A Nonlinear Integral Sliding Surface to Improve the Transient Response of a Force-Controlled Pneumatic Actuator With Long Transmission Lines

Author(s):  
Khurram Butt ◽  
Nariman Sepehri

AbstractA force-controlled pneumatic actuator with long connecting tubes is a well-accepted solution to develop magnetic resonance imaging (MRI)-compatible force control applications. Such an actuator represents an uncertain, second-order, nonlinear system with input delay. The integral sliding mode control, because of guaranteed robustness against matched uncertainties throughout the system response, provides a favorable option to design a robust controller for the actuator. However, if the controller is based on a linear integral sliding surface (LISS), the response of the actuator overshoots, especially when there are large initial errors. Minimizing overshoot results in a smaller controller bandwidth and a slower system response. This paper presents a novel nonlinear integral sliding surface (NLISS) for a sliding mode controller to improve the transient response of the actuator. The proposed surface is a LISS augmented by a nonlinear function of tracking error and does not have a reaching phase when there are initial errors and even multiple steps in the desired trajectory. The surface enables the integral sliding mode controller to offer variable damping, which changes from low to high as the transient error approaches small values and vice versa. Simulation studies and experimental results show that the controller based on the proposed sliding surface successfully eliminates the overshoot without compromising the controller bandwidth, rise, and settling times. For performance evaluation, the controller parameters are tuned using the globalized and bounded Nelder–Mead (GBNM) algorithm with deterministic restarts. The study also establishes the asymptotic stability of the controller based on the proposed sliding surface using Lyapunov's stability criterion.

2016 ◽  
Vol 829 ◽  
pp. 128-132 ◽  
Author(s):  
Van Van Huynh ◽  
Minh Hoang Quang Tran

In this paper, a new integral sliding mode control scheme is designed for the 3-pole active magnetic bearing system. First, a new integral sliding surface is designed such that the 3-pole active magnetic bearing system in the sliding mode is asymptotically stable under certain conditions. Then, an adaptive controller is designed to solve the unknown upper bound of matched uncertainty and guarantee the reachability of the integral sliding surface. Finally, the performance of the proposed integral sliding mode controller is applied to 3-pole active magnetic bearing system to demonstrate the efficacy of the proposed method.


Author(s):  
C. B. Kadu ◽  
A. A. Khandekar ◽  
C. Y. Patil

This paper deals with the design of sliding mode controller (SMC) with proportional plus integral sliding surface for regulation and tracking of uncertain process control systems. However, design method requires linear state model of the system. Tuning parameter of SMC has been determined using linear quadratic regulator (LQR) approach. This results in optimum sliding surface for selected performance index. Matched uncertainty is considered to obtain the stability condition in terms of its upper bound. A conventional state observer has been used to estimate the states. The estimated states are then fed to controller for determining control signal. The simulation study and experimentation on real-life level system have been carried out to validate performance and applicability of the proposed controller.


2020 ◽  
Vol 53 (7-8) ◽  
pp. 1309-1317
Author(s):  
Bei Liu ◽  
Yang Yi ◽  
Hong Shen ◽  
Chengbo Niu

This brief proposes a novel composite observer-based integral sliding mode tracking control algorithm for a class of nonlinear systems affected by both actuator faults and mismatched disturbances. First, different types of observers, including the extended state observer, the fault diagnosis observer, and the disturbance observer, are integrated to estimate the unknown system state, actuator faults, and mismatched disturbances timely. Then, in accordance with the estimation information, the integral sliding surface and the integral sliding mode controller are proposed, which can tolerate the actuator faults and reject the mismatched disturbances. Meanwhile, the state trajectories can be driven into the specified sliding surface in a finite time. Furthermore, not only the stability, but the favorable dynamical tracking and the output constraints of closed-loop augmented systems can be guaranteed. Finally, the validities of the proposed algorithm are embodied by the simulation results of typical A4D systems.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Lijun Gao ◽  
Yuqiang Wu

This paper addresses the problem ofH∞control for a class of uncertain stochastic systems with Markovian switching and time-varying delays. The system under consideration is subject to time-varying norm-bounded parameter uncertainties and an unknown nonlinear function in the state. An integral sliding surface corresponding to every mode is first constructed, and the given sliding mode controller concerning the transition rates of modes can deal with the effect of Markovian switching. The synthesized sliding mode control law ensures the reachability of the sliding surface for corresponding subsystems and the global stochastic stability of the sliding mode dynamics. A simulation example is presented to illustrate the proposed method.


Author(s):  
J. Fei ◽  
Celel Batur

This paper presents an adaptive tracking controller with a proportional and integral switching surface. A new adaptive sliding mode controller based on model reference adaptive state feedback control is proposed to deal with the tracking problem for a class of linear dynamic systems. First, a proportional and integral sliding surface instead of a conventional sliding surface is chosen and then an adaptive sliding mode controller is derived and its stability is proved. It is shown that the stability of the closed-loop system can be guaranteed with the proposed adaptive sliding mode control strategy. The adaptive design is extended to the multiple inputs system. The numerical simulation is investigated to show the effectiveness of the proposed adaptive sliding mode control scheme with proportional plus integral sliding mode action.


Author(s):  
Yong-Kun Lu

An adaptive fuzzy integral sliding-mode controller using nonlinear sliding surface is designed for the speed regulator of a field-oriented induction motor drive in this paper. Combining the conventional integral sliding surface with fractional-order integral, a nonlinear sliding surface is proposed for the integral sliding-mode speed control, which can overcome the windup problem and the convergence speed problem. An adaptive fuzzy control term is utilized to approximate the uncertainty. The stability of the controller is analyzed by Lyapunov stability theory. The effectiveness of the proposed speed regulator is demonstrated by the simulation results in comparison with the conventional integral sliding-mode controller based on boundary layer.


Author(s):  
J Fei ◽  
C Batur

This paper presents an adaptive sliding mode tracking controller with a proportional and integral switching surface. A novel adaptive sliding mode controller based on model reference adaptive state feedback control is proposed to deal with the tracking problem for a class of dynamic systems. First, a proportional and integral sliding surface instead of a conventional sliding surface is chosen and then a class of adaptive sliding mode controller with integral sliding term is developed. It is shown that the stability of the closed-loop system can be guaranteed with the proposed adaptive sliding mode control strategy. The numerical simulation of a triaxial gyroscope is investigated to show the effectiveness of the proposed adaptive sliding mode control scheme with proportional plus integral sliding mode action.


Author(s):  
Ahmet Okyay ◽  
Ender Cigeroglu ◽  
S Çağlar Başlamışlı

In this study, anti-lock brake system control using sliding-mode controller is investigated. Different alternatives for the switching function and the sliding surface, involved in the structure of the sliding-mode controller, are explored. It was aimed to reach a better controller performance with less chattering and robustness to actuator imperfections. Regarding applicability, tire force response was modeled as a uniformly distributed uncertain parameter during controller designs. Controllers are simulated for both constant and varying coefficient of friction roads, with optimized design parameters. The effects of actuator first-order dynamics and transportation delay, which come up in practical implementations, were considered. The sliding-mode control structure which employs derivative switching function with integral sliding surface is originally proposed in this study. It is found to produce less chattering and provide more robustness, which could not be achieved side by side using former designs.


Sign in / Sign up

Export Citation Format

Share Document