Improving the accuracy of industrial robots

The high load capacity, large work space and low investment costs of industrial robots offer a unique potential to reduce costs in numerous areas of production. However, many interesting applications can only be implemented cost-effectively if measures are taken to improve their accuracy.


Services

  • Pre-tests to determine achievable accuracy levels
  • Integration of sensors measuring relative or absolute positions to enhance accuracy
  • Development of compensation models (e.g. deformation models, kinematic models) to improve positioning accuracy
  • Geometric calibration of robot cells, robots and robot tools
  • Design, development and implementation of measures to enhance the accuracy of new or existing systems


Technologies

Fraunhofer IPA develops software modules and methods to improve robot accuracy:

  • Compensation for deviations in paths and positions via measurement value feedback (e.g. laser tracker, stereo camera system)
  • Robot referencing software to calibrate the robot from component features by matching point clouds
  • Rigidity model for 6-axis industrial robots to compensate for payload-related deviations
  • Software and methods for accurately calibrating robots and peripheral equipment


Advantages

Although robots have a very high repeat accuracy, their absolute accuracy is not so good. Absolute accuracy can be improved by making technical modifications. This opens up new application fields and offers numerous advantages:

  • Implementation of robots for machining tasks with low to average accuracy requirements. Compared to tooling machines, robots are more economical and also have a better orientation capacity
  • Automation of rework tasks (e.g. deburring, rounding)
  • Improved quality does away with the need for downstream processes
  • Robots are programmed faster because manual re-teaching with offline programming is no longer required; the system can also be integrated into the company’s CAD/CAM tool chain

COMET - adaptive production systems using industrial robots

VariProg: Effiziente Roboterprogrammierung und sensorgestütztes Entgraten mit Industrieroboter