Cooperative Robotics for Flexible Manufacturing

Manufacturing companies – especially small and medium-sized ones – are under pressure to produce an increasingly diverse range of products and components efficiently. Particularly with small batch sizes and frequently changing process steps, specialized machine tools reach their economic limits.

State of the Art

Conventional machine tools deliver the highest precision but are expensive and tailored to clearly defined tasks. Individual industrial robots, by contrast, offer more flexibility but fail at force-intensive machining processes such as milling or bending. A robotic arm is compliant due to insufficient stiffness, which leads to deviations in such process steps. Existing solutions also require specialized knowledge for programming.

Technology

Multi-robot systems are considered promising, but concepts for adaptive force distribution and simple operation have so far been lacking. Researchers from the Institute of Control Systems (IRS) at KIT have developed a new control and automation concept for this purpose: two industrial robots are physically coupled into one overall system and coordinated via a central computing unit that processes sensor data on position and load into control variables for both robots. Targeted trajectory planning (calculation of optimal motion paths) selects configurations with high stiffness within the workspace. Model predictive control (a forward-looking control approach based on a physical model) distributes process forces in a controlled manner and synchronizes highly precise movements. This allows both robots to guide tools or workpieces precisely along predefined paths. AI-based task planning enables intuitive operation: users formulate tasks in natural language, which the language model automatically translates into executable robot commands.

Advantages

Coupling multiple robots significantly increases stiffness and accuracy compared to single robots. Companies benefit from the high flexibility, as different manufacturing processes can be mapped onto the same robot cell. Looking ahead, the control concept also supports safe human-robot interaction without conventional protective enclosures.

Options for Companies

KIT is seeking partners – companies that manufacture or use robotics – who want to jointly develop the system further for specific industrial applications: from initial trials and incorporating their own process requirements to application-specific demonstrators.