This master's thesis deals with proposal and realization of electromechanical positional system for automatic optical inspection PCB bigger proportions and solution of automatic optical inspection. Problems are dispersed into of several prime area namely on mechanical part, driving hardware and software part. In every part is performed analysis problem and choice optimal solution.

Dynamics of a beam-based micro-electromechanical resonator is investigated theoretically and experimentally. The resonant structure comprises a micro-beam and two electrostatic comb-drives, one for exciting the vibration, and the other for detecting the response. Two identical resonators of this type can form a double-ended tuning fork. An analytical linear model of these resonators is developed by assuming the beam to obey the thin beam theory subjected to an axial force. The comb-drives are initially treated as a point mass. The point mass is free to be placed anywhere along the beam span. The exact natural frequencies and mode shapes of vibration are obtained. Further, the mass is considered to have rotary inertia. The influence of the rotary inertia on the natural frequencies and mode shapes of vibration are investigated. Subsequently, the model of a beam with a guided mass is studied to determine the upper limit of the natural frequencies of the resonator. The advantage of this model over the previous ones is in providing detailed insight into the dynamics of the resonator, particularly when the comb-drives are placed at locations other than the mid-point of the beam. It has been shown that the mode shapes of vibration of these resonators are not orthogonal to each other under its classic definition. The orthogonality condition of the mode shapes of the beam-lumped mass system is introduced, and used for studying the forced vibration response. The nonlinear vibration of the system due to stretching is considered for the case of free vibration and the primary resonance. The nonlinear model is used to investigate the effect of damping on the resonator response. The interaction of the electrostatic governing equations and the mechanical model is studied. This model is employed for designing the experiment circuits for testing fabricated resonators. The fabrication processes used are explained, and the design parameters of each resonator are provided. The experimental results are reported, and used to find the axial force and stress of the resonant beams. The model and results of this dissertation can be used in the design of beam-based micromachined resonators for different applications.

Dynamics of a beam-based micro-electromechanical resonator is investigated theoretically and experimentally. The resonant structure comprises a micro-beam and two electrostatic comb-drives, one for exciting the vibration, and the other for detecting the response. Two identical resonators of this type can form a double-ended tuning fork. An analytical linear model of these resonators is developed by assuming the beam to obey the thin beam theory subjected to an axial force. The comb-drives are initially treated as a point mass. The point mass is free to be placed anywhere along the beam span. The exact natural frequencies and mode shapes of vibration are obtained. Further, the mass is considered to have rotary inertia. The influence of the rotary inertia on the natural frequencies and mode shapes of vibration are investigated. Subsequently, the model of a beam with a guided mass is studied to determine the upper limit of the natural frequencies of the resonator. The advantage of this model over the previous ones is in providing detailed insight into the dynamics of the resonator, particularly when the comb-drives are placed at locations other than the mid-point of the beam. It has been shown that the mode shapes of vibration of these resonators are not orthogonal to each other under its classic definition. The orthogonality condition of the mode shapes of the beam-lumped mass system is introduced, and used for studying the forced vibration response. The nonlinear vibration of the system due to stretching is considered for the case of free vibration and the primary resonance. The nonlinear model is used to investigate the effect of damping on the resonator response. The interaction of the electrostatic governing equations and the mechanical model is studied. This model is employed for designing the experiment circuits for testing fabricated resonators. The fabrication processes used are explained, and the design parameters of each resonator are provided. The experimental results are reported, and used to find the axial force and stress of the resonant beams. The model and results of this dissertation can be used in the design of beam-based micromachined resonators for different applications.

Electromechanical systems dynamics analysis is approached through nonlinear differential equations and further creating a state space model for the system. There are three modules analyzed and validated, first module consists two magnet coupled with a mass spring damper system as a band-pass system, Low-pass equivalent system and Low-pass equivalent system through perturbation analysis. Initially Band Pass frameworks for the systems are formulated considering the relation between the mechanical forcing and current. Using Mathematical tools such as Hilbert transforms, Low-Pass equivalent of the systems are derived. The state equations of the systems are then used to design a working model in MATLAB and simulations investigated completely. The scope of the modules discussed for further development of tools various applications.

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.

