Browsing by Author "Ozgoren, M. Kemal"

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Citation - WoS: 1
Citation - Scopus: 1
Motion Control of a Spatial Elastic Manipulator in the Presence of Measurement Noises
(Springer Heidelberg, 2021) Kilicaslan, Sinan; Ider, S. Kemal; Ozgoren, M. Kemal; 108608
This paper presents a method for the end effector motion control of a spatial three-link robot having elastic second and third links including measurement noises. In the derivation of equations of motion, not to face with complex equations of motion, each link is modeled as though the links are not connected and the restrictions on the links due to connecting them by joints are written as constraint equations. After that the Lagrange multipliers are eliminated and the constraint equations at the acceleration level are substituted into the equations of motion to reduce the number of equations. To handle the non-minimum phase property, the equations of motion of the elastic manipulator are divided as the equations corresponding to a pseudostatic equilibrium and the equations of the deviations from them. Definition of the pseudostatic equilibrium used in this study can be given as a hypothetical state in which the end effector velocity and the end effector acceleration possess their reference values while the elastic deflections are instantly constant. The advantages of this control method are that the elastic deflections and the control inputs required for the pseudostatic equilibrium are obtained by an algebraic method and the feedback stabilization control inputs for the deviation equations are determined without linearizing the dynamic equations. The required measurements are obtained from the strain gauges on the links, the encoders placed on the joints and the position sensors attached to the end effector. For each sensor, a low pass filter is used. Simulations are made with low and high values of crossover frequencies to show the positive and negative effects of filtering on the responses of the system.
Citation - WoS: 12
Citation - Scopus: 17
Trajectory tracking control of an underactuated underwater vehicle redundant manipulator system
(Wiley, 2016) Korkmaz, Ozan; İder, Sıtkı Kemal; Ider, S. Kemal; Ozgoren, M. Kemal; 108608; 7866; Makine Mühendisliği
The purpose of this study is to control the position of an underactuated underwater vehicle manipulator system (U-UVMS). It is possible to control the end-effector using a regular 6-DOF manipulator despite the undesired displacements of the underactuated vehicle within a certain range. However, in this study an 8-DOF redundant manipulator is used in order to increase the positioning accuracy of the end-effector. The redundancy is resolved according to the criterion of minimal vehicle and joint motions. The underactuated underwater vehicle redundant manipulator system is modeled including the hydrodynamic forces for the manipulator in addition to those for the autonomous underwater vehicle (AUV). The shadowing effects of the bodies on each other are also taken into account when computing the hydrodynamic forces. The Newton-Euler formulation is used to derive the system equations of motion including the thruster dynamics. In order to establish the endeffector trajectory tracking control of the system, an inverse dynamics control law is formulated. The effectiveness of the control law even in the presence of parameter uncertainties and disturbing ocean currents is illustrated by simulations.