热风炉拱顶温度模糊自适应滑模控制策略

Fuzzy Adaptive Sliding Mode Control Strategy for Vault Temperature of Hot Blast Stove

针对高炉热风炉拱顶温度控制的大惯性、纯滞后和超调大的特点,提出一种模糊自适应滑模控制策略。将滑模控制强鲁棒性的特点与模糊自适应控制的良好逼近能力相结合,并考虑到系统不确定项和外部干扰会使系统状态偏离滑模面,引入附加控制项使系统轨迹能够在有限时间内趋向滑模面;利用模糊自适应控制逼近系统未知参数和不确定项,抵消由建模误差和外部扰动对系统的影响,实现对逼近误差的修正和补偿;借助Lyapunov方法导出模糊自适应律,通过调节自适应权重保证整个闭环系统的收敛性和稳定性。仿真结果表明:模糊自适应滑模控制策略与PID和常规滑模控制相比,加入干扰后调节时间最多减少35 s,超调量最多降低12.1%,系统抖振较常规滑模控制最多降低16%。工程应用表明:使用所提策略后,拱顶温度上下波动幅度小,偏差小于±5℃,系统稳定性和抗干扰能力显著提高,表明该模糊自适应滑模控制器具有抖振小、响应快、精度高的特点。

Aiming at the characteristics of large inertia,pure hysteresis and large overshoot of blast furnace hot blast stove vault temperature control,a fuzzy adaptive sliding mode control strategy is proposed.Combining the strong robustness of sliding mode control with the good approximation ability of fuzzy adaptive control,and considering that system uncertainties and external disturbances will cause the system state to deviate from the sliding mode surface,additional control items are introduced to enable the system trajectory to tend to the sliding mode surface within a finite time;fuzzy adaptive control is used to approximate the unknown parameters and uncertain terms of the system,so as to offset the influence of modeling errors and external disturbances on the system,and realize the correction and compensation of the approximation error;the Lyapunov method to derive the fuzzy adaptive law to ensure the convergence and stability of the entire closed-loop system by adjusting the adaptive weights.Simulation results show that compared with PID control and conventional sliding mode control,the fuzzy adaptive sliding mode control strategy can reduce the adjustment time by up to 35 s after interference is added,the overshoot can be reduced by up to 12.1%,and the system chattering can be reduced by up to 16%compared with the conventional sliding mode control.Engineering application shows that after using the proposed strategy,the vault temperature has a smaller fluctuation range,the deviation is less than±5℃,and the system stability and anti-interference ability are significantly improved,which indicates that the fuzzy adaptive sliding mode controller has smaller chattering,faster response,and higher precision.