1. A control apparatus comprising: a function of generating an operation signal applied to a control subject and a model that simulates characteristics of the control subject, a function of receiving an evaluation value signal calculated based on a measurement signal obtained by applying the operation signal to the control subject and the model, and a function of learning to generate the operation signal such that an expected value of a sum of the evaluation value signals obtained from a present state to a future state is either maximum or minimum; wherein the evaluation value signal calculated based on the measurement signal from the model is calculated by adding a first evaluation value obtained based on a deviation between the measurement signal obtained from the model and a setpoint value, and a second evaluation value obtained based on a difference in characteristics between the model and the control subject.