Calibrating a vision system into car frame

Automotive engineering Underbody protection

On a production line for applying undercoating and seam sealant to car bodies, the goal is to enable new car models to be introduced without calling on external service providers.

Calibrating a vision system into car frame

Cell description

In the customer's paint shop, 12 KUKA KR16 robots are used to apply undercoating to car bodies and another 6 KUKA KR 6 robots to apply sealant. The car bodies are measured with an ISRA measuring system when they are driven into the cabin. The offset between the current car and the master car is ascertained and sent to the robot controllers as a base correction.

Task definition

If a new model is to be introduced into the production line, it must first be set up in the ISRA system. Previously the relationship between car and robot was measured with a laser tracker. An external service provided was needed for this work. In future the customer wants to do the work himself using the LaserLAB and the base:in software.


Four measuring balls are attached to the car via suitable adapters. The positions of these balls are measured by a coordinate measuring system to establish the car frame. Then the master car is driven into the production cell and measured with each robot in succession. The result is the base transformation car – robot. This is transmitted to the robot. The master car is measured with the ISRA system in the same position in which it was measured with the robots, and stored as the reference measurement. In future the ISRA system will ascertain the offset between the current car and the master car and will carry out a base correction of the robots.

Customer benefit

The customer is now able to introduce new vehicle models into the production line without any external support.