Design And Optimization Of Wheel-Track Composite Stair-Climbing Assisted Robot

With the increasing concern of the society for the disabled,the corresponding disabled robots emerge in endlessly,but there is still a lot of room for development in the function of climbing the building.Most of the disabled robots with climbing ladder function at home and abroad have shortcomings.In order to further improve the quality of life of the disabled,this paper designs and optimizes a disabled robot which can realize the function of automatic climbing,including the following contents:By comparing and analyzing the advantages and disadvantages of climbing ladder in common disabled equipment,this design adopts wheel-track composite climbing ladder scheme.According to the staircase standard,the ergonomic standard determines the whole machine size,and completes the three-dimensional modeling of the preliminary scheme in the solidworks.According to the preliminary plan,the different modes and the action plan of climbing ladder are expounded in detail.mathematical modeling of the climbing ladder process and finding the center of gravity movement trajectory.Then the stability analysis index is introduced to evaluate the stability of the climbing robot,and the conclusion is that there is no tipping in the climbing process.Based on the theory of statics analysis,the chassis support frame,front and rear track support frame,machine seat and backrest parts of the key parts of climbing ladder disabled robot are analyzed to verify whether they meet the allowable requirements under different working conditions.The analysis results show that the stiffness of the front and rear track support frame is insufficient,and the safety margin of the chassis support frame is too large,which provides the direction for the subsequent optimization.Based on the modal analysis theory,the key parts of climbing ladder disabled robot are analyzed,and the first six order natural frequencies and modes are obtained to understand their dynamic characteristics.At the same time,by comparing the natural frequency range of the key components with the excitation range of the excitation source,it is concluded that it will not produce resonance in the working process.According to the results of dynamic and dynamic analysis,the stiffness optimization of the front and rear track support frames is carried out in two different ways,and the optimization effects of the two optimization methods of changing the shape of the section and increasing the reinforcement bars are compared.The reinforcement bars are selected as the final optimization scheme to make them meet the working requirements.The optimum size of chassis support frame is obtained byoptimizing the size of chassis support frame,and the weight reduction of chassis support frame is 27.2%.In order to achieve the maximum optimization effect,the topology optimization is carried out,and the optimized structure is verified to meet the allowable requirements.After two optimization,the total weight reduction of the chassis support frame is 36.2%,and the lightweight effect is very obvious.