Cited by 3Advanced Control Systems DesignStability and Control of Uncertain SystemsAdaptive Control of Nonlinear Systems

A comparative study on time-delay estimation for time-delay nonlinear system control

Open access
Nahri, Syeda Nadiah Fatima, Department of Electrical Engineering, Faculty of Engineering and the Built Environment, Tshwane University of Technology, Pretoria 0001, South Africa, Du, Shengzhi, van Wyk, Barend J., Ajayi, Oluwaseun Kayode·2025·AIMS Electronics and Electrical Engineering

Abstract

Time delay and disturbances are commonly encountered in real-world application systems, and their existence significantly hampers the operation of various controllers available in the discipline of control systems theory. Time-delay estimation and disturbance compensation are closely related to obtaining the desired system stability and efficient controller operation. This paper discusses state-of-the-art methods for time-delay estimation (TDE)-based methods related to active disturbance rejection control (ADRC) methods and proportional-integral-derivative (PID) controllers found in the latest literature on control systems theory. The methodology includes simulation designs incorporating the integration of predictive extended state observer-based ADRC (PESO-ADRC) and conventional PID controllers with the TDE mechanism, followed by their respective control on systems with time delay and disturbances. A comparative analysis performed on the TDE compensation methods highlights that TDE enhances the robustness to time delay, various uncertainties, and nonlinear dynamics existing in the controlled system. The time-varying delay, nonlinear backlash-like hysteresis, and an added system external disturbance were considered in the simulation. The performance was measured based on specific transient response characteristics such as the rise time, settling time, overshoot criteria, and performance index measures such as the integral of time-weighted absolute error (ITAE) and the percentage of improvement by the decrease in overshoot given by $ {P}_{i} $ (%). Further, a sensitivity analysis of TDE parameters to the controllers' operation was also performed. Experimental results indicate stability and a strong capacity to regulate the transient and steady-state responses under the impact of various uncertainties. Therefore, the comparative analysis conducted between TDE-ADRC and TDE-PID control methods signifies the importance of TDE with disturbance compensation in time-delayed systems, commonly found in real-world industrial applications.

AI snapshot

Written from the paper’s full text.

TL;DR

This paper compares time-delay estimation (TDE)-based predictive ESO-ADRC and TDE-based PID controllers for a second-order time-delay system under hysteresis, parameter perturbation, external disturbances, and varying delay. It finds TDE improves robustness, with TDE-PESO-ADRC better for nonlinear/periodic disturbances and TDE-PID better for larger time delays.

Key findings

  • With no uncertainties, TDE-PESO-ADRC improved rise time by 23.81%, settling time by 62.07%, overshoot by 55.25%, and ITAE by 52.26%; TDE-PID improved rise time by 19.49%, settling time by 25.18%, and ITAE by 28.54%, but overshoot increased from 0.0000% to 1.2581%.
  • Under nonlinear backlash-like hysteresis, TDE-PESO-ADRC improved ITAE by 81.23% and overshoot by 52.29%; TDE-PID improved settling time by 61.09% and ITAE by 64.74%, but rise time worsened by 20.04% and overshoot improved only 0.68%.
  • Under hysteresis plus 25% parameter perturbation, TDE-PESO-ADRC improved settling time by 34.79%, ITAE by 80.44%, and overshoot by 42.64%; TDE-PID showed ITAE improvement of approximately 0%, settling time improvement of 8.61%, overshoot improvement of 12.13%, and rise time improvement of 11.66%.
  • With added external disturbances, TDE-PESO-ADRC handled step and periodic disturbances where non-TDE PESO-ADRC was unstable; TDE-PID was unstable under the periodic disturbance. For varying delays, TDE-PID withstood delays up to 0.6 s, while TDE-PESO-ADRC compensated up to 0.16 s.

