Force Generation And Evaluations Of Virtual Hand Operations

How to evaluate the haptic authenticity of virtual hand operations is a public challenge in thehuman-machine interaction research field. In this paper, we carry out the experiment researchesto validity the physical-based virtual hand grasp force mathematic model. Combining the graspstability theory, we measure the grasp forces of human hand grasping objects, analyze themeasured data, evaluate the physical-based virtual hand grasp force mathematic model, anddevelop a prototype system to calculate the virtual hand grasp forces.The main contents of the paper are listed as follows:In chapter1, we introduce the necessary to research the virtual hand interaction with reliablehaptic perception, analyze the relative researches about the grasp force generation andevaluations of virtual hand operations, summary the achievements and defects of currentresearch results, propose our aims and contents to study the authenticity evaluations of virtualhand grasp forces.According to the relationships between force-closure and form-closure, we introduce theconceptions about the grasp stability for grasp planning in chapter2, and present a method tojudge the grasp stability of three fingers with force-closure.Experimental measurements of human hand grasp force are given in chapter3to validate thephysical-based virtual hand grasp force mathematic model. We build a human hand grasp forcemeasurement platform with the Tekscan Grip devices, design experimental contents, confirmexperimental steps, and seriously record the measured data of human hand grasp force. Themeasured data are detailedly analyzed in this paper with comparing the calculated values of thephysical-based virtual hand grasp force mathematic model, when the virtual hand grasps objectswith the corresponding operations of human hand. The compared results proof that thephysical-based virtual grasp force mathematic model is a reliable model to generate the vividgrasp force of virtual hand grasping objects.In chapter4, we further develop a prototype system, based on the physical-based virtual grasp force mathematic model, to calculate the virtual hand grasp force. The prototype systemincludes the grasped object mass solution module, inter-normal vector solution module of thegrasp points, grasp stability judgment module, and grasp force optimized solution module etc..This prototype system can calculate the grasp force for three fingers grasping objects withcylindrical or sphere forms.The conclusions of this paper and future works are listed in chapter5.