scholarly journals ROBUST ADAPTIVE CONTROL USING REINFORCEMENT LEARNING FOR NONLINEAR SYSTEM WITH INPUT CONSTRAINTS

2009 ◽  
Vol 12 (16) ◽  
pp. 5-18
Author(s):  
Luy Tan Nguyen ◽  
Thanh Thien Nguyen ◽  
Ha Thi Phuong Nguyen
Keyword(s):  
Reinforcement Learning ◽  
Learning Algorithm ◽  
Robust Stabilization ◽  
Robust Adaptive Control ◽  
Novel Approach ◽  
On Line ◽  
Robust Adaptive ◽  
Associative Law ◽  
Set Up ◽  
And Control

This paper proposes a novel approach to design a controller in discrete time for the class of uncertain nonlinear systems in the presence of magnitude constrains of control signal which are treated as the saturation nonlinearity. A associative law between reinforcement learning algorithm based on adaptive NRBF neural networks and the theory of robust control Ho is set up in a novel control structure, in which the proposed controller allows learning and control on-line to compensate multiple uncertain nonlinearities as well as minimizing both the H. tracking performance index function and the unknown nonlinear dynamic approximation errors. The novel theorem of robust stabilization of the closed-loop system is declared and proved. Simulation results verify the theoretical analysis.

Robust Adaptive Control of Nonlinear Output Feedback Systems Under Disturbances With Unknown Bounds

2004 ◽  
Vol 126 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Dong H. Kim ◽  
Hua O. Wang ◽  
Hai-Won Yang
Keyword(s):  
Output Feedback ◽  
State Feedback ◽  
Sliding Mode ◽  
Design Procedure ◽  
Adaptation Strategy ◽  
Robust Adaptive Control ◽  
Feedback Systems ◽  
Adaptive Controllers ◽  
Robust Adaptive ◽  
And Control

This paper describes a systematic procedure to design robust adaptive controllers for a class of nonlinear systems with unknown functions of unknown bounds based on backstepping and sliding mode techniques. These unknown functions can be unmodeled system nonlinearities, uncertainties and disturbances with unknown bounds. Both state feedback and output feedback designs are addressed. In the design procedure, the upper bounds of the unknown functions are estimated using an adaptation strategy, and the estimates are used to design stabilizing functions and control inputs based on the backstepping design methodology. The proposed controllers guarantee that the tracking errors converge to a residual set close to zero exponentially for both state feedback and output feedback designs, while maintaining the boundedness of all other variables.

Switching Control With Learning for a Class of Systems

2003 ◽  
Vol 125 (3) ◽  
pp. 448-450
Author(s):  
X. Zhang ◽  
S. S. Nair
Keyword(s):  
Adaptive Learning ◽  
Control Strategy ◽  
Controller Design ◽  
Switching Control ◽  
Robust Adaptive Control ◽  
Control Effort ◽  
On Line ◽  
Robust Adaptive ◽  
Adaptive Control Strategy ◽  
Stable Learning

Analytical details are developed for a robust adaptive control strategy that combines switching control and on-line adaptive learning, for a class of nonlinear systems. The condition for stable learning is derived, guidelines for design parameter selection are provided, and the tradeoff between performance and chattering control effort is examined. The results of the study are summarized in the form of a constructive procedure for controller design for the class of systems.

Adaptive Robust Control for a Class of Nonlinear Uncertain System With Unknown Input Backlash

2009 ◽  
Author(s):  
Jian Guo ◽  
Bin Yao ◽  
Jun Jiang ◽  
Qingwei Chen
Keyword(s):  
Robust Control ◽  
Nonlinear Dynamic System ◽  
Uncertain System ◽  
Robust Adaptive Control ◽  
Adaptive Robust Control ◽  
Unknown Input ◽  
Uncertain Disturbances ◽  
On Line ◽  
Parameterized Model ◽  
Robust Adaptive

An adaptive robust control (ARC) algorithm is developed for a class of nonlinear dynamic system with unknown input backlash, parametric uncertainties and uncertain disturbances. Due to the non-smooth dynamic nonlinear nature of backlash, existing robust adaptive control methods mainly focus on using approximate inversion of backlash by on-line parameter adaptation. But experimental results show that a linear controller alone can perform better than a controller including the selected backlash inverter with a correctly estimated or overestimated backlash gap. Unlike many existing control schemes, the backlash inverse is not constructed in this paper. A new linearly parameterized model for backlash is presented. The backlash nonlinearity is linearly parameterized globally with bounded model error. The proposed adaptive robust control law ensure that all closed-loop signals are bounded and achieves the tracking within the desired precision. Simulations results illustrate the performance of the ARC.

