Design And Research Of Variable Stiffness Continuum Munipulator Controlled By Air-Driven Rope

Continuum robots have received extensive attention in recent years due to their flexibility,safety and reliability,and have also played an important role in different fields.However,when facing the demand of large-capacity tasks,the anti-deformation ability of continuum robots is relatively poor.Therefore,this paper proposes an air-driven cablecontrolled variable stiffness continuum robot.The structural design,kinematics analysis,static stiffness analysis,motion control strategy research,airbag production process analysis,prototype construction and related experimental research of the continuum robot are carried out.Aiming at the requirement of improving the resistance to deformation of the continuum robot,a variable stiffness continuum robot driven by rope drive and air drive is proposed.Two flexible bending structures are designed,and the spring Hooke hinge structure is optimized to realize the flexible bending movement of the manipulator.The multi-layer connected airbag structure is designed and optimized.The position accuracy of the manipulator is controlled by the rope drive.The air drive improves the stiffness performance of the manipulator and realizes the variable stiffness of the manipulator in different states.According to the overall structural characteristics of the manipulator,kinematics and statics modeling and analysis are carried out.In terms of kinematics modeling,the relationship between ’ driving rope ’,’ joint angle ’ and ’ end attitude ’ is established,and the mapping relationship and inverse mapping relationship between the three are solved.The workspace of the manipulator is simulated and analyzed by MATLAB software.In the aspect of static modeling,the static equation is established and the space vector method is proposed to analyze it,and the theoretical analysis of the variable stiffness of the manipulator under different installation conditions is obtained.The control strategy of the whole manipulator is clarified,and the control mode of changing the airbag pressure to keep the rope tension stable is proposed.The hardware analysis and selection of the related control system and the programming design of the software are carried out.The multi-layer connection airbag production process was analyzed and optimized,and a high-pressure support airbag was produced.The relationship between ’ airbag deformation displacement ’,’ load force ’ and ’ airbag pressure ’ was analyzed through experimental tests.The overall prototype required for the experiment is built,and the stiffness performance of the manipulator under different installation conditions is analyzed.The relationship between the change of the attitude angle of the manipulator and the change of the rope length and the relationship between the change of the airbag pressure and the change of the rope tension are studied.The rationality and correctness of the kinematics theory and control method of the continuum manipulator are verified.In this paper,through the in-depth study of the variable stiffness continuum robot controlled by air drive rope,the robot arm is finally realized to enhance the stiffness to improve the ability to resist deformation when facing the bearing task,and the stiffness is reduced to ensure the flexible movement of the robot arm during movement.In addition,under the action of air bag pressure,the driving rope tension is slowed to a certain extent.