A comparative study of nonlinear observers applied to a DC servo motor

Al-Bayati, Ahmad Hussain; Skaf, Zakwan; Wang, Hong

doi:10.1109/wcica.2010.5554202

Cited by 9 publications

(7 citation statements)

References 27 publications

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“…The solution requires no a-priori knowledge of the boundedness or the statistical properties of the system and measurement noises. Testing results confirmed the superior performance of the DUIO over a DESO, as expected from the literature [29]. Simulations further highlighted its superiority by showing that the DUIO-based control generates smoother control signals for the steering angle, leading to smaller and less spiky tracking errors than those of the ADRC methodology.…”

Section: Discussionsupporting

confidence: 75%

Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers

Pedone

Fagiolini

2023

IEEE Trans. Contr. Syst. Technol.

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This brief addresses the robust lateral control problem for self-driving racecars. It proposes a discrete-time estimation and control solution consisting of a delayed unknown input-state observer (UIO) and a robust tracking controller. Based on a nominal vehicle model, describing its motion with respect to a generic desired trajectory and requiring no information about the surrounding environment, the observer reconstructs the total force disturbance signal, resulting from imperfect knowledge of the time-varying tire-road interface characteristics, presence of other vehicles nearby, wind gusts, and other model uncertainty. Then, the controller actively compensates the estimated force and asymptotically steers the tracking error to zero. The brief also presents a closed-loop stability proof of the method, ensuring perfect asymptotic estimation and tracking by the controlled vehicle. The proposed solution advantageously needs no a-priori information about the total disturbance boundedness, additional variables to model uncertainty, or observer parameters to be tuned. Its effectiveness and superiority to existing methods are studied in theory and shown in simulations where a full racecar model, based on the vehicle dynamics blockset, is required to track aggressive maneuvers. Through a faster and more accurate disturbance estimation, the solution robustly ensures better dynamic responses even with measurement noise.

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Section: Discussionsupporting

confidence: 75%

Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers

Pedone

Fagiolini

2023

IEEE Trans. Contr. Syst. Technol.

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“…where the addend E X k−2 has been added and subtracted in the last line of (18), and where Y k = Y k + N k . Now, the observer's convergence must be guaranteed for all delayed states X k−2 and all behaviors of the delayed unknown input w k−2 , and hence (18) should be made independent of them.…”

Section: Input-state Observer Design For Asrmentioning

confidence: 99%

“…The proposed solution builds upon the theory of delayed Unknown Input Observers (UIO), which allows estimating and compensating the model's uncertainties after only a few samples [17], compared to the dozen iterations needed for learning-based approaches. Compared to other existing solutions such as Extended State Observers (ESO), UIOs do not lean on assumptions on the disturbance dynamics and its boundedness, require no parameter tuning, have exact convergence guarantees, and outperform them [18] despite their simplicity. Moreover, the controllers' robustness to the robot and actuator model uncertainties facilitates its application and avoids the necessity for extensive a-priori model identification.…”

mentioning

confidence: 99%

Robust and Decoupled Position and Stiffness Control for Electrically-Driven Articulated Soft Robots

Pedone

Trumic

Jovanović

et al. 2022

IEEE Robot. Autom. Lett.

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The control of articulated soft robots, i.e. robots with flexible joints and rigid links, presents a challenge due to their intrinsic elastic elements and nonlinear force-deflection dependency. This letter first proposes a discrete-time delayed unknown inputstate observer based on a nominal robot model that reconstructs the total torque disturbance vector, resulting from the imperfect knowledge of the elastic torque characteristic, external torques, and other model uncertainties. Then, it introduces a robust controller, that actively compensates for the estimated uncertainty and allows bounded stability for the tracking of independent link position and joint stiffness reference signals. The convergence of the disturbance estimator and the overall system's stability in closed loop is proven analytically, while the effectiveness of the proposed control design is first evaluated in simulations with respect to large uncertainty conditions, and then demonstrated through experiments on a real multi-degree-of-freedom articulated soft robot.

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“…A DC motor is a second order system with multiple input and multiple outputs. The model [6] is designed according to the parameters, armature resistance, armature inductance, magnetic flux, voltage drop factor, inertia constant and viscous friction. It is studied as a linear system.…”

Section: Modeling Of DC Servo Motormentioning

confidence: 99%

Comparison of four state observer design algorithms for MIMO system

Vinodh¹,

Jerome²,

Ayyappan³

2013

Archives of Control Sciences

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A state observer is a system that models a real system in order to provide an estimate of the internal state of the system. The design techniques and comparison of four different types of state observers are presented in this paper. The considered observers include Luenberger observer, Kalman observer, unknown input observer and sliding mode observer. The application of these observers to a Multiple Input Multiple Output (MIMO) DC servo motor model and the performance of observers is assessed. In order to evaluate the effectiveness of these schemes, the simulated results on the position of DC servo motor in terms of residuals including white noise disturbance and additive faults are compared.

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A comparative study of nonlinear observers applied to a DC servo motor

Cited by 9 publications

References 27 publications

Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers

Robust Discrete-Time Lateral Control of Racecars by Unknown Input Observers

Robust and Decoupled Position and Stiffness Control for Electrically-Driven Articulated Soft Robots

Comparison of four state observer design algorithms for MIMO system

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