Department of Instrumentation & Electronics Engg., Jadavpur University, Sector III, Block LB/8, Salt-lake, Calcutta 700098, India.
ISA Trans. 2011 Apr;50(2):220-30. doi: 10.1016/j.isatra.2010.11.006. Epub 2010 Dec 21.
Responses of high-order systems under Ziegler-Nichols tuned PI controllers (ZNPIs) are characterized by excessive oscillation with a large overshoot. Although, a fixed set-point weighting based PI controller (FSWPI) may decrease the overshoot considerably, it fails to reduce the oscillation in the set-point response. Moreover, both FSWPI and ZNPI exhibit equally poor load regulation. Keeping in mind an overall improved performance, we propose an online dynamic set-point weighting technique for ZNPIs. The dynamic set-point weighting factor (β(d)) is heuristically derived from the instantaneous process trend. Performance of the proposed dynamic set-point weighting based PI controller (DSWPI) for various second- and third-order processes including a pH process shows a significant improvement during both the set-point and load disturbance responses over other methods. Stability and robustness of the proposed DSWPI are addressed. Effectiveness of the DSWPI is demonstrated through the real-time implementation on a practical DC position control system.
ZNPI 下的高阶系统的响应特点是超调量过大的过度振荡。虽然基于固定设定点加权的 PI 控制器 (FSWPI) 可以大大降低超调量，但它无法减少设定点响应中的振荡。此外，FSWPI 和 ZNPI 的负载调节性能都很差。考虑到整体性能的提高，我们提出了一种 ZNPI 的在线动态设定点加权技术。动态设定点加权因子 (β(d)) 是根据瞬时过程趋势启发式推导出来的。针对各种二阶和三阶过程（包括 pH 过程），提出的基于动态设定点加权的 PI 控制器 (DSWPI) 的性能在设定点和负载干扰响应方面均优于其他方法。讨论了所提出的 DSWPI 的稳定性和鲁棒性。通过在实际的直流位置控制系统中的实时实现证明了 DSWPI 的有效性。