Robust Combined Adaptive and Variable Structure Adaptive Control of Robot Manipulators

Robotica ◽  
1998 ◽  
Vol 16 (6) ◽  
pp. 623-650 ◽  
Author(s):  
H. Yu
Keyword(s):  
Adaptive Control ◽  
High Performance ◽  
Robot Manipulators ◽  
Variable Structure ◽  
Robust Adaptive Control ◽  
Variable Structure Systems ◽  
Control Approach ◽  
Robust Adaptive ◽  
And Control ◽  
Uncertainty Environment

The paper addresses the robust adaptive control problem of robot manipulators. The dynamic equations of robot manipulators and their fundamental properties that facilitate analysis and control system design are first reviewed. Then the direct, indirect, and combined direct and indirect adaptive control approaches of robot manipulators are presented. After that, a number of variable structure adaptive control approaches which combines features of the robust design based on variable structure systems with parameter adaptive control, are studied. After that, a new combined adaptive and variable structure adaptive control approach is proposed for the tracking control of robot manipulators under the uncertainty environment. This is a robust, high-performance adaptive control scheme that combines the advantages and overcomes the disadvantages of both types of techniques. Finally, the extensive comparing simulation results are presented to demonstrate the theory study.

scholarly journals Design and Simulation of Adaptive PID Controller Based on Fuzzy Q-Learning Algorithm for a BLDC Motor

2020 ◽  
Author(s):  
Reza Rouhi Ardeshiri ◽  
Nabi Nabiyev ◽  
Shahab S. Band ◽  
Amir Mosavi
Keyword(s):  
Reinforcement Learning ◽  
Pid Controller ◽  
Control Method ◽  
Learning Algorithm ◽  
Bldc Motor ◽  
Motor Speed ◽  
Q Learning ◽  
Brushless Dc ◽  
Intelligent Control Systems ◽  
And Control

Reinforcement learning (RL) is an extensively applied control method for the purpose of designing intelligent control systems to achieve high accuracy as well as better performance. In the present article, the PID controller is considered as the main control strategy for brushless DC (BLDC) motor speed control. For better performance, the fuzzy Q-learning (FQL) method as a reinforcement learning approach is proposed to adjust the PID coefficients. A comparison with the adaptive PID (APID) controller is also performed for the superiority of the proposed method, and the findings demonstrate the reduction of the error of the proposed method and elimination of the overshoot for controlling the motor speed. MATLAB/SIMULINK has been used for modeling, simulation, and control design of the BLDC motor.

scholarly journals Set up and application of an underwater Α-ray spectrometer for radioactivity measurements

2005 ◽  
Vol 6 (1) ◽  
pp. 35 ◽  
Author(s):  
C. TSABARIS ◽  
S. VLACHOS ◽  
C.T. PAPADOPOULOS ◽  
R. VLASTOU ◽  
C.A. KALFAS
Keyword(s):  
Marine Environment ◽  
Detection System ◽  
On Line ◽  
Parallel Measurement ◽  
Set Up ◽  
And Control ◽  
Potassium 40 ◽  
Radioactivity Measurements ◽  
Term Monitoring

The set up and control of an underwater measuring instrument for radioactivity pollution in the marine environment is described. The detection system is based on a NaI scintillator (RADAM III) with modifications for use in the marine environment with on-line measurements. The system is simple, has low power consumption and is stable for long-term monitoring (10 months). Before its deployment, the sensor was calibrated in the laboratory in a tank full of water to reproduce the marine environment. The calibrations were performed, by detecting the 661keV and 1461 keV gamma rays of known activity liquid sources 137 Cs and 40 K, respectively. The measured spectra in the laboratory were compared with spectra from a similar detector as acquired in the field. The analysis of the parallel measurement gave satisfactory agreement for the concentration of the potassium (40 K), as calculated from the salinity in the seawater, thus enabling the system for quantitative measurement of the seawater radioactivity.

Mechanical Structure Design of Ontology of the Automatic Line-Tracking Inspection Device Based on Pro/E Modeling and the Kinematics Analysis

2012 ◽  
Vol 220-223 ◽  
pp. 1131-1137
Author(s):  
Sheng Mei Luo ◽  
Le Tian ◽  
Bo Zhang
Keyword(s):  
Transmission Lines ◽  
Screw Theory ◽  
Characteristic Parameter ◽  
Structure Design ◽  
Kinematics Analysis ◽  
Modeling Software ◽  
On Line ◽  
Line Tracking ◽  
Set Up ◽  
And Control

A new line-tracking inspection device which can move on the high voltage transmission lines and control on the ground by people is presented in this paper. The device has three mechanical arms, every arm can lift and rotate automatically, and manipulator can open and close automatically. The flexible design is used in lower riding wheel, this design can make the upper and lower riding wheel automatically adjustment, so as to adapt to the change of wire diameter. Automatic checking and autonomous negotiating obstacles are realized successfully in this device. The biggest breakthrough is that its automatic on-line or off-line can be completed by operator operating the auxiliary tools on the ground. This article uses the Pro/E modeling software set up the virtual prototype of the line-tracking inspection device based on characteristic parameter model. The process of on-line or off-line automatically and the process of negotiating obstacles are discussed in this paper. Using the product of exponentials formula based the on screw theory, the kinematics analysis is processed in this paper. The forward and inverse solution of kinematics equations is presented and at last the Jacobian matrix is given. The results of experiments with simulation transmission lines demonstrate that the device has realized the specified work tasks and runs smoothly.

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