Modular MRI Guided Device Development System: Development, Validation and Applications

Since the first robotic surgical intervention was performed in 1985 using a PUMA industrial manipulator, development in the field of surgical robotics has been relatively fast paced, despite the tremendous costs involved in developing new robotic interventional devices. This is due to the clear advantages to augmented a clinicians skill and dexterity with the precision and reliability of computer controlled motion. A natural extension of robotic surgical intervention is the integration of image guided interventions, which give the promise of reduced trauma, procedure time and inaccuracies. Despite magnetic resonance imaging (MRI) being one of the most effective imaging modalities for visualizing soft tissue structures within the body, MRI guided surgical robotics has been frustrated by the high magnetic field in the MRI image space and the extreme sensitivity to electromagnetic interference. The primary contributions of this dissertation relate to enabling the use of direct, live MR imaging to guide and assist interventional procedures. These are the two focus areas: creation both of an integrated MRI-guided development platform and of a stereotactic neural intervention system. The integrated series of modules of the development platform represent a significant advancement in the practice of creating MRI guided mechatronic devices, as well as an understanding of design requirements for creating actuated devices to operate within a diagnostic MRI. This knowledge was gained through a systematic approach to understanding, isolating, characterizing, and circumventing difficulties associated with developing MRI-guided interventional systems. These contributions have been validated on the levels of the individual modules, the total development system, and several deployed interventional devices. An overview of this work is presented with a summary of contributions and lessons learned along the way

Wireless sensor networks for active vibration control in automobile structures

International audienceWireless Sensor Network (WSN) are nowadays widely used in monitoring and tracking applications. This paper presents the feasibility of using Wireless Sensor Networks in active vibration control strategy. The active control method used is an active-structural acoustic control using piezoelectric sensors distributed on the car structure. This system aims at being merged in wireless sensor network whose head node collects data and process control law so as to command piezoelectric actuators wisely placed on the structure. We will study the feasibility of implementing WSN in active vibration control and introduce a complete design methodology to optimize hardware/software and control law synergy in mechatronic systems. A design space exploration will be conducted so as to identify the best Wireless Sensor Network platform and the resulting impact on control

Mechatronic Tools for the Modeling and Design of Servo Motor Actuated Belt Driven Motion Systems

Mechatronics is defined as the synergistic integration of physical systems, electronics, controls, and computers through the design process, from the very start of the design process, thus enabling complex decision making. This definition reveals the elements involved yet it eludes to the complexity and the constant balance of tradeoffs which are prevalent in the context of applying Mechatronics to a successful design process. This work pursues the use of various tools for the application of Mechatronics to the modeling and design of a servo motor driven motion system. The use of Mechatronics is pervasive in and among today\u27s highly integrated devices and systems. By virtue of the fact that the phrase Mechatronics may carry different meaning depending upon ones discipline or industry, the most general definition is sought and embodied within the work. An overview of the relevant discipline specific perspectives is offered; as sufficient background for the systems modeling and analysis presented. In the course of developing and applying a Mechatronics design process for servo motor actuated motion systems, the use of frequency response analysis and alternative modeling techniques is emphasized, not only as a tool for understanding and applying the matter but, also for the purposes of model verification. These efforts culminate in the design and testing of a physical realization of one of the models presented; the servo motor actuated compliant belt system with compliance and friction. The results of this work underscore the notion that using a Mechatronics design process while devising a servo motor driven motion system enables optimization and functionality not otherwise realizable. These results are supported with experimental verification and comparison. The implications of this work are threefold: the work equips the Mechatronics practitioner with the tools required for verification of the results of modeling and analysis, the work provides an upgrade to the tools and equipment available in the College of Engineering at Marquette University, and the work will likely inspire additional related projects

Advances in Piezoelectric Transducers

The piezoelectric transducer converts electric signals into mechanical vibrations or vice versa by utilizing the morphological change of a crystal which occurs on voltage application, or conversely by monitoring the voltage generated by a pressure applied on a crystal. This book reports on the state of the art research and development findings on this very broad matter through original and innovative research studies exhibiting various investigation directions. The present book is a result of contributions of experts from international scientific community working in different aspects of piezoelectric transducers. The text is addressed not only to researchers, but also to professional engineers, students and other experts in a variety of disciplines, both academic and industrial seeking to gain a better understanding of what has been done in the field recently, and what kind of open problems are in this area

Mechatronic design, actuator optimization, and control of a long stroke linear nano-positioner

