Research On Dust Uniformity Control Of Dust Concentration Measuring Instrument Verification Device

Social life and production environment are generally threatened by high concentration dust caused by industrial production.In order to control the influence of dust concentration on social life and production,it is very important to ensure the accuracy of dust concentration measuring instrument.At the present stage,there is a lack of research on automatic control of dust uniformity for its verification device.Therefore,under the support of the national key research and development project of "Metrological technology research of new methane ventilation and dust-proof safety instruments in mines(2017YFF0205500)",the theoretical research was carried out on the control of dust uniformity,and a prototype of a stable and efficient dust uniformity control system was analyzed and designed.The main research contents of this thesis are as follows:Firstly,the principle of dust concentration measuring instrument and its verification device is studied theoretically.It mainly includes the principle of dust generation and the stress of dust particles.At the same time,a model is established to analyze the movement and influencing factors of dust in the verification device,so as to provide theoretical guidance for the design of the prototype of dust uniformity control system.Aiming at the problems of nonlinearity and multi disturbance in the process of dust uniformity control,a cascade control strategy based on Improved particle swarm optimization PID parameters is proposed.By adding the inertia weight coefficient decreasing with the number of iterations into the PSO model and introducing the cosine function and exponential function to dynamically adjust the learning factor,the flexibility and adaptive ability of particles in the process of searching the optimal solution are guaranteed,and the accuracy and convergence speed of the algorithm are improved.In addition,combined with improved particle swarm and PID control algorithm,IPSO-PID dust uniformity cascade control method is proposed.The simulation results show that,compared with other methods,the system has fast stability,small overshoot,good robustness,and strong adaptive ability,which can meet the requirements of dust uniformity control process.Secondly,the hardware and software design of dust uniformity control system is completed.Hardware design XY plane dynamic dust generating device,dust uniformity detection unit and wind speed flow field control unit.Aiming at the problem of fixed position of dust outlet of verification device,dust generating device and T slide table are used to move dust in XY plane.To solve the problem that it is difficult to install a sensor in the air duct,the dust uniformity detection unit fixes the sensor on the hexagonal bracket to form a detection point,which can change the detection position with the movement of the bracket position.The wind speed flow field control unit controls the fan by frequency conversion of the main control unit to stabilize the wind speed in the air duct.The software part includes the design of the underlying control program and the visualization software based on the Qt framework,which provides users with means to control the system and observe data.Finally,the experimental platform of dust uniformity control is built.The IPSO-PID cascade control strategy is applied to the dust uniformity control system,which improves the control performance and stability of the system.Through three different concentrations of experimental tests,a stable and uniform dust environment can be rapidly formed in the air duct,which proves that the system meets the design requirements.The thesis has 69 pictures,21 tables,and 74 references.