Nonlinear Analysis And Automatic Control For The System Of Unloading Of Powder Material Truck

It is eager to be solved that automatic unloading is one of difficult problem. the studyof automatic control valves are carried out in our country,and foreign consider the needs ofadaptive control. The butterfly and its driver with adaptive control system for controllingis studied on the flow of liquid in depth, but don't aim at powder materials. The butterflyand its driver and adaptive control system is Studied, and the technology is the key toachieve automatic unloading of powder material truck.In view of automatic unloading of powder material truck, fluid dynamics is used firstto analyze the effects of two-phase fluid (a mixture of gas and powder) on the dynamictorque and bearing torque of butterfly valve opening/closing when the fluid flows atdifferent entry speed, and to analyze the seating torque. Free streamline theory is also usedto calculate the fluid's contraction coefficient when it passes the butterfly valve in variousopening angles. Second, the drive system of electromagnetic actuator is built and itselectromagnetic properties are analyzed in order to calculate the electromagnetic forceneeded to drive the butterfly valve and the correlation between electromagnetic force andcurrent. Meanwhile, the transient analysis of first-order circuit is used to study R-L circuitand calculate the effects caused by the offset of actuator armature on current fluctuation.Then, mechanical dynamics is used to conduct a nonlinear analysis of the system made upof butterfly valve and its electromagnetic actuator. Different fluid speeds are set forentering the butterfly valve and Simulink is used for numerical simulation. Current,butterfly valve opening/closing speed and the change pattern of valve opening angle areanalyzed to obtain design parameters that can result in less current fluctuation and steadiervalve rotation speed in the automatic unloading system.Fluid characterization of powder materials and their impact on the butterfly valveopening and closing force is analyzed, and according to the actual unloding of steps, thecontrol circuit of automatic unloading valve is design on the basis of electromagneticdriving force, mechanical dynamics equations and numerical simulation.The use ofmicrocontroller A/D module is designed to detect pressure valve opening angle detectiondevice. The detection signal is fed to the microcontroller to read out the current barometricpressure and valve opening angle. The servo motor is used to adjust to the variable resistorto control the drive current of the H-bridge, and then increase or decrease the driving forceof the electromagnetic drive, the angle of opening and closing of the valve reaches apredetermined value, with the combination of these various functional modules,the Clanguage PIC16F877microcontroller is used to compile the control program.