scholarly journals Modeling and Control for an Underwater Vehicle using Dual Quaternions.

2021 ◽  
Author(s):  
Angel Zamora ◽  
Miguel Garcia ◽  
Adrian Manzanilla ◽  
Filiberto Muñoz ◽  
Sergio Salazar ◽  
...  
Keyword(s):  
Tracking Error ◽  
Computational Cost ◽  
Euler Angle ◽  
Adaptive Controller ◽  
Underwater Vehicle ◽  
System Stability ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Dual Quaternions ◽  
Unknown Disturbances

Abstract In this work, the analysis of the dynamic general model of an unmanned underwater vehicle (UUV) based on dual quaternions is presented, then the general dynamic model is reduced to a specific vehicle of 4 DoF, this model eliminates the singularities that exist with the representation of the Euler angle and that the model is more compact than others proposed in the literature [1],[2]. To demonstrate the applicability of the model, three controller strategies are proposed for tracking a trajectory, the first controller is a PD + G, under unknown disturbances it produces a considerable tracking error, the second is an adaptive controller that estimates unknown hydrodynamic parameters, and the third is a robust controller for unknown disturbances and parameter uncertainties. The closed-loop system stability analysis for each controller is based on Lyapunov’s theory, a set of numerical simulations is performedto show the behavior of the vehicle with the proposed controllers. The efficiency of the controllers is shown in Table 2 where it is deduced that the adaptive controller has a better performance. The graphics show that the robust controller has little error tracking and the computational cost is lower.

Robust model reference control for second-order descriptor linear systems subject to parameter uncertainties

2021 ◽  
pp. 014233122110450
Author(s):  
Guang-Tai Tian ◽  
Guang-Ren Duan
Keyword(s):  
Linear Systems ◽  
Tracking Error ◽  
Sufficient Conditions ◽  
Second Order ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Model Reference ◽  
Robust Model ◽  
Robust Compensation ◽  
Descriptor Linear Systems

This paper is devoted to designing the robust model reference controller for uncertain second-order descriptor linear systems subject to parameter uncertainties. The parameter uncertainties are assumed to be norm-bounded. The design of a robust controller can be divided into two separate problems: a robust stabilization problem and a robust compensation problem. Based on the solution of generalized Sylvester matrix equations, we obtain some sufficient conditions to guarantee the complete parameterization of the robust controller. The parametric forms are expressed by a group of parameter vectors which reveal the degrees of freedom existing in the design of the compensator and can be utilized to solve the robust compensation problem. In order to reduce the effect of parameter uncertainties on the tracking error vector, the robust compensation problem is converted into a convex optimization problem with a set of linear matrix equation constraints. A simulation example is provided to illustrate the effectiveness of the proposed technique.

The control of the electro-hydraulic shaking table based on dynamic surface adaptive robust control

2016 ◽  
Vol 39 (8) ◽  
pp. 1271-1280 ◽  
Author(s):  
Wei Shen ◽  
Jun-zheng Wang ◽  
Shou-kun Wang
Keyword(s):  
Robust Control ◽  
Computational Cost ◽  
Adaptive Robust Control ◽  
Working Environment ◽  
Shaking Table ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Dynamic Surface ◽  
Vibration Direction ◽  
And Control

The electro-hydraulic shaking table is investigated, in the present paper, to simulate the vibrational working environment of industrial components and equipment. Adaptive robust control can be applied to the shaking table system because electro-hydraulic systems suffer from internal parameter uncertainties and external disturbances. However, the adaptive robust controller design is complicated and has a large computational cost owing to the ‘explosion of terms’ problem. Thus dynamic surface control is applied in the design procedure of adaptive robust controllers to overcome the ‘explosion of terms’ problem. In this work, dynamic surface adaptive robust control is proposed. It simplifies the designed procedure of the controller and decreases its computational cost. Firstly, the structure of a shaking table is formulated and the operation principles of the shaking table, including the hydraulic and control principles, are analysed. A change is made in the mechanical-hydraulic system of the fluid circuit to address the problem of changing the vibration direction. Secondly, a dynamic model of a shaking table is proposed. Based on analysis of this model, the design of a dynamic surface adaptive robust controller for a shaking table is presented so as to improve its performance. Finally, comparative simulations and experiments are carried out. The comparison of performance results with proportional-integral-derivative control verify the correctness of the hydraulic scheme and control principle, as well as the high-performance of the dynamic surface adaptive robust controller. The shaking table achieves a guaranteed dynamical performance and tracking accuracy for the output in the presence of parameter and load uncertainties.

