In-depth cross-coupling analysis in high-performance induction motor control     

Luis A. Amézquita-Brooks  Carlos E. Ugalde-Loo  Eduardo Licéaga-Castro  Jesús Licéaga-Castro 《Journal of The Franklin Institute》2018,355(5):2142-2178

High-performance field oriented control (FOC) of induction motors (IMs) relies on the accurate control of their electrical dynamics. In particular, perfect decoupling control of the stator currents should be ideally achieved for a FOC scheme to be efficient. However, the decoupling effectiveness afforded by most stator currents controllers may be influenced not only by the parameters and the operating condition, but also by the specific controller structure and the adopted coordinate system. A measure to assess decoupling effectiveness is non-existent in the IM control literature. To bridge this gap, an in-depth analysis of the cross-coupling inherent characteristics of the electrical subsystem of IMs under different well-known control structures is presented in this paper. Specifically, four control strategies previously studied and experimentally validated in the literature are critically assessed in this work: (1) stationary frame proportional-integral (PI) control, (2) synchronous frame PI control, (3) synchronous frame PI control with decoupling networks, and (4) improved stationary frame diagonal control. The decoupling capabilities of controllers in stationary and synchronous coordinates are examined, with a detailed insight on the role of decoupling methods. The analysis is performed in the frequency domain under the framework of individual channel analysis and design (ICAD). By application of ICAD, the decoupling effectiveness of FOC schemes is clearly exposed and quantified, with an assessment of the effects of parametric uncertainty being carried out for completeness. The effect of the inverter dynamics over cross-coupling is also treated using digital simulations. The results are useful to determine the conditions in which each control strategy has either advantages or disadvantages. Additionally, it is possible to determine the effect of several operating parameters over the stator currents cross-coupling such as nominal flux and torque levels.  相似文献   

Neural network adaptive control design for robot manipulators under velocity constraints     

Hamed Rahimi Nohooji  Ian Howard 《Journal of The Franklin Institute》2018,355(2):693-713

This paper studies the neural adaptive control design for robotic systems with uncertain dynamics under the existence of velocity constraints and input saturation. The control objective is achieved by choosing a control Lyapunov function using joint error variables that are restricted to linear growth and furthermore by introducing a secant type barrier Lyapunov function for constraining the joint rate variables. The former is exploited to bind the forward propagation of the position errors, and the latter is utilized to impose hard bounds on the velocity. Effective input saturation is expressed, and neural networks are employed to tackle the uncertainty problem in the system dynamics. Feasibility conditions are formulated, and the optimal design parameters are obtained by solving the constrained optimization problem. We prove that under the proposed method, semi-global uniform ultimate boundedness of the closed-loop system can be guaranteed. Tracking errors meanwhile converge to small neighborhoods of the origin, and violations of predefined velocity constraints are avoided. Finally, numerical simulations are performed to verify the effectiveness of the theoretical developments.  相似文献   

Lag synchronization for fractional-order memristive neural networks with time delay via switching jumps mismatch     

Lingzhong Zhang  Yongqing Yang  Fei wang  Xin sui 《Journal of The Franklin Institute》2018,355(3):1217-1240

This paper studies drive-response synchronization in fractional-order memristive neural networks (FMNNs) with switching jumps mismatch. A comparison theorem for fractional-order systems with variable order is provided first. Theories of fractional order Filippov differential inclusions are used to treat FMNNs because the parameters of FMNNs are state dependent and the FMNNs has discontinuous right hand sides. Based on Laplace transform and linear feedback control, some lag quasi-synchronization conditions are obtained with variable order α: 0?<?α?<?1 and 1?<?α?<?2. The error level is estimated and the larger synchronization regain is discussed. Finally, two numerical examples are presented to illustrate the effectiveness of our proposed theorems.  相似文献   

Observer-based fault detection for uncertain nonlinear systems     

Huayun Han  Ying Yang  Linlin Li  Steven X. Ding 《Journal of The Franklin Institute》2018,355(3):1278-1295

This paper addresses L₂ observer-based fault detection issues for a class of nonlinear systems in the presence of parametric and dynamic uncertainties, respectively. To this end, three different types of uncertain affine nonlinear system models studied in this paper are described first. Then, the integrated design schemes of L₂ observer-based fault detection systems are derived with the aid of Hamilton–Jacobi inequalities (HJIs), respectively. Numerical examples are also provided in the end to demonstrate the effectiveness of the proposed results.  相似文献   

Fault-tolerant anti-windup control for hypersonic vehicles in reentry based on ISMDO     

Yizhen Meng  Bin Jiang  Ruiyun Qi  Jianwei Liu 《Journal of The Franklin Institute》2018,355(5):2067-2090

