The Design And Properties Research Of The Foldable Waterbomb Wheel Structure Of The Coal Mine Rescue Robot

The underground environment is complicated after the coal mine accident.In order to ascertain the underground post-disaster environment as soon as possible,prevent rescuers from being injured after entering the post-disaster environment,and protect the life safety of those trapped underground,there is an urgent need for a coal mine rescue robot instead of rescuers to enter the post-disaster mine for environmental detection and rescue work.Aiming at the problem of poor adaptability of existing rescue robots in the complex unstructured environment of catastrophic underground mines,a foldable waterbomb wheel structure of the coal mine rescue robots was proposed based on the origami theory,and the mechanical characteristics of the foldable waterbomb wheel structure of the coal mine rescue robots were analyzed The main research contents are as follows:By refining the kinematic modeling of the foldable waterbomb wheel structure and designing the crease diagram of the parallelogram foldable waterbomb wheel structure,the unified parametric kinematic modeling theory of the foldable waterbomb wheel structure with square,rectangular and parallelogram as the basic unit was proposed for the first time.The folding motion process and the movement trend of each layer of the foldable waterbomb wheel structure were analyzed,and the expandability tests of the foldable waterbomb wheel structure manufactured by multi-material 3D printing were carried out.Aiming at the non-rigid folding phenomenon in the folding process of the foldable waterbomb wheel structure,combined with the deformation mode of the foldable waterbomb wheel structure in the actual working process,the mechanical characteristics of square,rectangular and parallelogram foldable waterbomb wheel structure were explored.The folding process of the foldable waterbomb wheel structure with three different basic elements were simulated using the finite element software ABAQUS/Explicit explicit dynamic solver.The influence of the side length ratio,the element gap and the inclination angle on the axial compression buckling critical load and the radial stiffness of the foldable waterbomb wheel structure were analyzed,and verified by quasi-static axial and radial compression experiments.Aiming at the damage and failure of the foldable waterbomb wheel structure under repeated axial loading and impact,the influence of the thickness,element gap and inclination angle on the degradation degree of bearing capacity was studied.The model was manufactured by multi-material 3D printing and the compression test was carried out to verify the results.An optimization model with the minimum axial compression degradation ratio and impact degradation ratio as the objective,the ultimate bearing capacity as the constraint,and the thickness,element gap and inclination angle of the foldable waterbomb wheel structure as the design variables was established and then solved.According to the response surface method and damage mechanics theory,the fold-to-length ratio and fatigue life of the foldable waterbomb wheel structure under the conditions of three different basic units and side lengths t_a and t_b were calculated.The parameters matching and combination optimization of the thickness,unit gap and inclination angle affecting the bending ratio and fatigue life of the foldable waterbomb wheel structure were carried out by the method of Box-Behnken experimental design and ABAQUS numerical simulation.The deformable rescue robot was designed and its physical prototype was manufactured.The visual,driving and control modules were loaded into the physical prototype.The reasonable structural parameters were determined to assemble the waterbomb wheel structure on the prototype,and the robot experimental platform was built,and its obstacle crossing ability was tested.The results obtained in this paper can provide certain design ideas and research methods for perfecting the research on the mechanical characteristics of the foldable waterbomb wheel structure of the coal mine rescue robots,and provide a certain foundation for the processing and manufacture of waterbomb wheel structure and the development and application of coal mine deformable rescue robots.The paper has 104 figures,58 tables,128 references.