Dynamic delayed controllers for recycling systems with internal delays and complex poles

Recycling systems are a challenging problem from the control viewpoint due to their detrimental effects. This paper proposes a simple way to stabilize and control a class of high‐order recycling systems with time delays, internal instability, and possible complex conjugate poles. The strategy proposes P / P I / P D / P I D ‐like delayed controllers. Conditions to guarantee the stability of the controlled closed‐loop system are stated. The performance of the proposed delayed controllers is illustrated via numerical simulations of a high‐order unstable recycling system and an industrial chemical process.