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Im Rahmen eines universitätsübergreifenden Projekts soll eine universell einsetzbare Fertigungsstraße konzipiert werden [1]. Diese gestaltet die gesamte Produktion mithilfe von baugleichen Maschinen mit einer roboterähnlichen Kinematik. Ein Teilprozess dieser Fertigungsstraße ist die Herstellung eines Batteriegehäuses. Hierbei wird unter anderem ein Aluminiumwerkstück zerspanend bearbeitet. Die Zerspanung läuft mittels Fräsen und unter der Zuhilfenahme eines oder mehrerer gekoppelter Industrieroboter ab.

Neben klassischen Handhabungs- und Montageaufgaben übernehmen Industrieroboter zunehmend auch komplexere Fertigungsaufgaben und werden beispielsweise zur Zerspanung eingesetzt. Eine im Vergleich zu Werkzeugmaschinen verringerte Steifigkeit führt dabei zur Verschlechterung der Fertigungsqualität bei hohen Prozesskräften. In diesem Fachbeitrag wird ein Konzept zur Reduktion der resultierenden Prozesskräfte am Roboter untersucht, dem konventionellen Prozess gegenübergestellt und bewertet. In addition to classic handling and assembly tasks, industrial robots are increasingly used for more complex manufacturing tasks, such as machining. A reduced stiffness in comparison to machine tools results in reduction of the manufacturing quality at high process forces. In this paper, a concept for reducing resulting process forces on the robot compared to the conventional process is examined and evaluated.

Der Beitrag berichtet über das Weiterbildungsangebot der Leibniz-Universität Hannover für Senior*innen während und nach Corona.

In this article, we derive a mechanical distributed parameter model for the annular sector plate segments of the Extremely Large Telescope’s deformable mirror M4. Additionally, we modally analyse t...

Due to the increasing individualization of products, modern production facilities ask for highly flexible logistic systems like arm-type-robots on mobile platforms. To ensure good dynamics, minimal use of space and good reachability of connected machines, an ideal geometry of those systems would tend to be unstable due to the high center of mass, little weight and small ground base. The current paper describes briefly the development, modelling, simulation and validation of different types of stabilization strategies of robots on mobile platforms. It assesses the developed active stabilization devices and integrated control algorithms concerning their effectiveness and applicability within a production environment.

AOSAT is a python package for the analysis of single-conjugate adaptive optics (SCAO) simulation results. Python is widely used in the astronomical community these days, and AOSAT may be used stand-alone, integrated into a simulation environment, or can easily be extended according to a user's needs. Standalone operation requires the user to provide the residual wavefront frames provided by the SCAO simulation package used, the aperture mask (pupil) used for the simulation, and a custom setup file describing the simulation/analysis configuration. In its standard form, AOSAT's "tearsheet" functionality will then run all standard analyzers, providing an informative plot collection on properties such as the point-spread function (PSF) and its quality, residual tip-tilt, the impact of pupil fragmentation, residual optical aberration modes both static and dynamic, the expected high-contrast performance of suitable instrumentation with and without coronagraphs, and the power spectral density of residual wavefront errors. AOSAT fills the gap between the simple numerical outputs provided by most simulation packages, and the full-scale deployment of instrument simulators and data reduction suites operating on SCAO residual wavefronts. It enables instrument designers and end-users to quickly judge the impact of design or configuration decisions on the final performance of down-stream instrumentation., Comment: 18 pages, 11 figures

The telescope instrument Mid-infrared ELT Imager and Spectrograph (METIS) is currently under development and will enable high-resolution spectroscopic and coronagraphic imaging. To obtain diffraction-limited measurements despite wavefront disturbances, METIS uses a single conjugate adaptive optics (SCAO) system comprising the active mirrors M4/M5, a pyramid wavefront sensor, and a controller. Because tip-tilt wavefront disturbances are dominant, the main task of the METIS-SCAO system is their rejection. Since M4 and M5 can redundantly correct tip-tilt errors and M4 features much faster dynamics and smaller actuator strokes than M5, the METIS-SCAO system is a dual-stage system. In order to achieve a proper tip-tilt correction for METIS while splitting this correction efficiently between the active mirrors, we present a new crossover network (CN) based control concept. This concept assigns low-frequency high amplitude tip-tilt error components to M5 and high-frequency small amplitude components to M4 via a specific type of CNs. Subsequently, two independent single-input single-output controller command the active mirrors, such that the assigned error components are corrected. Simulations show that the presented control concept rejects tip-tilt wavefront errors well for medium observation conditions.

The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of three first light instruments on the ELT. It will provide high-contrast imaging and medium resolution, slit-spectroscopy from 3 – 19um, as well as high resolution (R ~ 100,000) integral field spectroscopy from 2.9-5.3µm. All modes observe at the diffraction limit of the ELT, by means of adaptive optics, yielding angular resolutions of a few tens of milliarcseconds. The range of METIS science is broad, from Solar System objects to active galactic nuclei (AGN). We will present an update on the main science drivers for METIS: circum-stellar disks and exoplanets. The METIS project is now in full steam, approaching its preliminary design review (PDR) in 2018. In this paper we will present the current status of its optical, mechanical and thermal design as well as operational aspects. We will also discuss the challenges of building an instrument for the ELT, and the required technologies.