Hydrogen sensors have obtained increased interest with the widened application of hydrogen energy in recent years. Among them, various chemiresistor based hydrogen sensors have been studied due to their relatively simple structure and well-established detection mechanism. The recent progress in micro/nanotechnology has accelerated the development of small-scale chemical sensors. In this work, MEMS (Micro-Electro-Mechanical Systems) sensor platforms with interdigitated electrodes have been designed and fabricated. Integrating indium doped tin dioxide nanoparticles, these hydrogen sensors showed improved sensor characteristics such as sensitivity, response and selectivity at room temperature. Design parameters of interdigitated electrodes have been studied in association with sensor characteristics. It was observed that these parameters (gap between the electrodes, width and length of the fingers, and the number of the fingers) imposed different impacts on the sensor performance. In order to achieve small, robust, low cost and fast hydrogen micro/nano sensors with high sensitivity and selectivity, the modeling and process optimization was performed. The effect of humidity and the influence of the applied voltage were also studied. The sensor could be tuned to have high sensitivity (105), fast response time (10 seconds) and low energy consumption (19 nW). Finally, a portable hydrogen instrument integrated with a micro sensor, display, sound warning system, and measurement circuitry was fabricated based on the calibration data of the sensor.

The power requirements imposed on an active vibration isolation system are quite important to the overall system design. In order to improve the efficiency of an active isolation system we analyze different feedback control strategies which will provide electrical energy regeneration. The active isolation system is modeled in a state-space form for two different types of actuators: a piezoelectric stack actuator and a linear electromagnetic (EM) actuator. During regenerative operation, the power is flowing from the mechanical disturbance through the electromechanical actuator and its switching drive into the electrical storage device (batteries or capacitors). We demonstrate that regeneration occurs when controlling one or both of the flow states (velocity and/or current). This regenerative control strategy affects the closed loop dynamics of the isolator which sees its damping reduced. / Master of Science

Elastic and inelastic interactions are studied in tunnel junctions of a superconducting nanoelectromechanical setup and in response to resent experimental superconducting scanning tunneling microscope findings on a paramagnetic molecule. In addition, the electron density of molecular graphene is modeled by a scattering theory approach in very good agreement with experiment. All studies where conducted through the use of model Hamiltonians and a Green function formalism. The nanoelectromechanical system comprise two fixed superconducting leads in-between which a cantilever suspended superconducting island oscillates in an asymmetric fashion with respect to both fixed leads. The Josephson current is found to modulate the island motion which in turn affects the current, such that parameter regions of periodic, quasi periodic and chaotic behavior arise. Our modeled STM setup reproduces the experimentally obtained spin excitations of the paramagnetic molecule and we show a probable cause for the increased uniaxial anisotropy observed when closing the gap distance of tip and substrate. A wider parameter space is also investigated including effects of external magnetic fields, temperature and transverse anisotropy. Molecular graphene turns out to be well described by our adopted scattering theory, producing results that are in good agreement with experiment. Several point like scattering centers are therefore well suited to describe a continuously decaying potential and effects of impurities are easily calculated.

There are various energy dissipation mechanisms that affect the dynamic response of microstructures used in MEMS devices. A cumulative effect of such losses is captured by an important characteristic of the structure called Quality factor or Q-factor. Estimating Q-factor at the design stage is crucial in all applications that use dynamics as their principle mode of operation. A high Q-factor indicates sharp resonance that, in turn, can indicate a broad flat response region of the structure. In addition, a high Q-factor typically indicates a high sensitivity. Microstructures used in MEMS are generally required to have much higher Q-factors than their macro counterparts. However some damping mechanisms present in microstructures can reduce the Q-factor of the structure significantly. In the present work, we investigate the dependence of Q-factor on the squeeze film damping an energy dissipation mechanism that dominates by a couple of orders of magnitude over other losses when a fluid (e.g., air) is squeezed through gaps due to vibrations of a microstructure. In particular, we show the effect of nonlinear terms in the analysis of squeeze film damping on the Q-factor of a structure. We also show the effect of rarefaction, surface roughness along with their coupled effect and with different boundary conditions such as open border effect, blocked boundary effect on the squeeze film damping. Finally, we develop similitude laws for calculating squeeze film damping force in up-scaled structures. We illustrate the effects by studying various type of microstructures including parallel plates, beams, plate and beam assemblies such as MEMS microphone, vibratory gyroscope etc. We view the contributions of this work as a significant in investigating and integrating all important effects altogether on the squeeze film damping, which is a significant factor in the design and analysis of MEMS devices.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17985号 / 工博第3814号 / 新制||工||1584(附属図書館) / 80829 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 川上 養一, 教授 藤田 静雄, 准教授 浅野 卓 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM