Study On Wall Obstacle-crossing,Transition And Gripping Mechanism Of Wall-climbing Robot

Wall-climbing robots are a special type of robot that can effectively improve work efficiency and ensure operational safety by using ground movement technology and wall adsorption technology to complete various high-intensity,high-risk,and repetitive work tasks on steep walls.However,most wall-climbing robots can only perform tasks on a single flat wall surface,while actual working environments often have complex walls with step obstacles,cross walls,and rough surfaces.In such complex wall environments,the coordination and unification of the adsorption and mobile devices of most wall-climbing robots can be difficult,leading to problems such as insufficient adsorption force,adsorption failure,and robot falls.Additionally,the mobile device may not be able to cross,transition,and move on complex walls due to its weak function.To improve the adaptability of wall-climbing robots in complex wall environments,it is necessary to study the problems of wall crossing,transition,and rough wall adsorption of wall-climbing robots in different complex environments in addition to their ability to stably adsorb and efficiently move on the wall.The main research objectives of this paper are summarized as follows:(1)To address issues such as weak obstacle-surmounting performance,slow movement,and insufficient adsorption force when working on complex wall surfaces,this study proposes a wall-climbing robot based on planetary gear track obstaclesurmounting and hybrid double adsorption compensation.The performances of movement and obstacle-surmounting on the wall are studied.Firstly,a mechanical model is built based on the movement principle of the robot working on the wall,and the adsorption force required by the robot to move on the wall and surmount obstacles is calculated.Furthermore,the adsorption force compensation model and the planetary gear track obstacle-surmounting model in the climbing and surmounting phases are analyzed with stress distribution taken into consideration.The relationship between the maximum obstacle-surmounting height,critical working conditions,and optimal adsorption force distribution is also discovered.On this basis,a simulation model is built to conduct static and dynamic simulations of the two common failure modes including slip and overturn,and the conditions for stable work are analyzed.The experiments show that the wall-climbing robot can move on the wall and surmount obstacles stably,demonstrating excellent performances in flexible movement,stable adsorption,and robust obstacle-surmounting.(2)To address the issue of wall-climbing robots being limited to a single wall surface and unable to transition between walls in different environments,a hybrid dualadsorption wall-climbing robot capable of multiple wall transitions is proposed.The innovative designs and optimization improvements of the adsorption device,movement device,and transition device of the wall-climbing robot are analyzed.Six transition schemes for cross-wall environments are proposed.The different mechanical models of each phase in all transition schemes are studied and analyzed to determine the maximum adsorption force required in each phase and obtain feasible constraints.Finally,prototype experiments verify that the designed wall-climbing robot with wall transition function can achieve wall transition under various conditions.(3)To address the issue of the weak gripping ability on rough and steep walls and ceilings,as well as the low efficiency of gripping and detachment,this study proposes a bionic gripping mechanism for wall-climbing robots.The mechanism is based on elastic claws and symmetric gripping discs.Firstly,an elastic claw was designed based on the structural characteristics of insect claws,analyzing the spherical contact model of the claw spine and the rough wall surface for gripping attachment.The design was inspired by the rigid claw spine gripping attachment,and a gripping model driven by double sliders was analyzed,taking inspiration from the toe foot of birds.The gripping model was divided into three groups along the array,and a symmetric gripping disc was designed.Secondly,a bionic gripping mechanism based on the elastic claw and the symmetric gripping discs is proposed by combining the structural advantages of both.A mechanical model of the gripping mechanism is established for vertical wall surfaces,inclined wall surfaces,and ceiling wall surfaces.The analysis covers two failure conditions: wall slip and overturning.A simulation gripping model is established in Adams to calculate the maximum gripping force that can be provided.Finally,an experimental prototype of the bionic gripping mechanism was built,and its gripping performance and efficiency were verified through experiments.The results confirm the rationality of the structural design,theoretical analysis,and simulation.