Methods

  • Simulation-based comparative study of TDE-PESO-ADRC and TDE-PID on a second-order time-delay system \(G(s)=2/(s^2+3s+2)e^{-\tau s}=1/((s+1)(0.5s+1))e^{-\tau s}\), with system delay \(\tau=0.1\) s and state-space matrices \(A=[-3\ 1;2\ 0]\), \(B=[0;2]\), \(C=[1\ 0]\).
  • Seven experiments: no uncertainty; Duhem backlash-like hysteresis; 25% parameter perturbation at 20 s; added step and periodic external disturbances; varying system time delay; control signal saturation; and sensitivity analysis of TDE parameters.
  • Performance measured by rise time, response time, settling time, overshoot, ITAE, and percentage improvement \(P_i(\%)\); ADRC parameters were optimized using MATLAB genetic algorithm, while PID gains were manually tuned to \(K_p=1\), \(K_i=0.8\), \(K_d=0.1\), with gain factor \(b=0.2\).

Limitations

  • The paper states future work is needed for adaptive TDE gains under periodic disturbances, improved TDE for unknown and higher delay values, and consideration of noise and friction on higher-order systems; hardware-based human-machine interface and digital twin work is underway.
  • Evident from the text: the study is simulation-only on a second-order benchmark, not a hardware validation; TDE-PESO-ADRC was tested only up to 0.16 s delay, and TDE-PID responses oscillated for delay values of 0.5 s and above.
  • Evident from the tables: several comparisons are limited by unstable or unplotted responses, such as non-TDE PESO-ADRC under added disturbance and TDE-PID under periodic disturbance, so some \(P_i(\%)\) values could not be tabulated.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3934/electreng.2025015

Cites

31 of 32 references verified0 citation errors · 1 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

3 of 29 cited sources checked · 2 supported · 0 flagged · accuracy not yet measured

  • Findingown data

    For the PID control scheme, rise time was 1.0316 s with TDE versus 1.1677 s without TDE.

    “The RT was 1.0316 s with TDE vs 1.1677 s without TDE for the PID control scheme, and 0.4007 s with TDE compared to 0.7052 s without TDE for the PESO-ADRC approach.”
    Quote in the paperSubstantial claim
  • Findingown data

    For PESO-ADRC with TDE control, ITAE value is decreased by 52.26%.

    “Further, the settling time, ITAE value, and overshoot are decreased by 62.07%, 52.26%, and 55.25%, thus showing a greater performance improvement for PESO-ADRC with TDE control.”
    Quote in the paperSubstantial claim
  • Findingown data

    For the TDE-PID controller with added disturbance f1, the overshoot decreased by 14% between 20 and 25 seconds.

    “However, for the TDE-PID controller with added disturbance in Equation ( 21), the overshoot decreased by 14% between 20 and 25 seconds.”
    Quote in the paperNot a substantial claim
  • Findingown data

    For the TDE-PESO-ADRC method, the initial system response's overshoot was greatly reduced by 45%.

    “For the TDE-PESO-ADRC method, the initial system response's overshoot was greatly reduced by 45%; however, for the case of PID with TDE, the decrease in initial overshoot was not observed.”
    Quote in the paperSubstantial claim
  • Findingown data

    For PESO-ADRC with TDE control, settling time is decreased by 62.07%.

    “Further, the settling time, ITAE value, and overshoot are decreased by 62.07%, 52.26%, and 55.25%, thus showing a greater performance improvement for PESO-ADRC with TDE control.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 20
  • May combine two claims. 15
  • The quote only partly states this claim. 4
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Other controller methods commonly used in integration with the TDE mechanism for attenuation of system nonlinearities include PID, adaptive sliding mode controller (SMC), and fuzzy logic approach-based control methods.

