Next Generation Deep Drawing Using Smart Observers, Close-Loop Control, and 3D-Servo-Press
Final Report Abstract
Deep drawing is one of the most widely used manufacturing processes in metal forming. In the past, many attempts at a closed loop control based on tool integrated actuators have been proposed, which lead to significant costs for each of these “intelligent” tools. A novel type of single acting press developed at PtU, a 3D servo press offers additional degrees of freedom compared to conventional forming machines. These two additional degrees of freedom could be used for actuation during a closed loop control of a forming process to allow for reaction to outside disturbances on the drawing process. During the project, a novel forming tool with a cardanic blank holder was developed, which can make use of the additional degrees of freedom provided by the 3D servo press. It was demonstrated that the passive use of a cardanic blank holder can aid in the local distribution of the blank holder pressure. To allow for closed loop control of the process, two observers were developed and successfully implemented into the machine controller. The first one is based on the location of the resulting blank holder forces and can be an indicator for an offset in the machine, while the second one is monitoring the occurring wrinkles during the process. Actuating the blank holder actively using non-linear ram movements, the developed control strategies successfully stabilize the process and thus increase robustness. To allow for a better assessment of the chosen observers and controllers prior to carrying out experimental work, a numerical model was implemented. This model contained the tool, including the cardanic blank holder, as well as the developed observers and control strategies. Thus, the process could be investigated numerically before experimental work was carried out. Lastly, a promising step was taken in terms of failure localization using acoustic emission sensors. It has been shown that three acoustic emission sensors mounted on the punch of a Marciniak test, can pinpoint the location of failure ex-situ, just before the failure becomes visible in the optical systems. While this can currently only be done ex-situ, the approach itself is promising and could lead to an in-situ observer with further research. Future work should aim to transfer the observers developed in this project to different materials. In addition, the acoustic based approach should be further investigated to allow real-time evaluation of the only onset of necking.
Publications
- 2019. „AA1100-O Cylindrical Cup-Drawing Using 3D Servo-Press“. IOP Conference Series: Materials Science and Engineering 651 (November): 012094
Ha, J., A. Breunig, J. Fones, F. Hoppe, Y. P. Korkolis, P. Groche, and B. L. Kinsey
(See online at https://doi.org/10.1088/1757-899X/651/1/012094) - 2019. „Localized Blank-Holder Pressure Control in Cup Drawing through Tilting of the Ram“. In Proceedings of NUMIFORM 2019: The 13th International Conference on Numerical Methods in Industrial Forming Processes, 4. Portsmouth, NH, USA
Breunig, Alexander, Florian Hoppe, und Peter Groche
- 2022. „Acoustic Emission Monitoring for Necking in Sheet Metal Forming“. Journal of Materials Processing Technology 310 (Dezember): 117758
Baral, Madhav, Ali Al-Jewad, Alexander Breunig, Peter Groche, Jinjin Ha, Yannis P. Korkolis, and Brad L. Kinsey
(See online at https://doi.org/10.1016/j.jmatprotec.2022.117758) - 2022. „Effectiveness of Different Closed-Loop Control Strategies for Deep Drawing on Single-Acting 3D Servo Presses“. CIRP Annals, May
Groche, Peter, Alexander Breunig, Kelin Chen, Dirk A. Molitor, Jinjin Ha, Brad L. Kinsey, und Yannis P. Korkolis
(See online at https://doi.org/10.1016/j.cirp.2022.04.072) - 2022. „Robustness of Deep-Drawing Finite-Element Simulations to Process Variations“. International Journal of Material Forming 15 (3): 45
Chen, Kelin, Alexander Breunig, Jinjin Ha, Brad L. Kinsey, Peter Groche, und Yannis P. Korkolis
(See online at https://doi.org/10.1007/s12289-022-01695-3)
