Research On Deformation Analysis And Coordinated Locomotion Control For Soft Modular Robots

Soft modular robots are composed of basic soft modules which have motion ability.It has connections at both ends to realize connect and disconnect with other modules.Therefore,it could form various configurations of soft modular robot.Compared with the traditional modular robots,the main charcteristics of soft modular robots are manufacturing materials and driving methods.The soft module,which is made of highly elastic material,has infinite degrees o f freedom to form continuous deformation.The driving methods are no longer confined to steering engines and motors,it has many novel methods which include pneumatic method,chemical reaction method,Metal memory alloy,and so on.Therefore,combine the soft materials and driving methods with the modular concept,and r ealize the coordinated locomotion of soft modular robot is a challenging subject.Under the given drving method,how to ahcive both moving and reconfigurable abilities,bulit the relationship of driving method and deformation,and relaize the coordinated locomotion are main problems in the research of soft modular robots.Thus,the problems are also the main research content in the subject.The basic soft module structre can directly affect deformation,configurations and locomotions.In this paper,we are utlizing the modular concept to design the soft module.The design principles are repeatability,reconfigurability,substitutability.Utlizing the pneumatic method to drive the soft module to brake traditional rigid robots are dependent on dirver.However,there has an problem is needed to be solved,which is relationship between of soft module's structure and bending function.Thereforore,analyze the relationship between soft module's structure and bending funtion from a series of simulations by using software.Furthermore,optimal parameters of soft module's struture are obtained.We desing a novel conneting part that can relize the connected and disconnected functions,and let the soft module has shear resistance.It provides guarantee for the realization of reconstruction and motion function of soft modular robot.Meanwhile,we give the whole process of manufacturing soft module.And analyze hysteresis characteristics,work space and mechanical properties of the soft module.Therefore,the soft module provides effective physical model for mechanics modeling and coordinated locomotion of soft modular robots.The soft modular robots are made of silica gel,which has high elasticity,shock resistance and infinite degrees of freedom.Silica has nonlinear characteristics when it under stress.For instense,it can be extend to several times the length of the body when it under stress.And it can return to original shape when the stree disappears.Therefore,how to obtain the relationship of bending angle and pressure value is a key problem to control the soft modular robot.So combine with Principle of material mechanical deformation,we derive nonlinear deformation modeling of pressure values and stress based on the soft module.Then,bring mechanical modeling method,we built the mechanical modeling of soft module.We establish solving framework and utlize programming software to achieve the relationship of bending angle and pressure values.Meanwhile,bending experiments are testing on the physical model of soft module.And compare the simulation data and experimental results.The core advantages of soft modular robot over other robots are various configurations and multiple locomotions.Combine with soft material has large deformation capacity,the adaptive capacity to environment of soft module is enhanced.However,the calculated amount is increased as the number of modules increases.Therefore,planning locomotion of soft modular can not depened on person planning.Thus,nerve cell is introduced as basic conrtoller of soft mdoule.We built neural network of soft modular robot,which provides a method to relize various coordinated locomtions for different confingurations of soft robot.Meanwhile,coordinated locomtions of typical configurations are obtianed,which include inchworm motion,imitate earthworm motion,swimming-like motion,and turning motion.To verify the bending ability and coordinated locomtions of soft modular robot,we built manufacture intact and reliable soft modules and pneumatic experimental platform.The soft module not only has conneted and disconneted fuctions and bending ability,but also perfomances well moving ability.At the same time,experiments of imitate earthworm motion,crawling motion,and turning motion are tested on the penumatic platform.The results show effectiveness correctness of neural network method for planning locomtions,and nonlinear mechanics modeling is a key technology to relize motions.Meanwhile,recongfiruable motion experiments verify the soft module's channing configurations ability and moving capacity,and prove the soft module's structure is rational.