Robotic Ultrasonic QC Provides Adaptive Inspection of Vehicle Folded Glue Joints

FRS Robotics has introduced a new adaptive robot cell that flexibly automates the highly sensitive ultrasonic inspection of folded glue joints of Audi vehicle doors. By innovating adaptive robot control software, FRS adds the required robot intelligence to continuously take valid ultrasonic measurements along the folded door edge. The robotized measurements revolutionize today’s manual ultrasonic quality control that is time consuming and error prone. FRS’s adaptive ‘Robotic Ultrasonic QC’ outperforms traditional automated quality control purely based on the vehicle door computer model. As a result, Audi benefits from a robot cell that is able to flexibly execute robust ultrasonic inspection on different door types. The robot cell speeds up ultrasonic door inspection and also reduces measurement preparation time thanks to straightforward door positioning and system calibration.

Fold glue joints inspection on car doors

Metrology plays an important role in verifying the quality of sheet metal stamping and assembly operations. Certain vehicle door types consist of metal sheet inner and outer parts which are glued, plied and welded along the door edges. Ultrasonic inspection is performed manually to verify correct glue bonding. Audi asked FRS Robotics to automate the highly sensitive ultrasonic quality control of the doors’ fold glue joints.

Manual ultrasonic quality control lacks process efficiency and measurement robustness. A skillful and experienced operator requires dedication and concentration to properly inspect a complete door. For this reason, robot motion driven solely on the basis of the vehicle door CAD model does not deliver sufficient local sensor positioning accuracy throughout the process. The traditional robotic programming approach is therefor unable to consistently account for the local part-to-CAD deviations of individual doors, resulting in invalid ultrasonic measurements.

Revolutionizing ultrasonic inspection

FRS has introduces ‘Robotic Ultrasonic QC’ which applies accurate adaptive sensor positioning to obtain valid measurements. It is a totally different solution that challenges traditional robotic quality control that is purely based on the vehicle door computer model. Based on contact forces and ultrasonic measurements, FRS continuously adjusts the position and orientation of the ultrasonic sensor in real time. This automated approach guarantees robust ultrasonic quality inspection along the entire door edge.

Concretely, inspections in the FRS robot cell start with an operator positioning a door on an elementary stand or table. Adaptive robotized inspection does not require precision fixation nor clamping of the door, so door positioning and system calibration are fairly straightforward. The operator manually moves the robot arm to bring the ultrasonic sensor to the position where the inspection starts and clicks a button to begin automated inspection. Alternatively, the robot moves autonomously to the starting position and starts inspection. Inspection continues along the door edge until the quality control of the fold glue joints of the car door is completed.

Automating the most challenging tasks

The FRS robot cell is able to execute robust ultrasonic inspection of series of vehicle doors – flexibly handling geometric variations in production. Switching to a series of another door type only requires clicking a software button. Compared to manual inspection, it is like having your best quality control operator on the job and increase productivity at the same time. The automated adaptive process delivers more reliable ultrasonic quality control, which leads to consistently better vehicle doors. Overall, the FRS robotic software is able to automate a range of ultrasonic and other manual quality control applications, which have not been automated so far for technical or economic reasons.

FRS Robotics will demonstrate ‘Robotic Ultrasonic QC’ on Audi vehicle doors at the upcoming Control 2018 Exhibition – Hall 3, Booth 3616-1.

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