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Articles 1 - 11 of 11
Full-Text Articles in Engineering
Analysis Of Blood Pressure Waveform For Detection And Diagnosis Of Cardiovascular Anomalies, Atul Shrotriya
Analysis Of Blood Pressure Waveform For Detection And Diagnosis Of Cardiovascular Anomalies, Atul Shrotriya
Mechanical and Aerospace Engineering Theses
Cardiovascular diseases are the leading cause of mortalities worldwide as well as in the United States. Early diagnosis and prediction of these diseases is critical to mitigate the risks to the patient. A common method to assess a person’s heart health is through the use of cuff type oscillometric devices placed on the arm of the patient. As the mean pressure in the cuff is increased the blood flow in the brachial artery becomes blocked. When the cuff pressure is reduced the blood starts flowing again; during this cycle, pressure fluctuations in the cuff are measured using a pressure transducer. …
Flutter Suppression By Active Controller Of A Two-Dimensional Wing With A Flap, Abdallah Tarabulsi
Flutter Suppression By Active Controller Of A Two-Dimensional Wing With A Flap, Abdallah Tarabulsi
Theses
Flutter is a divergent oscillation of an aeroelastic structure, and one of a family of aeroelastic instability phenomena, that results from the interaction of elastic and inertial forces of the structure with the surrounding aerodynamic forces. Airfoil Flutter is important due to its catastrophic effect on the durability and operational safety of the structure. Traditionally, flutter is prevented within an aircraft's flight envelope using passive approaches such as optimizing stiffness distribution, mass balancing, or modifying geometry during the design phase. Although these methods are effective but they led to heavier airfoil designs. On the other hand, active control methods allow …
Optimal Tracking In Switched Systems With Free Final Time And Fixed Mode Sequence Using Approximate Dynamic Programming, Tohid Sardarmehni, Xingyong Song
Optimal Tracking In Switched Systems With Free Final Time And Fixed Mode Sequence Using Approximate Dynamic Programming, Tohid Sardarmehni, Xingyong Song
Mechanical Engineering Faculty Publications and Presentations
Optimal tracking in switched systems with fixed mode sequence and free final time is studied in this article. In the optimal control problem formulation, the switching times and the final time are treated as parameters. For solving the optimal control problem, approximate dynamic programming (ADP) is used. The ADP solution uses an inner loop to converge to the optimal policy at each time step. In order to decrease the computational burden of the solution, a new method is introduced, which uses evolving suboptimal policies (not the optimal policies), to learn the optimal solution. The effectiveness of the proposed solutions is …
A Real-Time Algorithm To Achieve Precise Coordinated Arrival Times In A Time-Variant Environment, Shawn S. Stephens
A Real-Time Algorithm To Achieve Precise Coordinated Arrival Times In A Time-Variant Environment, Shawn S. Stephens
Theses and Dissertations
The coordinated arrival time problem seeks to control a vehicle's trajectory to achieve some pre-defined final state at a desired arrival time. The persistent monitoring problem is a type of coordinated arrival problem where a stationary or moving ground target must be constantly observed by a group of aircraft. This research simplifies the problem to overfly the target at specific time intervals relative to the other aircraft in the group while increasing the difficulty of the problem by considering aircraft traveling at vastly different airspeeds. The result of this research is a real time guidance algorithm which accurately guides a …
Exact And Approximate Relaxation Techniques For Computational Guidance, Sheril Avikkal Kunhippurayil
Exact And Approximate Relaxation Techniques For Computational Guidance, Sheril Avikkal Kunhippurayil
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The focus of this dissertation is in the development and application of relaxation techniques that enable efficient and real-time solution of complex computational guidance problems. Relaxations transform a non-convex constraint into a convex constraint and provides proof that the optimal solutions to the relaxed problem are optimal for the original problem. Unique contributions of this work include: 1) a relaxation technique for solving fixed final time problems between fixed points, 2) a performance analysis on the application of computational guidance for the Mars Ascent Vehicle, and 3) establishment of sufficient conditions for non-singularity of optimal control for problems on a …
Centralized And Decentralized Optimal Control Of Variable Speed Heat Pumps, Ryan S. Montrose, John F. Gardner, Aykut C. Satici
Centralized And Decentralized Optimal Control Of Variable Speed Heat Pumps, Ryan S. Montrose, John F. Gardner, Aykut C. Satici
Mechanical and Biomedical Engineering Faculty Publications and Presentations
