Quasi-Sliding Mode Control of a High-Precision Hybrid Magnetic Suspension Actuator

2013 ◽  
Vol 25 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Dengfeng Li ◽  
◽  
Hector Martin Gutierrez

A novel 1-DOF hybrid magnetic suspension actuator for precise motion control is presented. The actuator is designed to achieve sub-micron positioning accuracy over a range of motion in excess of 1000 µm while avoiding large nominal levitation currents and iron core saturation. The proposed passive push-active pull configuration offers precise motion control with moderate actuator effort when a payload is to be accurately suspended over a large range of travel. The proposed actuator can be used modularly to control multiple axes of motion in a multi-DOF positioning application that requires millimeter-range travel with submicron accuracy. A Quasi-Sliding Mode controller (QSM) is presented in which the sliding mode dynamics are directly designed, as opposed to the typical Lyapunov function approach that is solely based on stability. Since full knowledge of the state vector is required, a nonlinear high-gain observer was also designed and implemented. Performance of the QSM algorithm in controlling the proposed actuator is compared to that of a PID controller with standard feedback linearization. Several experiments are conducted to demonstrate both the positioning and tracking capabilities of the proposed actuator. The proposed QSM method shows better transient performance than the standard PID feedback linearization approach. QSM also shows better tracking performance, which is highly desirable in systems in which fast and accurate motion control along a desired path is critical.

Author(s):  
Yan Liu ◽  
Dirk So¨ffker

This paper introduces a robust nonlinear control method combining classical feedback linearization and a high-gain PI-Observer (Proportional-Integral Observer) approach that can be applied to control a nonlinear single-input system with uncertainties or unknown effects. It is known that the lack of robustness of the feedback linearization approach limits its practical applications. The presented approach improves the robustness properties and extends the application area of the feedback linearization control. The approach is developed analytically and fully illustrated. An example which uses input-state linearization and PI-Observer design is given to illustrate the idea and to demonstrate the advantages.


Author(s):  
Vahid Bahrami ◽  
Ahmad Kalhor ◽  
Mehdi Tale Masouleh

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback linearization approach. To this end, the system dynamics formulation is developed using Lagrange approach and then the so-called Wrench-Closure Workspace (WCW) analysis is performed. Moreover, in the feedback linearization approach, the PD and PID controllers are used as auxiliary controllers input and the stability of the system is guaranteed as a whole. From the simulation results it follows that, in the presence of bounded disturbance based on Roots Mean Square Error (RMSE) criteria, the PID controller has better performance and tracking error of the 2-DoF robot joints are improved 15.29% and 24.32%, respectively.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6753
Author(s):  
Subarto Kumar Ghosh ◽  
Tushar Kanti Roy ◽  
Md. Abu Hanif Pramanik ◽  
Md. Apel Mahmud

This paper proposes a composite nonlinear controller combining backstepping and double-integral sliding mode controllers for DC–DC boost converter (DDBC) feeding by constant power loads (CPLs) to improve the DC-bus voltage stability under large disturbances in DC distribution systems. In this regard, an exact feedback linearization approach is first used to transform the nonlinear dynamical model into a simplified linear system with canonical form so that it becomes suitable for designing the proposed controller. Another important feature of applying the exact feedback linearization approach in this work is to utilize its capability to cancel nonlinearities appearing due to the incremental negative-impedance of CPLs and the non-minimum phase problem related to the DDBC. Second, the proposed backstepping double integral-sliding mode controller (BDI-SMC) is employed on the feedback linearized system to determine the control law. Afterwards, the Lyapunov stability theory is used to analyze the closed-loop stability of the overall system. Finally, a simulation study is conducted under various operating conditions of the system to validate the theoretical analysis of the proposed controller. The simulation results are also compared with existing sliding mode controller (ESMC) and proportional-integral (PI) control schemes to demonstrate the superiority of the proposed BDI-SMC.


2016 ◽  
Vol 3 (4) ◽  
pp. 312-321 ◽  
Author(s):  
Samin Akbari ◽  
Fatemeh Fallahi ◽  
Tohid Pirbodaghi

Abstract Dynamic behaviour of a slider–crank mechanism associated with a smart flexible connecting rod is investigated. Effect of various mechanisms' parameters including crank length, flexibility of the connecting rod and the slider's mass on the dynamic behaviour is studied. Two control schemes are proposed for elastodynamic vibration suppression of the flexible connecting rod and also obtaining a constant angular velocity for the crank. The first scheme is based on feedback linearization approach and the second one is based on a sliding mode controller. The input signals are applied by an electric motor located at the crank ground joint, and two layers of piezoelectric film bonded to the top and bottom surfaces of the connecting rod. Both of the controllers successfully suppress the vibrations of the elastic linkage. Highlights Dynamic behaviour of a slider–crank mechanism associated with a smart flexible connecting rod is investigated. Effect of various mechanisms' parameters including crank length, flexibility of the connecting rod and the slider's mass on the dynamic behaviour is studied. Two control schemes are proposed for elastodynamic vibration suppression of the flexible connecting rod and also obtaining a constant angular velocity for the crank. Controllers are based on feedback linearization approach and sliding mode controller.


Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3077 ◽  
Author(s):  
Madan Mohan Rayguru ◽  
Mohan Rajesh Elara ◽  
Balakrishnan Ramalingam ◽  
M. A. Viraj J. Muthugala ◽  
S. M. Bhagya P. Samarakoon

This work is inspired by motion control of cleaning robots, operating in certain endogenous environments, and performing various tasks like door cleaning, wall sanitizing, etc. The base platform’s motion for these robots is generally similar to the motion of four-wheel cars. Most of the cleaning and maintenance tasks require detection, path planning, and control. The motion controller’s job is to ensure the robot follows the desired path or a set of points, pre-decided by the path planner. This control loop generally requires some feedback from the on-board sensors, and odometry modules, to compute the necessary velocity inputs for the wheels. As the sensors and odometry modules are prone to environmental noise, dead-reckoning errors, and calibration errors, the control input may not provide satisfactory performance in a closed-loop. This paper develops a robust-observer based sliding mode controller to fulfill the motion control task in the presence of incomplete state measurements and sensor inaccuracies. A robust intrinsic observer design is proposed to estimate the input matrix, which is used for dynamic feedback linearization. The resulting uncertain dynamics are then stabilized through a sliding mode controller. The proposed robust-observer based sliding mode technique assures asymptotic trajectory tracking in the presence of measurement uncertainties. Lyapunov based stability analysis is used to guarantee the convergence of the closed-loop system, and the proposed strategy is successfully validated through numerical simulations.


1989 ◽  
Vol 111 (4) ◽  
pp. 631-640 ◽  
Author(s):  
S. H. Z˙ak

This paper examines the problem of robust state-feedback stabilization of a class of nonlinear multi-input dynamical systems. Four approaches to the problem are investigated: the variable structure control (VSC) method, the high-gain feedback technique, the feedback linearization algorithm, and finally the deterministic approach to the control of uncertain systems. It is shown that each design method can lead to a controller such that the closed-loop system exhibits a sliding mode property. The sliding mode is a desirable property since it results in a robust control. The analysis is illustrated by means of a simple numerical example.


2011 ◽  
Vol 7 (1) ◽  
pp. 19-24
Author(s):  
Aamir Hashim Obeid Ahmed ◽  
Martino O. Ajangnay ◽  
Shamboul A. Mohamed ◽  
Matthew W. Dunnigan

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