Partner:

CMES

Challenge: 

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 aluminum, weighing from 5 kg to 10 kg. This leads to safety issues and a 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.

Solution:

PhoXi 3D Scanner

After the machining process, the caliper body unit comes out and the robot picks it and places it to the unloading jig, one by one. One unloading jig has the capacity of 80 caliper body units. It moves to the next assembly line, using a forklift. For a fully automated unloading system, 3D vision is essential because the positions of the unloading jigs can differ whenever a full jig is replaced by an empty one. In addition, unloading jigs are produced by several companies, which causes deviations. CMES 3D unloading system can find each unloading position whenever the robot picks a part for the unloading. The PhoXi 3D Scanner attached to the robot acquires a high-resolution image and the algorithm developed by CMES can easily find the unloading position. The 3D vision – robot calibration tool also makes it easy to transform the unloading position to robot coordinates, which is directly communicated to a Fanuc robot.

The PhoXi 3D Scanner attached to the robot acquires a high-resolution 3D image and transfers it to the processor within 1 second. The scanner is not only used for the high-quality 3D imaging of each unloading position but also for the layer bar recognition because the unloading jig has 4 layers and the upper layer should get down when the preceding layer is fully stacked.

Discussion:

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 was to be 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 scanner’s laser light source is very helpful in blocking the ambient light reflection without any shroud. The gripper weighs 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 unloading system replaced human workers, who were working day and night shifts.