An Enhanced Smith Predictor Based Control System Using Feedback-feedforward Structure for Time-delay Processes

Mohammadzaheri, Morteza; Tafreshi, Reza

doi:10.24200/tjer.vol14iss2pp156-165

Cited by 5 publications

(2 citation statements)

References 26 publications

(16 reference statements)

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“…Equation ( 7) would be a nonlinear equation in Laplace domain. A Smith-predictor-based control system or a similar method might be able to use (7) in continuous domain; however, that would impose an extra loop and its complexities to the control system [44]. The second afore-listed advantage removes a wellknown drawback of feedback linearization control of unmanned helicopters: high sensitivity to noises [28].…”

Section: Resultsmentioning

confidence: 99%

A Discrete Approach to Feedback Linearization, Yaw Control of An Unmanned Helicopter

et al. 2022

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Nonlinear control laws often need to be implemented with digital hardware. Use of digital control systems leads to communication/processing delays which are widely neglected in control of mechanical systems. This paper proposes a discrete approach to feedback linearization that considers these commonly overlooked delays in design. The proposed approach is shown to both improve the performance and remove the need for continuous derivative terms. In feedback linearization control systems, designed in the continuous domain, derivative terms are required to speed up the control response of mechanical systems, but disadvantageously cause high sensitivity to noise. The proposed approach was used to design a feedback linearization control system for a common turning maneuver of an unmanned helicopter in yaw. At this maneuver, the helicopter centroid motion and pitch rotational speed are almost zero. Governing differential equations of the helicopter at this maneuver are nonlinear and coupled. A feedback linearization law was proposed to curb nonlinearity and, a discrete control system, considering the inevitable delay due to the use of digital control systems, was adopted to complete the control law. This innovative approach resulted in less sensitivity to noises and performance boost. Practical limits in terms of control input, rotor speed, sampling frequency and noises of the gyroscope, the tachometer and the acceleration sensor were taken into account in this research. The results show that the proposed control system leads to fast and smooth yaw turns even at a high pitch angle (close to vertical) or in the case of being hit by external objects.

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Section: Resultsmentioning

confidence: 99%

A Discrete Approach to Feedback Linearization, Yaw Control of An Unmanned Helicopter

et al. 2022

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“…We defer the discussion on the sampling frequency to future studies. However, interested readers can refer to the relevant topic in reference [20].…”

Section: Test System Descriptionmentioning

confidence: 99%

Force-Fighting Phenomena and Disturbance Rejection in Aircraft Dual-Redundant Electro-Mechanical Actuation Systems

Han

Im²,

Hahn

2023

Actuators

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This paper presents a robust control system that addresses two key challenges in redundant actuators using Permanent Magnet Synchronous Motors (PMSM) for an aircraft nose wheel steering system: the elimination of force-fighting phenomena and the ability to respond effectively to unexpected disturbances. In detail, a control method was devised to enhance the mitigation of force-fighting phenomena and disturbances by accurately observing and compensating for the torque-induced load applied to the PMSM. This was achieved through the utilization of a Q-filter-based Disturbance Observer (DOB). The proposed control approach was implemented and evaluated on a redundant system consisting of the PMSM and the nose wheel steering system. The performance of the proposed method was verified through extensive simulation studies. The simulation results confirmed the effectiveness and reliability of the method in accurately observing and responding to the force-fighting phenomenon that occurs in the redundant driving device. By subjecting the system to various scenarios and disturbances, the simulation provided a comprehensive evaluation of the proposed method’s ability to handle force-fighting phenomena. The results demonstrated that the method successfully observed and responded to the force-fighting phenomenon, thereby mitigating its adverse effects on the system’s performance. Therefore, these outcomes serve as empirical evidence supporting the validity and efficiency of the proposed method in addressing the force-fighting phenomenon encountered in the redundant driving device. These findings substantiate the effectiveness of the proposed approach and its potential for practical implementation in real-world systems.

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Whale optimization algorithm based controller design for air-fuel ratio system

Ekinci,

Izci

2024

Handbook of Whale Optimization Algorithm

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An Enhanced Smith Predictor Based Control System Using Feedback-feedforward Structure for Time-delay Processes

Cited by 5 publications

References 26 publications

A Discrete Approach to Feedback Linearization, Yaw Control of An Unmanned Helicopter

A Discrete Approach to Feedback Linearization, Yaw Control of An Unmanned Helicopter

Force-Fighting Phenomena and Disturbance Rejection in Aircraft Dual-Redundant Electro-Mechanical Actuation Systems

Whale optimization algorithm based controller design for air-fuel ratio system

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