| With the gradually mature of robot technology and the popularity of applications in various industries,"Robots instead of human" has become the realistic choice of textile and garment industry.At present,many robots have appeared gradually in the textile and garment industry.However,because of the pile shape of flexible fabric is inconclusive.There are still some technical difficulties for robots used in fabric grasp handle,which limits its application.Dexterous hand is the robot end-effector that can be directly action on the environment and has a high degree of flexibility,which can be achieved grasping arbitrary shape object through the reasonable planning.Therefore,the purpose of this paper research is based on grasping planning and design of dexterous robot hand to achieve grasping fabric.The subject is carried on in-depth research and analysis in this paper.Firstly,the structure of multi-finger dexterous hand with three fingers is designed by combining with the features of fabric and the characteristics of dexterous hand.Each finger has four degrees of freedom and its structure and properties are similar,and conducting obverse and inverse kinematics analysis,then,kinematics model of dexterous hand is established by using D-H parameter method describe homogeneous coordinates transformation relation of fingers' connecting rod,fianily,we can get the location and gesture matrix of the top of the finger.Meanwhile,the dynamics of dexterous hand is analyzed.The reliability of the kinematic model is verified by using the MATLAB simulation soft-ware,and the finger space has carried on simulation analysis.Secondly,through the analysis of the motion path of dexterous hand grasp fabric,motion trajectory planning is completed.The joint space trajectory planning and Cartesian space trajectory planning are combined to assurance the dexterous hand fingers can accurately reach to the grasp point.Five times polynomial planning algorithm in joint space is used from initial point of fingers to close to the fabric.Linear interpolation planning algorithm in Cartesian space is used from closer to the fabric to grasp point.At last,the accuracy and reliability of trajectory planning are verified by simulation software.Thirdly,the realization of autonomous grasp planning for fabric is researched.By identifying the fabric's geometric feature and according to the requirements of the grasp tasks,grasp model classification is built without considering grasping force,and grasp model classification is based on RBF neural network algorithm to realize fabric grasp planning.Then,the grasp force planning of dexterous hand is analyzed,and discussing the optimal grasping planning.Finally,on the basis of the previous study,the accuracy problems of dexterous hand fabric grasp is analyzed.The method of kinematics calibration is used to improve the accuracy of dexterous hand grasping and puts forward a kinematics calibration method based on a virtual closed kinematic chain.In addition,based on visual direction of dexterous hand grasping location technology has carried on brief discussion and study.There are 87 figures,3 tables and 70 references in this paper. |
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