This paper investigates algorithms for constructing velocity approximations from discrete position versus time data. The study is limited to algorithms suitable to provide velocity information in discrete-time feedback control systems such as microprocessor-based systems with a discrete position encoder. Velocity estimator based on lines per period reciprocal-time Taylor erie expansions, backward difference expansions, and least-square curve fits are presented. Based on computer simulation comparisons of relative accuracies of the different algo-rith~s are made. Tbe lea t-sqoares velocity estimator • tillered the effect of imperfect measurements (" noise") best, whereas the Taylor series expansions and backward difference equation estimators respond better to velocity transients.

No abstract