WiToPro – Method for knowledge-based tolerance assignment and function-oriented process design

In industrial practice, tolerance assignment is usually carried out separately from manufacturing process planning. As a result, reliable information on achievable precision, production effort, and process limits is lacking during component design. Designers often choose tolerances that are either too tight or too loose, leading to unnecessary effort or quality risks. Furthermore, there is no seamless data and knowledge flow between CAD and CAM systems, preventing manufacturing experience from being fed back into development. There is therefore a need for a method that digitally captures manufacturing knowledge, supports tolerance decisions, and jointly optimizes functionality, effort, and accuracy.

Objectives

The goal of WiToPro is to develop a knowledge-based method that links tolerance assignment with manufacturing planning. To this end, geometric deviations and production efforts for individual form elements are modeled and integrated into an ontology-based assistance system. This system enables partially automated, function-oriented tolerance assignment directly within the CAD environment. The method provides transparency regarding costs, accuracy, and functionality, shortens coordination processes, and improves the efficiency of subtractive manufacturing.

Benefits

• Process reliability – realistic tolerance planning
• Quality – precise, functionally compliant components
• Productivity – fewer iterations, shorter development time
• Resources – reduced planning and manufacturing effort

Approach

The IFW models form-element-specific manufacturing deviations and efforts, develops an ontology-based knowledge model, and integrates these into an assistance system for tolerance assignment within the PLCM. This system is implemented in a CAD environment (Siemens NX) and validated using a demonstrator component at the IFW. In this way, a comprehensive method for knowledge-based tolerance management and function-oriented process planning is created, making collaboration between product development and manufacturing both more efficient and more seamless.

Are you also interested in a cooperation project?

Contact Andrii Skryhunets via email at skryhunets@ifw.uni-hannover.de or by phone at +49 511 762 18351.