Article

The exact and unique solution for phase-lead and phase-lag compensation

Intelligent Control & Syst. Eng. Center, Chinese Acad. of Sci., Beijing, China
IEEE Transactions on Education (Impact Factor: 1.22). 06/2003; DOI: 10.1109/TE.2002.808279
Source: IEEE Xplore

ABSTRACT Phase-lead and -lag compensation is one of the most commonly used techniques for designing control systems in the frequency domain, especially when the Bode diagram or root locus is used. In most cases, the graphic-based approximation or trial-and-error approach has been utilized in the design process. This paper presents the exact and unique solution to the design of phase-lead and phase-lag compensation when the desired gains in the magnitude and phase are known at a given frequency. It also gives the concise condition for determining the existence of single-stage lead or lag compensation.

5 Followers
 · 
953 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Brushless direct current (BLDC) motors have advantages viz. high torque per weight, high torque per watt, increased reliability, reduced noise and a longer lifetime. A BLDC motor is an electronically commutated motor. Electronic commutation is sparkless because it does not involve any mechanical commutator and brush. It also eliminates electromagnetic interference. Because of these advantages, BLDC motors can also be used in hazardous environments. They find wide applications in industrial positioning and actuation. The wider usage of BLDC motors demands optimum position control in such applications for high efficiency, accuracy and reliability. A first order compensated BLDC drive is proposed in this paper to achieve effective position control. Simulation results at different loads clearly reveal that the proposed first order compensated BLDC drive system could yield comparable results with a proportional integral derivative controlled BLDC drive system. A proposed first order compensator is designed using analog components and the experimental results of compensated BLDC drive system are obtained to show the usefulness of the compensator for effective position control.
    Journal of Vibration and Control 07/2013; 21(4). DOI:10.1177/1077546313486276 · 4.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a simple method for determining analytical solutions to lag/lead cascade and general second order compensator design problems in the frequency domain. Only linear and quadratic equations are used in the proposed approach. Results obtained here can be used to eliminate conventional graphic-based trial-and-error method used in past and contemporary control textbooks, which are tedious and time-consuming, and rewrite them into simple and analytical non-trial-and-error steps. Index Terms—Lag/lead compensators, cascade compensation, trial-and-error, analytic solution.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Continuous monitoring of respiratory activity is required in many clinical settings from emergency departments to operating theatres and high dependency intensive care units. Current techniques such as nasal thermistors, capnography and monitoring of transthoracic impedance are prone to movement artifact or difficult to use in a continuously ventilating patient. To help overcome some of these problems, it was reported in literature that it is possible to extract respiratory activity from the Photoplethysmogram (PPG) using wavelet transform based methods. In this paper, we present a robust yet simple ICA based signal processing method to extract the surrogate respiratory activity from non-invasive recordings of artifact corrupted PPG signals. To prove the efficacy of proposed method, experimental results are carried out considering two commonly encountered motion artifacts of PPG signals. Simulation results and statistical calculations in terms of Magnitude Squared Coherence (MSC), Relative Correlation Co-efficient (RCC) and Accuracy Rate (AR) indicated a strong correlation between the extracted respiratory signal with that of original respiratory signal.
    Recent Advances in Intelligent Computational Systems (RAICS), 2011 IEEE; 01/2011

Preview

Download
58 Downloads
Available from