Accuracy improvement rack-and-pinion drives through model-based compensation of backlash

• Applicant: Professor Dr.-Ing. Alexander Verl
• Subject Area: Production Automation and Assembly Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 447112572

The achievable production quality and performance of modern production systems is decisively affected by the drive systems installed. Rack-and-pinion drives (RPD) are predominantly used when long travel distances and high acceleration and feed forces are required. The achievable production quality and performance of modern production systems is decisively affected by the drive systems installed. Rack-and-pinion drives (ZRA) are predominantly used when long travel distances and high acceleration and feed forces are required. In order to minimize the negative effects of geometrical backlash, electrically preloaded drives are frequently utilized. However, this entails considerable additional costs, which are increasingly becoming a problem as cost pressure grows. The scope of this project therefore is to investigate, how the accuracy of single RPDs can be increased through a model-based compensation of the backlash. The basis for this will be a comprehensive experimental investigation of the varying backlash and the state-dependent friction characteristics. Thereupon, simulation models will be developed in combination with methods for their identification on industrially used systems. Utilizing these models, a state-dependent backlash compensation will be developed. To further increase the accuracy, state-dependent friction and acceleration feedforward controls will be added. The developed approaches will be experimentally validated on a test bench and their robustness will be verified.

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Armin Lechler