Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Article Citation - WoS: 17Citation - Scopus: 18Least Square Approximate Motion Generation Synthesis of Spherical Linkages by Using Chebyshev and Equal Spacing(Elsevier Ltd., 2013) Alizade, Rasim; Can, Fatih Cemal; Kilit, ÖzgürIn this paper, approximate motion synthesis of spherical linkages is presented. Rigid body guidance of a spherical four-bar mechanism is performed by a spherical RR open chain. In the first step, position of a point on rigid body and orientation of a rigid body on a unit sphere are described. Synthesizing function of spherical dyad is derived by means of using unit vectors that describe location of two revolute joints and tip point. Being based on the theory of function approximation and besides the linearization of nonlinear synthesis equations by using superposition method, the design procedure for real solutions of fourth order polynomial equation is developed. In the second step, approximate motion generation synthesis of spherical dyad is presented by using least-square approximation. Chebyshev spacing and equal spacing are used in the determination of poses. In the final step, two numerical examples are given to show how error graph is varied in terms of selected poses. The spherical motion generation synthesis of spherical four-bar mechanism is obtained by the combination of the two real solutions of the synthesis of two spherical dyads. © 2012 Elsevier Ltd.Article Citation - WoS: 15Citation - Scopus: 20Structural Synthesis of Euclidean Platform Robot Manipulators With Variable General Constraints(Elsevier Ltd., 2008) Alizade, Rasim; Can, Fatih Cemal; Gezgin, ErkinIn this paper, new method for structural synthesis of Euclidean platform robot manipulators with variable general constraints (EPRM) is presented. Three dimensional motion of the base moving platform is generated by the motion of dyads on the Euclidean planes. Each dyad is connected to the moving base platform by universal, spherical or spherical in torus (St) kinematic pairs. This allows solving the structural synthesis of Euclidean robot manipulators with various DoF and different platform motions. New structural formulations with variable general constraints for the platform motion and the mobility of robot manipulators are presented. The new structural classification of simple structural groups with variable general constraints including platforms, hinges, legs and branch loops from different subspaces and space is also introduced. Moreover, new method for structural synthesis of serial, parallel and serial-parallel EPRM is illustrated along with examples. © 2007 Elsevier Ltd. All rights reserved.Conference Object Citation - Scopus: 2Characterization of Swarm Behavior Through Pair-Wise Interactions by Tsallis Entropy(CSREA Press, 2005) Can, Fatih Cemal; Bayram, Çağdaş; Toksoy, Ahmet Kaan; Avşar, Hakan; Özdemir, SerhanThis paper tries to look at the interactions of a swarm of two at an elementary level. The change in the swarm entropy during the interactions is investigated. The characterization of swarm behavior has been subsumed in four modes, i.e. normal-free, normal-swarm, feeding and obstacle modes. Based on these modes, an entropy based algorithm is constructed to observe pair-wise interactions for each mode. For these modes, individuals of swarm are taken into account as self-driven interacting particles in the mathematical model. Statistical entropy definitions are used to control individual's behavior in feeding and obstacle modes. Individuals lose interactions enabling swarm behavior in feeding mode because of the priority of feeding for individuals as in nature. On the other hand, when swarm confronts an obstacle, individuals interact as much as they can. However they may lose interaction, depending on the size of the obstacle and position of the individuals. For feeding and obstacle modes, it is observed that Tsallis Entropy fits in the simulation better than other entropy definitions such as Shannon and Renyi.