Due to the extreme large flight scale of Hypersonic Vehicle (HSV), the system inevitably possesses strong nonlinearity, coupling, fast time-variability and is also sensitive to disturbance and fault. The method of external anti-windup system combined with the terminal sliding mode control law (TSMC) is presented for the nonlinear control problem under the restriction of control surfaces for HSV. It can realize the compensation for the control surface saturation and let the HSV smoothly track the command signals. Then, the improved sliding mode disturbance observer (ISMDO) is proposed to estimate unknown parameters and strong external disturbance as well as the unknown actuator fault. This method does not need the information of disturbance and the fault bounds and has fewer learning parameters, which makes it suitable for the real-time control. Finally, the simulation test of attitude control for the reentry HSV is conducted, and the results show the effectiveness and robustness of the proposed scheme.  相似文献   

Multiple switching-time-dependent discretized Lyapunov functions/functionals methods for stability analysis of switched time-delay stochastic systems     

Shixian Luo  Feiqi Deng  Wu-Hua Chen 《Journal of The Franklin Institute》2018,355(2):949-964

This paper presents novel approaches for stability analysis of switched linear time-delay stochastic systems under dwell time constraint. Instead of using comparison principle, piecewise switching-time-dependent discretized Lyapunov functions/functionals are introduced to analyze the stability of switched stochastic systems with constant or time-varying delays. These Lyapunov functions/functionals are decreasing during the dwell time and non-increasing at switching instants, which lead to two mode-dependent dwell-time-based delay-independent stability criteria for the switched systems without restricting the stability of the subsystems. Comparison and numerical examples are provided to show the efficiency of the proposed results.  相似文献   

The benefits of multivariate singular spectrum analysis over the univariate version     

Paulo Canas Rodrigues  Rahim Mahmoudvand 《Journal of The Franklin Institute》2018,355(1):544-564

Singular Spectrum Analysis (SSA) is a relatively simple and powerful method in the area of time series analysis that is mainly based on matrix analysis. In this paper, we present a methodological comparison between the univariate and multivariate versions of SSA. Additionally, we explore the advantages of multivariate SSA in terms of theoretical results and with application to a real data set on currency exchange rates.  相似文献   

Tracking-protection-recovery switching control for aero-engines     

Chao Chen  Jun Zhao  Yan-Feng Sui 《Journal of The Franklin Institute》2018,355(1):1-30

This paper presents a novel tracking-protection-recovery switching strategy to solve the thrust tracking and safety protection multi-objective control problem for the aero-engines. The proposed switching control strategy overcomes the contradiction between the tracking performance and the safety requirement. The design procedure is with larger degree of freedom and less conservatism. The proposed switching controller can be designed in three steps. For the tracking stage, the tracking controller is designed only according to the rapidity requirement for the thrust tracking with less consideration of safety. For the protection stage, the protection controller is activated to limit the protected output in the safety region. Because of the properly designed protection controller, it is unnecessary to switch on the protection controller before the protected output reaches the safety boundary. That reduces conservatism and makes the tracking performance improved. For the recovery stage, the recovery controller, as well as the properly designed resetting law, is utilized to guarantee finite number of switches and the resulting asymptotic tracking. Because of the properly designed switch-off condition for the protection controller, the thrust tracking performance gets improved. The protected output is also successfully limited. Finally, a case study for a two-spool turbofan engine is performed to verify the effectiveness of the proposed scheme. It is also indicated that the proposed tracking-protection-recovery switching strategy can improve both safety performance and the tracking transient performance.  相似文献   

Exact expressions for the bit error rate and channel capacity of a dual-hop cooperative communication systems over Nakagami-m fading channels     

Amer M. Magableh  Neameh Jafreh 《Journal of The Franklin Institute》2018,355(1):565-573

Cooperative diversity has been widely used in wireless communication systems since they greatly improves and enhances the quality of service as being virtual antennas without physically placing multiple antennas at the transmitter or the receiver sides. In this paper, we consider the amplify and forward (AF) relay-based communication systems under the influence of Nakagami-m multipath fading channels in both channel links. Several performance metrics are considered in this study, including, the bit error rate (BER), the ergodic channel capacity, and the outage capacity. The obtained expressions are in closed-form and can reduce to the Rayleigh channel model, as a special case. Numerical results are also provided for the obtained expressions and some conclusions are drawn.  相似文献   

Enhanced efficiency in vector control of a Surface-mounted PMSM drive     

S.M. Tripathi  Chandan Dutta 《Journal of The Franklin Institute》2018,355(5):2392-2423

In this paper, emphasis has been put on providing the result of a detailed simulation study on the dynamics and efficiency of a vector-controlled voltage source inverter (VSI)-fed surface-mounted permanent magnet synchronous motor (SPMSM) drive; which employs firstly a model-based loss-minimization algorithm (MLMA) and secondly a binary search-based online loss-minimization algorithm (BSOLMA), so as to reduce the total controllable electrical losses without much affecting the dynamic performance of the drive. The steady-state SPMSM model taking into account the core loss has been considered. The dynamic performances of the SPMSM drive employing individually the abovementioned loss minimization algorithms (LMAs) have been compared with that employing conventional zero d-axis current control (ZDCC) through extensive digital computer simulations. The simulation results show that efficiency of the drive enhances with the employment of the LMA.  相似文献