other phases perhaps due to changes from minimum phase to non minimum phase system characteristics when the dynamic characteristics are changing drastically and rapidly the identifier cannot update the system model often enough thereby introducing unacceptable mismatch errors in the system performance another advantage of the invention due to the elimination of the on line system identifier is that there is no need to use a test signal to persistently excite the input to the identifier as well as to the controlled system to excite all the significant system modes so as to obtain a model that is not influenced by the input frequency spectrum usually this additional input consists of a pseudo random binary sequence with varying amplitudes or pulse widths having alternate opposite signs for a certain application the effect of this additional signal may be unimportant or acceptable but for others it may be totally undesirable to continuously perturb the controlled system therefore not to have this signal at all is more advantageous than having it for certain applications and not having it for others fig3 is a flowchart indicating steps which would be performed in a software implementation of the circuit shown in fig2 the description of the flowchart of fig3 will refer to the element or device of fig2 which provides the same function the software implementation starts at block 44 in fig3 and proceeds to block 46 which computes the desired future trajectory similar to block 16 in fig2 next the system output is read as indicated by block 48 and the model weight sequence is read as indicated by block 50 both of these inputs to the input predictor are used to compute the predicted model reference adaptive control input sequence as indicated in.