METIS is the Mid-infrared Extremely large Telescope Imager and Spectrograph, one of the first generation instruments of ESO's 39m ELT. All scientific observing modes of METIS require adaptive optics (AO) correction close to the diffraction limit. Demanding constraints are introduced by the foreseen coronagraphy modes, which require highest angular resolution and PSF stability. Further design drivers for METIS and its AO system are imposed by the wavelength regime: observations in the thermal infrared require an elaborate thermal, baffling and masking concept. METIS will be equipped with a Single-Conjugate Adaptive Optics (SCAO) system. An integral part of the instrument is the SCAO module. It will host a pyramid type wavefront sensor, operating in the near-IR and located inside the cryogenic environment of the METIS instrument. The wavefront control loop as well as secondary control tasks will be realized within the AO Control System, as part of the instrument. Its main actuators will be the adaptive quaternary mirror and the field stabilization mirror of the ELT. In this paper we report on the phase B design work for the METIS SCAO system; the opto-mechanical design of the SCAO module as well as the control loop concepts and analyses. Simulations were carried out to address a number of important aspects, such as the impact of the fragmented pupil of the ELT on wavefront reconstruction. The trade-off that led to the decision for a pyramid wavefront sensor will be explained, as well as the additional control tasks such as pupil stabilization and compensation of non-common path aberrations.

METIS is the Mid-infrared E-ELT Imager and Spectrograph, one of three first generation instruments of the European Extremly Large Telescope (E-ELT). The primary mirror of the E-ELT has a diameter of 39 meter. This huge aperture requires an adaptive optics system in order to provide the performance close to the diffraction limit that is needed for all scientific observing modes of METIS. METIS will be be equipped with a single conjugated adaptive optics (SCAO) system that makes use of a near-infrared wavefront sensor. A real-time computer (RTC) reconstructs the wavefront and sends correction commands to the deformable mirror M4 and the field stabilization mirror M5. The METIS SCAO team evaluates computer workstations with the many-core processor Intel® Xeon Phi™ Knights Landing (KNL) for the real-time computation within the wavefront control loop. This processor is a promising candidate to satisfy the METIS AO needs as it allows for massively parallel computations. This parallelization is achieved by utilizing up to 272 logical CPUs, the new SIMD (single instruction, multiple data) instruction set AVX-512 and the high-bandwidth on-CPU memory MCDRAM. This paper describes the SCAO RTC concept, evaluates the computational performance that a wavefront control loop could have when using a Xeon Phi KNL, and compares it to the identified requirements. The measurements will be conducted with the AO system software of the LINC- NIRVANA project under Linux. Especially, the real-time capability is analyzed.

LINC--NIRVANA (LN) is an MCAO module currently mounted on the Rear Bent Gregorian focus of the Large Binocular Telescope (LBT). It mounts a camera originally designed to realize the interferometric imaging focal station of the telescopes. LN follows the LBT binocular strategy having two twin channels: a double Layer Oriented Multi-Conjugate Adaptive Optics system assisting the two arms, supplies high order wave-front correction. In order to counterbalance the field rotation, a mechanical derotation is applied for the two ground wave-front sensors, and an optical (K-mirror) one for the two high layers sensors, fixing the positions of the focal planes with respect to the pyramids aboard the wavefront sensors. The derotation introduces a pupil images rotation on the wavefront sensors, changing the projection of the deformable mirrors on the sensor consequently., 9 pages, 6 figures, proceeding of the SPIE Astronomical Telescopes + Instrumentation meeting, Conference Adaptive Optics Systems VI held in Austin Convention Center, Austin, Texas, United States, 10 - 15 June 2018

This paper reports on early commissioning of LINC-NIRVANA (LN), an innovative Multi-Conjugate Adaptive Optics (MCAO) system for the Large Binocular Telescope (LBT). LN uses two, parallel MCAO systems, each of which corrects turbulence at two atmospheric layers, to deliver near diffraction-limited imagery over a two-arcminute field of view. We summarize LN's approach to MCAO and give an update on commissioning, including the achievement of First Light in April 2018. This is followed by a discussion of challenges that arise from our particular type of MCAO and the solutions implemented. We conclude with a brief look forward to the remainder of commissioning and future upgrades.

We have tested and confirmed the proper functioning of our solution to the MCAO partial illumination issue in the context of the LINC-NIRVANA (LN) MCAO module, both in the laboratory and on-sky. We present the results in this paper. Availability of direct AO-telemetry for individual layers from the LN MCAO system can be potentially used to improve not only the stability of the independent AO loops, but also the wavefront sensor efficiency. We introduce this idea, called "wind- predictive wavefront control."