    “Other controller methods commonly used in integration with the TDE mechanism for attenuation of system nonlinearities include, for example, the PID controller [18], adaptive sliding mode controller (SMC) [19], and fuzzy logic approach-based [20] control methods.”
    Quote in the paperNot a substantial claim1 of 3 sources checked
    • cites [18] Wang Y, Peng J, Zhu K, Chen B, Wu H (2020) Adaptive PID-fractional-order nonsingular terminal sliding mode control for cable-driven manipulators using time-delay estimation. <i>Int J Syst Sci</i> 51: 3118‒3133. https://doi.org/10.1080/00207721.2020.1808732. source
    • cites [19] Taefi M, Khosravi MA (2024) A model free adaptive‐robust design for control of robot manipulators: time delay estimation approach. <i>Int J Robust Nonlinear Control</i> 34: 8227‒8247. https://doi.org/10.1002/rnc.7379 source
    • cites [20] Glida HE, Chelihi A, Abdou L, Sentouh C, Perozzi G (2023) Trajectory tracking control of a coaxial rotor drone: Time-delay estimation-based optimal model-free fuzzy logic approach. <i>ISA T</i> 137: 236‒247. https://doi.org/10.1016/j.isatra.2022.12.015 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The PID controller depicts decent accomplishment in overcoming various nonlinearities, such as the chattering effect, delay, and external disturbances present in robotic industries.

    “The PID controller depicts decent accomplishment in overcoming various nonlinearities, such as the chattering effect, delay, and external disturbances present in robotic industries [14].”
    Quote in the paperNot a substantial claim1 of 1 sources checked
    • cites [14] Pham TT, Nguyen CN (2023) Adaptive PID sliding mode control based on new Quasi-sliding mode and radial basis function neural network for Omni-directional mobile robot. <i>AIMS Electronics &amp; Electrical Engineering</i> 7: 121‒134. https://doi.org/10.3934/electreng.2023007 source

      The Abstract and Conclusions report reduced chattering for a PID sliding-mode controller combined with a quasi-sliding-mode function and an RBF neural network. Section 4 reports robust trajectory tracking under simulated sensor noise and parameter changes. The paper does not show that a PID controller alone overcomes these effects or demonstrate that the proposed controller overcomes communication delay; delay appears only as a problem mentioned in the Introduction. Page numbers are unavailable in our copy. (LLM, conf=0.87)

      Experimental — accuracy not yet measured
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    The selection of the ESPO observer bandwidth ωe is regulated by the Hurwitz stability criterion.

    “The Hurwitz stability criterion regulates the selection of 𝜔 𝑒 ; thus, the complete details of the ESPO used in this study are outlined in [30,31].”
    Quote in the paperNot a substantial claim1 of 2 sources checked
    • cites [30] Nahri SNF, Du S, van Wyk BJ (2023) Predictive Extended State Observer-Based Active Disturbance Rejection Control for Systems with Time Delay. <i>Machines</i> 11: 144. https://doi.org/10.3390/machines11020144 source
    • cites [31] Xue W, Liu P, Chen S, Huang Y (2016) On extended state predictor observer based active disturbance rejection control for uncertain systems with sensor delay. <i>2016 16th International Conference on Control, Automation and Systems (ICCAS), </i> 1267‒1271. IEEE. <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1109/ICCAS.2016.7832475">https://doi.org/10.1109/ICCAS.2016.7832475</ext-link> source
  • May combine two claims.

    Findingown data

    The TDE mechanism improved performance for the PID controller regarding quicker settling time, smaller steady-state error, and smaller ITAE.

    “Meanwhile, the TDE mechanism improved performance for the PID controller regarding quicker settling time, smaller steady-state error, and smaller ITAE.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    For the PID controller, rise time was 1.5263 s with TDE and 1.8958 s without the TDE mechanism.

    “It was observed that with the TDE present, the controlled system rose faster for both control scenarios (TDE-PID and TDE-PESO-ADRC), i.e., for the PID controller RT = 1.5263 s with TDE, and RT = 1.8958 s without the TDE mechanism.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The TDE-PESO-ADRC could conquer the unsteady behavior and provide an acceptable response curve that demonstrated considerable resistance to system uncertainties.

