No abstract

Periyodik bakım ve arıza/hasar tespiti genellikle bakım personeli tarafından manuel olarak gerçekleştirilmektedir. Arızanın tespiti için sadece gözlemin yeterli olduğu bazı durumlar olmasına rağmen genellikle ölçüme de ihtiyaç duyulmaktadır. Diğer taraftan arızanın giderilmesi için de birçok durumda yine bakım personelinin doğrudan müdahalesine ihtiyaç duyulmaktadır. Bakım personelinin gerçekleştirdiği faaliyetlerin tümünün robotlara devredilmesi günümüz teknolojisinde henüz mümkün değildir. Bu nedenle günümüzde bakım, arıza tespiti ve onarımda kullanılan robotlar daha çok bakım personellerine yardımcı ekipmanlar olarak görülmektedir. Her türlü bakım ihtiyacı için kullanılabilecek tek bir robot olmadığından, birçok uygulama görev tabanlı robotları gerektirir. Bu çalışmada robotik bakım uygulamaları ve sağladığı avantajlar değerlendirilmiştir.

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.

No abstract

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.