| With the extensive research on bionics and material science,flexible robots have become a research hotspot due to their flexibility,good human-computer interaction and environmental adaptability,and have a wide range of application prospects in biological rescue,medical inspection,underwater detection and other fields.Based on the research on the performance of a new electronically controlled intelligent material-shape memory alloy(SMA),this paper designs and manufactures a multi-cavity crawling robot driven by an SMA spring,and carry out analysis and experimental research on each component and robot prototype.The main research contents and results are as follows:First,the memory effect and superelastic effect of SMA alloy are analyzed,and the advantages and disadvantages of different alloy properties were analyzed,Ni Ti alloy was selected as the driving material for this subject;Secondly,this article gives the theoretical design and preparation method of SMA spring,the experimental test platform was built for the memory effect and mechanical properties of the SMA spring,and it was obtained that the recovery rate of the SMA spring was the best when the heat treatment temperature was 450?and the number of training was 20 times;Finally,carry out electric drive experiments to study the change law of SMA spring drive performance under different currents and loads,the analysis shows that the elastic coefficient of the SMA spring is proportional to the temperature during the austenite transformation process,the critical current when the selected SMA spring reaches stable driving force is 2.18 A,and the stable driving force is 9.48N;During the heating process,the contraction speed of the SMA spring decreases with the increase of the load.When cooling,the recovery speed increases with the increase of the load,which verifies the feasibility of the SMA spring as a flexible driver.Based on the principle of bionics,through imitating the creeping movement of earthworms in nature,the multi-cavity flexible crawling robot with SMA spring-fluid compound drive was designed,preliminary modeling of the multi-cavity flexible crawling robot was carried out using modeling software,it also analyzed the movement principle of its single-cavity deformation module and the overall movement law of the robot.Detailed design calculations and experimental verification of the structure of the flexible crawling robot's drive module,foldable telescopic module and friction gastropod have been carried out,and for the relevant flexible parts in the crawling robot,the design and preparation of the pouring mold are carried out.Finally,according to the differential motion law of the front and rear driving modules of the flexible crawling robot,the motion control strategy of the crawling robot is designed.Using ABAQUS to carry out static simulation of the hydraulic expansion tube,established the simulation model of the hydraulic expansion tube and fitted the model and parameters of the Ecoflex series silica gel,the effect of different types of silica gel,crosssectional shape and key structural parameters on its deformation performance was verified,the research shows: compared with static air,the working cycle of a single drive module can be reduced from 30 s to 22.5s through the liquid cooling system.This article prepared and assembled the key parts of the flexible robot,the experimental test platform for hydraulic telescopic tubes was built,tested the relationship between the volume of liquid and the elongation of the hydraulic telescopic tube under different resistance conditions.Finally,the whole machine motion experiment of the flexible crawling robot shows that: when the driving current is 2.18 A,the maximum displacement in one movement cycle is 3cm. |
PDF Full Text Request