抄録
This paper deals with the eigenvalue problem of a multiple eigenvalue filter which was proposed in the previous paper. The system with the proposed filter derived by means of parallel learning not only reduces control variable deviation without losing stability, but also has PID (Proportional, Integral and Derivative) control action although the original control system before learning only has just proportional control action. In this paper, the reason for what is shown from the viewpoint of an eigenvalue problem and Nyquist stability criterion.