Spelling suggestions: "subject:"linear actuators""
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Design and Manufacture of a Cam Type Linear ActuatorTsai, Meng-Che 02 September 2004 (has links)
The drawbacks of the mechanical linear actuator which is applied to punch flexible printed circuit boards(FPCBs), are many components involved, low transmission efficient, and high proportion of energy consumption. In order to design and manufacture a device that can generate a rapid and high quality punching processes, the fundamental rules that can be followed are to use few parts with light weight design, good working piece, energy conserved, and perfect efficient. To improve the kinematic and dynamic characteristics of the existing mechanism, design, manufacture, and assessment are to be taken for developing new linear actuated mechanisms. The first step is to analyze the performance of the existing linkage actuator . The second step is to design a over-head cam mechanism of non-constant rotational speed to substitute the pulley and the rock arm according to the design specifications. The performance of the new type actuated device is superior to the existing mechanism, and this research had preliminary verified the viewpoint of the energy in high speed punching. The achievements of this research also provide references for linear actuator designers and high speed punching producers.
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ACTIVE SUSPENSION CONTROL WITH DIRECT-DRIVE TUBULAR LINEAR BRUSHLESS PERMANENT-MAGNET MOTORLee, Seungho 16 January 2010 (has links)
Recently, active suspension has been applied to many commercial automobiles. To develop the control algorithm for active suspension, a quarter-car test bed was built by using a direct-drive tubular linear brushless permanent-magnet motor (LBPMM) as a force-generating component. Two accelerometers and a linear variable differential transformer (LVDT) are used in this quarter-car test bed. Three pulse-width-modulation (PWM) amplifiers supply the currents in three phases. Simulated road disturbance is generated by a rotating cam. Modified lead-lag control, linear-quadratic (LQ) servo control with a Kalman filter, and the fuzzy control methodologies were implemented for active-suspension control. In the case of fuzzy control, asymmetric membership functions were introduced. This controller could attenuate road disturbance by up to 78%. Additionally, a sliding-mode controller (SMC) is developed with a different approach from the other three control methodologies. While SMC is developed for the position control, the other three controllers are developed for the velocity control. SMC showed inferior performance due to the drawback of the implemented chattering-proof method. Both simulation and experimental results are presented to demonstrate the effectiveness of these four control methodologies.
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ACTIVE SUSPENSION CONTROL WITH DIRECT-DRIVE TUBULAR LINEAR BRUSHLESS PERMANENT-MAGNET MOTORLee, Seungho 16 January 2010 (has links)
Recently, active suspension has been applied to many commercial automobiles. To develop the control algorithm for active suspension, a quarter-car test bed was built by using a direct-drive tubular linear brushless permanent-magnet motor (LBPMM) as a force-generating component. Two accelerometers and a linear variable differential transformer (LVDT) are used in this quarter-car test bed. Three pulse-width-modulation (PWM) amplifiers supply the currents in three phases. Simulated road disturbance is generated by a rotating cam. Modified lead-lag control, linear-quadratic (LQ) servo control with a Kalman filter, and the fuzzy control methodologies were implemented for active-suspension control. In the case of fuzzy control, asymmetric membership functions were introduced. This controller could attenuate road disturbance by up to 78%. Additionally, a sliding-mode controller (SMC) is developed with a different approach from the other three control methodologies. While SMC is developed for the position control, the other three controllers are developed for the velocity control. SMC showed inferior performance due to the drawback of the implemented chattering-proof method. Both simulation and experimental results are presented to demonstrate the effectiveness of these four control methodologies.
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Optimalizace termoelektrického lineárního aktuátoru / Optimalization of thermoelectric linear actuatorTlach, Michal January 2009 (has links)
This dissertation describes the process of designing, process of optimalization and the following implementation of the changes of the thermoelectric linear actuator which operates the opening and the closing of the valves used in the most modern buildings for example for floor heating. It is a product produced in large series with the annual production of more than half of a million items. The reason for the optimalization is the instability during the assembly in the production and the reduction of costs, whereas the final assembly takes place in Germany. The dissertation deals with designing of the conceptions for solving of the trouble parts of the current version of the actuator. The chosen concept is consequently optimalized, tested and put into production.
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Systémy průmyslového vidění a snímání 3D obrazu / Robot vision and 3D image acquiringArnošt, David January 2011 (has links)
Master´s thesis is describing basic concepts in machine vision. Used camera systems and possible imaging 2D and 3D are described. Practical part deals with constructin of scanning device with linear actuator, conveyor belt, camera and laser. For experimental use is construction of scanning device made for 2D and 3D image using several methods.
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Návrh snímacího portálu pro snímání 3D obrazu / Design of an experimental stand for three-dimensional image acquisitionMužný, Lukáš January 2012 (has links)
This thesis deals with the possibilities of 3D vision. The theoretical part describes the principles of machine vision, constitutes the basic elements, description and the methods of measurement and 3D. The practical part is focused on the design of experimental workplace, which is consists of conveyor, experimental stand, industrial robot and PLC control. The system used to recognize and grasp objects undirected. Construction chapter focuses on the treatment needs of the conveyor for sensing applications and design of experimental stand with linear axis, which is equipped with camera and lasers. Furthermore solved by a communication network between the elements of work includes the design of their communications with the description of the control of its individual elements.
