scholarly journals Numerical Approach on Hybrid PID-AFC Controller using Different Intelligent Tuning Methods to Reduce the Vibration of the Suspended Handle

2021 ◽  
Vol 26 (1) ◽  
pp. 28-40
Author(s):  
Mohd Hafiz Abdul Satar ◽  
Wong Jen Nyap ◽  
Ahmad Zhafran Ahmad Mazlan
Keyword(s):  
Controller Design ◽  
Numerical Approach ◽  
Best Response ◽  
Control Scheme ◽  
Control Schemes ◽  
Internal Disturbance ◽  
Crude Approximation ◽  
Power Tools ◽  
Tuning Methods ◽  
Tuning Strategy

This paper focusses on the study of vibration attenuations for suspended handle models that are generated from power tools using an intelligent active force control (AFC) tuning strategy. Four types of control schemes are comparatively evaluated in suppressing the vibration of the handle, such as proportional-integral-derivative (PID), PID-AFC-crude approximation (AFCCA), PID-AFC-fuzzy logic (AFCFL) and PID-AFC-iterative learning method (AFCILM) control schemes. In all control schemes, the estimated counter force is generated from the actuating force and appropriate estimated mass M* that has been intelligently tuned to counter the system disturbances. The disturbances are modelled based on the power tools vibration (i.e., internal disturbance) and uncertainties during the operation (i.e., external disturbances). The study shows that the AFCCA scheme demonstrates the best performance when the M(CL) is tuned at 0.04 kg. For the AFCFL control scheme, the best response is obtained for the membership function of trapezoidal shape with M(FL) of 0.0403 kg, while for AFCILM control scheme, the best response is achieved when M(ILM) is tuned to 0.04 kg, with both parameters (A and B) set at 0.6. Overall, PID-AFCCA scheme shows the best performances for all of the case studies, followed by PID-AFCFL and PID-AFCILM. The findings of this study can benefit the power tool manufacturers and provide the basis of effectively intelligent controller design for the power tools application.

Tracking Error Analysis for Feedback Systems With Hysteresis Inversion and Fast Linear Dynamics1

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Mohamed Edardar ◽  
Xiaobo Tan ◽  
Hassan K. Khalil
Keyword(s):  
Controller Design ◽  
Feedforward Control ◽  
Piecewise Linear ◽  
Tracking Error ◽  
Analytical Approximation ◽  
Feedback Systems ◽  
Closed Loop Systems ◽  
Hysteresis Nonlinearity ◽  
Control Scheme ◽  
Control Schemes

Analysis of closed-loop systems involving hysteresis is important to both the understanding of these systems and the synthesis of control schemes. However, such analysis is challenging due to the nonsmooth nature of hysteresis nonlinearities. In this paper, singular perturbation techniques are employed to derive an analytical approximation to the tracking error for a system consisting of fast linear dynamics preceded by a piecewise linear hysteresis nonlinearity, which is motivated by applications such as piezo-actuated nanopositioning. The control architecture considered combines hysteresis inversion and proportional-integral feedback, with and without a constant feedforward control. The analysis incorporates the effect of uncertainty in the hysteresis model, and offers insight into how the tracking performance depends on the system parameters and the references, thereby offering guidance in the controller design. Simulation and experimental results on a piezo-actuated nanopositioning system are presented to support the analysis. In particular, the control scheme incorporating the feedforward element consistently outperforms the classical PI controller in tracking a variety of references.

scholarly journals Nonlinear Current-Mode Control of SCIG Wind Turbines

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 55
Author(s):  
Nicholas Hawkins ◽  
Bhagyashri Bhagwat ◽  
Michael L. McIntyre
Keyword(s):  
Current Mode ◽  
Nonlinear Controller ◽  
Flux Observer ◽  
Current Mode Control ◽  
Mode Control ◽  
Squirrel Cage ◽  
Control Scheme ◽  
Control Schemes ◽  
Rotor Flux ◽  
Squirrel Cage Induction Generator

In this paper, a nonlinear controller is proposed to manage the rotational speed of a full-variable Squirrel Cage Induction Generator wind turbine. This control scheme improves upon tractional vector controllers by removing the need for a rotor flux observer. Additionally, the proposed controller manages the performance through turbulent wind conditions by accounting for unmeasurable wind torque dynamics. This model-based approach utilizes a current-based control in place of traditional voltage-mode control and is validated using a Lyapunov-based stability analysis. The proposed scheme is compared to a linear vector controller through simulation results. These results demonstrate that the proposed controller is far more robust to wind turbulence than traditional control schemes.

