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In this study, it was aimed to determine the forces and torques acting on the shoulder and elbow joints of the upper limbs, which are the most commonly used body parts in daily life. The subject was asked to take a certain load on the table while standing upright, bring him closer to himself and leave it back. A dynamic model was created using the Newton-Euler method to determine the joint force and torque occurring in the shoulder and elbow during the movements performed by the selected subject while performing this task. Wearable motion sensors were used to measure the location data of the joints. The torque and link force values in the joints were calculated using the dynamic model created with the motion data received from these sensors. The calculation results obtained were evaluated comparatively and it was revealed in which cases the forces and torques acting on the joints increased and what measures could be reduced. [ABSTRACT FROM AUTHOR]

This paper is concerned with compliant haptic contact and deformation of soft objects. A human soft fingertip model is considered to act as the haptic interface and is brought into contact with and deforms a discrete surface. A nonlinear constitutive law is developed in predicting normal forces and, for the haptic display of surface texture, motions along the surface are also resisted at various rates by accounting for dynamic Lund-Grenoble (LuGre) frictional forces. For the soft fingertip to apply forces over an area larger than a point, normal and frictional forces are distributed around the soft fingertip contact location on the deforming surface. The distribution is realized based on a kernel smoothing function and by a nonlinear springdamper net around the contact point. Experiments conducted demonstrate the accuracy and effectiveness of our approach in real-time haptic rendering of a kidney surface. The resistive (interaction) forces are applied at the user fingertip bone edge. A 3-DoF parallel robotic manipulator equipped with a constraint based controller is used for the implementation. By rendering forces both in lateral and normal directions, the designed haptic interface system allows the user to realistically feel both the geometrical and mechanical (nonlinear) properties of the deforming kidney. [ABSTRACT FROM AUTHOR]

This article is concerned with the haptic deformation display of discrete viscoelastic surfaces by means of a human fingertip. The virtual surface of a deformable quadrilateral mesh is interactively deformed by a Kelvin–Voigt soft fingertip model attached to the end-effector of a haptic interface device. In achieving this task, a nonlinear constitutive model approximating experimental data from literature is developed for determining the contact point deformations. By employing a new kernel weighting function, the deformations are distributed dependently on the discrete surface topology based on a nonlinear spring–damper net around the contact location. For illustration and evaluation of the proposed approach, a parallel robotic device with a constraint-based controller is adopted. The grip of the device is moved by the user to feel a sense of touch as the soft fingertip deforms the mesh surface of an ex vivo porcine liver tissue. Experimental data indicates stable realistic interactions thorough mechanical coupling between the soft fingertip and the deforming liver tissue. Dynamic response data of liver show rate-dependent hysteretic deformations and match closely with experimental indentation data from literature. A thorough analysis of mesh node count on the sample rate and the rendering quality is also presented. [ABSTRACT FROM PUBLISHER]

In this article, a constraint-based controller is developed for two-manifold oriented viscoelastic surfaces that guarantees smooth and compliant haptic rendering. The approach is direct and uses a pseudo-inverse projection of the haptic device end effector onto the virtual surface. The rendering algorithm enables the user to freely move a soft fingertip model along a highly curved deformable surface and perceive surface roughness in the normal direction by feeling a nonlinear contact force. The normal force is governed by a physically based three-dimensional constitutive model, which accounts for both geometric and material nonlinearities. In experimental implementation, the soft fingertip model acts as the compliant haptic interface (robot) and the user manually guides the manipulator to explore the deformable surface properties in real time. The (nonlinear) reaction force normal to the surface is applied at the soft fingertip edge of the fingertip bone (distal phalanx). The robustness of the approach is illustrated by experimental data in rendering highly curved compliant surfaces. [ABSTRACT FROM AUTHOR]

In this study, Undergraduate Education Program and Mechanical Engineering Education in the USA are emphasized. Some universities of U.S.A. are investigated, compared with the Undergraduate Curriculum of universities in Turkey and then the differences are evaluated. While comparing, courses are collected in four main categories which are Basic Sciences, Engineering Sciences, Mechanical Engineering and Social Sciences. Total credits of courses in each category arc compared for the mentioned countries. At the end of the examination, the largest difference is determined in the total credits of Social Sciences. [ABSTRACT FROM AUTHOR]