Study On Wall-climbing Robot With Gap-type Single Suction Cup

With the rapid increase in the height of high-rise building of themodern city, wall cleaning, damage detection, equipment maintenance andeven anti-terrorist reconnaissance aspects become difficult problems. The useof robots instead of manual operation not only can reduce the risk and cost ofthe operation, but also improve the operating efficiency. So the research andapplication of wall-climbing robot have the vital engeneeing background anda very broad application prospects. Wall-climbing research has become thefoucs of attention of many researchers and achieved great progress.Sliding wall-climbing robot is always in the state of sliding frictionbetween the sucker and wall in the course of campaign. This would requirethe sucker has good wear resistance and small coefficient of sliding friction,so that finding the right sucker materials becomes a difficult. At the sametime, the friction hinders the flexible movement of the robot. The suction cupof the negative pressure type wall-climbing without sealed mechanism doesnot contact with the wall, so the robot motion resistance decreases, but it’snegative pressure generator creates small pressure, this requires larger suckervolume and motor power. Based on these two negative pressure adsorptionwall-climbing robot’s shortcomings, This project designed a sealedmechanism of gap-type suction cup reducing the sucker cavity air leakage, toensure the robot safety adsorption and improve the wall adatability and sportsperformance. In this paper, the following works were completed:(1) First, we analysed the advantages and disadvantages of the variousadsorbed and mobile methods of the wall-climbing robots. A kind ofchuck-seal mechanism was designed and the effect of the sealing structurewas verified though the simulation of the chuck cavity air flow distribution ofa typical circular sucker based on the fluid simulation software Fluent. Athree-dimensional model of the wall-climbing robot was established using Solidworks technology and the prototype was processed.(2) In the security force analysis of four-wheel-drive wall-climbingwithout sliding friction, security adsorption conditions of the robot under anyposture were obtained. Dynamic model of the sports institutions wasestablished, and dynamic simulation analysis was performanced. Drivingtorque curves were drawn under different adsorption pressure to determinethe relevant parameters of the drive motor, provided a theoretical basis forthe robot motion control.(3) In the analysis of the control system compoents and the derivation ofthe fan suction cup system thermodynamic model, negative pressuresimulation model has been established based on fuzzy PID control andsimulation has been conducted using the Matlab/Simulink tools. Thesimulation results show: control system with fuzzy PID has small overshoot,good steady-state performance, good regulation of the negative pressure withthe real-time nonlinear change.(4) According to the motion and adsorption requirements of thewall-climbing robot, this paper designed control system based on DSP2812.The control system hardware includes power conversion circuit, motordriving module and signal isolation module. Software compents usingmodular thinking include system main program design, the timer interruptprogram design, fuzzy PID control algorithm design and PWM softwarerealizing.(5) Finally, the test system has been set up. Negative pressure testexperiments under different gap height and adsorption-crawling tests underdifferent wall environment were done. Experimental results show that: therobot is able to adapt to less than6mm gap height; it can adsorpt on glasswall, expanse wall and tile wall; robot’s maximum walking speed reaches30m/min. The robot moves flexibly and adsorpts reliably with a strong walladaptability, basically meets the project requirements.