摘要：
针对咬钢时突加载荷作用下的系统过渡过程的动态速降及扭矩放大特性,以某冷连轧机F3机架为对象,将多自由度的弹簧-质量系统简化为二自由度的系统.同时,将电机的延迟环节引入被控系统,并将负载扰动作为一个状态量写入状态空间方程,通过状态空间转化与合并,建立了基于状态空间的轧机主传动系统仿真模型.基于模型,提出了基于LQG的扭振控制策略,保证了系统的鲁棒性,滤除系统随机干扰信号,使得系统能够在短时间内达到最优控制效果.通过LQG 控制系统的鲁棒性分析可知:延迟时间减少时,系统时域性能变好,反之变差,且当Td=50ms时,系统开始发散;转角频率减少时,系统时域性能变好,反之变差,且当ωcc=30 rad/s时,系统开始发散;扭转刚度的变化对系统的时域性能没有太大的影响,但当扭转刚度达到140MN·m/rad 以后,系统的稳定状态为小幅值的等幅振荡.%For the dynamic descent and torque amplification characteristics in the process of system transition when bite the steel under the effect of sudden load,this paper takes the F3frame of a cold tandem mill as the research object,the multi-degree of freedom of the spring and the quality system is reduced to two degrees of freedom system. At the same time, the delay of the motor into the accused system and load the disturbance as a state quantity into the state space equation,through the state space conversion and merging, a simulation model of main drive system of rolling mill based on state space is established.Based on the model,the torsional vibration control strategy based on LQG is proposed,to ensure the robustness of the system.Filter out the system random interference signal,so that the system can be in a relatively short period of time to achieve optimal control effect.Through the robustness analysis of LQG control system,it can be seen that when the delay time is reduced,the system time domain performance becomes better,and otherwise bad.And when Td=50ms,the system begins to diverge; when the corner frequency is reduced, the time domain performance of the system becomes better, and otherwise bad.And when ωcc=30rad/s,the system begins to diverge.The change in torsional stiffness does not have much effect on the time domain performance of the system.However,when the torsional stiffness reaches 140MN·m/rad,the steady state of the system is small amplitude equal amplitude oscillation.
