This article deals with the problem of controlling a tandem line of manufacturing machines such that an unknown production demand is tracked with a desired accuracy. To study this problem, a manufacturing machine is approximated by an integrator which is subject to input saturation as a result of the finite capacity of the machine. To solve the problem in the case of unknown demand rate, a combination of feedforward–feedback controller with a reduced-order observer is proposed. The decentralised feedback control strategy for a line of machines is proposed and studied both in continuous time-domain and in frequency-domain representation. The presented illustrating example for a line of four machines underlines the efficiency of the proposed frequency-domain-based performance analysis tool.
Andrievsky, B., Starkov, K., & Pogromski, A. Y. (2013). Frequency and time-domain analysis on performance of a production line operated by observer-based distributed control. International Journal of Systems Science, 44(10), 1885-1896. https://doi.org/10.1080/00207721.2012.670300