Analysis of Noncatastrophic Failures in Digital Guidance Systems

A method is presented for weighting noncatastrophic failures in digital guidance systems in accordance with their effect on system accuracy. The method is discussed for one particular class of malfunctions, the transient, and the velocity and thrust termination errors of an inertially guided rocket are derived from several statistical models for transient failures assuming Poisson arrival and random duration of the failures. The accuracy degradation caused by transient failures in the information path of a guidance computer during boost appears to be considerable and, certainly, not negligible compared with instrument anomalies.