| With the development of robot technology and the emergence of artificial intelligence technology,the application of robots is gradually extended to lots of fields.However,it also confronts problems like the complex and changeable operating environment and complicated types of objects.Therefore,the requirement of the adaptative performance of robots is getting higher than before.Recent years,advances in soft robotics,materials science,and stretchable electronics have enabled rapid progress in soft grippers.The soft robot consists of hyperplastic materials which can sustain large strain.The hyperplastic material has infinite degrees of freedom for continuous deformation capability,so the soft robot has strong adaptability and flexibility.This thesis,based on the imitation of human finger's structure and function as well as soft robotics,produces the bionic hand whose shape and function both imitate that of human fingers and carries out a systematic study on the design,actuator,preparation and control mode of the bionic hand.First,this research designs a bending actuator conforming to the rule of human figures' movement by 3D printing technology,according to human fingers' structure and movement features.The bending actuator has three flexible bending joints,and each flexible bending joint is controlled independently by external air-tube so that it can imitate the movement of human fingers.In addition,this study also establishes a static theoretical model of the bending actuator.Second,this thesis tests the stress-strain curve at different rates of extension of the material Ecoflex 00-50 and PDMS used by the bending actuator through uniaxial tensile test,and this study also makes an FEM Simulative Analysis of the flexibility of the bending actuator with the help of the software Abaqus and makes a comparative analysis between the experimental result and FEM Simulative Analysis as well.The experimental result shows that the bending angle of the actuator can reach up to 217 ° when the external pressure is 50 kPa.This paper systematically investigates the influence of three parameters of the actuator(chambers wall thickness,chambers number and Chambers radius)on the flexibility of the bending actuator according on the basis of the theoretical model of the bending actuator.Third,this research produces a bionic hand whose shape and function imitate humanhands' through the manufacturing technology and optimization of kinematic parameters of the bionic hand and makes experiments of each finger's flexibility and finger load capacity of the bionic hand.The experimental result presents that the bionic finger has 14 unidirectional bending joints altogether,and the max bending angle of each joint is from 80°to 100°.Moreover,the movement trajectory of each finger of the bionic hand is consistent with the actual movement trajectory of human hands,and the finger load capacity is from324 mN to 592 mN.Besides,this research carries out experiments of some basic actions and grasps imitating human hands.Thereby,the flexibility and grasping ability of the bionic hand are verified.Finally,this study constructs a pneumatic control system platform of bionic hand and produces a wearable data glove which can monitor the signals of finger bending by taking advantage of the bending sensor.The data glove changes the value of the resistance of bending sensor through the movement of human fingers to affect the input voltage of the sensor.Thus,the operating state of air inflation,keep and air escape for the bionic hand is achieved,and also,the bionic hand and human hands can be controlled in real time to produce synchronous movement.Meanwhile,due to the addition of Bluetooth mode,not only the movement of the bionic hand can be controlled within a range of about 10 meters,but also the physical isolation between the sensor and control components can be achieved.This research provides the rehabilitation therapy and extremely harsh experiment environment of the bionic hand with potential application value. |
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