| With the development of science and technology,the more and more high requirements of industrial mixing for mixing equipment and the complexity of the high viscosity and variable viscosity of the mixing materials,traditional mixing methods can no longer meet the production needs,so electromagnetic mixing technology has emerged.It plays an important role in improving the mixing degree of mixing materials,the quality of molten metal casting,improving the internal microstructure of the metal,and improving the performance of metal materials.In this paper,Through the numerical analysis of the magnetic current coupling of a new type of agitator for DC motor,it is found that the agitation efficiency is greatly affected by the speed of agitator within a certain speed.That is to say,if we control the speed of the motor in the electromagnetic stirring device,the ideal stirring state can be obtained.Then two different chaotic ways of motor speed are proposed,and both of them verified the effectiveness of these two methods through simulation.Based on the delay feedback control mode,the DC motor control system is built by using DSP data processor TMS320F28335,and the hardware and software design of the motor speed up to chaotic speed is completed.Finally,the rationality and feasibility of the design are verified by chaotic stirring experiment.The main contents of this paper are as follows:1.Firstly,the type and working principle of electromagnetic stirring device are introduced.After designed a dc electromagnetic stirring device,and has carried on the magnetic current coupling numerical simulation to the device,then the cause of low mixing efficiency is analyzed,the rotating speed is obtained for the influence of the mixing efficiency,combined with the chaos theory,lead to chaos speed mixing way and puts forward the concept of motor driven chaotic change.2.Aiming at the concept of chaotic motor drive,the driving principle of generalized synchronization chaosing is proposed.By designing a suitable synchronization controller,using the Lorenz system to generate a chaotic signal to drive the permanent magnet DC motor to make it work in a chaotic state.The influence of univariate coupling and multivariable coupling on the dynamic characteristics of their respective systems is discussed,and then the feasibility of the method is verified by simulation.3.A method of using nonlinear time-delay feedback to control chaos is proposed,and the analytic expressions that the average steady-state speed and the amplitude of speed oscillation are the same as the system parameters and the control parameters are derived.At the same time,the chaotic control parameters were optimized.Through MATLAB simulation analysis,the best chaotic state was found,and the optimal parameters under the best chaotic state were obtained.4.The hardware part of the system controller of the DC electromagnetic stirring device with DSP as the main processor is designed,and the software control program of the system is completed according to the functional requirements of the system.The control algorithm adopted is the classic PID control algorithm.Later,by designing a chaotic stirring experiment,using the method of acid-base neutralization titration to compare the stirring efficiency of chaotic speed stirring,uniform stirring and variable speed stirring,and also by comparing the stirring efficiency of chaotic stirring under different speed thresholds to find the optimal control parameters.To improve mixing performance. |
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