GCRIS

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Enhancing Earthquake Performance of Civil Structures Via Structural Control
(Izmir Institute of Technology, 2021) Şenol, Vedat; Turan, Gürsoy
In this study, two different benchmark buildings (3 and 20-story) are employed to attenuate structural responses under seismic disturbances. As control devices, active (actuators), semi-active (Magneto-rheological dampers), passive (Tuned mass dampers and Friction Pendulum Bearings), and hybrid controllers are utilized. The 3-story structure is modeled linearly and employed to apply to different control strategies. Some control algorithms: LQR, PDD-state-feedback, pole-placement, $H_{\infty}$, $ H_2 $, are used with active and semi-active control devices. As passive devices, TMDs and FPBSs are utilized on the nominal-linear model. Thereafter, hybrid controllers are employed: one composed of a TMD and actuator/MRD and one composed of an FPBS and actuator/MRD. A robust controller, $\mu$-synthesis, is employed to control the same linear structure having uncertainties in mass, stiffness, and damping matrices within reasonable ranges. A nonlinearly-modeled 20-story benchmark structure is employed to implement passive and hybrid control strategies. As passive devices, STMD and MTMD setups are employed. Further, a robust control algorithm is used through an actuator serially connected to the STMD. Subsequently, variations caused by nonlinearities are determined. These variations are regarded as uncertainties, and the $\mu$-synthesis is utilized in the design of a robust controller on a truncated linear model. Then, the designed robust control is employed to control the 20-story benchmark structure modeled nonlinearly. The structural responses in both frequency and time domains are discussed. Matlab, Python, and OpenSees framework (Tcl/Tk) were employed to realize all linear and nonlinear simulations throughout the study.
Control of Redundant Robot Manipulators With Telerobotic Applications
(Izmir Institute of Technology, 2016) Çetin, Kamil; Tatlıcıoğlu, Enver
This thesis focuses on task-space control of kinematically redundant robot manipulators with telerobotic applications. The first aim is to design asymptotically stable sub-task controllers for kinematically redundant robot manipulators subject to parametric uncertainties in their dynamics. Initially, a novel combined analysis of the task-space tracking and sub-task controllers is performed for redundant robots having only one extra degree of freedom. Next, an extended task-space controller is designed by integrating manipulator Jacobian with the sub-task Jacobian. Both controllers ensure task-space tracking and sub-task objectives at the amount of redundant degree of freedom. As the second aim, two robust control methods are proposed for task-space tracking of robot manipulators. First, a novel continuous robust controller is designed despite dynamic model and Jacobian uncertainties to ensure asymptotic task-space tracking while requiring measurements of joint positions and velocities. Then, a robust output feedback controller is proposed to ensure ultimately bounded task-space tracking requiring neither measurements of joint positions or velocities nor accurate knowledge of kinematic and dynamic models. The third aim is to develop a passive decomposition method for task-space control of bilateral teleoperation systems. The proposed method ensures coordination of master and slave robots while achieving a desired overall motion for the bilateral teleoperation system. The proposed method is firstly considered for teleoperation systems consisting of kinematically similar master and slave robots, then extended to be applicable to kinematically redundant teleoperation systems. Simulation and experimental studies are performed to present the viability of the proposed methods.
Robust Control Design for Mechatronic Systems Having Non-Symmetric Input Gain Matrix
(Izmir Institute of Technology, 2016) Bıdıklı, Barış; Tatlıcıoğlu, Enver
Their highly uncertain and complex structures make the control problem of mechatronic systems a challenging task. This problem becomes more challenging when some special cases that make the input gain matrix of these systems non–symmetric are taken into account. Solving this problem is the main motivation of this dissertation. To realize this purpose, a robust controller that is independent from the structure of the input gain matrix is designed. Since, mechatronic systems are modeled as multi–input multi–output nonlinear systems, this design is realized for a broader class of these type of systems. Asymptotic stability of the designed controller is proven via Lyapunov–based arguments. Since, control gain adjusting process is one of the most restrictive and most important aspects of this design, designed controller is supported by proposing a self–tuning method. After completing the control design process by proposing this self–tuning method, three fundamentally different mechatronic systems are utilized to demonstrate the effectiveness of the designed controller in conjunction with the proposed self–tuning method. Position and orientation control of dynamically positioned surface vessel and unactuated surface vessel manipulated by 6 uni–directional tugboats under the influence of added mass effects, and attitude control of small–scaled unmanned helicopter are ensured by utilizing a lower order version of the designed controller. Each of these mechatronic systems constitutes an example of different cases that make input gain matrix non–symmetric. Performance of the designed controller and proposed self–tuning method are demonstrated via simulations and experiments.

Phd Degree / Doktora

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