The Design And Simulation Study Of Shortcut Hydraulic Wrist Of Demolition Robot

With the rapid development of society and the speeding up of urbaniation,so the occurrence of natural disasters will lead to heavy casualties and property losses.Advanced rescue equipment is important guarantee to reduce the secondary injury after a disaster.Based on this demand,the development of large forcible entry robots and the function appurtenance has been on the agenda.It not only can complete complex difficult rescue missions and can replace people to work in a dangerous environment.In order to achieve this requirement,this paper designs a 2-dof quickly changed device which can realize automatic oil circuit switching is referred to as the shortcut hydraulic wrist.It is the critical component for forcible entry robot to realize multi-functional and automation as an important part of forcible entry robot,and has changed the traditional substitute mode of appurtenance,not only saving the resources,manpower and work efficiency but greatly improving the forcible entry robot conformability.The main research contents of this thesis are as follows:Firstly,this paper briefly introduces the structure and development of the forcible entry robot,then summarizes the development and research status at home and abroad of quickly changed device.In order to achieve functional and more automation requirements of the forcible entry robot,the overall design project of shortcut hydraulic wrist is designed based on summarizing the predecessors' designs,which is mainly consists of three parts,respectively called the swing mechanism,the rotating mechanism and the hydraulic automatic switching mechanism.The design and lectotype of each part are discussed in detail,especially for the hydraulic automatic switching mechanism which includes quick connector designing scheme,sealing scheme and accurate and reliable connection scheme.The 3D model of each part of the shortcut hydraulic wrist is constructed and assembled by the Solidworks.Then,the virtual prototype model is constructed by the ADAMS,and the correctness of swing angle design and oil cylinder thrust theory analysis is verified by analysis results of kinematics and dynamics simulation analysis,at the same time to prepare for subsequent analysis.In order to explore the feasibility while shortcut hydraulic wrist device connecting different appurtenances,the loads of three kinds of typical operation conditions which including capture,forcible entry and excavate are respectively analyze.After building the finite element model of shortcut hydraulic wrist by the HyperMesh,the static simulation analysis of the mechanism is done in 6 different working conditions,on which the strength and stiffness of shortcut hydraulic wrist is checked.Safety and stability of the structure under the external excitation source are verified by modal analysis under four different positions.Finally,the rigid-flexible coupling model of hortcut hydraulic wrist is establishedby combing HyperMesh and ADAMS.The dynamic stress of the upper connecting frame is separately analyzed under three difference conditions,shortcut hydraulic wrist braked under different braking acceleration in the process of swing and rotating,mechanical arm braked under different braking acceleration in the process of rotating and falling and specific mining condition.Safe braking time is obtained according to the analysis results and has theoretical guiding significance for safely and reliably operating shortcut hydraulic wrist.The design research results in this study provide basis and reference value to the designs not only for this but for other similar products.