Optimization Design And Experimental Study Of Multi-chamber Soft Actuator With Variable Curvature Bending

Soft robots can change their structure according to different application environments and output object characteristics,and have a wide range of application prospects in medical rescue,bionic detection,assisted rehabilitation and other fields.Soft drives are used to drive soft robots and are an important part of soft robots.In view of the lack of research on the bending characteristics of software drivers and the lack of specific optimization scheme for the design parameters of software drivers,this thesis takes the software driver with a multichamber structure in the software driver as the research object,and studies the production materials,structural parameter influence,design parameter optimization,production method,experimental platform design and other aspects of the multi-chamber software driver.The main research contents of the thesis are as follows:Firstly,the multi-chamber soft driver is taken as the research object,the properties of some silicone rubber materials are compared and analyzed,and the 00-30 two-component silicone of the Ecoflex series is selected as the production material of the driver,and the Yeoh model is selected as the constitutive model of the material.Based on the principle of virtual work and the constitutive model of the material,a mathematical model of the bending angle of a single chamber is established,and the results of finite element analysis and the model calculation are compared,and it is concluded that the increase of chamber height,width and input pressure will lead to an increase in bending angle,and the increase of chamber width,length,wall thickness and adjacent chamber gap will lead to a decrease in bending angle.Secondly,based on the bending model of a single chamber,the optimization model of the structural parameters and input pressure of a single chamber is derived,and according to different bending states,the design parameter optimization model of Constant Curvature Soft Actuators(CCSA)and the Variable Curvature Soft Actuators(VCSA)design parameter optimization model.The ideal curve of constant curvature and the ideal curve of variable curvature are given to simulate the specific bending state,and the ideal curve examples of different bending states are proposed to verify the correctness of the model,and the ideal curve of different bending states is segmented by using the segmented constant curvature hypothesis model,and the arc length and arc are used as the length and bending angle of a single chamber,which are substituted into the corresponding optimization model to obtain the optimization results of the remaining design parameters,and the corresponding CCSA or VCSA is established by modeling software.The simulation software is used to analyze the bending state of the software driver under the optimal input pressure condition obtained based on the optimization model,and the coordinates of the bottom curve of the software driver are extracted,and the corresponding ideal curve is fitted and analyzed,and the maximum Euclidean distance corresponding to CCSA and VCSA is found to be 0.007265 and 0.12648,respectively,which proves the correctness of the optimization design model.Finally,the hydraulic experimental platform of the software driver is built to realize the two-way transmission of fluid,and the practicability of the CCSA and VCSA design parameter optimization models is verified respectively,and the minimum correlation coefficients between the experimental curve,finite element simulation curve and ideal curve are 0.97 and 0.93 respectively according to the bottom curve of CCSA and VCSA obtained experimentally,which are strongly correlated,which proves the practicality of the optimization design model.Based on the optimization design methods of CCSA and VCSA,the normal curvature curved pectoral fin and variable curvature curved pectoral fin were produced,and the simulation and experimental verification showed that the propulsion force of the variable curvature curved pectoral fin was 10% greater than that of the normal curvature curved pectoral fin.