As the status of the system SA(s) vanes, the relative error
e(s) occurs and the output dm(s) of the transformer T(s) is changed. In the minimum relative error control model, the
error e(s) is transformed into re(s) by the error compensation
controller Ce(s) considering the reference relative property
dr(s) and re(s) is compensated in the input XB(s) of the system SB(s). This relation can be expressed as in (1).