    “However, by incorporating the TDE mechanism in this circumstance, the TDE-PESO-ADRC could conquer this unsteady behavior and provide an acceptable response curve that demonstrated considerable resistance to system uncertainties (Figure 10 and Table 4).”
    Quote in the paperSubstantial claim
  • The quote only partly states this claim.

    Findingown data

    Both TDE-PID and TDE-PESO-ADRC controlled systems displayed a shorter rise time (RT) when TDE was introduced under hysteresis, parameter perturbation, and added external disturbance.

    “As indicated in Table 4, Figures 9 and 10 demonstrate that both the controlled system with the TDE mechanism displayed a shorter rise (RT) when the TDE was introduced.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    There is a minimal decrease in system overshoot in the TDE-PID control strategy and a longer rising time.

    “However, as shown in Table 2, there is a minimal decrease in system overshoot in the TDE-PID control strategy and a longer rising time.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    Experimental results indicate stability and a strong capacity to regulate the transient and steady-state responses under the impact of various uncertainties.

    “Experimental results indicate stability and a strong capacity to regulate the transient and steady-state responses under the impact of various uncertainties.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Time delay is the most crucial aspect that greatly impairs the performance of the controlled system.
    • Rests on an assumption: Time delay impairments include response overshooting with oscillations, reduced damping ratio, and moving the closed-loop system response to instability.
  • May combine two claims.

    Findingown data

    Integrating TDE with the predictive ADRC method gives a system response with robustness, less oscillatory behavior, reduced overshoot, and quick system recovery to uncertainties, contrary to the TDE-PID system response and performance.

    “Furthermore, by integrating the TDE with the predictive ADRC method, the system response in Figure 7 shows robustness and thus less oscillatory behavior, reduced overshoot, and quick system recovery to uncertainties, contrary to the TDE-PID system response and performance.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Time delay is the most crucial aspect that greatly impairs the performance of the controlled system.
    • Rests on an assumption: Time delay impairments include response overshooting with oscillations, reduced damping ratio, and moving the closed-loop system response to instability.
  • The quote only partly states this claim.

    Findingown data

    The TDE mechanism in TDE-PESO-ADRC showed a decrease in overshoot at the beginning of the transient response under hysteresis, parameter perturbation, and added disturbance f1.

    “In addition, the TDE mechanism in the TDE-PESO-ADRC showed a decrease in overshoot at the beginning of the transient response”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim.

    Findingreasoning

    Both Figure 10 and Table 4 do not include the system response's performance measures for the TDE-PID method because of the oscillatory character of the periodic external disturbance f2 added to the system under test.

    “Similarly, both Figure 10 and Table 4 do not include the system response's performance measures for the TDE-PID method because of the oscillatory character of the periodic external disturbance given in Equation ( 22) added to the system under test, seen in Equation (18).”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The systems responded more quickly and had a shorter rise when TDE was present.

    “Table 3 and Figure 8 demonstrate that the systems responded more quickly and had a shorter rise when TDE was present.”
    Quote in the paperSubstantial claim
  • The quote only partly states this claim.

    Findingown data

    For the TDE-PESO-ADRC method, the initial amplitude of the control signal is reduced from almost 10 to 5 when a saturation block with upper limit 5 and lower limit -5 is added.

    “As observed in Figure 14(a), for the TDE-PESO-ADRC method, the initial amplitude of the control signal is reduced from almost 10 to 5.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    For the TDE-based PESO-ADRC controller, system responses were oscillatory for greater system latencies, but they could compensate for nonlinear uncertainties, demonstrating decent strength and steady performance for distinct delay scenarios.

    “It is seen that the system responses were therefore oscillatory for greater system latencies, but they could compensate for nonlinear uncertainties, demonstrating decent strength and steady performance for distinct delay scenarios.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Findingown data

    The performance criteria displayed in Table 6 for changes in the TDE-PID controlled system delay responses showed robustness and significant compensation for all forms of disturbances present.

