The LECTOR 620 image based code reader from SICK is being used to identify windshields accurately during truck assembly at the Daimler plant in Wörth, Germany.
Cycle times are high in commercial vehicle production at one of the biggest truck assembly plants in the world with up to 470 trucks leaving the assembly shop every day. This translates into one vehicle rolling off the line every three minutes, a total of up to 70,000 different variations and six different production series (last year).
SICK’s LECTOR 620 image based code reader is used to identify the right windshield for each truck model. Assembling the windshield is the last step of finishing work for the driver’s cab. Each windshield has a data matrix code printed on the lower left edge that is read by the LECTOR 620 image-based code reader with integrated red and blue lighting so that the proper windshield is inserted into the right truck.
The transparency of the windshield however, makes reading of the code difficult as there is no sufficient contrast between the code and the background. To obtain a stable and process-reliable reading, a white plastic surface was installed behind the windshield and the code.
The LECTOR 620 is now able to read the code accurately as the cells of the data matrix code printed in black provide a superb contrast against the white surface. This set-up is used twice in the course of the assembly: once when feeding the windshields on the conveyor belt and shortly before the gluing process in the final installation position.
The LECTOR 620 code reader is integrated into the plant control via PROFINET, which transmits both the ‘start reading’ command and the reading results by means of the CDM425 connection module. For optimum connection of the LECTOR 620 to the Simatic S7 controller, SICK provided a specific function block that facilitated integration of the sensor into the PROFINET environment, thus reducing commissioning effort.
SICK provided Daimler with a complete solution, starting with code detection all the way to data transfer in the plant control.
The LECTOR 620 image-based code readers are available from SICK.