Calipers are key components of the car brake system. The caliper body is made through a casting and machining process and then moves to the final assembly line to assemble another parts.
The caliper body was manually stacked in a jig to move on the assembly line. The body is made of heavy aluminium, weighting from 5 kg to 10 kg. This leads to safety issues and decrease in productivity.
The customer needed to improve the stacking process using 3D vision and an industrial robot – a so called 3D un-loading system.
PhoXi 3D Scanner
After the machining process, the caliper body unit comes out and the robot picks it and places it to the un-loading jig, one by one. One un-loading jig has the capacity of 80 caliper body units. It moves to the next assembly line, using a forklift. For a fully automated un-loading system, 3D Vision is essential because the un-loading jig positions can be different whenever a full jig is replaced by an empty one. In addition, un-loading jigs are produced by several companies which causes deviations. CMES 3D un-loading system can find each un-loading position whenever the robot picks a part for the un-loading. The PhoXi 3D scanner attached to the robot obtains a high-resolution image and the algorithm developed by CMES can easily find the un-loading position. The 3D vision – robot calibration tool also makes it easy to transform the un-loading position to the robot coordinates which is directly communicated to the Fanuc robot.
The PhoXi 3D Scanner attached to the robot takes a high-resolution 3D image and transfers it to the processor within 1 second. The scanner is used not only for acquiring high quality 3D imaging of each un-loading position but also for the layer bar recognition because the un-loading jig has 4 layers and the upper layer should get down when the preceding layer is fully stacked.
The PhoXi 3D Scanner provides an ultra high resolution which leads to higher accuracy. The customer’s desired target cycle time was 13 seconds whereby the vision process should have been finished within 4 seconds. In this application we achieved 3 seconds (2.1sec~2.7sec) thanks to the PhoXi 3D Scanner’s fast scanning speed. The scanner also provides a robust image quality (laser structured). The factory environment posed a challenge for the vision system based on the various light sources (Halogen, fluorescent light). Moving vehicles can also affect the light conditions (AGV, forklift). The PhoXi’s laser light source is very helpful in blocking the ambient light reflection without any shroud. The gripper weights almost 10 kg, the PhoXi 3D Scanner’s carbon body less than 1 kg – this makes them a perfect match for the system.
The customer saved almost 40,000$/month(460,000$/Yr) and reduced safety risks because the 3D un-loading system replaced human workers, who had been working day and night shifts.