Sliding mode pressure controller for an electropneumatic brake: Part II—parameter identification and controller tests

2018 ◽  
Vol 232 (5) ◽  
pp. 583-591 ◽  
Author(s):  
Zhuojun Luo ◽  
Mengling Wu ◽  
Jianyong Zuo
Keyword(s):  
Steady State ◽  
Closed Loop ◽  
Sliding Mode ◽  
Frequency Characteristics ◽  
Step Response ◽  
Cylinder Pressure ◽  
Closed Loop System ◽  
Reference Signals ◽  
Pressure Controller ◽  
Brake Cylinder

In this article, the parameters of the sliding mode pressure controller proposed in part I of this article are identified using direct and indirect methods. A test bench, including hardware and software, is designed to test the performance of the controller. Step response tests are carried out to test controller transient and steady-state control performances. Pressure tracking tests, in which the pressure in the brake cylinder chamber is required to track sinusoidal reference signals, are carried out to test the magnitude and phase frequency characteristics of the closed-loop system. The test results suggest that the proposed controller has excellent closed-loop control performances. It can make full use of the available bandwidth of the electropneumatic brake and regulate the brake cylinder pressure to its required value quickly and precisely without obvious overshoot or undershoot in the step response tests. Steady-state error in the step response tests is no more than ±6 kPa. In the pressure tracking tests, the controller can make the brake cylinder pressure accurately track sinusoidal reference signals at low frequencies. The magnitude and phase frequency characteristics of the closed-loop system with different tube lengths and inner diameters are also given.

LPV Based Sliding Mode Control for Limit Protection of Aircraft Engines

2018 ◽  
Author(s):  
Shubo Yang ◽  
Xi Wang
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
Aircraft Engine ◽  
Gain Scheduling ◽  
Engine Control ◽  
Aircraft Engines ◽  
Sliding Surface ◽  
Closed Loop System ◽  
Limit Protection ◽  
The Stability

Limit protection, which frequently exists as an auxiliary part in control systems, is not the primary motive of control but is a necessary guarantee of safety. As in the case of aircraft engine control, the main objective is to provide the desired thrust based on the position of the throttle; nevertheless, limit protection is indispensable to keep the engine operating within limits. There are plenty of candidates that can be applied to design the regulators for limit protection. PID control with gain-scheduling technique has been used for decades in the aerospace industry. This classic approach suggests linearizing the original nonlinear model at different power-level points, developing PID controllers correspondingly, and then scheduling the linear time-invariant (LTI) controllers according to system states. Sliding mode control (SMC) is well-known with mature theories and numerous successful applications. With the one-sided convergence property, SMC is especially suitable for limit protection tasks. In the case of aircraft engine control, SMC regulators have been developed to supplant traditional linear regulators, where SMC can strictly keep relevant outputs within their limits and improve the control performance. In aircraft engine control field, we all know that the plant is a nonlinear system. However, the present design of the sliding controller is carried out with linear models, which severely restricts the valid scope of the controller. Even if the gain scheduling technique is adopted, the stability of the whole systems cannot be theoretically proved. Research of linear parameter varying (LPV) system throws light on a class of nonlinear control problems. In present works, we propose a controller design method based on the LPV model to solve the engines control problem and achieve considerable effectiveness. In this paper, we discuss the design of a sliding controller for limit protection task of aircraft engines, the plant of which is described as an LPV system instead of LTI models. We define the sliding surface as tracking errors and, with the aid of vertex property, present the stability analysis of the closed-loop system on the sliding surface. An SMC law is designed to guarantee that the closed-loop system is globally attracted to the sliding surface. Hot day (ISA+30° C) takeoff simulations based on a reliable turbofan model are presented, which test the proposed method for temperature protection and verify its stability and effectiveness.

