基于阀芯位移观测的步进梁速度闭环控制

Walking beam speed closed-loop control based on valve core displacement observation

步进梁由固定梁与移动梁构成。由液压缸驱动的移动梁托起数百吨重的钢坯做矩形运动,使钢坯在炉内加热过程中一步一步地自入炉侧向出炉侧移动。移动梁的运动速度和位移精度非常重要,速度控制不准,移动梁托起或放下钢坯时会发生碰撞损伤步进梁。位移控制不准会造成误差积累,导致钢坯不能正常出炉。因此,步进梁运动速度和位移的准确控制至关重要。文章在分析研究步进梁系统工作原理及数学模型的基础上,采用状态观测器对阀芯位移进行重构,设计了阀芯位移与移动梁速度双闭环串级控制系统,并利用Matlab/Simulink进行了仿真研究。结果表明,与开环控制、单闭环控制相比,双闭环串级控制策略可实现速度的准确跟踪和位移的准确控制。

Walking beams consist of fixed beams and moving beams .Driven by hydraulic cylinder , moving beams lift hundreds of tons of steel billets ,doing the rectangular movement .Thus ,they make steel billets step from the entrance to the outside in the heating furnace .The movement speed and dis-placement precision of moving beams are very important .If the speed of moving beams is not accu-rate ,the walking beams will be damaged by collision when moving beams hold up or down steel bil-lets .And the inaccuracy of displacement will cause the steel billets to be unable to step outside the furnace normally because of the accumulation of step error .Therefore ,the accurate control of the walking beam movement speed and displacement is essential .By analyzing the principle of the walking beam system and mathematical model ,and adopting the method of state observer to reconstruct the valve core displacement ,a double closed-loop control strategy is proposed with feedback of valve core displacement and walking beam movement speed .Meanwhile ,the system is simulated by Matlab/Simulink .By comparing with traditional open-loop control and single closed-loop control ,it is shown that double closed-loop control strategy can realize accurate tracking of the speed and accurate control of the displacement .