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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Studie membránového čerpadla s lineárním motorem / Study of diaphragm pump with linear motor

Dubový, Ľuboš January 2010 (has links)
The content of this master‘s thesis is a study of diaphragm pump with linear drive. Linear motor was used as the linear drive. Thesis is well – founded by theoretic calculation of pump and its design draft. Likewise, the thesis includes optimalization of suction, or pressure, valve for pump, created by using computer fluid dynamics software. Thesis is complemented by basic view of different types of pumps based on the classification by hydrodynamic and hydrostatic pumps. Subsequently, the preview of blood – flow pumps is presented.

Design and construction of a precision tubular linear motor and controller

Murphy, Bryan Craig 30 September 2004 (has links)
A design for a novel tubular high-precision direct-drive brushless linear motor has been developed. The novelty of the design lies in the orientation of the magnets in the mover. In conventional linear motors the magnets of the armature are arranged such that the attractive poles are adjacent throughout, in an NS-NS-NS orientation, where N denotes the north pole and S denotes the south pole of the magnet. In the new design, the magnets in the moving part are oriented in an NS-NS-SN-SN orientation. This change in orientation yields greater magnetic field intensity near the like-pole region. The magnets of the mover are encased within a brass tube, which slides through a three-phase array of current-carrying coils. As the coils are powered, they induce a force on the permanent magnets according to the Lorentz force equation. The primary advantages of the motor are its compact nature, fast, precise positioning due to its low-mass moving part, direct actuation, extended travel range, and ability to extend beyond its base. The linear motor is used in conjunction with a position sensor, power amplifiers, and a controller to form a complete solution for positioning and actuation requirements. Controllers were developed for two applications, with a lead-lag as the backbone of each. For the first application, the principal requirements are for fast rise and settling times. For the second application, the primary requirement is for near-zero overshoot. With the controller for application 1, the motor has a rise time of 55 ms, a settling time of 600 ms, and 65% overshoot. With the controller for application 2 implemented, the motor has a rise time of 1 s, a settling time of 2.5 s, and 0.2% overshoot. The maximum force capability of the motor is measured to be 26.4 N. The positioning resolution is 35 ?m. This thesis discusses the motor's physical design, construction, implementation, testing, and tuning. It includes specifications of the components of the motor and other necessary equipment, desired and actual motor performance, and the primary limitations on the precision of the system.

The Design, Fabrication, and Modeling of a Piezoelectric Linear Motor

Vaughan, Mark Edward 02 January 2002 (has links)
The focus of this research was to create a linear motor that could easily be packaged and still perform the same task of the current DC motor linear device. An incremental linear motor design was decided upon, for its flexibility in which the motor can be designed. To replace the current motor it was necessary to develop a high force, high speed incremental linear motor. To accomplish this task, piezoelectric actuators were utilized to drive the motor due their fast response times and high force capabilities. The desired overall objectives of the research is to create an incremental linear motor with the capability of moving loads up to one hundred pounds and produce a velocity well over one inch per second. To aid the design process a lumped parameter model was created to simulate the motor's performance for any design parameter. Discrepancies occurred between the model and the actual motor performance for loads above 9.1 kilograms (20 pounds). The resulting model, however, was able to produce a good approximation of the motor's performance for the unloaded and lightly loaded cases. The phase one design was limited by time constraints so a relatively low risk design was produced. The resulting incremental linear motor produced a velocity of 4.9 mm/sec (0.2 in/sec) at a drive frequency of 50 Hz. The velocity of the motor was limited by the drive frequency that the amplifiers could produce. The motor was found to produce a respectable stall load of 17 kilograms (38 pounds). The stall load of the phase one design was severely limited by clearance losses. An analysis of the motor's performance was conducted, possible improvements and future work recommendations for a phase two design are presented. / Master of Science

Hybrid Fuzzy PID Controller for an Active Vibration Control System via Genetic Algorithms

Cheng, Chung-Yi 21 June 2002 (has links)
Abstract We use the non-binary coding ,elitist strategy, increasing mutation rate, extinction, and immigration strategy to improve the simple genetic algorithms in this study. We expect that the search technique can avoid falling into the local optimum due to the premature convergence, and purse the chance that finding the near-optimal parameters in the larger searching space could be obviously increased. The accelerometer is then taken as the feedback sensor for output measurement, and the designed actuator and the PID fuzzy logic controller (PIDFLC) is implemented to actively suppress the vibration of the supporting mechanism that is due to the excitation effect of the high-speed and precision positioning action of the linear motor. From the computer simulations and the experimental results, it is obvious that the near-optimal PIDFLC controller designed by modified genetic algorithms can improve the effect of the vibration suppression; the settling time is also decrease. For the vibration suppressions of high-speed precision positioning problems, the vibrating supporting mechanism can quickly be stabilized.

