The Design And Theoretical Research On The Control System Of High Pressure Fire Water Cannon

The water supply pressure of the existing fire water cannon is about 1MPa,relying on the large flow to increase the range,the demand for large-capacity water sources is large,and due to the uncertainty of the fire,it is often impossible to fire in time by manual labor alone,in order to reduce the flow demand and the ability to automatically extinguish fires are designed.In this paper,an intelligent high-pressure fire water cannon is designed.Theoretical research is carried out on key technical issues such as component design,software design,jet trajectory prediction and system dynamic performance,and related simulations are carried out which laid the foundation for prototype development.This paper firstly carried out the structural design of high-pressure fire water cannon based on the traditional fire water cannon.Combining the existing experimental conditions and national standards,a fire water monitor with a rated pressure of 5MPa and a rated flow of 500 L / min was designed.Using finite element software,the strength of key components was simulated and verified to ensure the safety and rationality of the structure.Secondly,a flame recognition algorithm was designed,and the recognition false alarm rate of flame video and street lamp video was within 9%,with good recognition performance;according to the relevant theory of ballistics,a mathematical model of fire trajectory of fire water gun was established,using Matlab and The fourth-order Runge-Kutta method is used to solve the model to obtain the jet trajectory curve.At the same time,the flow field simulation is carried out on the water gun jet trajectory,and the simulation results are fitted to the trajectory curve.Assuming that the flow field simulation trajectory is similar to the actual jet trajectory of the water gun,the predicted trajectory of the mathematical model of the jet and the simulated trajectory of the flow field are compared and analyzed using statistical methods.When the average variance of the ordinates of the corresponding points taken by the two is the smallest,the undetermined coefficient a of the predicted trajectory of the mathematical model of the jet is 9.9.The high prediction relative error is within 10%;according to the imaging principle of the camera,a method of binocular positioning in flame space is designed,and the spatial coordinate system of two cameras to detect the overlapping area and the space centered on the fire water cannon are established respectively coordinate system,based on the geometric relationship between the two coordinate systems and the jet trajectory curve and flame recognition algorithm can achieve fire water cannons to fire tracking,location and automatically adjusted.Finally,the mathematical model of the system is established,the PID controller of the speed loop and the position loop of the system is designed by frequency domain analysis method according to the classic control theory,and the simulation model is built in Matlab / Simulink according to the mathematical model,and the system dynamic performance simulation verification,the dynamic response of the system can follow the input signal changes well.At the same time,the physical model of the system was simulated in Proteus,which verified the correctness and rationality of hardware selection and software design.