We have proposed a new parameter adjustment law that guarantees the stability of the error system that has a positive definite solution for a Riccati equation instead of the strictly positive realness condition, even if the plant has exogenous disturbances. However, the parameter adjustment law has a disadvantage that the transient response of the closed-loop system has large overshoot. In this paper, we try to improve the transient performance by introducing the imaginary axis shifting. Moreover, we apply an adaptive scheme to the position control of current-fed induction motors by the field-oriented control method.