Adaptive controller for a biomimetic underwater vehicle

2013 ◽  
Vol 01 (01) ◽  
pp. 1-13 ◽  
Author(s):  
Nicolas Plamondon ◽  
Meyer Nahon
Keyword(s):  
Good Accuracy ◽  
Tracking Error ◽  
Caribbean Sea ◽  
Adaptive Controller ◽  
Underwater Vehicle ◽  
Dynamics Simulation ◽  
Dynamics Model ◽  
Mcgill University ◽  
The Caribbean ◽  
Time Periodic

Aqua is an underwater biomimetic vehicle designed and built at McGill University that uses six oscillating paddles to produce control and propulsion forces. These oscillating paddles provide a time-periodic thrust. Using an existing dynamics model of the vehicle and a numerical simulation, an adaptive controller was developed to provide trajectory tracking capabilities to the vehicle. The performance of the controller was first assessed on a dynamics simulation using different trajectories in roll and pitch. The same controller was then tested experimentally in the Caribbean Sea. We found that the adaptive controller was able to track the roll angle with good accuracy, while the tracking error in the pitch motion was more significant.

scholarly journals A MRAC Principle for a Single-Link Electrically Driven Robot with Parameter Uncertainties

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Carlos Aguilar-Avelar ◽  
Javier Moreno-Valenzuela
Keyword(s):  
Tracking Error ◽  
Adaptive Controller ◽  
Parameter Uncertainties ◽  
Rigid Link ◽  
Control Schemes ◽  
Single Link ◽  
Electrically Driven Robot ◽  
Model Reference Adaptive ◽  
Control Methodology ◽  
Experimental Comparisons

In this paper, a model reference adaptive control (MRAC) principle for a one-degree-of-freedom rigid-link electrically driven robot is presented. The proposed control methodology addresses the problem of trajectory tracking with parameter uncertainties in the dynamic model of the system and proposes adaptation laws for the electrical and mechanical parameters. Closed-loop stability is rigorously discussed, proving that the tracking error trajectories converge to the origin exponentially. With the aim of performing experimental comparisons, two control schemes are also revisited theoretically and experimentally: one is an algorithm previously reported in the literature and the other is an adaptive controller derived under the assumption that the electrical dynamics of the actuator are negligible. All the discussed controllers have been implemented in an experimental setup consisting in a rigid-link robot actuated with brushed DC motor. The comparison indicates that better results are obtained with the new MRAC scheme.

scholarly journals NonlinearH∞Optimal Control Scheme for an Underwater Vehicle with Regional Function Formulation

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Zool H. Ismail ◽  
Matthew W. Dunnigan
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Tracking Error ◽  
Underwater Vehicle ◽  
Control Technique ◽  
Control Law ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Control Scheme ◽  
Highly Nonlinear ◽  
Region Tracking

A conventional region control technique cannot meet the demands for an accurate tracking performance in view of its inability to accommodate highly nonlinear system dynamics, imprecise hydrodynamic coefficients, and external disturbances. In this paper, a robust technique is presented for an Autonomous Underwater Vehicle (AUV) with region tracking function. Within this control scheme, nonlinearH∞and region based control schemes are used. A Lyapunov-like function is presented for stability analysis of the proposed control law. Numerical simulations are presented to demonstrate the performance of the proposed tracking control of the AUV. It is shown that the proposed control law is robust against parameter uncertainties, external disturbances, and nonlinearities and it leads to uniform ultimate boundedness of the region tracking error.

scholarly journals Doubly fed induction generators to enhance inter-area damping based on a Robust controller: $${{\varvec{H}}}_{2}/{{\varvec{H}}}_{\infty }$$ Control

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ali Goodarzi ◽  
Ali Mohammad Ranjbar ◽  
Moslem Dehghani ◽  
Mina GhasemiGarpachi ◽  
Mohammad Ghiasi
Keyword(s):  
Working Conditions ◽  
Reactive Power ◽  
Wind Farms ◽  
System Stability ◽  
Pole Placement ◽  
Linear Matrix ◽  
Robust Controller ◽  
Induction Generators ◽  
Doubly Fed ◽  
Oscillation Damping

AbstractIn this study, an auxiliary damping controller based on a robust controller considering the active and reactive power control loops for a doubly-fed induction generator for wind farms is proposed. The presented controller is able to improve the inter-area oscillation damping. In addition, the proposed controller applies only one accessible local signal as the input; however, it can improve the inter-area oscillation damping and, consequently the system stability for the various working conditions and uncertainties. The oscillatory modes of the system are appointed using the linear analysis. Then, the controller’s parameters are determined using the robust control approaches ($${H}_{\infty }/{H}_{2})$$ H ∞ / H 2 ) with the pole placement and linear matrix inequality method. The results of the modal analysis and time-domain simulations confirm that the controller develops the inter-area oscillation damping under the various working conditions and uncertainties.

