Dangxiao Wang

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Six-degree-of-freedom (6-DOF) haptic rendering for fine manipulation in narrow space is a challenging topic because of frequent constraint changes caused by small tool movement and the requirement to preserve the feel of fine-features of objects. In this paper, we introduce a configuration-based constrained optimization method for solving this rendering(More)
It is difficult to implement a stable and realistic haptic simulation for cutting rigid objects that is based on a damping model because of an inevitable conflict between stability and high output force. This paper presents pas-sivity techniques to show that an excessive damping coefficient causes the output stiffness to exceed the maximum output stiffness(More)
In this paper, we present the methods to generate a stable and realistic simulator for dental surgery. Firstly, a simplified force model is derived from grinding theory by considering the complex bur shape and dental handpiece's dynamic behavior. While the force model can be evaluated very fast to fulfill the high update rate of haptic rendering, it also(More)
Performance evaluation is indispensable for a surgical simulator to become acceptable. A haptics-based dental simulator (iDental) has been developed and preliminary user evaluation on its first-generation prototype has been carried out to gain the knowledge. Based on detailed requirement analysis of Periodontics procedures, a combined evaluation method(More)
Piecewise linear polygonal model has only G 0 continuity, thus users can easily feel the edges when using haptic device to touch a solid represented by coarse polygonal meshes. To produce an appealing haptic sensation for smooth solids, a large number of polygons are needed in conventional approaches. This, however, slows down computation and consumes much(More)
Consistency between haptic display and visual display is an important requirement to construct high fidelity virtual reality systems. Spatial registration method for accurate collocated haptic-visual display based on half-silvered mirror is proposed in this paper. The registration accuracy is defined to be the distance between the virtual avatar and the(More)
—Virtual stiffness is a critical performance measure for haptic devices. This paper proposes a new controller to increase the virtual stiffness. The design of the controller is based on theoretical analysis of the system stability condition, which indicates that by adding a current closed loop the stability can be increased. We implemented the current(More)