Trajectory tracking control of electric sail with input uncertainty and saturation constraint

2016 ◽  
Vol 39 (7) ◽  
pp. 1007-1016 ◽  
Author(s):  
Yu Wang ◽  
Bingxiu Bian
Keyword(s):  
Solar Wind ◽  
Trajectory Tracking ◽  
Closed Loop ◽  
Sliding Mode ◽  
Input Saturation ◽  
Asymptotically Stable ◽  
Closed Loop System ◽  
Saturation Constraints ◽  
Non Linear System ◽  
Input Saturation Constraints

The electric sail (ES) is a novel propellantless propulsion concept, which extracts the solar wind momentum by repelling the positively charged ions. Due to the difficulty of attitude adjustment by the large flexible structure and the uncertainty of ion density, velocity and electron temperature by solar wind, there exist thrust input uncertainty and saturation with time-varying bounds for ES. The trajectory tracking problem for ES in three-dimensional (3-D) space is studied, and the composite sliding mode control scheme with corresponding guidance strategy is proposed for the single-input–multiple-output (SIMO) non-linear system. The hierarchical sliding surfaces are constructed with an auxiliary design system to analyse the effect of input saturation constraints and decouple the SIMO non-linear system to reduce the control complexity. Also, the disturbance estimation based on a super-twisting algorithm is employed to decrease the switch chattering and improve the system robustness. It is proved that all the sliding mode surfaces are asymptotically stable, and all the signals of the closed-loop system are bounded with input saturation constraints. Furthermore, all the signals are converging to zero and the closed-loop system is asymptotically stable without saturation. Finally, the simulation demonstrates the proposed composite sliding mode control is fit for ES 3-D trajectory tracking.

Sliding Mode Output Feedback Control of Vibration in a Flexible Structure

2007 ◽  
Vol 129 (6) ◽  
pp. 851-855 ◽  
Author(s):  
M. C. Pai ◽  
A. Sinha
Keyword(s):  
Output Feedback ◽  
Control Algorithm ◽  
Closed Loop ◽  
Sliding Mode ◽  
Output Feedback Control ◽  
Flexible Structure ◽  
Numerical Verification ◽  
Closed Loop System ◽  
New Approach ◽  
Small Gain

This paper presents a new approach for the robust control of vibration in a flexible structure in the presence of uncertain parameters and residual modes. The technique is based on the sliding mode control algorithm using direct output feedback and assumes that actuators and sensors are not collocated. The uncertainty matrix need not satisfy the invariance or matching conditions. The small gain theorem/μ analysis is applied to analyze the asymptotic behavior of the closed-loop system with parametric uncertainties inside boundary layers. The model of a flexible tetrahedral truss structure is used to conduct numerical verification of the theoretical analysis.

scholarly journals Comparison of Disturbance Compensators for a Discrete-Time System with Parameter Uncertainty

2020 ◽  
Vol 10 (18) ◽  
pp. 6219
Author(s):  
Zhongyi Guo ◽  
Haifeng Ma ◽  
Qinghua Song
Keyword(s):  
Discrete Time ◽  
Parameter Uncertainty ◽  
Closed Loop ◽  
Sliding Mode ◽  
External Disturbance ◽  
Comparative Investigation ◽  
Industrial Applications ◽  
System Stability ◽  
Discrete Time System ◽  
Closed Loop System

The control design for many industrial applications requires compensation for parameter uncertainty and external disturbance. Reported in many previous works, the parameter uncertainty and external disturbance are combined as a lumped disturbance, which is assumed to be smooth and bounded. However, for a discrete-time sliding mode control (DSMC) system, the above assumption may not hold. Here, the parameter uncertainty, along with its compensation in the DSMC system, are reconsidered and reevaluated. The influence of parameter uncertainty on the closed-loop system stability is first addressed. Then, the comparative investigation of the performance of six state-of-the-art disturbance compensators for parameter uncertainty compensation is conducted. Simulation results show that none of these compensators can effectively observe and compensate for the parameter uncertainty.

