Abstract
The paper studies the control problem for nonlinear uncertain systems with the situation that only the current reference signal is available. By constructing a memory structure to save the previous reference signals, a novel error-based active disturbance rejection control with an approximation for the second-order derivative of reference signal is proposed. The transient performance of the proposed method is rigorously studied, which implies the high consistence of the closed-loop system. More importantly, to attain the satisfactory tracking performance, the necessary condition for nominal control input gain is quantitatively investigated. Furthermore, the superiority of the proposed method is illuminated by contrastively evaluating the sizes of the total disturbance and its derivative. The proposed method can alleviate the burden of the estimation and compensation for total disturbance. Finally, the experiment for a manipulator platform shows the effectiveness of the proposed method.
Highlights
Uncertainties, including external disturbances, unmodeled nonlinear dynamics and parametric perturbations, are ubiquitous in industrial process
Among various substantially developed control methods, uncertainty estimation and compensation-based methods show the powerful capability of tackling uncertainties and the simplicity of practical implementation, including but not limited to disturbance observer–based control,[1,2,3] uncertainty and disturbance estimator–based control,[4] unknown input observer–based control,[5,6] and active disturbance rejection control (ADRC).[7,8]
ADRC is innovatively proposed by Jingqing Han,[7] which is featured with two-degree-of-freedom (2-DOF) design
Summary
Uncertainties, including external disturbances, unmodeled nonlinear dynamics and parametric perturbations, are ubiquitous in industrial process. Based on the reference signal at the current time, a modified ADRC for a large scope of nonlinear uncertainty f and uncertain control input term (b À b)u is presented . By approximating the second-order derivative of the reference signal based on additional memory structure, the total disturbance is shown in (7), which can effectively alleviate the estimating burden of ESO. The properties of the proposed ADRC are comprehensively investigated, including transient performance, necessary condition for nominal control input gain and superiority of memory design. To ensure the satisfied transient performance of the proposed ADRC, that is, (3), (5), and (8)–(11), the necessary condition for nominal control input gain is studied.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
