A hybrid control approach for the cracking outlet temperature system of ethylene cracking furnace

Emerging applications of autonomous robots requiring stability and reliability cannot afford component failure to achieve operational objectives. Hence, identification and countermeasure of a fault is of utmost importance in mechatronics community. This research proposes a Fault-tolerant control (FTC) for a robot manipulator, which is based on a hybrid control scheme that uses an observer as well as a hardware redundancy strategy to improve the performance and efficiency in the presence of actuator and sensor faults. Considering a five Degree of Freedom (DoF) robotic manipulator, a dynamic LuGre friction model is derived which forms the basis for design of control law. For actuator’s and sensor’s FTC, an adaptive back-stepping methodology is used for fault estimation and the nominal control law is used for the controller reconfiguration and observer is designed. Fault detection is accomplished by comparing the actual and observed states, pursued by fault tolerant method using redundant sensors. The results affirm the effectiveness of the proposed FTC strategy with model-based friction compensation. Improved tracking performance as well robustness in the presence of friction and fault demonstrate the efficiency of the proposed control approach.

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Hybrid Control of a Pendubot System Using Nonlinear H∞ and LQR

WSEAS TRANSACTIONS ON SYSTEMS AND CONTROL ◽

10.37394/23203.2021.16.12 ◽

2021 ◽

Vol 16 ◽

pp. 155-161

Author(s):

Seif-El-Islam Hasseni

Keyword(s):

Dynamic Modeling ◽

Nonlinear Model ◽

Equilibrium Position ◽

Hybrid Control ◽

Control Law ◽

Lagrange Method ◽

Control Approach ◽

Linearized Model ◽

Active Link ◽

Pendubot System

In this paper, a hybrid control approach is synthesized for stabilizing an under-actuated mechanical system, the Pendubot. This kind of system is divided into two modes, the swing-up mode, and the balancing mode. First, dynamic modeling is established by the Euler-Lagrange method. Next, the robust nonlinear H∞ is designed for the swing-up mode, which handles with the nonlinear model. To weaken the under-actuation characteristic, the control law is developed for the active link with its coupling with the passive link. The LQR is designed for the balancing mode where LQR handles with the linearized model about the unstable top equilibrium position. A simulation is achieved under the MATLAB/Simulink environment. It shows robustness against the external inputs and the fast convergence to the equilibrium position.

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Elevation, pitch and travel axis stabilization of 3DOF helicopter with hybrid control system by GA-LQR based PID controller

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v10i2.pp1868-1884 ◽

2020 ◽

Vol 10 (2) ◽

pp. 1868 ◽

Cited By ~ 1

Author(s):

Ibrahim K. Mohammed ◽

Abdulla I. Abdulla

Keyword(s):

Pid Controller ◽

Hybrid Control ◽

Research Work ◽

Linear Quadratic Regulator ◽

Optimization Method ◽

Feedback Gain ◽

Algorithm Optimization ◽

Linear Quadratic ◽

Control Approach ◽

Lqr Controller

This research work presents an efficient hybrid control methodology through combining the traditional proportional-integral-derivative (PID) controller and linear quadratic regulator (LQR) optimal controlher. The proposed hybrid control approach is adopted to design three degree of freedom (3DOF) stabilizing system for helicopter. The gain parameters of the classic PID controller are determined using the elements of the LQR feedback gain matrix. The dynamic behaviour of the LQR based PID controller, is modeled and the formulated in state space form to enable utlizing state feedback controller technique. The performance of the proposed LQR based LQR controller is improved by using Genetic Algorithm optimization method which are adopted to obtain optimum values for LQR controller gain parameters. The LQR-PID hybrid controller is simulated using Matlab environment and its performance is evaluated based on rise time, settling time, overshoot and steady state error parameters to validate the proposed 3DOF helicopter balancing system. Based on GA tuning approach, the simulation results suggest that the hybrid LQR-PID controller can be effectively adopted to stabilize the 3DOF helicopter system.

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