Parameterization of Robotic Welding Trajectories from Demonstration

The rise of mass customization is leading to more frequent production changes. Being able to program robots quickly is paramount to reduce production downtimes. However, this requirement contrasts with the lack of robotic experts in industries. To solve this issue, robot manufacturers invested in developing intuitive programming interfaces for tasks commonly tackled by robots. Programming by Demonstration is particularly appealing for welding since it allows the robot to learn how to execute the task directly from a sample hand-guided execution of the welding trajectory. Nevertheless, solutions on the market are limited to interfaces to support the operator in saving motion waypoints. In this paper, we target the problem of parameterizing the whole welding trajectory from a single kinesthetic demonstration without the need to save waypoints. The parameterized trajectory is then translated into a sequence of suitable robot instructions for the execution of the welding. Furthermore, the paper shows how the parameterized trajectory can be extended for welding a batch of workpieces of the same shape in a predefined pattern.