Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Time-Domain Interpretation of PD Control

Time-Domain Interpretation of PD Control

Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization.
Consider the example of control of motor torque. Initially, a positive...

Routh-Hurwitz Criterion I

Routh-Hurwitz Criterion I

Consider an electrical power grid, where stability is essential to prevent blackouts. The Routh-Hurwitz criterion is a valuable tool for assessing system stability under varying load conditions or faults. By analyzing the closed-loop transfer function, the Routh-Hurwitz criterion helps determine whether the system remains stable.
To apply the Routh-Hurwitz criterion, a Routh table is constructed. The table's rows are labeled with powers of the complex frequency variable s, starting from the...

Routh-Hurwitz Criterion II

Routh-Hurwitz Criterion II

In the application of the Routh-Hurwitz criterion, two specific scenarios can arise that complicate stability analysis.
The first scenario occurs when a singular zero appears in the first column of the Routh table. This situation creates a division by zero issues. To resolve this, a small positive or negative number, denoted as epsilon (∈), is substituted for the zero. The stability analysis proceeds by assuming a sign for ∈. If ∈ is positive, any sign change in the first column of the Routh...

Second Order systems II

Second Order systems II

In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
If ζ...

Expected Frequencies in Goodness-of-Fit Tests

Expected Frequencies in Goodness-of-Fit Tests

A goodness-of-fit test is conducted to determine whether the observed frequency values are statistically similar to the frequencies expected for the dataset. Suppose the expected frequencies for a dataset are equal such as when predicting the frequency of any number appearing when casting a die. In that case, the expected frequency is the ratio of the total number of observations (n) to the number of categories (k).

The Anderson-Darling Test

The Anderson-Darling Test

The Anderson-Darling test is a statistical method used to determine whether a data sample is likely drawn from a specific theoretical distribution. Unlike parametric tests, it does not require assumptions about specific parameters of the distribution. Instead, it compares the sample's empirical cumulative distribution function (ECDF) with the cumulative distribution function (CDF) of the hypothesized distribution. Critical values for the test are specific to the chosen distribution rather than...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

QTOF and Orbitrap Technologies in Modern Pesticide Analysis: Applications in Residue Detection and Degradation Pathway Elucidation.

Journal of analytical methods in chemistry·2026

Same author

Longitudinal analysis of peripheral blood immune status and prognosis dynamic prediction for advanced colon cancer with first-line chemotherapy.

Cancer immunology, immunotherapy : CII·2026

Same author

Recognition of basic affective prosody in children with autism spectrum conditions: A three-level meta-analysis based on emotional dimension theory.

Journal of communication disorders·2025

Same author

MDSF-YOLO: Advancing Object Detection With a Multiscale Dilated Sequence Fusion Network.

IEEE transactions on neural networks and learning systems·2025

Same author

Fault-Tolerant Synchronization Control of Switched Complex Networks by a Proportional-Integral Intermediate Observer Approach.

IEEE transactions on cybernetics·2025

Same author

Pulmonary Artery Denervation for Idiopathic Pulmonary Arterial Hypertension: A Case Report.

Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions·2025

Search research articles

Related Experiment Video

Updated: Jul 13, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

Published on: December 9, 2015

Modified Smith predictor design for periodic disturbance rejection.

Han-Qin Zhou¹, Qing-Guo Wang, Liu Min

¹Control Systems Engineering, Jacobs Engineering Group, Inc., Houston, TX 77072, USA.

ISA Transactions

|August 1, 2007

Summary

A modified Smith predictor control scheme enhances periodic disturbance rejection in time-delayed processes. This improved control strategy maintains excellent setpoint response while boosting regulation performance and non-periodic disturbance rejection.

More Related Videos

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Published on: January 31, 2014

Related Experiment Videos

Last Updated: Jul 13, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data

Published on: December 9, 2015

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Published on: January 31, 2014

Area of Science:

Control Engineering
Process Systems Engineering

Background:

Time-delay systems present significant control challenges, particularly in rejecting periodic disturbances.
Traditional Smith predictor control offers good setpoint tracking but can be limited in disturbance rejection capabilities.

Purpose of the Study:

To propose a modified Smith predictor control scheme for enhanced periodic disturbance rejection.
To improve the regulation performance of stable and unstable time-delay processes under periodic disturbances.
To maintain the inherent advantages of Smith predictor control regarding setpoint response.

Main Methods:

A modified Smith predictor control algorithm is designed.
The internal stability of the closed-loop system is rigorously analyzed.
The proposed scheme is validated through extensive simulations.
Experimental testing on a thermal system is conducted to demonstrate effectiveness.

Main Results:

The modified Smith predictor significantly enhances periodic disturbance rejection.
Superior setpoint response of the original Smith predictor is preserved.
Improved asymptotic rejection of non-periodic disturbances is achieved.
Internal stability of the closed-loop system is confirmed.

Conclusions:

The proposed modified Smith predictor control scheme effectively addresses periodic disturbance rejection in time-delay systems.
The enhanced control strategy offers a practical solution for improving process regulation.
The method is validated for both simulated and real-world experimental systems.