钛合金电子束焊熔宽PID控制系统建模与仿真

Modeling and simulation of PID control system of titanium alloy electron beam welding

由于焊接过程的复杂性,因此很难得到熔池动态过程的解析数学模型,使得焊接过程建模成为焊接过程控制的一大难题.为了建立电子束焊熔池动态过程模型,采用阶跃响应法确定出了钛合金电子束焊电子束流与熔宽的数学模型的类型和结构,计算出了该模型的参数,建立了电子束流与熔宽的传递函数模型.利用获得的电子束流与熔宽的数学模型,采用Z-N经验公式法确定出了PID控制器参数,在此基础上利用MATLAB/SIMULINK建模与仿真平台建立了钛合金电子束焊熔宽PID控制系统模型,并对该模型进行了仿真试验.结果表明,所设计的控制系统动态性能和稳态性能良好.

Due to the complexity of the welding process,it was difficult to obtain the analytic mathematical model of dynamic process of molten pool,that was why the modeling of welding process became a major problem to the welding process control.For the purpose of establishing the model of dynamic process of molten pool of the electron beam welding.The step-response method was used to determine the type and structure of mathematical model of electron beam current and molten width of titanium alloy electron beam welding,the parameters of model were calculated,and the transfer function model of electron beam current and molten width was established.The Z-N empirical formula was used to obtain the parameters of PID controller based on the mathematical model.On this basis the MATLAB/SIMULINK platform was used to establish the model of PID control system of molten width of titaniumalloy electron beam welding.The simulation experiment was done and the results show that the dynamic performance and steady-state performance of designed control system are eminent.