A Micro-Model Based Linear Motor Sub-micron and Fast Positioning Controller

Wang, Chuang-Lin 12 September 2002 (has links)
In position control systems like linear motor, friction is a key factor to influence the control performance when micron or sub-micron meter accuracy is required. To overcome the effect of the friction, besides a general model of the linear motor system, past researches have shown an additional static friction model of the system is necessary for a better control performance when the motor move into the micro region of the system (usually <100£gm). Two models, macro and micro model of the system have been well constructed by two different identification methods. After model construction, two different controllers are also designed for each model. A traditional pole-placement PID controller can be easily obtained for the macro model to move into the micro region quickly and stably. Then in micro model design, from the experiments, it is found that system parameter varies and thus degrades the positioning performance of the system. So, a Sliding-Mode Controller is designed to improve these problems. With a two step control strategy, macro and micro step, the linear motor positioning system can achieve a 0.1£gm accuracy within 0.2 sec.

Development of a Novel Linear Magnetostrictive Actuator

Sadighi, Ali 2010 August 1900 (has links)
This dissertation presents the development of a novel linear magnetostrictive actuator. The magnetostrictive material used here is Terfenol-D, an alloy of the formula Tb0.3Dy0.7Fe1.92. In response to a traveling magnetic field inside the Terfenol-D element, it moves in the opposite direction with a peristaltic motion. The proposed design offers the flexibility to operate the actuator in various configurations including local and conventional three-phase excitation. The conceptual design of the linear magnetostrictive actuator was performed during which different configurations were analyzed. Finite Element Analysis (FEA) was extensively used for magnetic circuit design and analysis in conceptual design. Eventually one of these designs was chosen based on which detailed design of linear magnetostrictive actuator was carried out. A new force transmission assembly incorporates spring washers to avoid the wear due to the sudden collision of Terfenol-D element with the force transmission assembly. All mechanical parts were then fabricated at the mechanical engineering machine shop. The power electronics to operate the motor in a local three-phase mode was designed and implemented. It was demonstrated that the power consumption can be reduced significantly by operating the magnetostrictive linear actuator in the local excitation mode. A finite-element model of the actuator was developed using ATILA and an empirical model was presented using the data gathered from numerous tests performed on the actuator. The closed-loop control system was implemented using relay control which resulted in an optimal closed-loop performance. The magnetostrictive actuator has demonstrated 410-N load capacity with a travel range of 45 mm, and the maximum speed is 9 mm/min. The maximum power consumption by the motor is 95 W. The sensorless control of the linear magnetostrictive actuator was successfully conducted using two different approaches. First, using a linear-approximation method, we achieved a position estimation capability with ±1 mm error. Then, an adaptive neuro-fuzzy inference system was employed for estimating the position which resulted in a position estimation capability with only a ±0.5 mm error.

Řízení elektromechanické soustavy s lineárním motorem / Control of the Electromechanical System with a Linear Motor

Judinyová, Katarína January 2009 (has links)
The submitted Master’s thesis deals with the general principle of the electric drives’ functioning and with the construction of a synchronous electric motor. A comparison of a linear drive and a rotary drive with rack and pinion system is provided, as well as an overview of common type linear drives. A mathematical model of a rotary synchronous motor, the Clark’s and Park’s transformation and the principle of vector control is explained. A method of the linear parameters’ conversion to the rotary equivalents is demonstrated. A block diagram to motor control is designed. The control quality is tested by various criteria. Lastly, there is a simulation provided on how the changes of motor’s parameters affect the control quality.

Návrh řízení osy s lineárním motorem / Design of control of axis with linear motor

Chaloupka, Roman January 2015 (has links)
This thesis deals with construction, connection and control axis with linear motor. The beginning of thesis is focused on principle of functioning and characteristics of linear motors. The following part describes used components of axis, their mechanical configuration and electrical wiring. Further thesis deals with creating PLC program and user interface for control axis in TwinCAT system. In last part is dealing correct software settings of axis.

Policy Hyperparameter Exploration for Behavioral Learning of Smartphone Robots / スマートフォンロボットの行動学習のための方策ハイパーパラメータ探索法

Wang, Jiexin 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第20519号 / 情博第647号 / 新制||情||112(附属図書館) / 京都大学大学院情報学研究科システム科学専攻 / (主査)教授 石井 信, 教授 杉江 俊治, 教授 大塚 敏之, 銅谷 賢治 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

Elektronická jednotka pro řízení pohonu kostelních zvonů / Control Unit for Church Bell Electric Drive

Bureš, Petr January 2009 (has links)
This work deals with analysis induction motors. There are described their principle and methods of starting, the engine controls and the stop braking. In terms of this study it was determined the engine controls type for control unit for church bell electric drive design. In next part there is complete hardware and software design of control unit.

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