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Full-Text Articles in Mechanical Engineering
Open-Loop Control Of Electrostatic Levitation Actuators To Enhance The Travel-Range Of Optical Switches, Mohammad Mousavi, Mohammad Alzgool, Daniel Lopez, Shahrzad Towfighian
Open-Loop Control Of Electrostatic Levitation Actuators To Enhance The Travel-Range Of Optical Switches, Mohammad Mousavi, Mohammad Alzgool, Daniel Lopez, Shahrzad Towfighian
Mechanical Engineering Faculty Scholarship
Command shaping is a driving technique for handling the large settling time of the high-Q-MEMS actuators. The strong nonlinearity due to the electrostatic actuation limits the linear operation range in cantilevered or torsional micro-mirrors where command shaping techniques can be applied for positioning. Experimental and simulation results of this research demonstrate the effectiveness of using electrostatic levitation to overcome the actuation nonlinearities and a significant increase in the operation range. The motivation for this research is that applying the nonlinear command shaping causes complexity in command manipulation and requires an accurate knowledge of the nonlinear terms involved in the system …
Advanced Mechatronics, Hao Su
Advanced Mechatronics, Hao Su
Open Educational Resources
Project-based course on the design of mechatronic devices to address needs identified by hospital-based clinicians and industry. Students work in teams to develop a mechatronic prototype. The lectures will cover the design of medical devices and robotics including sensors, actuators, and robots. The students will communicate with customers to understand design needs, then conduct study on prior art, intellectual property, due diligence, and idea conceptualization. Students will present ideas in class and to a broad audience from local industry. Students will also write a publication-quality final report, which they will be encouraged for publication submission.
Engineering Design I, Hao Su
The Arched Flexure Vsa: A Compact Variable Stiffness Actuator With Large Stiffness Range, Joseph M. Schimmels, Daniel Garces
The Arched Flexure Vsa: A Compact Variable Stiffness Actuator With Large Stiffness Range, Joseph M. Schimmels, Daniel Garces
Mechanical Engineering Faculty Research and Publications
The high stiffness of conventional robots is beneficial in attaining highly accurate positioning in free space. High stiffness, however, limits a robot's ability to perform constrained manipulation. Because of the high stiffness, geometric conflict between the robot and task constraints during constrained manipulation can lead to excessive forces and task failure. Variable stiffness actuators can be used to adjust the stiffness of robot joints to allow high stiffness in unconstrained directions and low stiffness in constrained directions. Two important design criteria for variable stiffness actuation are a large range of stiffness and a compact size. A new design, the Arched …
Transparent Actuator Made With Few Layer Graphene Electrode And Dielectric Elastomer, For Variable Focus Lens, Taeseon Hwang, Hyeok-Yong Kwon, Joon-Suk Oh, Jung-Pyo Hong, Seung-Chul Hong, Youngkwan Lee, Hyouk Ryeo Choi, Kwang J. Kim, Mainul Hossain Bhuiya, Jae Do Nam
Transparent Actuator Made With Few Layer Graphene Electrode And Dielectric Elastomer, For Variable Focus Lens, Taeseon Hwang, Hyeok-Yong Kwon, Joon-Suk Oh, Jung-Pyo Hong, Seung-Chul Hong, Youngkwan Lee, Hyouk Ryeo Choi, Kwang J. Kim, Mainul Hossain Bhuiya, Jae Do Nam
Mechanical Engineering Faculty Research
A transparent dielectric elastomer actuator driven by few-layer-graphene (FLG) electrode was experimentally investigated. The electrodes were made of graphene, which was dispersed inN-methyl-pyrrolidone. The transparent actuator was fabricated from developed FLG electrodes.The FLG electrode with its sheet resistance of 0.45 kΩ/sq (80 nm thick) was implemented to mask silicone elastomer. The developed FLG-driven actuator exhibited an optical transparency of over 57% at a wavenumber of 600 nm and produced bending displacement performance ranging from 29 to 946 μm as functions of frequency and voltage. The focus variation was clearly demonstrated under actuation to study its application-feasibility in …
Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder
Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The Point-Collocation Non-intrusive Polynomial Chaos (NIPC) method has been applied to a stochastic synthetic jet actuator problem used as one of the test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. The test case included the simulation of an actuator generating a synthetic jet issued into quiescent air. The Point-Collocation NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field due to the uniformly distributed uncertainty introduced in the amplitude and frequency of …
Design And Validation Of A General Purpose Robotic Testing System For Musculoskeletal Applications, Lawrence D. Noble, Robb W. Colbrunn, Dong-Gil Lee, Antonie J. Van Den Bogert, Brian L. Davis
Design And Validation Of A General Purpose Robotic Testing System For Musculoskeletal Applications, Lawrence D. Noble, Robb W. Colbrunn, Dong-Gil Lee, Antonie J. Van Den Bogert, Brian L. Davis
Mechanical Engineering Faculty Publications
Orthopaedic research on in vitro forces applied to bones, tendons, and ligaments during joint loading has been difficult to perform because of limitations with existing robotic simulators in applying full-physiological loading to the joint under investigation in real time. The objectives of the current work are as follows: (1) describe the design of a musculoskeletal simulator developed to support in vitro testing of cadaveric joint systems, (2) provide component and system-level validation results, and (3) demonstrate the simulator’s usefulness for specific applications of the foot-ankle complex and knee. The musculoskeletal simulator allows researchers to simulate a variety of loading conditions …
System Design And Integration For Repeated Impact Tests, Cheng Lin, Gene Hou, Sebastian Bawab, Timothy Coats, Hesham Nassar
System Design And Integration For Repeated Impact Tests, Cheng Lin, Gene Hou, Sebastian Bawab, Timothy Coats, Hesham Nassar
Engineering Technology Faculty Publications
The design and integration of an impact-testing machine is particularly for the test of an object which is repeatedly dropped down from a specified height. Four linear actuators with two on each of the two magnetic rails are used to lift up an object weighing up to 70 lbs. Each actuator is powered and controlled by an industrial amplifier. A Programmable Logical Controller (PLC) is applied to activate these four actuators simultaneously and repeatedly. Accelerometers using an National Instruments (NI) data acquisition system are used to measure the impact force during the tests. Students gain design and implementation experiences from …
Optimal Control Of A Class Of One-Dimensional Nonlinear Distributed Parameter Systems With Discrete Actuators, Radhakant Padhi, S. N. Balakrishnan
Optimal Control Of A Class Of One-Dimensional Nonlinear Distributed Parameter Systems With Discrete Actuators, Radhakant Padhi, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Combining the principles of dynamic inversion and optimization theory, a new approach is presented for stable control of a class of one-dimensional nonlinear distributed parameter systems with a finite number of actuators in the spatial domain. Unlike the existing ''approximate-then-design'' and ''design-then-approximate'' techniques, this approach does not use any approximation either of the system dynamics or of the resulting controller. The formulation has more practical significance because one can implement a set of discrete controllers with relative ease. To demonstrate the potential of the proposed technique, a real-life temperature control problem for a heat transfer application is solved through simulations. …
Optimal Design Of Low Order Controllers Satisfying Sensitivity And Robustness Constraint, Mark L. Nagurka, O. Yaniv
Optimal Design Of Low Order Controllers Satisfying Sensitivity And Robustness Constraint, Mark L. Nagurka, O. Yaniv
Mechanical Engineering Faculty Research and Publications
The set of all stabilizing controllers of a given low order structure that guarantee specifications on the gain margin, phase margin and a bound on the sensitivity corresponds to a region in n-dimensional space defined by the coefficients of the controllers. For several practical criteria defined in the paper it is shown that the optimal controller lies on the surface of that region. Moreover, it is shown how to reduce that region to avoid actuator saturation during operation.