液压万能材料试验机的PID控制

PID control for hydraulic universal material testing machines

如何科学有效地达到对材料试验机的应力速率及应变速率控制,是目前试验机领域的关键问题。PID控制是应用最为广泛的一种自动控制方法,在液压控制系统中具有广泛的应用,但目前普遍采用的增量式PID控制,其控制效果理想与否取决于控制参数KP、KI、KD的调整。由此在原有基础上作了一定改进,得到比例积分适时调整PID控制方法。该控制方法在液压万能材料试验机上获得了良好的应力速率、应变速率、位移速率控制以及定荷、定应变、定位移控制的试验结果,使控制性能得到了较大改善。

How to control the stress rate and strain rate of material testing machines scientifically and effectively is a key problem in the testing machine field. The PID control is a widely applied autocontrol method and is widely used in hydraulic control systems. But the control result of the most popularly used increment PID control rests with the adjustment of control parameters KP, KI and KD. The proportion integral real-time adjustment PID control method is presented on the basis of those mentioned above. By the new PID control method, very good testing results of stress rate, strain rate, displacement rate and constant stress, constant strain and constant position have been obtained in hydraulic testing machines. At the same time, the control performance is improved greatly.