scholarly journals Constant Transmission Efficiency Dimming Control Scheme for VLC Systems

Photonics ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Jia-Ning Guo ◽  
Jian Zhang ◽  
Gang Xin ◽  
Lin Li
Keyword(s):  
Visible Light Communication ◽  
Transmission Efficiency ◽  
Error Performance ◽  
Constant Weight ◽  
Block Coding ◽  
Control Scheme ◽  
Control Schemes ◽  
Indoor Wireless ◽  
Communication Function ◽  
Dimming Control

As a novel mode of indoor wireless communication, visible light communication (VLC) should consider the illumination functions besides the primary communication function. Dimming control is one of the most crucial illumination functions for VLC systems. However, the transmission efficiency of most proposed dimming control schemes changes as the dimming factor changes. A block coding-based dimming control scheme has been proposed for constant transmission efficiency VLC systems, but there is still room for improvement in dimming range and error performance. In this paper, we propose a dimming control scheme based on extensional constant weight codeword sets to achieve constant transmission efficiency. Meanwhile, we also provide a low implementation complexity decoding algorithm for the scheme. Finally, comparisons show that the proposed scheme can provide a wider dimming range and better error performance.

A computationally efficient adaptive robust control scheme for a quad-rotor transporting cable-suspended payloads

2021 ◽  
pp. 095441002110136
Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  
Keyword(s):  
Robust Control ◽  
Fractional Order ◽  
Sliding Mode ◽  
Adaptive Robust Control ◽  
Computationally Efficient ◽  
Control Scheme ◽  
Control Schemes ◽  
Adaptive Laws ◽  
Unknown Disturbances ◽  
The Stability

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.

scholarly journals Super-Twisting Algorithm Applied to Velocity Control of DC Motor without Mechanical Sensors Dependence

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6041
Author(s):  
Fredy A. Valenzuela ◽  
Reymundo Ramírez ◽  
Fermín Martínez ◽  
Onofre A. Morfín ◽  
Carlos E. Castañeda
Keyword(s):  
Controller Design ◽  
Sliding Mode ◽  
Dc Motor ◽  
Experimental Results ◽  
Resistive Load ◽  
Velocity Control ◽  
Velocity Sensor ◽  
Control Scheme ◽  
Mechanical Sensors ◽  
Twisting Algorithm

A DC motor velocity control in feedback systems usually requires a velocity sensor, which increases the controller cost. Additionally, the velocity sensor used in industrial applications presents several disadvantages such as maintenance requirements and signal conditioning. In this work, we propose a robust velocity control scheme applied to a DC motor based on estimation strategies using a sliding-mode observer. This means that measurements with mechanical sensors are not required in the controller design. The proposed observer estimates the rotational velocity and load torque of the motor. The controller design applies the exact-linearization technique combined with the super-twisting algorithm to achieve robust performance in the closed-loop system. The controller validation was carried out by experimental tests using a workbench, which is composed of a control and data acquisition Digital Signal Proccessor board, a DC-DC electronic converter, an interface board for signals conditioning, and a DC electric generator connected to an adjustable resistive load. The simulation and experimental results show a significant performance of the proposed control scheme. During tests, the accuracy, robustness, and speed response on the controller were evaluated and the experimental results were compared with a classic proportional-integral controller, which uses a conventional encoder.

scholarly journals 2D Legendre Moments-Based Visual Control

2012 ◽  
Vol 162 ◽  
pp. 487-496 ◽  
Author(s):  
Aurelien Yeremou Tamtsia ◽  
Youcef Mezouar ◽  
Philippe Martinet ◽  
Haman Djalo ◽  
Emmanuel Tonye
Keyword(s):  
Visual Servoing ◽  
Dynamic Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Interaction Matrix ◽  
Geometric Moments ◽  
Control Scheme ◽  
Control Schemes ◽  
Legendre Moments ◽  
Set Of Points

Among region-based descriptors, geometric moments have been widely exploited to design visual servoing schemes. However, they present several disadvantages such as high sensitivity to noise measurement, high dynamic range and information redundancy (since they are not computed onto orthogonal basis). In this paper, we propose to use a class of orthogonal moments (namely Legendre moments) instead of geometric moments to improve the behavior of moment-based control schemes. The descriptive form of the interaction matrix related to the Legendre moments computed from a set of points is rst derived. Six visual features are then selected to design a partially-decoupled control scheme. Finally simulated and experimental results are presented to illustrate the validity of our proposal.

