the bin does not obscure the workpiece.

Risk: For reflective shafts incoming in an orderly manner, the angle between the axis direction of the shaft and the structured light direction of the camera is random. When the axis direction of the shaft is parallel to the structured light direction of the camera, the point cloud quality obtained by the camera is the worst, which affects the success rate and locating accuracy of vision recognition.

Fix:

Risk: Serious deformation of the bin will lead to difficulty in bin identification, and collisions are prone to occur when the shaft is picked.

Fix: Limit the allowable degree of deformation of the bin in the technical agreement.

Risk:

Fix:

Risk: When using magnetic grippers to pick up workpieces such as shafts (excluding non-ferromagnetic workpieces such as stainless steel), there is a potential risk that the suction force will decrease and the shaft will fall off due to the small contact area.

Solution: The magnetic gripper can be designed as a V-shaped structure to expand the contact area between the gripper and the shaft, and it is suitable for picking shafts of various diameters.