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Dipl.-Ing. Christopher Ehrmann

Group leader industrial projects amtc
department: Machines, Equipment and Process Automation
office hours: to be agreed
room: Jiren Building
phone: +86 182 2137 4597
Christopher EhrmannUza2∂partner kit edu

4800 Cao An Road, Jiading District
Shanghai 201804
P.R. China

Dipl.-Ing. Christopher Ehrmann

Areas of Research:

  • Mechatronic subsystems for machine tools
  • Diagnosis and prognosis of rack & pinion drives


[ 1 ] Ehrmann, C. & Herder, S. (2013), "Integrated Diagnostic and Preload Control for Ball Screw Drives by Means of Self-Sensing Actuators". Advanced Materials Research, eds. M. Merklein, pp. 271-277.
Piezoelectric ceramics can be used as sensors, as well as actors. The concept of a selfsensing actuator tries to use both modes of operation in one device, allowing the economic integration of mechatronic systems. Possible fields of application are ball screws of machine tools, where wear-induced degradation of the preload can be compensated. Furthermore, the signal processing part of such a system can be used to gather information related to the condition of the ball screw. Both excitation signal generation and filtering of the measured signal have to offer high flexibility and signal fidelity. In this article the concept of a power amplifier and its corresponding signal processing system are presented.

[ 2 ] Ehrmann, C.; Isabey, P. & Fleischer, J. (2016), "Condition Monitoring of Rack and Pinion Drive Systems: Necessity and Challenges in Production Environments". Procedia CIRP, eds. Seliger, G.; Kohl, H. & Mallon, J., pp. 197-201.
Rack and pinion drives are linear actuators commonly found in feed axes of machine tools and handling systems. Despite their use in demanding production environments and the possibility of failure due to foreseen or unforeseen cause, as of this writing, no condition monitoring systems are used in such applications. This paper shows the prospects of condition monitoring of rack and pinion drive systems concerning predictability of faults and saving of resources. Additionally the current state of the art of science and technology in this field and the challenges of condition monitoring of such drive systems under the circumstances of production environments are outlined. The publication concludes the need for action and gives an outlook on ongoing developments in condition monitoring of rack and pinion drives.

[ 3 ] Barton, D.; Gönnheimer, P.; Schade, F.; Ehrmann, C.; Becker, J. & Fleischer, J. (2019), "Modular smart controller for Industry 4.0 functions in machine tools". Procedia CIRP, eds. Butala, P.; Govekar, E. & Vrabič, R., pp. 1331-1336.
In machine tools, Industry 4.0 functions can increase availability through predictive maintenance, while other functions improve productivity and workpiece quality through process supervision and optimisation. Many of these functions rely on data communication between systems from different suppliers. Requirements regarding latency and computing vary widely depending on the application. Based on an analysis of these requirements, a smart controller for the implementation of Industry 4.0 is designed, using a hypervisor to allow for the integration of soft real-time and best-effort applications.