Research On The Construction And Performance Of Soft Dexterous Hands

Soft robots have expanded the research field that traditional rigid robots have not arrived,and have become a hot spot in robot research.The soft dexterous hand is the end executor of the operational soft robots.Based on the research of new materials and new processes,it is also rapidly developing as a new research direction.The soft dexterous hand is different from the traditional manipulator,and the flexible material is used as their main structure.According to the different materials,the corresponding new driving method is selected.The flexible material itself has the characteristics of changing shape according to the environment,and the structural features are given according to bionics,thus the soft dexterous hand is flexible,light and safe.In this paper,flexible pneumatic actuators made of silica gel is constructed.And a soft dexterous hand system is established upon the actuators,which can get stable performance and long service life.The main research and achievements are as follows:(1)According to the principle of actuation,four flexible pneumatic actuators are designed,which are elongated,one-way bending,two-way bending and omnidirectional bending actuators.The relationship between the deformation elongation or bending angle and the ventilation is analyzed.The trajectories of the end of each actuator are drew by MATLAB,and the feasibility of their actuation is verified with ABAQUS simulation.(2)The soft dexterous hand system is constructed,which mainly includes smart fingers,support mechanism and pneumatic control system etc..The molds of actuators and the support mechanism are designed.The molding process of soft dexterous hand was also introduced.The DH coordinate matrix transformation is used to calculate the spatial location of joints of smart fingers.The three-finger soft dexterous hand prototype is completed,and its grasping test has been done.(3)For the problem of low output force,it is proposed to change the actuator stiffness with embedded variable stiffness structure.The shape memory polymer is used and the processing method of blend polymer mixed by PLA and TPU is studied.The shape memory effect and mechanical properties of the outcome is characterized.(4)With ABAQUS simulation method,the bending angle and end contact force of the one-way bending actuators embedded with SMP of different thicknesses is analyzed.The actuator prototype is tested and to be found feasible and effective.