To address the reentry guidance problem of a lifting reentry vehicle that simultaneously satisfies typical path constraints, terminal conditions and no-fly zone constraints, a trajectory planning and guidance method b...
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ISBN:
(纸本)9781665426480
To address the reentry guidance problem of a lifting reentry vehicle that simultaneously satisfies typical path constraints, terminal conditions and no-fly zone constraints, a trajectory planning and guidance method based on artificial potential field and drag acceleration profile is proposed. In the longitudinal profile, a drag acceleration profile tracking guidance is used to calculate the bank angle magnitude that satisfies the flight range. In the lateral profile, an improved artificial potential field method is used to obtain the heading angle corridor, which can determine the sign of bank angle and guide the lifting reentry vehicle to avoid the no-fly zone and sudden threats. The results show that the proposed algorithm is effective to address the reentry guidance problem with no-fly zone constraints.
The problem of circuitry of quality indicators increase of analogue IP blocks for mixed-signal SoC is formulated. On the basis of the generalized structure analysis of the linear electronic circuits, consisting of ope...
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The problem of circuitry of quality indicators increase of analogue IP blocks for mixed-signal SoC is formulated. On the basis of the generalized structure analysis of the linear electronic circuits, consisting of operational amplifiers (OA) and RC-circuits, the principle of cancellation of influence of active elements dominating parameters on characteristics and parameters of basic circuits is offered. The sufficiency and uniqueness of the principle of such compensation is shown. General conclusions are formulated.
Event-triggered control aims at reducing the communication load over the feedback link in networked controlsystems by adapting the information exchange to the current needs. This paper firstly extends a common approa...
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Event-triggered control aims at reducing the communication load over the feedback link in networked controlsystems by adapting the information exchange to the current needs. This paper firstly extends a common approach to event-triggered control by incorporating a PI controller and by showing the setpoint-tracking properties of the extended scheme. Second, it investigates the consequences of actuator saturation on the behavior of the event-triggered PI-control loop. Simulations show that the effect of actuator saturation depends on the selection of the event threshold which might even destabilize the closed-loop system due to integrator windup. Finally, anti-windup techniques are discussed to overcome this problem.
This paper presents a method of identification of nonlinear system with unknown time varying parameters "based on an idea of orthogonal approximation of function. Here, block pulse functions are chosen as the ort...
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This paper presents a method of identification of nonlinear system with unknown time varying parameters "based on an idea of orthogonal approximation of function. Here, block pulse functions are chosen as the orthogonal set. The systems discussed are bilinear system, polynomial system and the two above mentioned systems with time-delay. The method gives recursive algorithms of identification of time varying parameters, and is not only computationally much simpler f but also allows higher numerical accuracy. Computational examples are presented to illustrate the utility of this method
The models of chemical and biological processes are typically composed of unknown and known parts. This paper recalls a multivariable control strategy that deals explicitly with the existence of incomplete models. The...
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The models of chemical and biological processes are typically composed of unknown and known parts. This paper recalls a multivariable control strategy that deals explicitly with the existence of incomplete models. The suggested strategy uses estimation of the unknown rates in the model and feedback linearization to achieve good closed-loop performance with simple tuning of design parameters and without the need of a complete model. The main contribution of this paper is the development of methods for quantitative analysis of the local stability and performance of the control strategy in the continuous-time case, based on a system description using transfer functions. The approach is illustrated via a simulated example of reactor control.
Identification for control is demonstrated on a small servo system. It is shown how to go through the entire cycle of modeling and identification with the aim of obtaining models suitable for controller design. Contro...
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Identification for control is demonstrated on a small servo system. It is shown how to go through the entire cycle of modeling and identification with the aim of obtaining models suitable for controller design. controllers are designed and implemented in the real time from the identified models.
The growing demands of lithium-ion batteries with high energy density motivate the development of high-capacity electrode materials. The critical issue in the commercial application of these electrodes is electrochemo...
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The growing demands of lithium-ion batteries with high energy density motivate the development of high-capacity electrode materials. The critical issue in the commercial application of these electrodes is electrochemomechanical degradation accompanied with the large volume change, built-in stress, and fracture during lithiation and delithiation. The strong and complex couplings between mechanics and electrochemistry have been extensively studied in recent years. The multi-directional couplings, e.g.,(de)lithiation-induced effects and stress-regulated effects, require cooperation in the interdisciplinary fields and advance the theoretical and computational models. In this review, we focus on the recent work with topics in the electrochemomechanical couplings of deformation and fracture of conventional and alloying electrodes through experimental characterization, theoretical and computational models. Based on the point of view from mechanics, the strategies for alleviating the degradation are also discussed, with particular perspectives for component-interaction patterns in the composite electrodes. With interdisciplinary principles, comprehensive understanding of the electrochemomechanical coupled mechanism is expected to provide feasible solutions for low-cost, high-capacity, high-safety and durable electrodes for lithium-ion batteries.
This paper addresses the problem of sliding-mode control for large-scale fuzzy descriptor systems subject to unknown uncertainties. First, a CMAC neural network is used to approximate the unknown uncertainties, and th...
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An accurate model and prediction of traffic plays a crucial role in mobile network planning and design. However, it is difficult to obtain an analytical model of the mobile traffic due to the high complexity of the mo...
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An accurate model and prediction of traffic plays a crucial role in mobile network planning and design. However, it is difficult to obtain an analytical model of the mobile traffic due to the high complexity of the mobile network. In this study, a novel prediction method based on historical traffic data from the mobile networks, which is considered as chaotic time series, is proposed. It is built on the theory of dynamic system reconstruction, the Takagi-Sugeno (TS) fuzzy model and the support vector machines (SVMs). Because those new elements are involved, it can deal with the time series with noise, and has strong robustness. At First, to reconstruct the dynamic system in phase space, the method to calculate a suitable embedding dimension and time delay is discussed according to the mobile traffic time series. Then, the fuzzy model of the dynamic system is set up, and its parameters are obtained by using subtractive cluster and SVMs. Finally, prediction of mobile traffic with the fuzzy model is analyzed and its comparison with TS model is given. The experiment results show that the proposed method can be applied to various chaotic time series with noise.
This paper establishes two invariance principles for delay differential *** delay differential inclusions are required to satisfy the basic assumptions:the right-hand sides are upper semicontinuous and take nonempty c...
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This paper establishes two invariance principles for delay differential *** delay differential inclusions are required to satisfy the basic assumptions:the right-hand sides are upper semicontinuous and take nonempty compact and convex values on the *** classical La Salle's invariance principle for delay differential inclusions is established successfully by locally Lipschitz Lyapunov-Krasovskii functionals and several stability corollaries are ***,the concept of limit delay differential inclusions is proposed to generalize the invariance principle to time-varying delay differential *** numerical examples are given to show the effectiveness of the proposed results.
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