Contact Stability and Contact Safety of a Magnetic Resonance Imaging-Guided Robotic Catheter Under Heart Surface Motion

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Ran Hao ◽  
E. Erdem Tuna ◽  
M. Cenk Çavuşoğlu
Keyword(s):  
Contact Force ◽  
Force Control ◽  
Motion Prediction ◽  
Resonance Imaging ◽  
Contact Stability ◽  
Heart Motion ◽  
Control Scheme ◽  
Control Schemes ◽  
Position Feedback ◽  
Contact Force Control

Abstract Contact force quality is one of the most critical factors for safe and effective lesion formation during catheter based atrial fibrillation ablation procedures. In this paper, the contact stability and contact safety of a novel magnetic resonance imaging (MRI)-actuated robotic cardiac ablation catheter subject to surface motion disturbances are studied. First, a quasi-static contact force optimization algorithm, which calculates the actuation needed to achieve a desired contact force at an instantaneous tissue surface configuration is introduced. This algorithm is then generalized using a least-squares formulation to optimize the contact stability and safety over a prediction horizon for a given estimated heart motion trajectory. Four contact force control schemes are proposed based on these algorithms. The first proposed force control scheme employs instantaneous heart position feedback. The second control scheme applies a constant actuation level using a quasi-periodic heart motion prediction. The third and the last contact force control schemes employ a generalized adaptive filter-based heart motion prediction, where the former uses the predicted instantaneous position feedback, and the latter is a receding horizon controller. The performance of the proposed control schemes is compared and evaluated in a simulation environment.

PpBAC

2018 ◽  
Vol 30 (4) ◽  
pp. 14-31 ◽  
Author(s):  
Suyel Namasudra ◽  
Pinki Roy
Keyword(s):  
Cloud Computing ◽  
Access Control ◽  
Data Storage ◽  
Control Method ◽  
Cloud Environment ◽  
Authorized User ◽  
Control Scheme ◽  
Control Schemes ◽  
Confidential Data ◽  
Efficient Data

This article describes how nowadays, cloud computing is one of the advanced areas of Information Technology (IT) sector. Since there are many hackers and malicious users on the internet, it is very important to secure the confidentiality of data in the cloud environment. In recent years, access control has emerged as a challenging issue of cloud computing. Access control method allows data accessing of an authorized user. Existing access control schemes mainly focus on the confidentiality of the data storage. In this article, a novel access control scheme has been proposed for efficient data accessing. The proposed scheme allows reducing the searching cost and accessing time, while providing the data to the user. It also maintains the security of the user's confidential data.

scholarly journals Tuning of Nacelle Feedback Gains for Floating Wind Turbine Controllers Using a Two-DOF Model

2020 ◽  
Author(s):  
Eben Lenfest ◽  
Andrew J. Goupee ◽  
Alan Wright ◽  
Nikhar Abbas
Keyword(s):  
Production Performance ◽  
Offshore Wind ◽  
Feedback Gain ◽  
Tuning Method ◽  
Floating Offshore Wind Turbines ◽  
Integral Controller ◽  
Proportional Integral Controller ◽  
Angular Displacements ◽  
Tuning Methods ◽  
Tuning Strategy

Abstract Designing a collective blade pitch controller for floating offshore wind turbines (FOWTs) poses unique challenges due to the interaction of the controller with the dynamics of the platform. The controller must also handle the competing objectives of power production performance and fatigue load management. Existing solutions either detune the controller with the result of slowed response, make use of complicated tuning methods, or incorporate a nacelle velocity feedback gain. With the goal of developing a simple control tuning method for the general FOWT researcher that is easily extensible to a wide array of turbine and hull configurations, this last idea is built upon by proposing a simple tuning strategy for the feedback gain. This strategy uses a two degree-of-freedom (DoF) turbine model that considers tower-top fore-aft and rotor angular displacements. For evaluation, the nacelle velocity term is added to an existing gain scheduled proportional-integral controller as a proportional gain. The modified controller is then compared to baseline land-based and detuned controllers on an example system for several load cases. First-pass results are favorable, demonstrating how researchers can use the proposed tuning method to efficiently schedule gains for adequate controller performance as they investigate new FOWT configurations.

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