Showing papers by "Richard H. Middleton published in 1986"
TL;DR: In this article, it is shown that the shift operator and its associated Z -transform can be replaced by delta operators and their associated transform, which is designated a Δ-transform.
Abstract: This paper examines some of the consequences of finite word lengths in digital control. It is shown that, in many cases of practical importance, the usual shift operator formulation is inferior to an alternative formulation which we designate the delta operator approach. This latter approach is shown to give better coefficient representation and less roundoff noise in many cases. We thus argue that the shift operator and its associated Z -transform can be replaced by delta operators and their associated transform which we designate a Δ-transform. An added advantage of this approach is that discrete designs and transforms converge to their continuous-time counterparts as the sampling rate is increased.
448 citations
TL;DR: This alternative model is used to develop a new discrete model reference adaptive control law and a convergence analysis for the algorithm is presented.
269 citations
01 Dec 1986
TL;DR: This work brings many existing ideas together and explores the effect of various design parameters available to a user and extends the theory in the following areas: how the problem of pole-zero cancellation in the estimated model can be overcome by running parallel estimations and how asymptotic tracking can be achieved in the presence of unmodelled dynamics.
Abstract: The contributions of this paper are in two main areas. The first is an "integrated" approach to the development of a practical adaptive control algorithm. In particular, we bring many existing ideas together and explore the effect of various design parameters available to a user. We also extend the theory in the following areas: we show how the problem of pole-zero cancellation in the estimated model can be overcome by running parallel estimations and we show how asymptotic tracking can be achieved in the presence of unmodelled dynamics. A feature of our presentation is that we treat continuous and discrete systems in a unified framework.
41 citations
Journal Article•
TL;DR: In this article, a root locus interpretation is presented for damping the step response of stepper motors and a method for providing damping when using a Pulsewidth Modulation (PWM) chopper is presented and it is shown to be possible to introduce damping in "single" or "multi"-phase excitation modes.
Abstract: The possibility and desirability of damping the step response of stepper motors has been noted by many authors. A root locus interpretation is presented in this paper which shows concisely some aspects of the damping. A method for providing damping when using a Pulsewidth Modulation (PWM) chopper is presented and it is shown to be possible to introduce damping in "single" or "multi"-phase excitation modes. These ideas have been implemented by the authors on three different stepper motors and some practical conclusions are presented.
8 citations
TL;DR: In this article, a root locus interpretation is presented for damping the step response of stepper motors and a method for providing damping when using a Pulsewidth Modulation (PWM) chopper is presented and it is shown to be possible to introduce damping in "single" or "multi"-phase excitation modes.
Abstract: The possibility and desirability of damping the step response of stepper motors has been noted by many authors. A root locus interpretation is presented in this paper which shows concisely some aspects of the damping. A method for providing damping when using a Pulsewidth Modulation (PWM) chopper is presented and it is shown to be possible to introduce damping in "single" or "multi"-phase excitation modes. These ideas have been implemented by the authors on three different stepper motors and some practical conclusions are presented.
6 citations