Design And Research On Variable Stiffness Of Compliant Joint

According to the development trend of robots in the future,the situation of human and robot cooperation is increasing day by day.When they come in contact with people,rigid robots will have problems such as insufficient safety of interaction and poor adaptability to unknown and complex environments.At present,the rigid design and flexible control strategy used by the robot can't meet the security requirements.The flexible joint robot with variable stiffness has a flexible element inside to reduce the impact of the impact on the human body and ensure human-robot safety.This subject is based on the principle analysis of the variable stiffness mechanism,and designed a variable stiffness compliant joint based on a serial dual drive method.Firstly,this paper analyzed the research status of variable-stiffness joints at home and abroad,and proposed proposes a series dual drive joint structure,and establishes a variable stiffness compliant joint model.The principle of the variable stiffness mechanism is analyzed and summarized.By comparing the advantages and disadvantages of various variable stiffness mechanisms,a new type of variable stiffness mechanism scheme is proposed.The joint parts of the variable stiffness mechanism are designed in a parametric manner.In order to reduce system friction,parts with the special structure were designed,and the selection and verification of the elastic parts were completed.The selection and verification of the joint drive section was completed.Secondly,mechanical calculations and finite element analysis were performed on key parts to complete the static check.Based on the realization principle of variable stiffness mechanism,the output characteristics of joint stiffness and the adjustment characteristics of joint stiffness were analyzed.Thirdly,through the modeling method of the tandem actuator model,the joint dynamics simulation model was established,the parameters in the model were calculated,and the simulation results were analyzed.The open-loop system based on force control and the influence of joint stiffness on the system are analyzed.At the same time,the characteristics of the closed-loop system are also analyzed.Finally,the virtual prototype model of compliant joint is established in ADAMS,and the parameters of the virtual prototype model are set up.The virtual prototyping model was imported into MATLAB,and the module exported by the virtual prototype model was run in MATLAB.The joint output characteristic were finally obtained and analyzed.