H. Mutlu

A Novel Approach in the Direct Kinematics of Stewart Platform Mechanisms with Planar Platforms

In handling the kinematic analysis of two rigid bodies connected to each other by six legs through the use of six double spherical joints, methods have been implemented both in the formulation and solution phases of the problem. A three-dimensional problem has been viewed, in fact, as a multitude of two-dimensional works on several planes, the intersections of which yield relationships allowing transition between adjacent planes. Thus formulation is purely based on the geometric structure consisting of eight planes of interest, ending in the three fundamental equations involving three angles between the base and side triangular planes. In solving the resulting three equations, an efficient strategy has been established to come up with 16 solution sets effectively. Extensions of the theory have been shown to include the analyses of other Stewart platform models. Efficiency and effectiveness of the approach has been verified on numerical examples.

Displacement Analysis of Robotic Frames for Reliable and Versatile Use as External Fixator

External fixators are widely used in the area of orthopedics to manage deformities and fractures. The historical trend in obtaining a mechanical infrastructure has shifted from simple devices like pins, rods, and hinges to more sophisticated frames involving parallel manipulators. Despite advantages of such robotic frames especially in removing stiffness issues, there are still problems associated with the reliable deployment of these modern devices. Problems like singularity, possibilities of guiding fragments along many different trajectories have been handled in this paper. A method has been shown how to detect singularity in displaced, aligned, and intermediate positions of the fragments. How the robotic system could be actuated according to different functions have been investigated, in addition to their effects on trajectories of distal fragment end. These considerations have been demonstrated on numerical examples.

MOBİLYA ENDÜSTRİSİ İÇİN YENİ KANEPE YATAK MEKANİZMASI SİSTEMİ

Mobilya sektorunde bugun ergonomiyi ve insan konforunu gelistiren calismalar giderek artiyor. Buna ek olarak, yaygin olarak uretilen oturma ve yatak gruplarinda kullanilan mekanizma sistemlerinin mevcut durumunun gelistirilmesi, her gecen gun guclenmektedir. Arzulanan fonksiyonu saglayan mekanizmalarin tasarimi, mekanizmalarin kinematik sentezi icerisinde degerlendirilir. Mekanizmalarin kinematik sentezi, fonksiyon, yorunge ve hareket sentezi olmak uzere uc ana kategoride incelenmektedir. Mekanik sistemleri hareket ettirirken istenen yorungeyi takip etmesi, mekanik sistemlerin hareketi sirasinda arzu edilen konum ve alan-hacim kullanimi optimum olmasi beklenmektedir. Bu gereksinimleri saglayan mekanizmalar sayesinde, makine, alet vb. kaliteleri artacaktir. Bu calismada, mobilya sektorunde kullanilan acma ve kapama sistemlerinin iyilestirilmesi amaciyla, bu parcalarin hareketi sirasinda alanin ve hacmin en uygun sekilde kullanilmasini saglamak icin bir mekanizma sistemi tasarlanmis ve sanal prototipleri gerceklestirilmistir.

Singularity analysis of a fixator by closest points approach

External fixators are robotic devices widely used in orthopaedics. While bringing the bone fragments to a desired position, these devices should not present any threat to the patient health. One of the threat causes is singularity. In a singular position, stable structure of the fixator is lost and its top and bottom rings may move independently. In this work, singularity analysis is performed with a geometric method, closest points approach. It has been shown that results of this approach are consistent with the other singularity analysis methods.