    “Furthermore, the performance criteria displayed in Table 6 for changes in the TDE-PID controlled system delay responses showed robustness and significant compensation for all forms of disturbances present.”
    Quote in the paperSubstantial claim
  • The quote only partly states this claim.

    Findingown data

    For the TDE-PID control method, the initial peak is reduced from 11 to 5 when a saturation block with upper limit 5 and lower limit -5 is added.

    “Moreover, for the TDE-PID control method, the initial peak is reduced from 11 to 5.”
    Quote in the paperNot a substantial claim
  • May combine two claims.

    Findingown data

    The TDE-PID controller showed good robustness to various uncertainties, with shorter rise time and settling time, stable system response, and decreased oscillations.

    “Also, the TDE-PID controller showed good robustness to various uncertainties, with shorter rise time and settling time, stable system response, and decreased oscillations.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Premisecitation

    In control systems, hysteresis can result in oscillation, instability, and incorrect positioning.

    “Therefore, in control systems, hysteresis can result in oscillation, instability, and incorrect positioning.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [27] Ikhouane F (2018) A survey of the hysteretic Duhem model. <i>Arch Comput Method Eng</i> 25: 965‒1002. https://doi.org/10.1007/s11831-017-9218-3 source
    • cites [28] Jing N, Qiang C, Xuemei R (2018) Chapter 16 - Hysteresis Dynamics and Modeling. In: Jing N, Qiang C, Xuemei R, editors. <i>Adaptive Identification and Control of Uncertain Systems with Non-smooth Dynamics</i>, 249‒256. <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1016/B978-0-12-813683-6.00021-0">https://doi.org/10.1016/B978-0-12-813683-6.00021-0</ext-link>

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The ESO is an integral feature of the ADRC controller and accomplishes the active disturbance measurement and compensation.

    “This is accomplished with an extended state observer (ESO), an integral feature of the ADRC controller [7].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Han J (2009) From PID to Active Disturbance Rejection Control. <i>IEEE T Ind Electron</i> 56: 900‒906. https://doi.org/10.1109/TIE.2008.2011621 source
  • May combine two claims.

    Interpretationown data

    TDE enhances the robustness to time delay, various uncertainties, and nonlinear dynamics existing in the controlled system.

    “A comparative analysis performed on the TDE compensation methods highlights that TDE enhances the robustness to time delay, various uncertainties, and nonlinear dynamics existing in the controlled system.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Time delay is the most crucial aspect that greatly impairs the performance of the controlled system.
    • Rests on an assumption: In most TDE-based methods, the stability and performance of the controller design are greatly impaired under the influence of external disturbances and varying system time-delay circumstances.
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Model-free control approaches consider a variety of system uncertainties, including internal and external disturbances, nonlinear hysteresis, sensor noise, and varying time delay.

    “In contrast, the latter considers a variety of system uncertainties, including internal and external disturbances, nonlinear hysteresis, sensor noise, and varying time delay [4][5][6].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4][5][6]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    For α < 1, the error e will decrease to zero more quickly.

    “For 𝛼 < 1, the error (𝑒) will decrease to zero more quickly.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S2 (checkable).

    Premisecitation

    Despite consistent efforts to conquer the time-delay problem, the adverse effects of delay are still difficult to overcome.

    “However, despite consistent efforts to conquer the time-delay problem, the adverse effects of delay are still difficult to overcome.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [15] Ran M, Wang Q, Dong C, Xie L (2020) Active disturbance rejection control for uncertain time-delay nonlinear systems. <i>Automatica</i> 112: 108692. https://doi.org/10.1016/j.automatica.2019.108692 source
    • cites [16] Chen S, Xue W, Zhong S, Huang Y (2018) On comparison of modified ADRCs for nonlinear uncertain systems with time delay. <i>Sci China Inform Sci</i> 61: 1‒15. https://doi.org/10.1007/s11432-017-9403-x source
  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The hysteresis effect affects the precision of both closed-loop and open-loop control systems and leads to persistent oscillations.