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.precisioneng.2018.01.007 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/In this paper, mechatronic design, actuator optimization and controls of a long-stroke (20 mm) linear nano-positioner are presented. The mechatronic design is described in terms of the stage's most prominent features regarding mechanical design, assembly, actuator configuration, and power supply. A novel air-bearing/bushing arrangement has been used in which the commonly employed double shaft arrangement is replaced with a single shaft supported by an air bearing from the bottom to constrain the roll motion. The assembly is greatly simplified by exploiting the self-aligning property of the air-bushings which are held in the housings by O-rings. Also, the footprint of the stage is reduced. Voice coil actuators (VCA) in moving magnet mode have been used in complementary double configuration for uniformity of force response. The performance objectives of previously optimized VCA's as standalone actuators are re-evaluated in this configuration. It is observed that while the performance objectives decrease a bit, the desirability of the design point is still retained. Controller design has been made for the current control and position control loops. Heydemann's method for the compensation of encoder quadrature detection errors is implemented. The positioning resolution of the stage as measured from the sensor output is experimentally determined to be +/-5 nm. Dynamic Error Budgeting (DEB) method has been used to analyze the contributing factors to the positioning error, and sensor broadband noise is determined to be the major contributor. The actual positioning accuracy of the stage is estimated by DEB to be 0.682 nm root-mean-square (RMS). The trajectory following accuracy is determined to be +/-15 nm. It is expected that trajectory following accuracy can substantially improve if more advanced compensation methods for encoder quadrature errors are implemented.Natural Sciences and Engineering Research Council of Canada [RGPIN-03879]Engage grant EGP [436910-12

Real-Time Implementation of a New MPPT Control Method for a DC-DC Boost Converter Used in a PEM Fuel Cell Power System

settings Open AccessArticle Real-Time Implementation of a New MPPT Control Method for a DC-DC Boost Converter Used in a PEM Fuel Cell Power System by Mohamed Derbeli 1,2,* [OrcID] , Oscar Barambones 1 [OrcID] , Mohammed Yousri Silaa 1 [OrcID] and Cristian Napole 1 [OrcID] 1 Engineering School of Vitoria, University of the Basque Country UPV/EHU, Nieves Cano 12, 1006 Vitoria, Spain 2 National Engineering School of Gabes, University of Gabes, Omar Ibn-Elkhattab, 6029 Gabes, Tunisia * Author to whom correspondence should be addressed. Actuators 2020, 9(4), 105; https://doi.org/10.3390/act9040105 Received: 30 August 2020 / Revised: 25 September 2020 / Accepted: 10 October 2020 / Published: 16 October 2020 (This article belongs to the Section High Torque/Power Density Actuators) Download PDF Browse Figures Abstract Polymer electrolyte membrane (PEM) fuel cells demonstrate potential as a comprehensive and general alternative to fossil fuel. They are also considered to be the energy source of the twenty-first century. However, fuel cell systems have non-linear output characteristics because of their input variations, which causes a significant loss in the overall system output. Thus, aiming to optimize their outputs, fuel cells are usually coupled with a controlled electronic actuator (DC-DC boost converter) that offers highly regulated output voltage. High-order sliding mode (HOSM) control has been effectively used for power electronic converters due to its high tracking accuracy, design simplicity, and robustness. Therefore, this paper proposes a novel maximum power point tracking (MPPT) method based on a combination of reference current estimator (RCE) and high-order prescribed convergence law (HO-PCL) for a PEM fuel cell power system. The proposed MPPT method is implemented practically on a hardware 360W FC-42/HLC evaluation kit. The obtained experimental results demonstrate the success of the proposed method in extracting the maximum power from the fuel cell with high tracking performance.This work was partially supported by Eusko Jaurlaritza/Gobierno Vasco [grant number SMAR3NAK ELKARTEK KK-2019/00051]; the Provincial Council of Alava (DFA) [grant number CONAVAUTIN 2] (Collaboration Agreement)

Shaping the future by engineering: 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme

Druckausgabe erschienen im Universitätsverlag Ilmenau: Shaping the future by engineering : 58th IWK, Ilmenau Scientific Colloquium, Technische Universität Ilmenau, 8 - 12 September 2014 ; programme / Department of Mechanical Engineering, Technische Universität Ilmenau. [Hrsg.: Peter Scharff. Red.: Andrea Schneider] Ilmenau : Univ.-Verl. Ilmenau, 2014. - 155 S. ISBN 978-3-86360-085-

