Robust Monotonically Convergent Iterative Learning Control for Discrete-Time Systems via Generalized KYP Lemma

Table 1

	Low frequency	Middle frequency	High frequency
Θ	|𝜃|≤𝜃𝑙	𝜃1≤𝜃≤𝜃2	|𝜃|≥𝜃ℎ
Ψ	011−2cos(𝜃𝑙)	0𝑒^𝑗𝜃𝑐𝑒^−𝑗𝜃𝑐−2cos(𝜃𝑤)	0−1−12cos(𝜃ℎ)

where 𝜃_𝑐=(𝜃₁+𝜃₂)/2, 𝜃_𝑤=(𝜃₂−𝜃₁)/2.