ELECTROMAGNETIC SUSPENSION SYSTEM

A change of performance of an electromagnetic suspension unit is detected. When an integral £| Vs'-Vs* | of an absolute value of a difference between an actual value Vs* and an estimated value Vs' of an expansion/contraction velocity of a shock absorber is larger than a performance change threshold value Sth, it is detected that the performance of the electromagnetic suspension unit is changed (S16). Further, when an integral £ | Vs* | of an absolute value of the actual value Vs* is larger than an integral £ | Vs' | of an absolute value of the estimated value Vs' by a predetermined value, performance of the shock absorber is changed such that a damping force of the shock absorber is reduced (S22, S23). Thus, the performance change of the electromagnetic suspension unit is detected based on the expansion/contraction velocity of the shock absorber.