Mechatronic Design, Dynamics, Controls, and Metrology of a Long-Stroke Linear Nano-Positioner

Precision motion systems find a broad range of application in various fields such as micro/nano machining tools, lithography scanners, testing and metrology machines, micro-assembly, biotechnology, optics manufacturing, magnetic data-storage, and optical disk drives. In this thesis, an ultraprecision motion stage (nano-positioner) is designed and built based on the concept of a low-cost desktop precision micro machine tool. Linear positioning performance requirements of such a machine tool are used as design objectives. The nano-positioner’s mechatronic design is carried out in such a way to integrate different components towards high performance in terms of high dynamic range, high feedrate, servo accuracy, and geometric accuracy. A self-aligning air-bearing/bushing arrangement is employed for frictionless motion with infinite theoretical resolution, as well as reduced assembly costs and footprint. The air discharge from the air bearings/bushings are also utilized for assistance in the removal of heat dissipated from actuator coils. A voice coil actuator (VCA) is chosen for continuous, non-contact operation, and designed from scratch. A number of dimensional variables of the cylindrical VCA are set according to required forces, motion range, production/assembly tolerances, magnet availability, leakage flux, etc. The remainder of variables is determined according to two novel optimization objectives defined independent of the coil wire gauge, which separately aim for maximum stage acceleration capacity and minimum heat generation per generated force. The actuators are operated in a complementary double configuration for control simplicity which allows for a straightforward and robust design for controller stability. Controller design is carried out at current control and position control levels. Current frequency response of the voice coil actuators is obtained, and they are observed to possess additional high frequency dynamics on top of the expected first order lumped resistance and inductance model. These are attributed to the eddy currents in the stator structure. A closed loop bandwidth of better than 907 [Hz] is achieved using the integrator plus lead current controller. The position controller is designed using the identified overall plant which includes the moving body, current dynamics and the force response. The lead-lag position controller is tuned at 450 [Hz] cross-over frequency and 40 [deg] phase margin. The control error during the tracking of a step trajectory filtered at 40 [Hz] is found to vary between ±5 [nm], indicating a 4 million dynamic range over the 20 [mm] stroke length. Dynamic Error Budgeting (DEB) method has been used to resolve the components of the error, and the largest contributor is found to be the sensor noise. The actual positioning error, which is an ideal signal excluding sensor noise is estimated using the same methodology and disturbance models, and it is found to be 0.680 [nm] root-mean-square (RMS). For the trajectory following case, experiments are carried out with and without a compensation scheme for encoder quadrature detection errors. The compensation is observed to reduce the ±45 [nm] control error to ±15 [nm]. For the assessment of stage performance and the verification of design choices, modal testing and laser interferometric metrology have been applied to the linear nano-positioner. For modal testing, two independent methods are used and their predictions are compared. In the first method, a graphical approach, namely the peak-picking method, is employed to identify modal parameters (natural frequency and damping ratio) and mode shapes. In the second method, a modal testing software package is used to identify the same using automated algorithms. The first mode, which is the most critical one for controller design, is identified at 65 [Hz] as a roll mode, followed by horizontal, vertical, and pitch modes at 450, 484, and 960 [Hz], respectively. The geometric errors of the system are identified using laser interferometric measurements, using various optical setups for linear and angular components. An error budget is formed using these results, together with the estimated thermal errors and servo errors. The accuracy of the stage is determined to be ±5.0 [μm], which had a ±1.1 [μm] non-repeatable component. In the future, the controller structure can be enhanced with an additional pole beyond the crossover frequency, in order to suppress unnecessary oscillations of the control effort signal around the set point due to the encoder noise transmitted to the controller input. Using an estimation of air bearing pitch stiffness from the catalogue values for normal stiffness, the roll mode was predicted at 672 [Hz]. The much lower natural frequency for that mode identified in modal testing (65 [Hz]) can be attributed to the shortcomings of the estimation method, primarily the neglect of the distortion of the supporting air cushion at the bearing interface due to out of plane rotations. In the future, experimental data can be obtained to characterize the air bearing pitch stiffness more accurately. It was observed that the preferred compensation scheme for the encoder quadrature detection errors is unable to match third and fourth harmonics of the encoder measurement error sufficiently. In the future, better compensation methods can be investigated for an improved match. During laser interferometric measurements, measurement uncertainty due to laser beam misalignment and air turbulence were inferred to be high. In the future, better ways to align the laser with the optics, as well as methods for improved assessment and compensation of environmental effects can be investigated