No description available.

This thesis explains the model-based design of a fork control system in a turret head operated Very Narrow Aisle forklift in order to evaluate and push the limits of the current hardware architecture. The turret head movement consists of two separate motions, traversing and rotation, which both are hydraulically actuated. The plant is thoroughly modeled in the Mathworks softwares Simulink/Simscape to assist in the design of the control system. The control system is designed in Simulink/Stateflow and code-generated to be evaluated in the actual forklift. Optimal control theory is used to generate a minimum-jerk trajectory for auto-rotation, that is simultaneous traversing and rotation with the load kept in centre. The new control system is able to control the system within the positioning requirements of +/- 10 mm and +/- 9 mrad for traversing and rotation, respectively. It also shows good overall performance in terms of robustness since it has been tested and validated with different loads and on different versions of the forklift. However, the study also shows that the non-linearities of the system, especially in the hydraulic proportional valves, causes problems in a closed-loop control system. The work serves as a proof of concept for model-based development at the company since the development time of the new control system was significantly lower than for the original control system.

With advances in material technology, allowing, for instance, engines to withstand higher combustion pressure and consequently improving performance, comes challenges to productivity. These materials are, in fact, more difficult to machine with regards to tool wear and especially machine tool stability. Machining vibrations have historically been one of the major limitations to productivity and product quality and the cost of machining vibration for cylinder head manufacturing has been estimated at 0.35 euro per part. The literature review shows that most of the research on cutting stability has been concentrating on the use of the stability limits diagram (SLD), addressing the limitations of this approach. On the other hand, research dedicated to development of machine tool components designed for chatter avoidance has been concentrating solely on one component at the time. This thesis proposes therefore to extend the stability limits of the machining system by enhancing the structure’s damping capability via a unified concept based on the distribution of damping within the machining system exploiting the joints composing the machine tool structure. The design solution proposed is based on the enhancement of damping of joint through the exploitation of viscoelastic polymers’ damping properties consciously designed as High Damping Interfaces (HDI). The tool-turret joint and the turret-lathe joint have been analysed. The computational models for dimensioning the HDI’s within these joints are presented in the thesis and validated by the experiments. The models offer the possibility of consciously design damping in the machining system structure and balance it with regards to the needed stiffness. These models and the experimental results demonstrate that the approach of enhancing joint damping is viable and effective. The unified concept of the full chain of redesigned components enables the generation of the lowest surface roughness over the whole range of tested cutting parameters. The improved machining system is not affected by instability at any of the tested cutting parameters and offers an outstanding surface quality. The major scientific contribution of this thesis is therefore represented by the proposed unified concept for designing damping in a machining system alongside the models for computation and optimisation of the HDIs. From the industrial application point of view, the presented approach allows the end user to select the most suitable parameters in terms of productivity as the enhanced machine tool system becomes less sensitive to stability issues provoked by difficult-to-machine materials or fluctuations of the work material properties that may occur in ordinary production processes. / <p>QC 20120413</p> / DampComat / Production 4 micro / FFI Robust Machining

Gun and gun turret systems are the primary units of the weapon systems of an aircraft. They are required to hit targets accurately during operations. That is why a complete, high precision control of weapon systems is required. This function is provided by accurate modeling of the system and the design of a suitable controller. This study presents the modeling of and controller design for the gun and turret system for an aircraft. For the controller design purpose, first the mathematical model of the system is constructed. Then the controller is designed to position the turret system as the target comes into sight. The reference input to the controller will either be obtained from a FLIR (Forward Looking Infrared) unit or from a HCU (Hand Control Unit). The basic specification for the controller is to hold theerror signal within the 5.5&deg / positioning envelope. This specification is satisfied by designing Linear Quadratic Gaussian and Internal Model Control type controllers. The performance of the overall system has been examined both by simulation studies and on the real physical system. Results have shown that the designed system is well over being sufficient.