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Efficiency verification of an electromechanical linear actuator / Verifiering av verkningsgraden hos ett elektromekanisk linjärt ställdonRåberg, Ingela January 2021 (has links)
Cascade Drives has developed an electromechanical linear actuator with a patented feature which allows for load sharing between multiple pinions interacting on the same rack. This arrangement has proven resilient for shock loads, and allows for compact gearbox designs with very high load rating. For the further development of the actuators, access to proper simulation models for various gearbox behaviours is important. One such behaviour is that of the gearbox efficiency. In 2020, a Simulink model for predicting the gearbox efficiency was produced. The aim of this thesis has been to verify the 2020-model using Romax, and also to continue the development of the Simulink model so that it can also handle gearbox acceleration and backdrive. The results from the Romax modelling were while not identical to the 2020 Simulink model results, close enough that the Simulink model could be considered verified through that method. The results from the new dynamic Simulink model were in the same order of magnitude as those of the other two models. To achieve an absolute accuracy for the models, efficiency testing on physical actuators should be executed. / Cascade Drives utvecklar en ny typ av elektromekaniska linjära ställdon. Ställdonen är elektromekaniska och följer konceptet med en kuggstång och pinjonger som drivs av en elektrisk motor. I själva växellådan finns patenterad teknik som tillåter att lasten från kuggstången fördelas jämnt mellan flera pinjonger utan att systemet överbestäms. Detta möjliggör kompakta växellådor till ställdonen som kan ta höga laster och dessutom fungerar utmärkt för chocklaster. I och med att det är helt ny teknik erfordras beräkningsmodeller så att växellådans beteende kan förutspås redan innan prototyper tillverkas. En beräkningsmodell för ställdonets statiska verkningsgrad utvecklades 2020 i Simulink. Detta arbete syftar till att genom Romax verifiera funktionaliteten av modellen från 2020. Dessutom utvecklades modellen vidare för att hantera de dynamiska lastfallen när ställdonet accelererar och drivs från last. Modelleringen Resultaten från modelleringen i Romax och de från den statiska Simulinkmodellen från 2020 var snarlika med en skillnad på ungefär ± 1 %. Graferna över växellådans verkningsgradsbeteende över varierande last och hastighet skiljde sig tillräckligt lite för att bedömningen skulle vara att den statiska modellen kan betraktas som verifierad av Romax. Även den nya dynamiska Simulinkmodellen genererade resultat som liknade de från de statiska Simulinkoch Romax modellerna. För att få en absolut precision på samtliga beräkningsmodeller rekommenderas att genomföra verkningsgradstester på fysiska prototyper för framtiden.
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Design and Realization of an Adjustable Fluid Powered Piston for an Active Air SpringHedrich, Philipp, Johe, Maik, Pelz, Peter F. 28 April 2016 (has links) (PDF)
In this paper, we present a new compact hydraulic linear actuator. The concept is developed to change the rolling piston diameter of an active air spring during usage. By doing so, the air spring can actively apply pressure and tension forces. The actuator is designed for small movements at high forces. It is insensitive to side forces, which are introduced by the bellows rolling on the rolling piston of the air spring. A diaphragm sealing is used to minimize friction. Hence a precise adjustment of small displacements at high dynamics is possible and the system is completely leakage-free. We describe the design and development of this actuator and show first measurement results from preliminary tests to show its functionality.
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Modelování lineárního pohonu s DC motorem pro potřeby řízení / Modelling of linear power drive with DC motor for control purposesVrbka, Michal January 2009 (has links)
In my diploma thesis, I developed the model of a linear actuator for the control purposes. The first part summarizes the literature research of currently available linear actuator systems. The work further describes some of the capabilities of the simulation environment Matlab which was used for the creation of the computer model of linear actuators. In the last part, this theoretical model is compared with already available physical model of the system.
