毕业设计 厚度自动控制系统设计.docVIP

厚度自动控制系统设计 摘要 ：厚度与板形精度是板带产品的两大质量指标。目前随着轧制理论、控制理论和人工智能理论的发展，以及它们在轧制过程中的应用，使得板材产品的厚度精度与板形指标有了很大的提高。 厚度控制是通过测厚仪或传感器对实际轧出厚度连续地进行测量，并根据实测值相比较后的偏差信号，借助于控制回路和装置或计算机的功能程序，改变压下位置，张力或轧制速度，把厚度控制在偏差范围内的方法。 影响厚度指标的因素很多，如来料厚度波动，硬度不均，张力不稳，速度不稳，轧辊偏心，轴承油膜和轧辊尺寸变化，均能使产品的出口厚度产生误差。为了解决这些问题造成的影响，所采取的控制方法也很多，如前馈，反馈，厚度计，张力，速度，补偿轧辊偏心等等的方法。这些措施就是轧制系统中已广泛采用AGC系统。由于该系统是利用机架弹塑性曲线进行厚度测量与反馈控制，因此其厚度精度决定于机架的弹性曲线与AGC模型的精度。这种控制方法可以保证板材的厚度均匀，但不能保证绝对厚度精度，所以实际系统往往是几种控制联合使用才能够满足需要。 我们此次设计首先从系统的稳定性快速性考虑，采用了厚度计AGC，此系统能够快速粗调，对于我们控制精度要求无法实现。为了提高轧制精度，我们又加入了由测厚仪组成的反馈系统加以辅助控制，同时还加入了前馈控制系统以消除来料厚度的波动对厚度影响。所以我们实际采用的是厚度计法和由测厚仪组成的反馈，前馈相结合的复合控制法。 关键词：AGC 厚度计 前馈 厚度自动控制 轧制 Design of automatic thickness control system Abstract: The accuracy of strip gauge and the strip flatness are two quality targets of strip production. At present., they have huge advancement with the development of rolling theory. control theory and artificial intelligence theory and their application in the rolling process. Thickness it controls to be through examine thick appearance or sensor to roll and publish thickness go on measurement in succession actually, and the deviation signal after comparing with according to the surveying value, with the aid of controlling the function procedures of the return circuit, device or computer, change and press the position, tension or rolling speed, control the method within the range of deviation of the thickness There are a lot of factors influencing thickness index , If the thickness of supplied materials fluctuates, the hardness is uneven, tension is unstable, the speed is unstable, the roll is partial, bearing oil film and roll measurement change, can make the thickness of export of the products produce the error . In order to solve the influence that these problems cause, controls method taken are a lot of too, such as the feed-forward, feed-back, the thickness is counted , tension, the speed, compensate the partial method to wait a moment of the roll . These measures are that have already