Predictive synchronization and restoration of corrupted velocity samples

Polynomial predictive filtering in control instrumentation: a review

“…The reported results show that a disturbing level of roundoff noise is produced, which necessitates the use of high-accuracy fixed-point or floatingpoint representations in internal computations. The roundoff noise problem was also observed in [13] and [20], in the implementation of RLSN-type predictors. Therefore, in [13], 32-b arithmetic was used in internal computations, and in the prototyping architecture of [20], 32-b floating-point arithmetic was applied.…”

“…The roundoff noise problem was also observed in [13] and [20], in the implementation of RLSN-type predictors. Therefore, in [13], 32-b arithmetic was used in internal computations, and in the prototyping architecture of [20], 32-b floating-point arithmetic was applied. On the other hand, Harju [35] reported that polynomial predictive filters with a low number of bits per coefficient can be constructed while preserving the desired magnitude response characteristics and predictive properties.…”

“…By using an optical pulse encoder and measuring the time between adjacent pulses, the angular velocity is obtained as a time-derivative approximation , where is the time difference between the encoder pulse appearance moments, and is the fixed rotation angle corresponding to one pulse. The angular velocity estimate obtained in this way contains several error sources [13]. At low velocities, a new velocity sample is not necessarily received during a fixed sampling period of the velocity controller, and a replica of the previous sample has to be used instead to substitute for the missing sample.…”

“…Thus, the applied signal model limits the application domain of polynomial predictors but, on the other hand, computationally efficient filtering schemes can be constructed. The implementations of [13] and [20] suggest, however, that high-precision arithmetic is required, which sets minimum requirements for the implementation architecture. As a conclusion, applications where polynomial prediction excels are characterized by good compliance with the polynomial signal model and low or moderate levels of noise and disturbances.…”

A practical approach to the time-derivative estimation problem based on PI-SOGI filters bank

“…In order to detect anomalous system behavior and then isolate its causes, a general framework is developed in [3] where the information to be dealt with is the sign of the first and second derivatives of the measurements. In engine control systems, acceleration estimate, needed for protective supervision, is accomplished with differentiated velocity information (see [4], [5]). A wellknown test, used to implement control techniques for antiblock and anti-spin systems for passengers car, is the braketestbrench [6], [7] which uses an estimate of the zero orderderivative of the wheel velocity.…”