Design Of Soft Anthropomorphic Manipulator

The software anthropomorphic robot designed and produced in this paper,comparing with human hands has a ratio of 1.2:1,which mainly includes two types of fingers,a thumb and the other four-finger.The other four-fingers have three knuckles,which are divided by some horizontally small air chambers,and composed of three layers of silica gel to form two air chambers.a curved chamber and a variable stiffness chamber.The curved chamber controls the bending of the soft finger.The stiffness chamber controls the stiffness of the soft finger.The design of the thumb is roughly the same as that of the other four fingers,but the thumb has only two knuckles.The distribution of the air chamber on the curved layer is different from the horizontal distribution of the other four fingers,but it is inclined at 30 degrees to the radial direction of the finger,it makes the thumb bends while achieving a certain angle of the side swing,imitating the grasping action of the human's thumb.In order to obtain the best gripping effect of the soft anthropomorphic robot,through finite element analysis,the geometric parameters of soft finger are optimized and the material is selected.Under the premise of other parameters are unchanged,the comparative finite element analysis were carried out by designing curved air chamber models with different wall thicknesses.After considering the practical application,acquired the optimal wall thickness of the fingers;The different radius curved chamber is designed to carry on the contrast finite element analysis.We also obtained the optimal radius value;The mechanical properties of each silica gel material were obtained by tensile test,and the mechanical properties of each material were used for comparative finite element analysis to determine the optimum mixing ratio.In the soft anthropomorphic robotic hand grabbing experiment,the relationship between the soft finger finger joint angle and the air pressure in the finite element analysis was verified.The experimental platform was built to measure the relationship between the soft finger fingertip's pressure and the air pressure.Designing experiments verified soft finger stiffness changes effected on grabbing weight.The grabbing experiment of the soft anthropomorphic robotic hand was carried out,and some conclusions were drawn: the soft body is very suitable for grabbing the cylindrical objects because of its own characteristics;The soft body can grasp the shape of the object according to the shape of the object itself,when grasping the non-cylindrical body.In the grabbing experiment,we also obtained the effective range of the grasping object diameter of the soft body,and made an experimental comparison under different stiffness of the soft anthropomorphic robot hand.