Design And Research On Water Gun Mechanism Of Fire Fighting Robot

With the development of robotics,fire engineering and simulation technology,the research value of the parallel fire fighting water gun has gradually highlighted in the field of fire fighting which can make up for the shortcomings of tandem fire fighting monitor.Based on the motion demand of fire monitor when extinguishing fire,the fire fighting water gun is designed in this paper,with extensive reference to the series fire fighting monitor which based on 3-SPR parallel mechanism and applied to fire robots.Meanwhile,parallel fire fighting water gun fire extinguishing model,mechanism design and optimization were studied.The work accomplished is as follows:Firstly,according to the conditions of different fire places,the misfire space model is established.And the jet trajectory under three typical angles is simulated and analyzed in Fluent software.The simulation parameters are extracted,and the jet trajectory equation in general scene was obtained through fitting and correction.The equation combined the influence of thermal radiation and the height of the fire fighting water gun nozzle from the ground to establish a fire-fighting robot fire fighting water gun extinguishing model,determining the fire fighting water gun parameters in different scenarios.Secondly,the structure and motion principles of series and parallel fire fighting water gun is analyzed to determine the design scheme of parallel fire fighting water gun mechanism,combining with the design requirements of firefighting robot.According to the working parameters of the fire fighting water gun,the fire fighting water gun mechanism with 3-SPR parallel mechanism as the main body is designed.The 3-SPR parallel mechanism workspace is solved by boundary search algorithm based on MATLAB,and the pitch and horizontal swing angle ranges of the parallel fire fighting water gun are obtained.With the motion/force transfer and constraint indexes analyzed,the main body mechanism of the fire fighting water gun is optimized based on the transfer indexes to improve its transfer performance.Thirdly,the flow path curve,the rectification section length and outlet diameter of the nozzle are simulated and analyzed by the finite element for the best combination of nozzle structure parameters.The nozzle is impacted by the jet,and the forces of the pushrod are analyzed by Recur Dyn for the minimum value of the pushrod self-locking force.Based on the rigid-flexible coupling,ANSYS Static Structural is used to perform stress and displacement analysis of the nozzle and the pushrod,and an optimization scheme is proposed.The first six orders of vibration patterns of the whole mechanism are extracted,and the inherent frequencies of each order of modes are determined to identify the weak parts in the mechanism as a reference for the subsequent prototype design.Finally,the prototype design and fabrication of the fire fighting water gun body mechanism of the fire-fighting robot are completed,and the experiments verified that the fire fighting water gun body mechanism of the fire-fighting robot designed in this paper can meet the motion requirements of the fire fighting water gun in the lead direction and horizontal direction,which provides reference for further research of the parallel mechanism in the field of fire fighting water gun.