No abstract is provided for this article.
This paper deals with the problem of output-feedback H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control for a class of active quarter-car suspension systems with control delay. The dynamic system of the suspension systems is first formed in terms of the control objectives, i.e., ride comfort, road holding, suspension deflection, and maximum actuator control force. Then, the objective is to the design of the dynamic output-feedback H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> controller in order to ensure asymptotic stability of the closed-loop system with H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> disturbance attenuation level and the output constraints. Furthermore, using Lyapunov theory and linear matrix inequality (LMI) approach, the existence of admissible controllers is formulated in terms of LMIs. With these satisfied conditions, a desired dynamic output-feedback controller can be readily constructed. Finally, a quarter-vehicle model is exploited to demonstrate the effectiveness of the proposed method.
Summary This paper studies the fault estimation problem for a class of nonlinear semi‐Markovian jump systems with partly unknown transition rates and output quantization. Firstly, a mode‐dependent intermediate variable is designed, which constructs an intermediate estimator to estimate fault signals of system. Secondly, the partly unknown transition rates and output quantization are considered and the sufficient conditions of stability for the error system are given in three cases by linear matrix inequalities. Moreover, the proposed nonlinear function satisfies Lipschitz condition, which can be employed in a multitude of practical systems. Finally, simulation results are provided to illustrate the effectiveness of the proposed theoretical results.
In marine guard, patrol, and racing scenarios, it is of great importance to autonomously helm an underactuated surface vehicle (USV) to accurately achieve successive waypoints tracking (SWT) with prescribed velocities and courses. In this paper, in the presence of completely unknown dynamics and environmental forces, the emerging SWT problem is innovatively solved by creating a novel model-free guidance-control integrated framework. In lieu of direct guidance to the waypoint which inevitably suffers from singularity, a new tool called bridge trajectory (BT) exactly passing through the generalized waypoint (GW) is first developed by defining marching and ahead points, i.e., a marching point (MP) and an ahead point (AP). Combining with pursuit guidance and finite-time unknown observer (FUO), successive BTs are switched ON and OFF, with the aid of MP and AP, respectively. By virtue of the FUO, cascade analysis, filtered backstepping, and Lyapunov approach, BT tracking control laws for surge and yaw motions are further synthesized to ensure successive GWs with desired positions, velocities, and courses can be tracked accurately, and thereby eventually contributing to a BT-guided model-free solution to the SWT problem. Simulation studies on a benchmark USV demonstrate remarkable performance of the proposed method.
This paper deals with the problem of adaptive output feedback neural network controller design for a SISO non-affine nonlinear system. Since in practice all system states are not available in output measurement, an observer is designed to estimate these states. In comparison with the existing approaches, the current method does not require any information about the sign of control gain. In order to handle the unknown sign of the control direction, the Nussbaum-type function is utilized. In order to approximate the unknown nonlinear function, neural network is firstly exploited, and then to compensate the approximation error and external disturbance a robustifying term is employed. The proposed controller is designed based on strict-positive-real (SPR) Lyapunov stability theory to ensure the asymptotic stability of the closed-loop system. Finally, two simulation studies are presented to demonstrate the effectiveness of the developed scheme.
This article investigates the issue of observer‐based sliding mode control for Markovian jump systems suffer from actuator attacks through an adaptive technique. During the communication channel from the plant output to estimator, a dynamic event‐triggered generator is employed in enhancing communication efficiency. Taking consideration of malicious attacks on the plant actuator, an adaptive compensator is put forward for security purposes. By designing a state observer, the desired sliding mode dynamics can be derived based on an integral‐type sliding surface. Further, maintaining the sliding motion with uncertain mode information is ensured in finite time by proposing a feasible sliding mode control law. In addition, both stochastic stability and performance conditions are established for closed‐loop systems in terms of linear matrix inequalities. Finally, a numerical example is offered to illustrate the validity of the constructed strategy.
This paper is concerned with the design problem of robust switching rule for Boost converters with uncertain parameters and disturbances. Firstly, the Boost converter is modeled as a switched affine linear system with uncertain parameters and disturbances. Then, using common Lyapunov function approach and linear matrix inequality (LMI) technique, a novel switching rule is proposed such that the model reference tracking performance is satisfied. Finally, a simulation result is provided to show the validity of the proposed method.
No abstract is provided for this article.
This paper considers the problem of local capacity H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control for a class of production networks of autonomous work systems with time-varying delays in the capacity changes. The system under consideration is modeled in a discrete-time singular form. Attention is focused on the design of a controller gain for the local capacity adjustments which maintains the work-in-progress (WIP) in each work system in the vicinity of planned levels and guarantees the asymptotic stability of the system and reduces the effect of the disturbance input on the controlled output to a prescribed level. In terms of a matrix inequality, a sufficient condition for the solvability of this problem is presented using an appropriate Lyapunov function, which depends on the size of the delay and is solved by existing convex optimization techniques. When this matrix inequality is feasible, the controller gain can be found by using LMI Toolbox Matlab. Finally, numerical results are provided to demonstrate the proposed approach.
The main objective of this paper is to investigate the sensitivity analysis and optimal design of a proportional solenoid valve (PSV) operated pressure reducing valve (PRV) for heavy-duty automatic transmission clutch actuators. The nonlinear electro-hydraulic valve model is developed based on fluid dynamics. In order to implement the sensitivity analysis and optimization for the PRV, the PSV model is validated by comparing the results with data obtained from a real test-bench. The sensitivity of the PSV pressure response with regard to the structural parameters is investigated by using Sobol׳s method. Finally, simulations and experimental investigations are performed on the optimized prototype and the results reveal that the dynamical characteristics of the valve have been improved in comparison with the original valve.
