Research On Modeling And Control Of Wall-climbing Robot Based On Micro-nano Structure

As an important branch of mobile robot,wall-climbing adhesion robot has always been the research focus of special motion robot.The adhesion structure of wall-climbing robot is the basis of its ability to adsorb and crawl on various surfaces.The adsorption modes of wall-climbing robot mainly include electromagnetic adsorption,vacuum adsorption,mechanical interlock and bionic adhesion.Among them,biomimetic adhesion is an extremely important and full of potential adsorption mode.There are many organisms with adsorption function in nature.Through research,researchers found that gecko has better wall climbing performance than other organisms(spiders,flies,etc.).At present,the research of bionic gecko adhesive materials is still in the initial stage,and the research mainly focuses on the adsorption mechanism of gecko adsorption structure,and there are few studies on improving the adsorption properties of adhesive materials.Biological geckos can move freely on negative surfaces such as smooth or rough floors,walls and ceilings.Autumn et al.experimentally verified that this special attachment ability is caused by the accumulation of "van der Waals forces" between a large number of fine bristles on the feet of geckos and molecules on the contact surface.At present,through the observation of the structure and motion mode of the foot of gecko,the synthesized micro and nano array which is similar to the structure of the bristle of gecko is applied to the foot structure of the wall-climbing robot,so that it has the advantages of the movement of gecko,which will greatly improve the motion ability of the wall-climbing robot and has a broad application prospect.Based on the observation of the adhesion structure of biological geckos,and based on the design of the adhesion structure and the construction of the control system of the gecko-like robot,this paper carried out the motion control experiment and the inclined plane adhesion experiment of the crawler robot.Firstly,based on the JKR(JohnsonKendall-Roberts)micro-scale contact theory,the mechanical properties of the gecko bristle array and rough surface desorbation process were analyzed theoretically,and the geometric conditions(length to diameter ratio,bristle spacing)needed to be met by the artificial bristle array to overcome the entanglement phenomenon were analyzed.Three kinds of micrometer bristle arrays were designed.The silicon wafer hole array mold of bristle array was fabricated by optical etching technology.The casting and demoulding experiments of micrometer silicon rubber bristle array were carried out by vacuum casting method.Then,the adhesive force measurement system was built to characterize the adsorption force,and then the adhesive structure was applied to the robot to realize the stable crawling movement of the inclined plane.Secondly,a control system modeled after gecko robot was designed.The hardware adopted STM32 microcontrol chip and PID control method were used to realize the straight running and turning control of the wall-climbing robot.Keiluvision5 was used as the software development environment of the motion control system to realize the real-time control of the mobile tracked robot.Realtime command of robot movement control via Bluetooth wireless transmission module;Finally,the ant colony algorithm combined with Astar path planning algorithm was used to realize the shortest path navigation movement of the wall-climbing robot,expand the application range,and lay the necessary foundation for the wall-climbing robot to complete the subsequent detection and analysis tasks.