Software architecture for display controller and operating system interaction

Article describes solutions for developing programs that provide interaction between Linux operating system and multiple display controller hardware blocks (outputs), that use one clock generation IP-block with phase-locked loop (PLL). There is no API for such devices in Linux, thus new software model was developed. This model is based on official Linux GPU developer driver model, but was modified to cover case described earlier. Article describes three models for display controller driver development – monolithic, component and semi-monolithic. These models cannot cover case described earlier, because they assume that one clock generator should be attached to one output. A new model was developed, that is based on component model, but has additional mechanics to prevent race condition that can happen while using one clock generator with multiple outputs. Article also presents modified model for bootloaders graphics drivers. This model has been simplified over developed Linux model, but also has component nature (with less components) and race prevention mechanics (but with weaker conditions). Hardware interaction driver components that are developed using provided software models are interchangeable between Linux and bootloader.

Ghost Beam Suppression in Deep Frequency Modulation Interferometry for Compact On-Axis Optical Heads

We present a compact optical head design for wide-range and low noise displacement sensing using deep frequency modulation interferometry (DFMI). The on-axis beam topology is realised in a quasi-monolithic component and relies on cube beamsplitters and beam transmission through perpendicular surfaces to keep angular alignment constant when operating in air or in a vacuum, which leads to the generation of ghost beams that can limit the phase readout linearity. We investigated the coupling of these beams into the non-linear phase readout scheme of DFMI and implemented adjustments of the phase estimation algorithm to reduce this effect. This was done through a combination of balanced detection and the inherent orthogonality of beat signals with different relative time-delays in deep frequency modulation interferometry, which is a unique feature not available for heterodyne, quadrature or homodyne interferometry.

Ghost Beam Suppression in Deep Frequency Modulation Interferometry for Compact on-Axis Optical Heads

We present a compact optical head design for wide-range and low noise displacement sensing using deep frequency modulation interferometry. The on-axis beam topology is realised in a quasi-monolithic component and relies on cube beamsplitters and beam transmission through perpendicular surfaces to keep angular alignment constant when operating in air or vacuum, which leads to the generation of ghost beams that can limit the phase readout linearity. We investigate the coupling of these beams into the non-linear phase readout scheme of DFMI and demonstrate adjustments of the phase estimation algorithm to reduce this effect. This is done through a combination of balanced detection and the inherent orthogonality of beat signals with different relative time-delays in deep frequency modulation interferometry that is a unique feature not available for heterodyne, quadrature or homodyne interferometry.

Additive Fertigung multi-funktionaler Bauteile/Additive manufacturing of multi-functional components – Methodical product development for complex geometries, case study: Heatpipe

Bauteile mit hoher Geometriekomplexität sind wirtschaftlich attraktiv für die Herstellung mit additiven Fertigungsverfahren. Der Einsatz des V-Modells nach dem Model Based Systems Engineering (MBSE) erlaubt die Beherrschung dieser Komplexität im Entwicklungsprozess. Eine Fallstudie einer mit Laser-Strahlschmelzen (L-PBF) gefertigten Heatpipe demonstriert diese Komplexität: Wärmetransport, Nutzung des Kapillareffekts sowie eine Vakuumisolierung sind in einem monolithischen Bauteil kombiniert.   Components with high geometric complexity are economically attractive to be realized in additive manufacturing processes. Using the V-model in accordance with Model Based Systems Engineering (MBSE) addresses this complexity in the development process. A case study of a heatpipe manufactured using laser powder bed fusion (L-PBF) demonstrates this complexity: Heat transport, use of capillary effect and vacuum insulation are combined into one monolithic component.

Effects of Helix Angle on Cutting Performance for Machining Thin-Wall Aerospace Monolithic Component

The thin-walled component is mostly used in the aerospace industry. During machining the thin-walled components, deflection of wall occurs and causes the surface dimensional error. This paper focuses on the effect of end mill helix angle on the surface dimensional error and surface roughness when machining thin wall structure. End mills uncoated carbide were fabricated with a difference helix angle which are 25°, 30°, 35°, 40° and 45°. The results show, helix angle 35° produce smaller surface dimensional error and smoothest followed by 40°, 45°, 30° and 25°. The smaller helix angle provided high cutting force that causes more surface dimensional error due to chatter and reduction of contact time when then end mill engage with the workpiece material. Results from this research help to guide the machinist to machine thin-wall component with the right cutting tool.

Establishment of Mathematical Relation Model between Dislocation Motion and Machining Deformation of Titanium Alloy Monolithic Component

According to dislocation dynamics, a distribution equation of mobile dislocations during the deformation of monolithic component was established. Slip deformation was solved through dislocation density and Burgers vector, and then the mathematical relationship between slippage and plastic deformation was established. Thus the mathematical relation model between dislocations and the machining distortion of monolithic component was established by plastic deformation as intermediate variable. It is shown that the machining distortion of monolithic component is upward embossment, and its maximum deformation occurs near the middle of the beam. The amount of machining distortion is directly proportional to the stress field at different depths of the surface layer, proliferation strength of dislocation and the length of the work piece, and inversely proportional to the thickness of the work piece.