Utility service providers are often challenged with the synchronization of thermostatically controlled loads. Load synchronization, as a result of naturally occurring and demand-response events, has the potential to damage power distribution equipment. Because thermostatically controlled loads constitute most of the power consumed by the grid at any given time, the proper control of such devices can lead to significant energy savings and improved grid stability. The contribution of this paper is the development of an optimal control algorithm for commonly used variable speed heat pumps. By means of selective peer-to-peer communication, our control architecture allows for the regulation of home …
Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell
Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell
Theses and Dissertations
The evolving space environment has created a demand for autonomous spacecraft that can maneuver in complex and sometimes contentious environments. Constraint enforcement, such as an avoidance zone to prevent collision with a target, is a key component of autonomous control to ensure safety and performance requirements are met. Finite-horizon Model Predictive Control (MPC) is a popular control method due to its improved computation time while optimizing performance. Two areas of MPC in need of expansion are time-varying constraints and phase transitions in multi-phase applications. In this work, MPC is employed to track the reference trajectory of a multi-phase satellite inspection …
Applied Reachability Analysis For Time-Optimal Spacecraft Attitude Reorientations, Layne C. Barrett
Applied Reachability Analysis For Time-Optimal Spacecraft Attitude Reorientations, Layne C. Barrett
Theses and Dissertations
Satellite attitude reorientation has been of significant interest in astronautical engineering, and being able to reorient in a time-optimal manner has been of exceeding interest since the 1970s. Ensuring a spacecraft mission set can be conducted within a certain amount of time begs the question of whether or not a certain maneuver can be completed with a bounded control. This thesis answers that question by using the concept of reachability to provide reachable sets for different spacecraft reorientation scenarios. The reachable sets generated provide a range of initial states that guarantee a satellite reach a desired end orientation given a …
Simulation Of Energy Optimization For Cooling Coil In Central Air-Conditioning System, Qinglong Meng, Xiuying Yan
Simulation Of Energy Optimization For Cooling Coil In Central Air-Conditioning System, Qinglong Meng, Xiuying Yan
Journal of System Simulation
Abstract: The optimized control of minimizing energy consumption in one air-conditioning system was studied. The main models that needed in the simulation software HVACSIM+ for air handling unit were introduced. The AHU and rooms of the first floor of certain Building were taken as the simulation target. Then the function describing the relation between the consumption of cooling coil and the chilled water velocity was found and taken as the objective function. With improved cyclic variable method, the controller^ parameters were optimized. Results show that the simulation system runs steadily while the controller works with the optimal parameters, and the …
Power-Based Modelling And Control: Experimental Results On A Cart-Pole Doubleinverted Pendulum, Tuğçe Yaren, Selçuk Ki̇zi̇r
Power-Based Modelling And Control: Experimental Results On A Cart-Pole Doubleinverted Pendulum, Tuğçe Yaren, Selçuk Ki̇zi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
This paper is concerned with the modeling framework based on power and control for a mechanical system that has nonlinear, unstable, and under-actuated characteristic features, based on an analogy, which is developed by using the Brayton and Moser's (BM) equations between mechanical and electrical systems. The analogy is based on a mixed-potential function generalized for BM. The mixed-potential function for a cart - pole double inverted pendulum (CPDIP) system is used as a new building block for modeling, analysis, and controller design. The analogy allows for the exact transfer of results from electrical circuit synthesis and analysis to the mechanical …
Constrained Discrete-Time Optimal Control Of Uncertain Systems With Adaptivelyapunov Redesign, Oğuz Han Altintaş, Ali̇ Emre Turgut
Constrained Discrete-Time Optimal Control Of Uncertain Systems With Adaptivelyapunov Redesign, Oğuz Han Altintaş, Ali̇ Emre Turgut
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the conventional estimation-based receding horizon control paradigm is enhanced by using functional approximation, the adaptive modifications on state estimation and convex projection notion from optimization theory. The mathematical formalism of parameter adaptation and uncertainty estimation procedure are based on the redesign of optimal state estimation in discrete-time. By using Lyapunov stability theory, it is shown that the online approximation of uncertainties acting on both physical system and state estimator can be obtained. Moreover, the convergence criteria for online parameter adaptation with fully matched and partially matched cases are presented and shown. In addition, it is shown that …