Combining Safe Collaborative and High-Accuracy Operations in Industrial Robots

We present a general approach for realizing safe collaborative behavior and high-accuracy operations in industrial robots. For example, collaborative behavior is required in human robot collaboration, whereas high-accuracy is needed in robotic machining. The operation sequence of a robot with corresponding often-contradictory demands on safety functions, control mode and accuracy is specified in a task-oriented path planner. The task planner generates optimized reference trajectories based on an environmental model, kinematic and task-specific constraints. The resulting reference path is fed into an online operation management, which monitors the workspace, ensures safety, and realizes different online control strategies especially for the dynamic tasks such as human robot collaboration or high-precision operations. For the high-accuracy tasks, we implemented a model predictive controller using a mechatronic model for predicting future configurations of the robot based on the measured present configuration. The model-predictive control is demonstrated for the compensation of deviations due to external forces that acts on the end effector of the robot.