Browsing by Author "Ider, S. Kemal"

Now showing 1 - 4 of 4

Citation - WoS: 1
Citation - Scopus: 1
Dynamic Analysis and Design Optimisation of a Heavy Military Vehicle
(inderscience Enterprises Ltd, 2021) Acar, Bulent; Ider, S. Kemal; Cicek, Burak Can; 108608
This paper investigates the dynamic response of a heavy military vehicle which is subjected to a dynamic firing load while it is settled on its outriggers. Dynamic behaviour of a settled heavy military vehicle under a dynamic firing load is one of the major design factors of a launching vehicle. Two different finite element (FE) models are created in ANSYS software to obtain the dynamic behaviour of the launching vehicle. The first model is a detailed finite element model (DFEM) and the second model is a simple and less degree of freedom (DOF) parametric FE model which is created with the ANSYS Parametric Design Language (APDL) in order to perform the design optimisation by swiftly varying the parameters such as clamp attachment positions on the chassis, outrigger deployment and outrigger case cross section.
Citation - WoS: 4
Citation - Scopus: 4
Hybrid Force and Motion Control of Flexible Joint Parallel Manipulators Using Inverse Dynamics Approach
(Taylor & Francis Ltd, 2014) Ider, S. Kemal; Korkmaz, Ozan; 108608
An inverse dynamics control algorithm is developed for hybrid motion and contact force trajectory tracking control of flexible joint parallel manipulators. First, an open-tree structure is considered by the disconnection of adequate number of unactuated joints. The loop closure constraint equations are then included. Elimination of the joint reaction forces and the other intermediate variables yield a fourth-order relation between the actuator torques and the end-effector position and contact force variables, showing that the control torques do not have an instantaneous effect on the end-effector contact forces and accelerations because of the flexibility. The proposed control law provides simultaneous and asymptotically stable control of the end-effector contact forces and the motion along the constraint surfaces by utilizing the feedback of positions and velocities of the actuated joints and rotors. A two degree of freedom planar parallel manipulator is considered as an example to illustrate the effectiveness of the method.
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) Ider, S. Kemal; Ozgoren, M. Kemal; Korkmaz, Ozan; 108608; 7866
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.