The ELT is a 39m large, ground-based optical and near- to mid-infrared telescope under construction in the Chilean Atacama desert. Operation is planned to start around the middle of the next decade. All first light instruments will come with wavefront sensing devices that allow control of the ELT's intrinsic M4 and M5 wavefront correction units, thus building an adaptive optics (AO) system. To take advantage of the ELT's optical performance, full diffraction-limited operation is required and only a high performance AO system can deliver this. Further technically challenging requirements for the AO come from the exoplanet research field, where the task to resolve the very small angular separations between host star and planet, has also to take into account the high-contrast ratio between the two objects. We present in detail the results of our simulations and their impact on high-contrast imaging in order to find the optimal wavefront sensing device for the METIS instrument. METIS is the mid-infrared imager and spectrograph for the ELT with specialised high-contrast, coronagraphic imaging capabilities, whose performance strongly depends on the AO residual wavefront errors. We examined the sky and target sample coverage of a generic wavefront sensor in two spectral regimes, visible and near-infrared, to pre-select the spectral range for the more detailed wavefront sensor type analysis. We find that the near-infrared regime is the most suitable for METIS. We then analysed the performance of Shack-Hartmann and pyramid wavefront sensors under realistic conditions at the ELT, did a balancing with our scientific requirements, and concluded that a pyramid wavefront sensor is the best choice for METIS. For this choice we additionally examined the impact of non-common path aberrations, of vibrations, and the long-term stability of the SCAO system including high-contrast imaging performance., Comment: 37 pages, 27 figures, accepted for publication in Experimental Astronomy

This paper reports on the installation and initial commissioning of LINC-NIRVANA (LN), an innovative high resolution, near-infrared imager for the Large Binocular Telescope (LBT). We present the delicate and difficult installation procedure, the culmination of a re-integration campaign that was in full swing at the last SPIE meeting. We also provide an update on the ongoing commissioning campaigns, including our recent achievement of First Light. Finally, we discuss lessons learned from the shipment and installation of a large complex instrument.

Multiconjugate adaptive optics (MCAO) promises uniform wide-field atmospheric correction. However, partial illumination of the layers at which the deformable mirrors are conjugated results in incomplete information about the full turbulence field. We report on a working solution to this difficulty for layer-oriented MCAO, including laboratory and on-sky demonstration with the LINC-NIRVANA instrument at the Large Binocular Telescope. This approach has proven to be simple and stable.

LINC-NIRVANA is an innovative, high-resolution near-infrared imager for the Large Binocular Telescope. Its Multi- Conjugate Adaptive Optics system uses natural guide-stars and provides high sky coverage for single-eye, binocular, and eventually, interferometric observations. We report on final lab integration and system level testing, as well as technical and logistical challenges of shipping and installing a large, delicate, complex instrument. LINC-NIRVANA is currently at LBT undergoing final alignment and tests before First Light late this fall. Managing the transition to operations involves the interactions between telescope alignment and calibration, commissioning of the instrument, and executing the Early Science plan.

METIS is one the first three instruments on the E-ELT. Apart from diffraction limited imaging, METIS will provide coronagraphy and medium resolution slit spectroscopy over the 3 – 19μm range, as well as high resolution (R ~ 100,000) integral field spectroscopy from 2.9 – 5.3μm, including a mode with extended instantaneous wavelength coverage. The unique combination of these observing capabilities, makes METIS the ideal instrument for the study of circumstellar disks and exoplanets, among many other science areas. In this paper we provide an update of the relevant science drivers, the METIS observing modes, the status of the simulator and the data analysis. We discuss the preliminary design of the optical system, which is driven by the need to calibrate observations at thermal IR wavelengths on a six-mirror ELT. We present the expected adaptive optics performance and the measures taken to enable high contrast imaging. We describe the opto-mechanical system, the location of METIS on the Nasmyth instrument platform, and conclude with an update on critical subsystem components, such as the immersed grating and the focal plane detectors. In summary, the work on METIS has taken off well and is on track for first light in 2025.

METIS is the Mid-infrared E-ELT Imager and Spectrograph, which will provide outstanding observing capabilities, focusing on high angular and spectral resolution. It consists of two diffraction-limited imagers operating in the LM and NQ bands respectively and an IFU fed diffraction-limited high-resolution (R=100,000) LM band spectrograph. These science subsystems are preceded by the common fore optics (CFO), which provides the following essential functionalities: calibration, chopping, image de-rotation, thermal background and stray light reduction. We show the evolution of the CFO optical design from the conceptual design to the preliminary optical design, detail the optimization steps and discuss the necessary trade-offs.

Pyramid wavefront sensors (PWFS) have been agreed to provide a superior faint-end performance with respect to Shack-Hartmann systems (SHS) quite some time ago. However, much of the advantage relies on the fact that PWFSs exploit the full resolution limit of the telescope. ELTs will thus confront PWFSs with an unprecedented number of resolved targets. To analyze the behavior of PWFS on extended targets in detail observationally is difficult. We will present the result of simulations representing the Single-Conjugated Adaptive Optics (SCAO) system of METIS on the European ELT (E-ELT).