Journal of Control
Year:2020 | Volume:13 | Issue:4 |Papers Count:8

In this paper, an offline energy management system (EMS) is proposed for parallel hybrid electric vehicles (HEVs). The proper energy management system is necessary for dividing torque between electrical motor and Internal Combustion Engine (ICE). The battery is a crucial component of hybrid electric vehicles and affects significantly the cost and the performance of the whole vehicle. The primary factors accelerating battery aging are high temperatures and high states of charge (SOC) of the battery. SOC is the most important state variable in EMS, and usually considered as the only dynamic variable in past researches, but the battery temperature is often considered to be constant for simplicity and the effects of EMS on the temperature variations are neglected. In this paper, first, dynamic programming is applied to a parallel HEV without considering variation of the temperature of the battery. Then, the model of battery is improved by modelling the cooling system to take into account temperature variations and show how neglecting thermal dynamics of the battery in EMS is impractical. Finally, by integrating the battery temperature as a state variable in the optimization problem, a new energy management strategy controlling variations of the battery temperature and SOC is proposed. The simulation results on tested vehicle show that in the proposed method charge and temperature of the battery is controlled so that the proposed EMS method prevents uncontrolled variations of the battery temperature and reduces the degradation rate of it.

The application of Networked Control Systems (NCS) in which sensory and control signals are transmitted via shared data communication networks, is growing significantly and these systems have been the subject of research during the last decade. On the other hand, multirate sampled data systems have been investigated since a long time. In this paper, conditions under which a networked control system could be modeled as a multi rate sampled data system are provided. After that, using recent results in the field of networked control systems, existing results for controllability and stabilizability of multi rate sampled data systems are enhanced. For this purpose, sufficient conditions are provided based on the system eigenvalues, to preserve controllability (stabilizability) of a multi rate sampled data system. The results are compared to the existing results in the literature. A numerical example is included as well for clarification and comparison.

In this paper, the coordinated control problem of a tractor-trailer and a combine harvester is taken into account in the presence of model uncertainties by using the leader-following approach to track a reference trajectory for the first time. At first, a second-order leader-follower dynamic model is developed in Euler-Lagrange form which preserves all structural properties of the dynamic model. Then, the tractor-trailer is controlled to maintain a separation distance and a relative bearing angle with respect to the combine harvester. For this purpose, the controller is designed by using an adaptive robust neural network technique. In this control scheme, the parametric uncertainties such as masses, the moments of inertia and other physical parameters are estimated by a radial basis function neural network (RBFNN) and, then, nonparametric uncertainties such as unmodeled dynamics, friction and the slippage of wheels are compensated by the adaptive robust control term. Moreover, it will be shown that the controller makes the tracking errors converge to a small bound around the origin in the presence of uncertainties. The stability of the proposed controller is demonstrated by an analysis based on Lyapunov theory. Finally, the proposed control scheme is simulated by MATLAB software and its validity will be shown and it is compared with the backstepping controller

There are various methods of power generation such as combined cycle power plants. There are many variables in a power plant boiler unit, but the most important variables are Pressure and specially drum level that control system should be put it in the safe range. The purpose of this article is, modifying the oscillatory behavior of the drum level of Kerman combined cycle power plant and especially control of drum level in trip conditions. At first in this article, high pressure drum boiler of Kerman combined cycle power plant is modeled and analyzed. Then drum level control logic of power plant is analyzed and modifications are being made to improve this logic and the results are compared in practice. In the new logic, a control loop (PI) is used for the error signal of the output steam and the input water to the drum and a control loop (PID) for the level error signal and for more accurate estimation, limiting the drum input water and protective conditions, drum pressure signal is used. In fact the new logic is cascade control by measuring four elements for estimating the input water to the drum. The results show that the new logic reduces the Kerman power plant drum boiler level oscillations and keeps the drum level in trip conditions very well.

This paper presents a novel attitude synchronization framework for tracking control of multiple identical/heterogeneous satellites in formation flying with connected communication graph. The main contribution of the paper is considering sensors' measurement error to derive control gains. Moreover, the proposed strategy need no angular velocity communication. Nevertheless, the tracking synchronization among the satellites' attitudes with individual set-points is guaranteed. Accordingly, based on the Lyapunov criterion, uniformly ultimately boundedness of the synchronization/tracking errors are investigated. The simulation results are presented to illustrate the performance of the developed algorithm

The robust carrier tracking is defined as the ability of a receiver to determine the phase and frequency of the input carrier signal in unusual conditions such as signal loss, input signal fading, high receiver dynamic, or other destructive effects of propagation. An implementation of tight tracking can be understood in terms of adopting a very narrow loop bandwidth that contradict with the requirements for tracking high user dynamics. Such a trade-off becomes the critical point and the main limitation of robust carrier tracking, since both noise rejection (and equivalently, recovery of the lost signal power) and agile carrier tracking must be appropriately balanced to avoid penalizing the performance criteria of the specific application under analysis. In practice, bandwidth must be adaptive so that with respect to input noise and dynamic values, optimal bandwidth could be chosen. In this article, first different carrier tracking systems is reviewed and their related features and applications are studied and determined. Then, with comparing existing methods it is shown that, the proposed intelligent type-2 neuro-fuzzy controllers in tracking system provide results that are more acceptable than others because of overcoming the uncertainties in the received carrier signal and environmental conditions.

This paper presents a new hybrid guidance law based on classical interception point strategy and intelligent fuzzy logic methodology for missile guidance in the terminal phase for high maneuvering targets tracking. Due to the linear relationships of the missile-target engagement against the low maneuvering targets, the guidance law will be simply obtained based on the desired course angle of the missile. Since the missile-target engagement equations are highly nonlinear models, the guidance law solution against the high maneuvering targets is so complicated and time consuming. Therefore, the new guidance law against the high maneuvering targets is provided to calculate the interception point and time by using the obtained guidance law from the low maneuvering target and fuzzy logic. Performance comparisons are shown between the new fuzzy collision point (FCP) guidance law and the traditional sliding mode control, recently proposed augmented proportional navigation and collision point methods. Reducing in interception times besides the considerably improvement in control effort on four different missile-target engagement scenarios are among the achievements of the new hybrid method.