    “The hysteresis effect is widely acknowledged to affect the precision of both closed-loop and open-loop control systems and lead to persistent oscillations.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [27] Ikhouane F (2018) A survey of the hysteretic Duhem model. <i>Arch Comput Method Eng</i> 25: 965‒1002. https://doi.org/10.1007/s11831-017-9218-3 source
    • cites [28] Jing N, Qiang C, Xuemei R (2018) Chapter 16 - Hysteresis Dynamics and Modeling. In: Jing N, Qiang C, Xuemei R, editors. <i>Adaptive Identification and Control of Uncertain Systems with Non-smooth Dynamics</i>, 249‒256. <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1016/B978-0-12-813683-6.00021-0">https://doi.org/10.1016/B978-0-12-813683-6.00021-0</ext-link>

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The TDE control mechanism is crucial for analyzing and mitigating all kinds of nonlinear phenomena subjected to a time-delayed system under control.

    “Therefore, this emphasizes how crucial the TDE control mechanism is for analyzing and mitigating all kinds of nonlinear phenomena subjected to a time-delayed system under control.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The ESO is a fundamental element of the ADRC that actively estimates and compensates for the overall disturbance f(t) imposed on the controlled object.

    “The ESO is a fundamental element of the ADRC that actively estimates and compensates for the overall disturbance 𝑓 𝑡 imposed on the controlled object given by Equation ( 1).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Han J (2009) From PID to Active Disturbance Rejection Control. <i>IEEE T Ind Electron</i> 56: 900‒906. https://doi.org/10.1109/TIE.2008.2011621 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    ADRC is one of the most widely employed model-free controllers, whose model is updated continually to perform disturbance compensation in time-delay control.

    “In the literature, one of the most widely employed model-free controllers is an active disturbance rejection control (ADRC), whose model is updated continually to perform disturbance compensation in time-delay control [7,8].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [7] Han J (2009) From PID to Active Disturbance Rejection Control. <i>IEEE T Ind Electron</i> 56: 900‒906. https://doi.org/10.1109/TIE.2008.2011621 source
    • cites [8] Nahri SNF, Du S, van Wyk BJ, Nyasulu TD (2024) Time-Delay Estimation Improves Active Disturbance Rejection Control for Time-Delay Nonlinear Systems. <i>Machines</i> 12: 552. https://doi.org/10.3390/machines12080552 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The PID controller is one of the most widely used control processes in the field of industrial applications.

    “The PID controller is one of the most widely used control processes in the field of industrial applications [32].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [32] Borase RP, Maghade D, Sondkar S, Pawar S (2021) A review of PID control, tuning methods and applications. <i>International Journal of Dynamics and Control</i> 9: 818‒827. https://doi.org/10.1007/s40435-020-00665-4 source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The performance of an ADRC controller concerning estimation and attenuation of nonlinear backlash-like hysteresis under time delay and uncertainties is greatly improved in conjunction with TDE mechanisms.

    “Moreover, recent research has shown that the performance of an ADRC controller concerning estimation and attenuation of nonlinear backlash-like hysteresis under time delay and uncertainties is greatly improved in conjunction with TDE mechanisms [8,17].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [8] Nahri SNF, Du S, van Wyk BJ, Nyasulu TD (2024) Time-Delay Estimation Improves Active Disturbance Rejection Control for Time-Delay Nonlinear Systems. <i>Machines</i> 12: 552. https://doi.org/10.3390/machines12080552 source
    • cites [17] Nahri SNF, Du S, Van Wyk B, Ajayi OK, Nyasulu TD, Yu H (2025) Improvement of Proportional-Integral-Derivative Control for Time-Delay Nonlinear Systems by a Time-Delay Estimation Method. <i>2025</i> <i>33rd Southern African Universities Power Engineering Conference (SAUPEC 2025), </i> 1‒6. IEEE. <ext-link ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://doi.org/10.1109/SAUPEC65723.2025.10944363">https://doi.org/10.1109/SAUPEC65723.2025.10944363</ext-link> source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The ESO component has been amended over time to accommodate ADRC operation in industrial applications, including robotic systems, power plants, teleoperation systems, and piezoelectric-related medical fields.

