Provided is a compensator with which it is possible to calculate an input value to be input to a control object with high accuracy on the basis of a small amount of data. The compensator (3) includes a processor (31), and a storage device (30) that is connected to the processor (31) and stores measured input values that are measured values of an input to a subject to control (2) and measured output values that are measured values of an output from the subject to control. The processor (31) performs processing for identifying, from the measured input values and the measured output values, a first coefficient configuring a finite impulse response filter, processing for determining, based on the first coefficient, a second coefficient configuring an infinite impulse response filter, and identifying an inverse system for the subject to control (2) , the inverse system including the second coefficient and a part of the first coefficient, and processing for estimating an input value to be input to the subject to control (2) from a weighted sum of target values of the output.
COMPENSATOR, CONTROL SYSTEM, COMPENSATION METHOD, AND PROGRAM