Host Institution

The research is hosted in the Budapest University of Technology and Economics. This university has long well-estabilished, more than 200 years history in teaching and research of engineering sciences.

Faculty

Faculty of Mechanical Engineering (GPK) at the Budapest University of Technology and Economics. Among many outstanding researchers and engineers Kármán Tódór (Theodore von Kármán) and Gábor Dénes (Dennis Gabor) were the student in the Faculty.

Department

In the Department of Applied Mechanics we are proud of our students who become great engineers and researchers. We can mention Reuss Endre (Endrew Reuss), who is known for the Prandtl-Reuss equations, and Tóbiás István (Stephen Albert Tobias), who become a pioneer scientist in the field of machine tool dynamics with his book and many publications.

Partners

The NKFI funds the research project, while the independent partners the IK4-Ideko and the Excel Csepel provide the industrial background. The Post Doctoral (PD) part of the NKFI project covers the work of the PI.

The main aim

Modeling machining process with active control solutions

The recent trend in manufacturing industry is to establish cyber physical system solutions that can bring the new era of completely automatized production. In the last 3rd industrial revolution numerical controls (NC) for machine tools become quite common and standard in today’s modern production systems. Although these machines can follow the path really accurately supposingly resulting in the desired accurate workpiece, these machines are not aware of the current geometry of the workpiece and cannot react to any special events. Computed Aided Manufacturing (CAM) software can guide process planners to design such paths that avoids catastrophic events of collisions. Although, collision detections are built in the CAM algorithms, and it was quite rare anyways in the industry to run a designed toolpath without the complete checking of its geometry regarding to the machine tool itself. However, unwanted vibrations can occur any time during machining. And this problem cannot be explained only with geometry, one needs to know dynamics to have the so-called self-excited phenomenon, that can cause damage in the workpiece.

The main benefits

The expected impact of the project

The project aim is to deal with the control of manufacturing processes including milling and axles rolling. Axles rolling is considered in this project, because it has an already established hydraulic force control system that provides the desired constant pressure to achieve plastic deformation on the workpiece. Milling is only on the verge to introduce such real time control mechanism to keep the process stable and more productive.

  • General milling model
  • General axles rolling model
  • Perform validation measurement for axles rolling force
  • Validation measuremnt in axles rolling dynamics

Results

So far we have performed these main steps

Milling is a time periodic system, where the regeneration of the surface can be arisen any time due to the consecutive rotating edges. The cutting process itself is more complicated than the rolling process, although its modelling is more established. The geometry and the cutting forces are quite commonly known. Therefore, it is easier to reach a hybrid model that can explain the milling process subjected to digital control.

Axles rolling process is a time independent process, so dynamically it is simpler than milling. However, there are no small parameter semi-analytical model of the process itself, or in other words, the relation between the rolling force and the indentation is completely unknown. Thus, even though, one can model the hydraulic force control quite straightforwardly the entire model has the lack of the process force, which brings in regeneration effect and plastic hardening.

  • General milling model without control (under release)
  • Milling dynamics combined with digital control (under publication)
  • Simple regenerative axles rolling model (published)
  • Predesigned axles rolling test bench