Development And Motion Control Strategy Research Of Soft Reconfigurable Modular Robots

With the development of society and the improvement of technology,people find higher demands on robots which cause the birth of Modular Robots.The concept of modular robots was born in the 1990 s.Modular robots are consisted of multi modules,which have similar structures and functions.As a highly flexible robot form,modular robots can change global topology easily through rearranging the relative positions and connection relationships of inner modules.The robots are able to perform a variety of operational tasks.Modular robots have flourished since they were born,however most research are still about rigid modular units.In recent years,people have gradually realized the drawbacks of purely rigid modular robots for its bad environmental compliance,so they gradually focused their attention on the combination of modular robots and soft robots.Compared to traditional modular robots,the combination of soft materials and modular concepts has increased environmental flexibility and extended application area of soft modular robots.Soft modular robots have great potential in many directions,such as,medical operations,deep space exploration,and adventure rescue.As a new kind of robots,the structural design,units modeling,module single-body motion control,and modules joint motion planning of soft modular robot are still facing many difficulties that need to be solved immediately.Therefore,this article focuses on the research of development and motion control strategy of soft reconfigurable modular robots.This thesis has designed a reconfigurable pneumatic soft module,and put forward exploratory methodology about of dynamic modeling,pressure closed loop feedback control strategy,and overall robots behavior regulation,and so on.Firstly,a pneumatic soft module that can achieve space bending was developed.The main deformation body of the robots consist of silicone material.This structure can achieve space-bending motion by the local strain difference of silicone material.The pressure of the air chamber is controlled by the electronic valve which is driven by a motor inside the module.Then,a structure for quick connection is designed which can link the module air chamber at the same time when connected.The relationship between the deformation of module and the geometry size of cavity has been analyzed by Workbench simulation,which help me pick out the best shape and size of air cavity.This paper also designed the preparation process of the soft module,and make it possible to manufacture the soft modules quickly.Secondly,the control system of soft module robots was established.This paper have built a pneumatic experiment platform for modular robots,which is consisted of well-chosen pressure sensor,air pump,etc.The recharging-deflation process was controlled by pump and electromagnetic valve,and the drive PCB was designed to receive the control signal to drive the pump and the valve.Air pressure closed-loop feedback control is realizing based on the incremental PID control principle.Wireless control of the soft module is realiz ing based on wireless signal transmission.Then,the dynamic modeling of the soft module is carried out.This article describes the deformation energy of modules with silicone material based on the Mooney-Rivlin model.Based on the energy conservation law,the correspondence between the driven pressure and the behavior of the module is established under a single cavity driven situation.Then based on the idea of equivalent radial force superposition,the behavior of modules under three cavity working together was studied,and the relationship between the pressures of three cavities and module bonding angle was studied too.A modular behavior measure platform was designed to perform kinetic experiments on the single cavity situation and the three cavities joint situation.Afterwards,according to the experimental results,the dynamic modeling of the soft module is solved.Finally,the experimental verification of the modular robots,which was developed in this paper,was carried out.For the single module,the module's motion form under the single cavity driven state and the three cavities combined driven state are studied respectively.Subsequently,based on the different connection states between modules,a variety of modular robots configurations,such as hook configuration,clamp configuration,and five-finger configuration are designed and assembled,and then operation gestures and experimental demonstrations are performed for each typical configuration.