    “Therefore, to mitigate the effects of different types of uncertainties acting on a concerned system, the ESO component has been amended over time to accommodate the ADRC operation in industrial applications; for example, in robotic systems [10], power plants [11], teleoperation systems [12], and piezoelectric-related medical fields [13].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [10] Fareh R, Khadraoui S, Abdallah MY, Baziyad M, Bettayeb M (2021) Active disturbance rejection control for robotic systems: A review. <i>Mechatronics</i> 80: 102671. https://doi.org/10.1016/j.mechatronics.2021.102671 source
    • cites [11] Sun L, Xue W, Li D, Zhu H, Su ZG (2021) Quantitative tuning of active disturbance rejection controller for FOPTD model with application to power plant control. <i>IEEE T Ind Electron</i> 69: 805‒815. https://doi.org/10.1109/TIE.2021.3050372 source
    • cites [12] Gu S, Zhang J, Liu X (2024) Event-Triggered Finite-Time Variable Gain ADRC for Master–Slave Teleoperated Parallel Manipulators. <i>IEEE Transactions on Circuits and Systems II: Express Briefs</i> 71: 3383‒3387. https://doi.org/10.1109/TCSII.2024.3359318 source
  • Classified as probably not a substantial claim.

    Premisecitation

    Time-delay estimation followed by compensation is still a work in progress for various disturbance rejection control methods.

    “Thus, time-delay estimation followed by compensation is still a work in progress for various disturbance rejection control methods [15,16].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [15] Ran M, Wang Q, Dong C, Xie L (2020) Active disturbance rejection control for uncertain time-delay nonlinear systems. <i>Automatica</i> 112: 108692. https://doi.org/10.1016/j.automatica.2019.108692 source
    • cites [16] Chen S, Xue W, Zhong S, Huang Y (2018) On comparison of modified ADRCs for nonlinear uncertain systems with time delay. <i>Sci China Inform Sci</i> 61: 1‒15. https://doi.org/10.1007/s11432-017-9403-x source
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    TDE reduces the total effect of cumulative disturbances.

    “Consequently, the TDE reduces the total effect of cumulative disturbances.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The characteristic feature of ADRC is its ability to measure internal and external disturbances actively, generally coined as total disturbance, and then compensate for these total disturbance effects in real-time via the feedback loop.

    “The characteristic feature of the ADRC controller is its ability to measure internal and external disturbances actively, generally coined as -total disturbance‖, and then compensate for these total disturbance effects in real-time via the feedback loop.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Han J (2009) From PID to Active Disturbance Rejection Control. <i>IEEE T Ind Electron</i> 56: 900‒906. https://doi.org/10.1109/TIE.2008.2011621 source
  • Classified as probably not a substantial claim.

    Study design and conductown data

    The results obtained were validated using measures such as performance index metrics and transient response characteristics.

    “The results obtained were validated using measures such as performance index metrics and transient response characteristics.”
    Quote in the paperSubstantial claim
  • May combine two claims.

    Interpretationown data

    The variations in performance criteria measures when b is varied are within acceptable limits, showing less sensitivity to varying b parameter in a relatively small range.

    “Hence, it is seen that the performance criteria measures experience certain changes when 𝑏 of the TDE-PID controller is varied, but these variations observed are within acceptable limits, hence showcasing less sensitivity to varying 𝑏 parameter in a relatively small range.”
    Quote in the paperNot a substantial claim
  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    A sensitivity analysis was conducted on the choice of specific TDE parameters for TDE-based controllers to validate their respective selected values.

