Wouter Gregoor | Searcharxiv

arXiv2026

Development of TIFUUN: Terahertz Integral Field Units with Universal Nanotechnology

TIFUUN (THz Integral Field Units with Universal Nanotechnology) is an ultra-wideband mm-submm wave imaging spectrometer that capitalizes on the highly scalable integrated superconducting spectrometer technology. TIFUUN has two slots for integral field units (IFUs), which can jointly be optimized as open-hardware for each astronomical observation in terms of spatial and spectral coverage. These IFUs can have observation frequencies in the range of 90--360 GHz, with spectral resolution up to $R\equiv F/\Delta F \le 1,000$, with up to $\sim$18,000 kinetic inductance detectors (shared by the two IFUs with a flexible ratio). The ultra-wide 4:1 (2 octave) bandwidth optics fits in a remarkably compact volume, by means of thin silicon lenses and a high chief ray angle design. The first pair of IFUs are being developed for the SUBLIME (Study of the Universe By Line Intensity Mapping Experiments) experiment that aims to map CII emission at redshift $\sim$6 to trace the cosmic large-scale structure and the buildup of galaxies during reionization, using TIFUUN on the ASTE 10-m telescope. The scalability, flexibility and compactness makes TIFUUN a highly compatible and portable system suited also for upcoming telescope facilities in the vicinity, such as FYST and AtLAST/LST.

astro-ph.IM↗

arXiv2019

A Dynamic Robotic Actuator with Variable Physical Stiffness and Damping

This study is part of research aiming at increasing the range of dynamic tasks for teleoperated field robotics in order to allow operators to use the full range of human motions without being limited by the dynamics of the robotic manipulator. A new variable impedance actuator (VIA) was designed, capable of reproducing motions through teleoperation from precise positioning tasks to highly dynamic tasks. The design requirements based on previous human user studies were a stiffness changing time of 50 ms, a peak output velocity of 20 rad/s and variable damping allowing to suppress undesired oscillations. This is a unique combination of features that was not met by other VIAs. The new design has three motors in parallel configuration: two responsible for changing the VIA's neutral position and effective stiffness through a sliding pivot point lever mechanism, and the third acting as variable damper. A prototype was built and its performance measured with an effective stiffness changing time of 50 to 120 ms for small to large stiffness steps, nominal output velocity of 16 rad/s and a variable damper with a damping torque from 0 to 3 Nm. Its effective stiffness range is 0.2 to 313 Nm/rad. This concludes that the new actuator is particularly suitable for highly dynamic tasks. At the same time, the new actuator is also very versatile, making it especially interesting for teleoperation and human-robot collaboration.

cs.RO↗