Cascade sliding mode–based robust tracking control of a magnetic levitation system

Abstract

Magnetic levitation systems are able to provide frictionless, reliable, fast and economical operations in wide-range applications. The effectiveness and applicability of these systems require precise feedback control designs because the magnetic levitation is an unstable process and have highly nonlinear dynamics. In this article, a robust sliding mode–based cascade control approach is proposed for effectively tracking the reference position of a magnetic levitation system. The magnetic levitation plant is described with electrical and mechanical models, and the control problems of these parts are treated with cascade controllers. An integral sliding mode and an output feedback sliding mode controllers are designed for use in the cascade loops. The performance of the sliding mode controllers is compared with a proportional–integral–velocity plus proportional–integral control structure. It is shown that the proposed control structure is able to provide a highly satisfactory tracking performance and can eliminate the effects of the inductance-related uncertainties and operating point originated disturbances. The experimental results are provided to validate the efficacy and feasibility of the approach.

An observer-based adaptive control design for the maglev system

“…These values are denoted by L 1 and L 2 ≜ L 0 + L 1 ∈ R , respectively. The inductance value between these limits is determined according to the position of the iron ball with the formula given as Eroglu and Ablay (2016)…”

“…They were considered and used as the main basis of development of magnetic train technologies (Givoni, 2006; Lee et al, 2006). Moreover, maglev systems can be utilized in many other applications such as vibration isolation in sensitive devices, and high precision positioning of chip plates in photolithography (Eroglu and Ablay, 2016). The efficiency of the usage of maglev systems in the mentioned applications and more is directly related with the efficiency of the controller designed to provide the control on the unstable equilibrium points of the system.…”

“…An application of an active magnetic bearing system used to levitate the elevation axis of an electro–optical sight mounted on a moving vehicle and controlled via the SMC by considering the robustness of this method against model uncertainties and its reducing capability on disturbance responses was described in Kang et al (2010). Cascade structured SMC designs presented in Eroglu and Ablay (2016) and Ginoya et al (2016) can be given as two of many SMC examples that can be found in the literature of maglev control systems in this process. In Tepljakov et al (2018), control of the maglev system was ensured via the fractional–order PID control.…”

Feedback controller designs for an electromagnetic micromanipulator

“…1 Some applications include measurement of adhesion strength, 36 investigation of receptor binding firmness, 37 torque generations, 38 magnetically driven microrobotic systems 39–41 and some industrial applications. 42…”

Hardware-in-the-loop simulation and implementation of a fuzzy logic controller with FPGA: case study of a magnetic levitation system

“…Zhang et al (2011) designed a global sliding mode technique that is able to stabilize a linearized system and compared the results with a classic PID controller. A robust sliding-mode-based cascade control approach was proposed for tracking the reference position of a maglev system by Eroğlu and Ablay (2016), and an observer-based feedback controller was designed by Baranowski and Piatek (2012). An adaptive backstepping controller and an adaptive fuzzy backstepping control for a maglev system was examined by Adıgüzel et al (2018) and Sadek et al (2017), respectively.…”