Based on the repeatability and nonlinearity of the actual system, the time-varying pilot factor–iterative learning control algorithm is proposed previously. To make this algorithm more intelligent and get a better control effect, an improved control algorithm is proposed. The improved control method mainly addresses the error divergence problem of the system under the influence of the phase delay. The convergence of the system under the control of this new control algorithm has been mathematically proved by using the repeatability and periodicity of the system, and the sufficient condition is given. The improved control algorithm converges even if the initial state of each iteration of the system is inconsistent. In the last section of this article, the improved algorithm is experimentally verified in an actual hydraulic servo system. The experimentally verified data shows that this new improved algorithm with control parameter learning has a faster convergence rate and better control effect than the previous time-varying pilot factor–iterative learning control algorithm.
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