Regularized error function-based extended Kalman filter for estimating the cancer chemotherapy dosage: impact of improved grey wolf optimization

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Utkarsha L. Mohite ◽  
Hirenkumar G. Patel
Keyword(s):  
Tumor Cells ◽  
Error Function ◽  
Drug Dosage ◽  
Parameters Estimation ◽  
Gray Wolf ◽  
Robust Performance ◽  
Parameter Uncertainties ◽  
Initial State ◽  
Robust Controller ◽  
Fine Tune

AbstractObjectivesThe main aim of this work is to introduce a robust controller for controlling the drug dosage.MethodsThe presented work establishes a novel robust controller that controls the drug dosage and it also carried out parameters estimation. Along with this, a Regularized Error Function-based EKF (REF-EKF) is introduced for estimating the tumor cells that could be adapted for different conditions. It also assists in solving the overfitting problems, which occur during the drug dosage estimation. Moreover, the performance of the adopted controller is compared over other conventional schemes, and the attained outcomes reveal the appropriate impact of drug dosage injection on immune, normal, and tumor cells. It is also ensured that the presented controller does a robust performance on the parameter uncertainties. Moreover, to enhance the performance of the proposed system and for fast convergence, it is aimed to fine-tune the initial state of EKF optimally using a new Improved Gray Wolf Optimization (GWO) termed as Adaptive GWO (AGWO). Finally, analysis is held to validate the betterment of the presented model.ResultsThe outcomes, the proposed method has accomplished a minimal value of error with an increase in time, when evaluated over the compared models.ConclusionsThus, the improvement of the proposed REF-EKF-AGWO model is proved from the attained results.

scholarly journals Implementation and intelligent gain tuning feedback–based optimal torque control of a rotary parallel robot

2021 ◽  
pp. 107754632110191
Author(s):  
Farzam Tajdari ◽  
Naeim Ebrahimi Toulkani
Keyword(s):  
Real Time ◽  
Tracking Error ◽  
Parallel Robot ◽  
Torque Control ◽  
Test Bed ◽  
Linear Quadratic ◽  
Control Effort ◽  
The Real ◽  
Unknown Disturbances ◽  
Quadratic Integral

Aiming at operating optimally minimizing error of tracking and designing control effort, this study presents a novel generalizable methodology of an optimal torque control for a 6-degree-of-freedom Stewart platform with rotary actuators. In the proposed approach, a linear quadratic integral regulator with the least sensitivity to controller parameter choices is designed, associated with an online artificial neural network gain tuning. The nonlinear system is implemented in ADAMS, and the controller is formulated in MATLAB to minimize the real-time tracking error robustly. To validate the controller performance, MATLAB and ADAMS are linked together and the performance of the controller on the simulated system is validated as real time. Practically, the Stewart robot is fabricated and the proposed controller is implemented. The method is assessed by simulation experiments, exhibiting the viability of the developed methodology and highlighting an improvement of 45% averagely, from the optimum and zero-error convergence points of view. Consequently, the experiment results allow demonstrating the robustness of the controller method, in the presence of the motor torque saturation, the uncertainties, and unknown disturbances such as intrinsic properties of the real test bed.

State Feedback Robust H∞ Control for Generalized Discrete System and Simulation

2013 ◽  
Vol 467 ◽  
pp. 621-626
Author(s):  
Chen Fang ◽  
Jiang Hong Shi ◽  
Kun Yu Li ◽  
Zheng Wang
Keyword(s):  
Discrete System ◽  
State Feedback ◽  
Closed Loop ◽  
The State ◽  
Linear Matrix ◽  
Sufficient Condition ◽  
Matrix Inequalities ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Closed Loop Systems

For a class of uncertain generalized discrete linear system with norm-bounded parameter uncertainties, the state feedback robust control problem is studied. One sufficient condition for the solvability of the problem and the state feedback robust controller are obtained in terms of linear matrix inequalities. The designed controller guarantees that the closed-loop systems is regular, causal, stable and satisfies a prescribed norm bounded constraint for all admissible uncertain parameters under some conditions. The result of the normal discrete system can be regarded as a particular form of our conclusion. A simulation example is given to demonstrate the effectiveness of the proposed method.

Adaptive Control of Pulse Width Modulation Voltage-Source Rectifier with Disturbance Signals

2013 ◽  
Vol 385-386 ◽  
pp. 977-980
Author(s):  
Bao Bin Liu
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Controller Design ◽  
Adaptive Controller ◽  
Voltage Source ◽  
Robust Controller ◽  
Reference Velocity ◽  
Velocity Tracking ◽  
Modulation Voltage ◽  
Robust Controller Design

A nonlinear adaptive controller is proposed for the design of pulse width modulation voltage-source rectifier with disturbance signals of harmonics to achieve reference velocity tracking. The procedure of the robust controller design is developed via improved backstepping method. With the proposed controller, PWM voltage-source rectifiers can guarantee accuracy of output voltage tracking. Global asymptotic stability of the closed-loop system has been proved. The simulation results demonstrate effectiveness of the presented method.

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