    “Furthermore, a sensitivity analysis was conducted on the choice of specific TDE parameters for TDE-based controllers to validate their respective selected values.”
    Quote in the paperNot a substantial claim
37 of 37
  • The paper relies on this without support.

    Time delay is the most crucial aspect that greatly impairs the performance of the controlled system.

    “Further, the time delay aspect is the most crucial aspect that greatly impairs the performance of the controlled system.”
  • The paper relies on this without support.

    Time delay impairments include response overshooting with oscillations, reduced damping ratio, and moving the closed-loop system response to instability.

    “Impairments include response overshooting with oscillations, reduced damping ratio, and moving the closed-loop system response to instability.”
  • The paper relies on this without support.

    In most TDE-based methods, the stability and performance of the controller design are greatly impaired under the influence of external disturbances and varying system time-delay circumstances.

    “Therefore, in most TDE-based methods, it has been observed that the stability and performance of the controller design are greatly impaired under the influence of external disturbances and varying system time-delay circumstances.”
  • The paper relies on this without support.

    When nonlinearity or disturbance is added to a PID-controlled system, it drives the system to instability or inadequate performance.

    “When nonlinearity or disturbance is added to a PID-controlled system, it drives the system to instability or inadequate performance.”
  • The paper relies on this without support.

    The second-order system with time delay is a benchmark system representative for various industrial plants.

    “Such a system is chosen as a benchmark system under testing for various industrial plants.”
  • The paper relies on this without support.

    Factors like time delay, hysteresis, parameter perturbation, external disturbances, and noise are inevitable in real-world system applications.

    “This is mainly due to factors like time delay, hysteresis, parameter perturbation, external disturbances, and noise, which are inevitable in real-world system applications.”
6 of 6

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Experiment 4 gives opposite stability claims for TDE-PESO-ADRC

    Minor

    The text says the TDE-PESO-ADRC response is unstable for both external-disturbance cases and is not plotted, then says adding TDE overcomes that instability and produces an acceptable response curve. Table 4 also lists numerical performance measures for both TDE-included cases.

  • State-space matrix does not represent the stated transfer function

    Minor

    The stated matrix A has a positive 2 in its lower-left position. Together with the stated B and C, it produces a denominator of s2+3s−2, rather than the s2+3s+2 denominator in Equation (18).

2 of 2

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Wen-bin Y, Dong Y (2015) Modeling and Simulation of an Active Disturbance Rejection Controller Based on Matlab/Simulink. <i>International Journal of Research in Engineering and Science (IJRES)</i> 3: 62‒69.

Cited by

Sorted by citations

Authors
Nahri, S. N. F., Department of Electrical Engineering, F. O. E. A. T. B. E., Du, S., van Wyk, B. J., & Ajayi, O. K.
Affiliations
Tshwane University of Technology (ZA)
Venue
AIMS Electronics and Electrical Engineering
Published
2025
Volume
9
Issue
3
Pages
314-338
ISSN
2578-1588 (ISSN-L)
OpenAlex
W4411110641
Cited by
3
References
31
Citations by year
2026: 2 · 2025: 1
FWCI
1.18
Type
journal article
Language
en
Open access
Licence
cc-by-nc-sa
Locations
  • AIMS Electronics and Electrical Engineering (publishedVersion, cc-by-nc-sa)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
  • National Research Foundation
  • Tshwane University of Technology
Topics
  • Physical Sciences › Engineering › Control and Systems Engineering › Advanced Control Systems Design
  • Physical Sciences › Engineering › Control and Systems Engineering › Stability and Control of Uncertain Systems
  • Physical Sciences › Engineering › Control and Systems Engineering › Adaptive Control of Nonlinear Systems
Keywords
time delay estimation, active disturbance rejection control, extended state observer, PID control, time-delay systems, disturbance compensation, backlash-like hysteresis, time-varying delays, nonlinear systems, transient response, robustness to uncertainty

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

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Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-12.

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