An observer-based adaptive control design for the maglev system

Abstract

In this study, a nonlinear adaptive controller that can be used to control a magnetic levitation (maglev) is designed. The designed controller is equipped with a nonlinear velocity observer to provide the control without measuring velocity. Its capability to adaptively compensate all parametric uncertainties during the control process is one of the main advantages of this controller. Utilizing this capability, control of the maglev system can be realized without using any knowledge about system parameters. Due to the fast convergence capability of the designed observer and the desired model dependent structure of the adaptation rules, the proposed control design provides better performance than most of the robust and adaptive controllers that have been frequently used to control maglev system. The observer dynamics are analyzed via a Lyapunov–like preliminary analysis. Then, convergence of the observation and the tracking errors under the closed–loop operation and stability of the closed–loop error dynamics are proven via a Lyapunov–based stability analysis where the result obtained in the mentioned preliminary analysis is used. Performance of the designed observer–controller couple is demonstrated via experimental results. The efficiency of the designed controller is tested against a robust proportional–integral–derivative (PID) controller and an another Lyapunov–based nonlinear robust controller called as robust integral of sign of error (RISE) controller. Experimental results show that the designed controller performs the best tracking performance with the least control effort among these three controllers.

Generalised Proportional Integral Control for Magnetic Levitation Systems Using a Tangent Linearisation Approach

“…is composed of a third degree Hurwitz polynomial whose roots are located sufficiently far into the left half on the complex plane, then the trajectories of the incremental output error e y δ (t), and their corresponding time derivatives exponentially converge to zero. Upon studying the control law proposed in (14) it will be noted that knowledge of the incremental velocity of the magnetic ball, ẏδ (t), is required, signifying that a variable of this nature must either be measured or estimated by an observer. In practise, the estimation is attained by means of online calculations based on high frequency samples of the trajectory of the incremental position variable.…”

“…However, cascading schemes are a solution in this case. For instance, a cascade control structure based on the electrical and electromechanical subsystems that make up MLS platforms and validated it through numerical and experimental tests has been designed [14]. In this approach, the voltage control input required to control the ball position was determined using a PI whose reference signal is the electromagnet current determined by a non-linear adaptive controller combined with a velocity observer to compensate for its missing measurement.…”

Adaptive event-triggered control for new type tyre systems based on vehicles

“…In Adil et al (2020) has proposed super-twisting sliding mode controllers for the magnetic levitation systems, such that the air gap is maintained at the stable value. It can be seen from Bidikli (2020) that the maglev systems can conduct system controlling without using any knowledge about system parameters. In addition, the magnetic levitation systems has been widely used in the field of various fields.…”

A NARX Model Reference Adaptive Control Scheme: Improved Disturbance Rejection Fractional-Order PID Control of an Experimental Magnetic Levitation System

“…As a third component, a PID controller was used for the stabilization of this three component control system. In addition to neural control approaches, some recent works also demonstrated the use of other control approaches such as observer-based adaptive control [31] and the Takagi-Sugeno fuzzy controller [32] a for magnetic levitation control problem. However, these works have not purposely focused on disturbance rejection control performance of magnetic levitation control system..…”