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Maximilian Herrmann

Publications and source records attributed to Maximilian Herrmann.

2 recordsLinked to original sources

Discrete Geometric Modeling and Extended State Estimation of Continuum Robots

In this paper, we present a fully discrete approach for the accurate and numerically efficient dynamical modeling and state estimation of continuum robots. The model is based on geometrically exact beams in a minimal, strain-based formulation and derived in the framework of Lie group variational integrators, allowing to preserve important geometric properties that we exploit to achieve high accuracy and numerical efficiency. We then propose a disturbance observer based on an extended Kalman filter formulation that reliably estimates system states as well as model uncertainties and external disturbances. Experiments on a real system validate the accuracy and efficiency of the proposed model and observer.

eess.SY

Spectroscopic performance of flight-like DEPFET sensors for Athena's WFI

The Wide Field Imager for the Athena X-ray telescope is composed of two back side illuminated detectors using DEPFET sensors operated in rolling shutter readout mode: A large detector array featuring four sensors with 512x512 pixels each and a small detector that facilitates the high count rate capability of the WFI for the investigation of bright, point-like sources. Both sensors were fabricated in full size featuring the pixel layout, fabrication technology and readout mode chosen in a preceding prototyping phase. We present the spectroscopic performance of these flight-like detectors for different photon energies in the relevant part of the targeted energy range from 0.2 keV to 15 keV with respect to the timing requirements of the instrument. For 5.9 keV photons generated by an iron-55 source the spectral performance expressed as Full Width at Half Maximum of the emission peak in the spectrum is 126.0 eV for the Large Detector and 129.1 eV for the Fast Detector. A preliminary analysis of the camera's signal chain also allows for a first prediction of the performance in space at the end of the nominal operation phase.

astro-ph.IM