针对大型立式淬火炉体积庞大,工况复杂,炉内温度分布呈本征非均匀性,具有多输入/多输出、非线性、强耦合等特性,难以实现炉内温度高精度高均匀性控制目标等问题,提出一种温度分布参数系统动态解耦控制算法,其原理是:采用有限维逼近方法将对象解耦为多个独立的子系统,简化控制器的实现过程;通过分析有限维逼近方法的收敛性,获得保证收敛性的空间和时间步长应满足的条件;解耦后的子系统采用自学习PID控制算法,实现炉内温度高精度和高均匀性控制以及升温过程的快速性和小超调.研究结果表明:温度均匀性由原来的-6~6 ℃提高到-2~2 ℃,升温时间由原来的40 min缩短到25 min,超调量由大于15 ℃减少到小于7 ℃.
Since large-scale vertical quench furnace is voluminous, whose working condition is a typically complex process with distributed parameter, nonlinear, multi-inputs/multi-outputs, close coupled variables, etc, dynamically decoupling control algorithm of temperature distributed parameter system in the furnace was presented, by which the whole system was decoupled to several subsystems and the implementation of controller was simplified. With finite difference approximation, the space and time step size was solved to ensure the convergency of finite difference approximation. After decoupling, the subsystems were controlled with self-learning PID control algorithm. The results show that the temperature control precision and homogeneity are improved; the overshoot and process in temperature rising period are reduced simultaneity. The uniformity of axial temperature distribution increases from -6-6 ℃ to -2-2 ℃; the rising period decreases from 40 min to 25 min, and the overshoot decrease from 15 ℃ to 7 ℃.