The basic philosophy of control is: for an unknown black box system, it is still possible to establish a control model according to observation, in short, that is, the control is reasonable. Whether it is physical system, biological system, social system, the mechanism of its control is consistent. It employs here is a generalized modeling, that is, we don't seek the physical model of the system, but seek a "useful" model. In fact, in mathematics has already prepared a variety of general model series, the most typical Taylor can establish different levels of polynomial models, which we have to do is to fit with different needs.
