| In recent years,the number of new tunnels in China has increased year by year,and the risk of tunnel fire has been increasing.Due to the closed structure of the tunnel space,the passage is long and not easy to evacuate,and if a fire occurs,high temperature air and smoke will quickly fill the tunnel,bringing great difficulties to the rescue work.At the same time,tunnel fires will also cause serious damage to tunnel facilities,causing interruptions in road efficiency for as short as several hours and as long as tens of hours,causing incalculable economic losses.Therefore,the use of robots to replace rescuers into tunnels for fire fighting and rescue operations has become a trend.Therefore,this paper develops a tunnel suspension rail fire extinguishing robot for complex and changeable tunnel fires.Reasonable,stable and reliable mechanical structure is the premise for the normal operation of fire extinguishing robots.The fire-fighting robot designed in this paper moves using a guide rail mounted on the tunnel wall,and is not limited by space,obstacles,etc.The walking mechanism of the extinguishing robot is determined according to the walking mode,and a cylinder containing the fire extinguishing agent is hung under the walking mechanism,and the nozzle that sprays the fire extinguishing agent is installed at the front end to form the overall mechanical structure of the fire extinguishing robot.The key to fire extinguishing robots performing fire extinguishing operations is the detection and positioning of fire sources.In this paper,the sprinkler mechanical mechanism of the fire extinguishing robot is designed,which collects the fire signal through the sensor installed at the nozzle nozzle,determines whether a fire occurs,and issues a fire alarm in time.Through the PTZ mechanism inside the nozzle,the nozzle rotates in the horizontal and vertical directions,and the scanning and positioning method is used to locate the center of the fire source to complete the detection and positioning of the fire source.And 3D modeling and virtual assembly in Solid Works to verify the rationality of the design.The jet trajectory of the fire extinguishing robot changes with the change of working conditions,thus affecting the fire extinguishing efficiency.Therefore,this paper analyzes the factors affecting the jet trajectory and establishes a theoretical model of the water flow trajectory under the influence of external factor wind.In Matlab,the jet trajectory was simulated and the variation law of the jet trajectory under different pitch angles,working pressures and different wind speeds and directions was analyzed.During the working process,the jet range decreases due to the attenuation of the working pressure of the nozzle,and the jet falling point can not coincide with the fire source.Therefore,it is necessary to adjust the nozzle angle so that the jet can cover the fire source again.In this paper,the jet range data of nozzles under different pitch angles and working pressures are processed through multiple regression analysis,and the fitting formulas of nozzle pitch angle with respect to working pressure and jet range are obtained,which are used to adjust the working angle of nozzles and provide theoretical reference for the subsequent research and development control of fire extinguishing robots. |
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