Optimizing the Feedback Gains of the Robust Linear Regulator

1999 ◽  
Vol 121 (3) ◽  
pp. 346-350
Author(s):  
Jie Huang
Keyword(s):  
Computer Simulation ◽  
Steady State ◽  
Transient Response ◽  
Closed Loop ◽  
Feedback Gain ◽  
Frobenius Norm ◽  
Closed Loop System ◽  
Optimal Feedback ◽  
Linear Regulator ◽  
Fixed Set

This paper aims to improve the transient response of a linear regulator system by optimizing the feedback gains associated with a fixed set of desirable eigenvalues of the closed-loop system. The optimal feedback gain is such that the Frobenius norm of the steady state of the compensator is minimized. Computer simulation shows that this scheme is effective in improving the transient response of the regulator system.

scholarly journals Fractional-Order Sliding Mode Control of Overhead Cranes   

2020 ◽  
Vol 31 (1) ◽  
pp. 68-76
Keyword(s):  
Sliding Mode Control ◽  
Fractional Order ◽  
Closed Loop ◽  
Control Structure ◽  
Adaptive System ◽  
Sliding Mode ◽  
Lyapunov Theory ◽  
Closed Loop System ◽  
Control Approach ◽  
Mode Control

We constitute a control system for overhead crane with simultaneous motion of trolley and payload hoist to destinations and suppression of payload swing. Controller core made by sliding mode control (SMC) assures the robustness. This control structure is inflexible since using fixed gains. For overcoming this weakness, we integrate variable fractional-order derivative into SMC that leads to an adaptive system with adjustable parameters. We use Mittag–Leffler stability, an enhanced version of Lyapunov theory, to analyze the convergence of closed-loop system. Applying the controller to a practical crane shows the efficiency of proposed control approach. The controller works well and keeps the output responses consistent despite the large variation of crane parameters.

scholarly journals Efficient and Novel voltage control method using DC-DC Cuk Converter under Load Variation

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Syed Mujtaba Mahdi Mudassir ◽  
Faheem Ahmed Khan ◽  
Shaziya Sultana
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Sliding Mode ◽  
Loop System ◽  
Control Mode ◽  
System Response ◽  
Switching Function ◽  
Sliding Modes ◽  
Closed Loop System ◽  
Cuk Converter

A control system is a set of mechanical or electronic devices that regulates other devices or systems by way of control loops. Typically, control systems are computerized. The mode of operation in a Control System where controlling variables is a function of the system and the structure is changed knowingly according to set of rules, which are already declared: for example a sensor based  system, is called as sliding control mode where the feedback control system response is limited and revolves around surface in the space to a point of equilibrium. In this mode of schemes, a switching variable dictates which form of control is to be used at a given instant, depending on the position of the state from the surface. First a set of points for which the switching function is null is used called as sliding surface. Sliding Mode Control (SMC) is a very robust technique which can handle sudden and large changes in dynamics of the system which can be applied to many areas like controlling of motor, aircraft and spacecraft, process control and power systems. SMC is one of the best tool in the industry to design controllers for the systems which has variable values, and provides robust properties against matched uncertainties, However,this use of SMC can only be achieved after the occurrence of the sliding mode. Before the occurrence of the switching function as null i.e. during the reaching phase, the system is affected by even matched ones. Several first order SMC applications for linear and nonlinear systems can be found in the literature [1]. Hence to eliminate the reaching phase and to make sure the ruggedness of the system throughout the entire closed-loop system response Integral Sliding Modes are used. In this paper a design procedure for sliding mode controllers for better control of voltage is applied, and then the ideas implemented are extended to all integral sliding modes in order to ensure optimum operation of entire system response[2]. Necessary conditions for the existence of sliding modes are also given. The closed-loop system is also proved to be exponentially stable. Simulation and experimental tests using the prototype of controlled DC-DC  CUK converter were performed to validate the proposed control approach.

Multi Observer-Based Sliding Mode Load Frequency Control With Input Delay Estimation

2021 ◽  
Vol 1 (4) ◽  
Author(s):  
Ark Dev ◽  
David Fernando Novella Rodríguez ◽  
Sumant Anand ◽  
Mrinal Kanti Sarkar
Keyword(s):  
Power Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Time Delay Estimation ◽  
Loop System ◽  
Load Frequency Control ◽  
System Stability ◽  
Input Delay ◽  
Delay Estimation ◽  
Closed Loop System

Abstract The letter proposes frequency stability in power systems with input delay. A closed loop system can be oscillatory or even unstable without the exact knowledge of delay. Therefore, it is desirable to design a control scheme which is based on the estimation of unknown delay. The proposed design consists of an infinite dimensional observer with an adaptive time delay estimation and a sliding mode controller (SMC). The merit of the proposed concept lies in the fact that the unknown delay is valued by just estimating the smallest delay segment. The controller input is obtained from a set of sequential observers that predicts the system states and ensures asymptotic stability of the closed loop system with input delay estimation. The existence of sliding mode and the closed loop system stability is proved thanks to the Lyapunov and Lyapunov–Krasovskii candidate functionals, respectively. Simulation results confirm the effectiveness of the proposed design.

