Sensor-based assembly

Increasing cost pressure in industrial productions, shorter lifecycles and high product diversity call for flexible cost-effective assembly systems that can be easily adapted to changing requirements. The ability to freely program robots makes them extremely adaptable but they do not possess either sensors or intelligence. Therefore, to meet market demands, sensors and analysis algorithms need to be incorporated into robots. Experts at Fraunhofer IPA develop sensor-controlled assembly processes to replace expensive devices, thus improving flexibility and cost-efficiency in assembly.


Services

Do you have manual assembly processes in your company which cannot be automated due to tolerances and inaccurate positioning? Or are your automated assembly processes not running as smoothly as they should because of tolerances and inaccurate positioning? Then get in touch with us. In a personal meeting, we can discuss the possibilities of integrating sensors into your company’s assembly processes.


Advantages

  • The integration of sensor technology into robot systems for assembly tasks enables positioning tolerances and component tolerances to be compensated for. In parts provision, this does away with the need for expensive, component-specific devices to position objects in a defined manner.
  • Component tolerances are compensated for in the course of the actual assembly process; this enables parts to be assembled even if they have not been pre-positioned correctly. This saves on costly positioning and indexing equipment and enhances process reliability.
  • The sensors can also be implemented in other applications, e.g. to take over completeness checks, detect the presence of parts, or enable uncomplicated interaction between the worker and the robot.
  • This generally improves cost-effectiveness and flexibility in assembly processes.


Sample project

Fraunhofer IPA adapted the lightweight robot KUKA LBR iiwa to enable it to screw a coupling onto the crankshaft of a chain saw. The couplings to be assembled are placed in the robot’s work space without the use of special equipment. The robot uses a fixed 3D camera mounted overhead to locate the approximate position of the coupling; it then approaches this position and identifies the exact position of the coupling with the aid of a stereo camera integrated into the robot tool. The assembly position, i.e. the crankshaft, is located in the same way, thus enabling the motor block to be flexibly positioned in the working area. Force control is used to fit the coupling onto the crankshaft and screw it on. This allows other tolerances to be compensated for. Errors occurring during the screwing process, e.g. canting, are also recognized and remedied directly.

Assistive robot for riveting operations