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The Haptic device is capable of interacting dynamically with the operator by the forces it can exert on human's hand. Controlling the haptic device and constraining it through the desired trajectory is the common task in the most of the training systems. Haptic interface application in virtual Persian handwriting learning system is investigated in this paper. Two different modes of learning is investigated: The full guidance mode, guides the user to follow a prerecorded trajectory by applying proper force to operator's hand; whereas in partial guidance, combination of haptics andvisual feedback guides the operator and prevents deviation from the desired trajectory. © 2009 IEEE  

Proper modeling of the human arm dynamic, as it interacts with telemanipulation and haptic systems, is important in enhancing the transparency of these systems. In this article, we introduced an adaptive identifier to estimate the impedance characteristic of a human operator as it interacts with a single translational degree of freedom mechanism. The five parameter model, including an extra spring and damper for a better approximation of the dynamic behavior of human arm, has been used. Since the impedance characteristic of human arm differs from one individual to another, it is important to estimate these parameters for each individual and update the controller to enhance the transparency... 

Tactile sense is a key element in developing virtual reality simulators or surgical training systems. In this regard, haptic interfaces, the generator of a sense of touch, play a significant role in producing a realistic haptic feedback force. Since the majority of practical control theories are model-based, the identification of the robot dynamic model is a process of high importance and application. The main concern, accordingly, is to find a precise dynamic model for the aforementioned user interfaces. In this research, we have implemented the Lion identification method to characterize the dynamics of a parallel haptic device in actuating a surgery simulation. We chose the Novint Falcon... 

For simulating the surgical procedures in a virtual environment, it is necessary to propose a suitable virtual environment model which can reflect the real physical tool-tissue interaction behavior and a proper human user interface appropriate dynamic model. In this study, a linear Kelvin-Voigt and a nonlinear Hunt-Crossley models have been utilized to describe human hand dynamics during interaction with a haptic interface. Using the Lyapunov stability criteria, an adaptive neural network based controller being designed for guaranteeing the stability of the entire system, considering a nonlinear model for the environment, an inertia for a virtual tool, a constant time delay for data... 

Haptic interfaces, a kinesthetic link between a virtual environment and a human operator play a pivotal role in the reproduction of realistic haptic force feedback of the virtual reality-based simulators. Since most of the practical control theories are model-based, the identification of the robot’s dynamics, for precise modeling of the system dynamics, is a process of high significance and usage. This research addresses dynamic characterization, performance issues, and structural stability, associated with a parallel haptic device interaction with an admittance type virtual environment. In this regard, considering the Lion identification scheme, we characterized the dynamics of a robot... 

Purpose - This paper aims to present the design and implementation of VirSense, a novel six-DOF haptic interface system, with an emphasis on its gravity compensation and fixed-base motors. Design/methodology/approach - In this paper, the design and manufacture of the VirSense robot and its comparison with the existing haptic devices are presented. The kinematic analysis of the robot, design of the components, and manufacturing of the robot are explained as well. Findings - The proposed system is employed to generate a Virtual Sense (VirSense) with fixed-base motors and a spring compensation system for counterbalancing the torques generated by the weight of the links. The fixed bases of the... 

Transparency is a measure of performance in haptic devices. In order to improve transparency and reduce the difference between the impedance transmitted to the user and the target impedance it is necessary to compensate for the dynamics of the haptic device. Due to stability reasons improvement of transparency is limited. Passivity as a stability criterion has been used widely in design and analysis of haptic devices, Since passivity is a conservative criterion, it acts as an obstacle in improving transparency of the haptic interfaces. In this paper instead of passivity, robust stability of the interaction is studied in the presence of parametric uncertainties due to variations in user hand... 

In this article, a nonlinear adaptive impedance control strategy is proposed to adjust the impedance of a one-degree of freedom Falcon robot to a pre-defined nonlinear impedance which is an approximate mathematical representation of the sino-nasal tissue. Further developments can be used for a training simulator system for the otolaryngology surgery training purposes. The stability of the proposed control strategy and convergence of tracking error are proved by using Lyapunov Stability Theorem. Two different scenarios are considered for simulation studies including a declining contact force and also an oscillatory contact force between the user hand and the haptic interface device....