Sliding Mode Control Laws Design by the ADAR Method with Subsequent Invariant Manifolds Aggregation

2019 ◽  
Vol 20 (8) ◽  
pp. 451-460 ◽  
Author(s):  
A. A. Kolesnikov ◽  
A. A. Kuz’menko
Keyword(s):  
Robust Control ◽  
Invariant Manifolds ◽  
Closed Loop ◽  
Sliding Mode ◽  
Design Procedure ◽  
Sliding Surface ◽  
Closed Loop System ◽  
External Disturbances ◽  
Control Laws ◽  
The Stability

Sliding mode control (SMC) laws are commonly used in engineering to make a system robust to parameters change, external disturbances and control object unmodeled dynamics. State-of-the-art capabilities of the theory of adaptive and robust control, the theory of fuzzy systems, artificial neural networks, etc., which are combined with SMC, couldn’t resolve current issues of SMC design: vector design and stability analysis of a closed-loop system with SMC are involved with considerable complexity. Generally the classical problem of SMC design consists in solving subtasks for transit an object from an arbitrary initial position onto the sliding surface while providing conditions for existence of a sliding mode at any point of the sliding surface as well as ensuring stable movement to the desired state. As a general rule these subtasks are solved separately. This article presents a methodology for SMC design based on successive aggregation of invariant manifolds by the procedure of method of Analytical Design of Aggregated Regulators (ADAR) from the synergetic control theory. The methodology allows design of robust control laws and simultaneous solution of classical subtasks of SMC design for nonlinear objects. It also simplifies the procedure for closed-loop system stability analyze: the stability conditions are made up of stability criterions for ADAR method functional equations and the stability criterions for the final decomposed system which dimension is substantially less than dimension of the initial system. Despite our paper presents only the scalar SMC design procedure in details, the ideas are also valid for vector design procedure: the main difference is in the number of invariant manifolds introduced at the first and following stages of the design procedure. The methodology is illustrated with design procedure examples for nonlinear engineering systems demonstrating the achievement of control goals: hitting to target invariants, insensitivity to emerging parametric and external disturbances.

Observer-based sliding mode control for piezoelectric wing bending-torsion coupling flutter involving delayed output

2020 ◽  
pp. 107754632094912
Author(s):  
Da Li ◽  
Hui Yang ◽  
Na Qi ◽  
Jiaxin Yuan
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Linear Matrix Inequalities ◽  
Closed Loop ◽  
Sliding Mode ◽  
Loop System ◽  
Linear Matrix ◽  
Matrix Inequalities ◽  
Closed Loop System ◽  
Piezoelectric Patch

An observer-based sliding mode control scheme is proposed for suppressing bending-torsion coupling flutter motions of a wing aeroelastic system with delayed output by using the piezoelectric patch actuators. The wing structure is modeled as a thin-walled beam, and the aerodynamics on the wing are computed by the strip theory. For the implementation of the control algorithm, the piezoelectric patch is bonded on the top surface of the beam to act as the actuator. Ignoring the effect of piezoelectric actuators on structural dynamics, only considering the bending moments induced by piezoelectric effects, the corresponding dynamic motion equation is established by using the Lagrange method with the assumed mode method. The flutter speed and frequency of the closed-loop system with time delay are obtained by solving a polynomial eigenvalue problem. An observer-based controller that does not dependent on time delay is developed for suppressing the flutter, and the corresponding gain matrices are obtained by solving linear matrix inequalities. The sufficient condition for the asymptotic stability of the closed-loop system is derived in terms of linear matrix inequalities. The simulation results demonstrate that the proposed control strategy based on the piezoelectric actuator is effective in wing bending-torsion coupling flutter system with a delayed output.

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