The Research And Experiments On Mechanism Of Self-assembling Modular Inchworm-like Intestinal Robot

Human intestinal tract is special environment to motion, but the inchworm crawling way has many advantages that other styles can can not match in in-intestinal moving, and the relatively wide space of stomach provides the possibility for the self-assembling of robot modules. This thesis implement modular design concept, combining the functions of self-assembling and self-separating to inchworm moving style, aims to design a mechanism to meet the small intestine.The whole robot body can be split into three independent function modules:a retractable module and two clamping modules, which can self-assembling and separating. The stretching structure of the first generation prototype are both driven directly by a liner motor, clamping feet act in rigid manners; while the second-generation prototype is using a combination of a motor, a springs and a nylon rope driving the stretching structure which makes it can be greatly curved, clamping feet act in rigid manners too. The self-assembling of modules is implemented by magnets attract each other, heating low-melting point bonding material so that a part of the module clamp off, then a compressed spring between the took off part and clamping module puts clamping module away which makes the retractable module and a clamping module departing spontaneous.The outer diameter of the first generation prototype is 20mm, length 150mm, and the outer diameter of the the improved prototype is 13mm,length 125mm.Focus on the the improved prototype, several experiments were conducted, they are silicone hose crawling, plastic film pipe crawling, self-assembly and self-separation. Results shows that the the improved prototype can pass simulated intestinal and also have a ability to bend. Some mechanical analysis were carried out to assess experiments and compared with the experimental results, which shows that the designed institution may work normally in small intestine.Finally, the robot mechanism optimized design, The third generation prototype using smaller magnets as connection guide elements and reinforcing with low-melting binder, amending the possibility of mis-assembly also provide sufficient connection strength. It also abandon the use of motor but using a kind of new type of artificial muscle as a driving force provider to reduce size and weight of modules. The outer diameter of the third generation prototype can be reduced to 10mm.Results of this study lay the foundation for the next step of designing a active robot that capable of operating in the real intestine.