Bhanu Pratap

Real-time implementation of Chebyshev neural network observer for twin rotor control system

This paper addresses the problem of observer design for the twin rotor multi-input-multi-output (MIMO) system which is a nonlinear system. Exact knowledge of the dynamics of twin rotor MIMO system (TRMS) is difficult to obtain but it is highly desired that the observer can dominate the effects of unknown nonlinearities and unmodeled dynamics independently to prevent the state estimations from diverging and to get precise estimations. The unknown nonlinearities are estimated by Chebyshev neural network (CNN) whose weights are adaptively adjusted. Lyapunov theory is used to guarantee stability for state estimation and neural network weight errors. A comparative experimental study is presented to demonstrate the enhanced performance of the proposed observer.

Optimal control of twin rotor MIMO system using output feedback

In this paper an optimal state regulator is designed for the twin rotor multi-input-multi-output (MIMO) system. The twin rotor MIMO system (TRMS) exemplifies a high order nonlinear system with significant cross couplings. From the nonlinear model of TRMS a linearised model is obtained and a controller is designed to regulate the states. The controller gain is updated iteratively, until optimal value is reached. Finally simulation results are presented to show the effectiveness of the proposed controller for the TRMS.

Sliding mode state observer for 2-DOF twin rotor MIMO system

This paper presents a sliding mode state observer for the 2-DOF twin rotor MIMO (multi-input-multi-output) system which belongs to a class of inherently nonlinear systems. Design parameters are selected such that on the defined switching surface, asymptotically stable sliding mode is always generated. Robust sliding and global asymptotic stability conditions are derived by using Lyapunov method. The unknown nonlinearities are estimated and the state estimation errors tend to zero asymptotically.

Real-time implementation of state observers for twin rotor MIMO system: an experimental evaluation

This paper presents an experimental evaluation of three different kinds of real-time state observers for twin rotor multiple-input-multiple-output (MIMO) system. The twin rotor MIMO system (TRMS) exemplifies a high order non-linear system with significant cross couplings. Based on the experimental results a comparative analysis of Chebyshev neural network-based observer and sliding mode observer with local state observer is presented. Finally, the robustness issues are also addressed.

State observer based robust feedback linearization controller for twin rotor MIMO system

This paper presents, a state observer based controller for the twin rotor multiple-input-multiple-output (MIMO) system. The twin rotor MIMO system (TRMS) belongs to a class of nonlinear system having high coupling effect between two propellers, unstable and nonlinear dynamics. A state observer is designed using coordinate change which transforms the TRMS into an approximate normal form. Based on the proposed observer, a feedback linearization controller is designed for TRMS. The control effort is further compensated using a compensator based on Chebyshev neural network (CNN) to ensure good tracking performance and bounded control effort. Finally simulation results are presented to illustrate the effectiveness of the proposed observer based controller.

Nonlinear robust observers for ball and beam system: A comparative analysis

Nonlinear robust observers for the ball and beam system are presented in this paper. Ball and beam control system is a class of nonlinear system which is used to balance a ball on a particular position on the beam. In the designing, Lyapunov theory is used for the stability analysis of the overall system and all the error signals are uniformly bounded. Proposed observers comprise of reduced order and full order robust observers. The presented methodology is easy in implementation. The simulation results demonstrate the important features and satisfactory tracking performance of the proposed observer design approach. Comparison between reduced and full order robust observers is also depicted in this paper.

Nonlinear feedback linearization controller design for half car suspension system

This paper investigates the nonlinear controller design of a half car suspension system. The half car suspension system is a multiple-input-multiple-output (MIMO) nonlinear system. The proposed controller design is based on a feedback linearization method. Its prime goal is the coordinated control of ride quality and handling performance which are nowadays challenging for suspension systems, for the applications on unpaved roads. The tracking performance of the proposed control technique in the presence of the deterministic road disturbance has been illustrated using simulation results.

Sliding mode observer based controller of uncertain systems: An LMI based approach

This paper presents a sliding mode observer based controller for a class of uncertain systems. Exponential stabilizability for the uncertain systems is considered and the rate of convergence is estimated. The proposed observer based controller is designed using linear matrix inequality (LMI) approach. The observer and controller gains are obtained from the feasible solution of LMI. A numerical example is given to illustrate the performance of observer based controller with simulation results.

Robust control design of variable speed wind turbine using quantitative feedback theory

A robust control design of a three blade, horizontal axis variable speed wind turbine is developed in this paper. The variable speed wind turbine model consists of higher order nonlinear dynamics where uncertainty has been considered in the plant parameters. Quantitative feedback theory is an effective and efficient, robust control technique through which the desired specifications over a specified range of parametric uncertainty can easily be achieved in the frequency domain. The proposed robust torque and pitch control in variable speed wind turbine using quantitative feedback theory satisfy prescribed gain and phase margin, degree of tracking for the robust performance, fast convergence, noise attenuation, and input and output disturbance rejection. The advantages of the proposed robust control design are the consideration of a wide range of performance specifications and achieving effective control over an increased operating frequency range. The simulation results demonstrate the satisfactory performance of proposed quantitative feedback theory-based controller and prefilter which fulfill the necessary conditions such as robust stability and robust tracking. Further, it has been shown that the performance of the quantitative feedback theory-based controller is better than the performance with a standard wind turbine controller and also from the performance by proportional-integral controller.

Continuous sliding mode controller design for inverted pendulum system

This paper presents a non linear robust controller for inverted pendulum system (IPS) using continuous sliding mode control (CSMC) technique. The CSMC is obtained by replacing the discontinuous element of integral sliding mode control (ISMC) approach. The super twisting control algorithm is used as a disturbance estimator which rejects the effect of disturbances. The undesirable chattering effect due to discontinuous term present in conventional ISMC has been completely removed using proposed continuous approach. Finally, the superiority of proposed control scheme has been demonstrated throw simulation results to depict its effectiveness.