<p>For all organisms, the ability to sense and react to noxious environments is fundamental to their survival. For multi-celled organisms this process generally involves a nervous system and an extensive network of signal transduction pathways. TRPV ion channels have been shown to participate in signal transduction in response to noxious stimuli. At the cellular level these channels function in sensing of mechanical, thermal, and osmotic stimuli, and at the organismal level they function in homeostasis and nociception. TRPV ion channels participate in nociceptive signal transduction via cation influx, but exactly how these channels function at a mechanistic level and lead to activation of the cell or induction of a specific behavior is elusive. Previous research has shown that the pore-forming unit of an ion channel is critical for channel regulation, gating, ion selectivity, and ion permeation. Various regulatory domains have been identified to date in the pore-forming unit of TRP channels and a clearer picture of channel gating is beginning to emerge, but less is known about ion permeation. </p><p>To better understand the specific domains that are critical to ion capture, selectivity, and permeation in TRPV channels, we investigated the function of these regions using the <italic>C. elegans</italic> TRPV channel OSM-9 <italic>in vivo</italic>, and the mammalian TRPV channel TRPV4 in heterologous cell culture. OSM-9 is the functional ortholog of mammalian TRPV4 and it is likely that critical domains identified in OSM-9 are functionally conserved in TRPV4 and play a similar role in other TRPV channels. OSM-9 is expressed in the ASH neurons and is responsible for all of the behaviors initiated by that cell. The stereotypical avoidance behavior mediated by ASH, in response to noxious stimuli, serves as a model for nociception in vertebrates. As OSM-9 is necessary for all of these behavioral responses, activation of ASH acts as a read-out for OSM-9 function.</p><p>Through targeted mutagenesis of the OSM-9 loop domains and transgenic expression directed to the ASH head sensory neurons in an <italic>osm-9</italic> null background, we discovered a critical role for the amino acids both N- and C- terminal to the pore helix in osmotic avoidance behavior. We confirmed the existence of a selectivity filter C-terminal to the pore helix and revealed that the turret is critical for channel function, possibly as a component of the inactivation gate.</p><p>We first identified the boundaries of the selectivity filter to be M601-F<super>609</super>. We also determined what properties of those residues were critical to Ca<super>2+</super> and Na<super>+</super> selectivity. <italic>In vivo</italic> Ca<super>2+</super> imaging strongly suggested that residues Y<super>604</super>, D<super>605</super>, and F<super>609</super> are critical for Ca<super>2+</super> entry into the cell. Patch-clamp electrophysiology of a chimeric ion channel consisting largely of rat TRPV4, but encompassing transmembranes 5 through 6 of OSM-9, revealed that OSM-9 conducts both Ca<super>2+</super> and Na<super>+</super>. Mutation Y604G disrupted both Ca<super>2+</super> and Na<super>+</super> conductance, whereas mutations Y604F and Y606A increased or maintained Na+ conductance and severely reduced Ca<super>2+</super> conductance, while maintaining avoidance behavior. Homology modeling of OSM-9, based on an alignment of OSM-9 to Kv1.2, suggests that Y<super>604</super> and F<super>609</super> serve structural roles in maintaining filter constraints. Thus, aromatic and negative residues in the OSM-9 selectivity filter are critical to ion permeation and selectivity. </p><p>Our studies involving the selectivity filter support previous research that the selectivity filter is critical for TRP channel function. We also provide evidence that the selectivity filter is critical for nocifensive animal behavior. Fewer studies, however, have investigated the TM5-pore helix linker, known as the turret. The turret is believed to function in the binding of ligands and toxins in K<super>+</super> channels, and more recently was suggested to be critical for temperature sensing in TRPV1. We investigated the function of the turret residues in several sensory submodalities of the OSM-9 channel and found that all deletions tested result in channel defects, including gain- and loss-of-function phenotypes. Several charge reversal mutations in the OSM-9 turret also resulted in partial defects. The discovery of a gain-of-function mutation indicates that the turret functions in gating. When the turret is mutated in this way, the channel is unable to enter into the inactivated state, allowing continued ion influx after repeated stimulation. The loss-of-function phenotypes indicate that the secondary structure of the turret is critical to the function of the channel, and perhaps gating. These findings, combined with the observed charge-reversal defects, support the conclusion that the turret is necessary for transducing conformational changes in response to stimuli.</p><p>Our <italic>in vivo</italic> findings on the external pore forming structures increase the understanding of ion permeation in TRP channels and clarify mechanisms of activation in nociceptor neurons <italic>in vivo</italic>. Furthermore, these studies enhance our insights into evolution of mammalian nociception in view of the established functional orthology of OSM-9 and TRPV4.</p> / Dissertation

The Laird rams, built from 1862-1865, reflected concepts of naval power in transition from the broadside of multiple guns, to the rotating turret with only a few very heavy pieces of ordnance. These two ironclads were experiments built around the two new offensive concepts for armoured warships at that time: the ram and the turret. These sister armourclads were a collection of innovative designs and compromises packed into smaller spaces. A result of the design leap forward was they suffered from too much, too soon, in too limited a hull area. The turret ships were designed and built rapidly for a Confederate Navy desperate for effective warships. As a result of this urgency, the pair of twin turreted armoured rams began as experimental warships and continued in that mode for the next thirty five years. They were armoured ships built in secrecy, then floated on the Mersey under the gaze of international scrutiny and suddenly purchased by Britain to avoid a war with the United States. Once purchased, they were largely forgotten. Historians rarely mention these two sister ironclads and if mentioned at all, they are given short shrift. Built with funds obtained in part through the Confederate Erlanger loan, these ironclads were constructed at Lairds shipyard in Birkenhead and represented an advanced concept of ironclad construction through new proposals involving turrets, the ram, heavy guns and tripod masts on an armoured ship, as advocated by Captain Cowper Coles, R.N. They proved too much of a leap in one design but when their roles caught up to the revised designs, the ships were modified to meet new requirements. After several mission and design changes they then performed to standard. This belated success occurred when the concept of the ideal armoured warship was in flux throughout the middle Victorian years.

