Mathematical Models of the MAE Signal and Its Informative Parameters

Two main approaches to creating mathematical models of physical signals are used to describe and analyze them. The first one concerns non-random, i.e., deterministic signals, whose values at any time or at any point in space are a priori known, or can be accurately predicted, determined, or calculated. The deterministic signal in this case is given, as a rule, by a mathematical function or a computational algorithm. The second approach implies the stochastic character of signals, the law of change of which in time (space) is random and which takes specific values with some probability. The model of such a signal is a description of the statistical characteristics of a random process by specifying the laws of the probability distribution, correlation function, spectral energy density, and others. Randomness can be determined both by the proper physical nature of the signals and by the probabilistic character of the registered signals both in the time and place of their occurrence and in content. In this chapter the mathematical model of the magnetoelastic acoustic emission (MAE) signal is proposed and substantiated, its informative parameters are considered, and algorithms of their estimation are developed. The influence of excitation conditions on the change of MAE signal parameters has been studied. Based on this, the algorithms for stabilizing the amplitude of the remagnetization current and induction of the remagnetization field have been proposed and developed.