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Requirements and Analysis of an Overload Protection Mechanism for an Electromechanical Linear Actuator / Kravställning och Analys av Skyddsmekanism mot Överlast för Linjärt Elektromekaniskt StälldonVesterberg, Mats January 2022 (has links)
Cascade Drives specializes in high-performance electromechanical linear actuators (EMA). The company has developed a range of linear rack and pinion actuators based on a patented load distribution technique that allows multiple pinions to interact with a single gear rack. A project where one of their EMAs is to be implemented into an excavator boom is about to be initiated. It is suspected that extreme shock loads are present in such applications. The shock loads could potentially cause problems for the structural integrity of the gear train. This master thesis focused on defining requirements for an overload protection mechanism and identifying and evaluating possible solutions that could be implemented into the EMA to protect it from damage. At the start of the thesis, a pre-study had already been conducted. The author found that the forces present during shock loading warrant some protection strategy to be researched and implemented into the EMA. A comprehensive multibody dynamics model (MBD) of the EMA was developed in MSC Adams (View) to validate the result from the pre-study. The MBD model was later expanded to include a torsional stiffness model derived from physical tests and the flexibility of the excavator boom itself, which was extracted from flexible body simulations of the excavator boom assembly in Adams. The expanded MBD model simulations revealed that a protection mechanism was needed in the thought application. Three protection mechanisms/strategies were simulated and evaluated in the MBD environment. A slipping solution in the form of a friction clutch, a disconnecting solution in the form of an electromagnetic clutch, and an active solution in which the electric motor was controlled to produce maximum torque in the opposite direction of motion at the point of impact to dampen the loads through the gear train. Running the motor in reverse at impact proved to be an insufficient strategy. Even for an idealized motor that combined the maximum torque from the strongest motor and the rotational inertia from the lightest motor available for the EMA, simulations resulted in loads above the static load limit through the gear train. The friction clutch was shown to be plausible but inefficient. The slipping torque of a friction clutch had to be detuned way below the static load limit due to the delays in peak torque throughout the gear train, which meant that the overall actuating force of the actuator was severely hampered. The electromechanical disconnecting clutch was proved to be the most promising alternative. The disconnecting clutch completely disengages the upstream components from the downstream components in the drive train, meaning that the overall system performance remained unchanged. The response times needed depended on where the clutch was installed, from around 16ms if only the motor was disengaged up to 17ms if both the motor and the brake were disengaged. Further analysis of triggering strategies and response times has to be conducted to definitely decide if an electromagnetic clutch is a viable option. Still, the result from this thesis shows that it is a promising path. / Cascade Drives är specialiserade på högpresterande elektromekaniska linjära ställdon. Företaget har utvecklat en rad linjära ställdon av kuggstångskonfiguration som bygger på en patenterad lastfördelningsteknik som möjliggör för flera pinjonger att interagera med en enda kuggstång. Ett projekt där ett av deras ställdon ska implementeras i en grävmaskinsbom är på väg att inledas och man misstänker att det i en sådan applikation kan uppstå extrema chocklaster, vilka potentiellt kan orsaka stora skador på ställdonets drivlina. Detta examensarbete fokuserade på att kravställa och analysera ett överbelastningsskydd och att identifiera och utvärdera olika möjliga lösningar som kan implementeras i ställdonet för att skydda det från skador. En förstudie kring problemet har redan genomförts där författaren fann att de krafter som uppstår vid chocklaster motiverar att någon form av skyddsstrategi undersöks och implementeras i ställdonet. En omfattande multibody dynamics (MBD) modell av ställdonet utvecklades i MSC Adams (View) för att validera resultatet från förstudien. MBD-modellen utvidgades senare till att innefatta en torsionsflexmodell härledd från fysiska tester och även flexibiliteten hos själva grävmaskinbommen som extraherades från flexible body-simuleringar av grävmaskinens bomaggregat i Adams. Resultat från de utökade MBD-modellsimuleringarna visade att en skyddsmekanism behövs för att skydda drivlinan i ställdonet mot överlast i den tänkta grävmaskinsapplikationen. Tre olika skyddsmekanismer/strategier simulerades och utvärderades i MBD-miljön. En glidande lösning i form av en friktionskoppling, en frånkopplande lösning i form av en elektromagnetisk koppling, och en aktiv lösning där elmotorn reglerades till att producera maximalt vridmoment bakåt vid tidpunkten för kollisionen för att minska belastningarna i drivlinan. Att köra motorn bakåt vid kollision visade sig vara otillräckligt. Även för en idealiserad motor som kombinerade det maximala vridmomentet från den starkaste motorn som simulerades med rotationströgheten från den lättaste motorn som simulerades resulterade simuleringar i krafter genom drivlinan överstigande den statiska maxbelastningen. Friktionskopplingen visade sig vara en möjlig men ineffektiv lösning. Friktionskopplingens utlösningsmoment måste trimmas ner långt under den statiska maxbelastningen på grund av tiden det tar för maxbelastningen att propagera genom drivlinan. Detta innebar att ställdonets totala prestanda minskade rejält. Den frånkopplande elektromekaniska lösningen visade sig vara det mest lovande alternativet. Det faktum att den frånkopplande kopplingen helt kopplar bort komponenterna uppströms från komponenterna nedströms i drivlinan innebar att systemets prestanda förblev oförändrad. Svarstiderna som krävdes berodde på var kopplingen var installerad, från cirka 16ms om bara motorn skulle kopplas ur och upp till 17ms om både motorn och bromsen kopplades ur. Ytterligare analyser av utlösningsstrategier och svarstider måste genomföras för att definitivt avgöra om en elektrisk frånkopplande koppling är ett bra alternativ, men resultaten från denna avhandling visar att det är en lovande väg.
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