This paper studies the performance of integer and fractional order controllers in a hexapod robot with joints at the legs having viscous friction and flexibility. For that objective the robot prescribed motion is characterized in terms of several locomotion variables. The walking performance is analysed through the Nyquist stability criterion and several indices that reflect the system dynamica...

Introduction: The recently introduced GRAPPA Operator Gridder (GROG) [1] has been shown to be useful for the regridding of fully-sampled non-Cartesian data. However, GROG can also be used to properly regrid undersampled non-Cartesian data, which cannot be performed with other common regridding schemes, such as the gold-standard convolution-based gridding [2]. GROG has the advantage that single ...

This chapter deals with the formulation of stability theory for two-dimensional dynamical systems, by generalizing the concepts used in the classical one-dimensional case. Both the input-output description and different forms of state-space representation are considered, leading to the definition of bounded-input bounded-output stability and asymptotic stability, with a discussion of the relati...

Square-root Nyquist transmit filtering is typically used in single-carrier (SC) transmission. By changing the filter roll-off factor, the bit-error rate (BER), peak-to-average power ratio (PAPR), and spectrum efficiency (SE) changes, resulting in a tradeoff among these performance indicators. In this paper, assuming SC with frequency-domain equalization (SC-FDE), we design a new transmit filter...

In time of arrival (TOA) estimation of received ultra-wideband (UWB) pulses, traditional maximum likelihood (ML) and generalized likelihood estimators become impractical because they require sampling at the Nyquist rate. Sub-Nyquist ML-based TOA estimation currently assumes a priori knowledge of the UWB channels in the form of the average power delay profile (APDP). In this paper, instead of as...

Active noise control (ANC) over a sizeable space requires a large number of reference and error microphones to satisfy the spatial Nyquist sampling criterion, which limits the feasibility of practical realization of such systems. This paper proposes a mode-domain feedforward ANC method to attenuate the noise field over a large space while reducing the number of microphones required. We adopt a ...

This paper considers the processing of radar signals in digital radar rangefinders. Special attention is focused on the case where limited performance of digital signal processors cannot provide the input signal sampling rate corresponding to the Nyquist criterion. The considered method of stroboscopic sampling allows overcoming this limitation. A suggested pseudo random modification of the str...

Two matlab-based tools have been developed for the convenient assessment of stability conditions for linear and nonlinear systems. The first is a more helpful and definitive version of nyquist, which has features of automatic zooming (to show all crossings of the real axis and thus display the corresponding critical gain points) and which displays on the real axis a numeral (‘0’, ‘1’ etc.) that...