Research On Joint Technology Of Quasi-continuous Manipulator

As the application scenarios of robots tend to be diversified and complex,such as electric vehicle charging,aerospace,petrochemical and other small and unstructured environments.Due to the limitation of the number of degrees of freedom and the structure of the traditional industrial robot,it is difficult to complete the relevant operations and requirements.The near horizontal continuous and controllable deformation quasi-continuous manipulator(rope-driven continuous manipulator,hyper-redundant manipulator)emerges as the times require.However,due to the limitation of the structure,length,weight of the link and joint,and the limitation of driving layout,it is difficult to meet the requirements of the long link and large joint angle during narrow and unstructured environment.In this paper,an under-actuated linkage joint group applied to the continuous manipulator is proposed.Besides,researches including the scheme,performance,prototype and experiments for the under-actuated linkage joint group are developed.First of all,on the basis of functional requirement analysis,the core elements of under-actuated linkage joint group are studied.Based on the analysis of the core elements,the detailed schemes are compared and analyzed,and the selection method is refined.At the same time,the characteristics of joint group are analyzed,and the difference between joint group and joint in workspace,avoidance performance,bearing capacity and motion continuity are compared.Furthermore,the selection criteria of joint group are determined.Secondly,based on the determined under-actuated joint group cases,the performance analysis of the joint group is carried out.According to the structural model and coordinate transformation of the joint group,the parametric model of the joint group is established,and the kinematic model based on the warping transmission,the elastic deformation of the linkage rope and the error model based on the non-tension of the linkage rope are established respectively.And kinematics analysis of under-actuated joint group is carried out,including mapping research between joint space and operation space and mapping research between joint space and driving space.Besides,the forward and inverse kinematics simulation of the joint group is carried out to verify the correctness of the theoretical derivation.Then,based on the research of under-actuated joint group scheme and the corresponding performance analysis,the prototype of under-actuated joint group is developed.The key technical indexes and the overall structure scheme of the under-actuated joint group are determined,and the design requirements of the joint group components are defined.According to the technical indicators,the structural parameters of the joint,the link and other main parts are designed,and the length of the Bowden cable is designed.According to the static analysis of the joint group,the maximum tension of the driving rope is obtained,and the parts of the driving system are designed.Besides,the key parts are checked by using the finite element software ANSYS.At last,the overall structure of the joint group is determined,and the parts of the joint group are processed and the whole machine is assembled to obtain the prototype of the joint group.Finally,on the basis of theoretical research,the experimental system of the joint group is constructed,and the experiments for scheme verification,motion function,repeated motion and load are carried out.The correctness and flexibility of the joint group are proved by the scheme verification experiment.And the performance of the joint group is verified by functional experiment.Besides,repetitive motion performance and the loading capacity of the prototype are verified through the experiments of repeated motion and load.