| The demolition robot is a kind of engineering robots that can work in hazardous and special environment relying on its own power and control.It is also called tele-operated multi-joint manipulator or multi-DOF robot.The traditional working mechanism of demolition robot has three arms,including first-arm?second-arm and third-arm.Although the working range and the flexibility of operation have been enhanced greatly compared with the excavator with only two arms,the capability also could not adapt to the complex post-disaster conditions such as many obstacles ?narrow rescue space and various seismic ruins and so on.In order to satisfy the needs of the arduous rescue task,this paper designs a new7-DOF working mechanism of demolition robot consisting of translational and rotational joints,and makes simulation analysis on it with CAE.The goal is to make this mechanism with the capability and characters of flexible manipulation ? large operating range?bearing heavy load and strong impact.The main contents of this thesis are as follows:(1)The development status of demolition robot at home and abroad is introduced briefly.(2)According to the design specifications of this project,the structure of this new working mechanism is designed based on the full reference of the demolition robot GTRC-50.And then the dimensions of the main parts are selected initially.At last,the 3D model of parts of the working mechanism are constructed and then assembled by the Solidworks.(3)The virtual prototype model of the working mechanism is constructed by the ADAMS and used to make kinematic analysis based on the formation process of the envelop curve of the operating range,and the work zone and work dimension limitation are gained.In addition,the driving force of every hydraulic cylinder is analyzed at the same time,on which we base to make the selection calculation of every hydraulic cylinder.(4)The Finite element model of the working mechanism is built by the HyperMesh.And the static simulation analysis of the working mechanism is done in 8different working conditions,on which the strength and stiffness of the mechanism are checked.Then the improvement and optimization of the weak parts are done in order to meet the design requirements.(5)The HyperMesh and ADAMS are united to make the rigid-flexible coupling dynamic analysis on the working mechanism,analyzing the dynamic stress of the main parts under the conditions of the entire smooth movement process andother different braking cases.Then the strength of the working mechanism is checked and the safe operation conditions are gained,which is the theory basis to make the operation manual.(6)The modal analysis and frequency response analysis on the working mechanism are made.Through modal analysis,the preceding six order mode shapes and natural frequencies of the working mechanism under 4 different positions are calculated.Through frequency response analysis,the dynamic stress response and displacement response on the working mechanism under the actual operating frequency of hydraulic hammer are calculated,and then the strength and stiffness of the mechanism are checked. |
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