The diploma thesis deals with the design of a direct drive tool turret, which serves as a tool magazine for a CNC lathe. In the introductory part of the work, a research was performed in the field of automatic tool change with a focus on tool turrets and their main structural units. The introductory research is followed by the main part of the work, which begins with the selection of appropriate design solutions, followed by a presentation of the tool turret design created in CAD software Autodesk Inventor 2021 and in the final part of thesis the key elements of the proposed design are verified by calculations.

Imposition of my diploma thesis is replace current fluid motor that the derive benefit from to indexing turret head behind electrically driven motor in the sliding headstock machine with indication KMX 326 C. Suggested system must be the most toughest and have to correspond with all the dated up parameters for cutting. Integral part of structural design is also becomingly select accurate blocking a turret head. Fluid motor substitutes behind electrical drive from next reasons: - high transmission loss on energy - sensitivity to cleanness liquid - characteristics mechanism depend upon features liquid ( thermal expansivity, fadeaway)

No description available.

<p>Detta arbete handlar om den tekniska utbildningen i Försvarsmakten, närmare beskrivet hur en kursbeskrivning för systemmekaniker och tornmekaniker genomförs praktiskt och hur den skall genomföras teoretiskt. Uppsatsen kommer inte att behandla hela utbildningen. Den kommer bara behandladen minsta delen av utbildningen - den del som innefattar soldatutbildningen. Syftet med att skriva detta arbete är att komma fram till om den tekniska utbildningen genomförs på ett kvalitativt sätt och kontrollera om en mekaniker kan agera i subarktisk miljö efter sin genomförda utbildning. Denna uppsats är uppbyggd på följande sätt. Först genomförde jag en kvalitativ innehållsanalys för att få en grundstomme i arbetet. Detta följdes av kvalitativa intervjuer för att få veta hur utbildningen genomförs i praktiken. Avslutningsvis diskuterades de frågor jag ställde för att kunna avrunda arbetet ur mina egna synvinklar samt att göra subjektiva bedömningar. Slutsatserna som dragits i denna uppsats är att det finns brister i utbildningen och i kursplaner av tornsystemmekaniker. Bristerna i utbildningen som blev uppenbara är att utbildare inte alltid utbildar på det som skall utbildas som är i detta fall ”kallt väder” utbildning. Detta på grund av att utbildare ser denna del av utbildning som tidstjuv och hellre fokuserar på den tekniska utbildningen. De brister i kursbeskrivningen som kom fram under min rapport är att torn- och systemmekanikerutbildningarna inte är i synk med varandra. Det innebär att utbildningarna inte alltid strävar mot samma mål. Tornmekanikerna genomför enligt kursplan en ”kall väder”-utbildning men inte systemmekanikerna och på grund av detta kan det vara svårt för dessa att samarbeta efter sin genomförda utbildning.</p> / <p>This work is about the technical training of the Armed Forces. It is a closer description how a course description for system mechanics and turret mechanics are implemented in practice and how it should be done theoretically. The essay will not treat the full training, it will only deal with the smaller part of the training, the soldier training. The purpose of writing this work is to show how the technical training is conducted in a qualitative way and check whether a mechanic can operate in a subarctic environment after the training is completed. This paper will be structured as follows. First, I conduct a qualitative content analysis to provide a foundation, this will be followed by qualitative interviews to discover how training is conducted in practice. Finally, I will discuss the issues I have set out, from my own points of view. The conclusions which have been drawn from this paper are that there are gaps in training and in curricula of turret-system mechanics. The shortcomings of the education that became obvious are that educators do not always deliver, "cold weather". This is because the trainer views this part of the training as taking away time, and would rather focus on the technical training. The shortcomings in the course description that developed from my report are that the turret and system mechanic training are not in sync with each other, it means that courses are not always pursuing the same objectives. Turret mechanics implement curriculum as a "cold weather" training, but not the system mechanics and for this reason it may be difficult for them to cooperate after their education is complete.</p>