Analysis of Differential Inclusions: Feedback Control Method

The feedback control based on the model and method of iterative learning control, which in turn is based on the macroscopic fundamental diagram (MFD), mostly belongs to the classification of single-layer boundary control method. However, the feedback control method has the problem of time delay. Therefore, a feedforward feedback iterative learning control (FFILC) method based on MFD of the multi-layer boundary of single-area oversaturated intersections is proposed. The FFILC method can improve the effectiveness of boundary control and avoid the time-delay problem of feedback control. Firstly, MFD theory is used to determine the MFD of the control area; the congestion zone and the transition zone of the control area are identified; and the two-layer boundary of the control area is determined. Then, the FFILC controllers are established at the two-layer boundary of the control area. When the control area enters into a congestion state, the control ratio of traffic flow in and out of the two-layer boundary is adjusted. The cumulative number of vehicles in the control area continues to approach the optimal cumulative number of vehicles, and it maintains high traffic efficiency with high flow rates. Finally, The actual road network is taken as the experimental area, and the road network simulation platform is built. The controller of the feedforward iterative learning control (FILC) is selected as the comparative controller and used to analyse the iterative effect of FFILC. Improvements in the use of traffic signal control indicators for the control area are analysed after the implementation of the FFILC method. Results show that the FFILC method considerably reduces the number of iterations, and it can effectively improve convergence speed and the use of traffic signal evaluation indicators for the control area.

Setting independent lanes for passenger vehicles and trucks respectively could reduce traffic accidents. But most management strategies for separating trucks from passenger vehicles are concentrated on fixed exclusive lanes, which couldn't be adjusted when the running state of traffic flow changes. This study proposed a modified model predictive control (MPC) method used for dynamic adjustment of lane division schemes, to improve traffic efficiency. An extended METANET model that considered vehicle types was established for predicting traffic status. A theory for searching for the optimal lane division scheme was constructed using a modified BRP road resistance function as the objective function. Through simulation of the urban mobility (SUMO) platform, the performance of the method was compared with the static lane division scheme and feedback control method. Simulation results reveal that the modified MPC method improves the traffic efficiency by 5.3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">%</sup> and more than 14.9% respectively compared with the static lane division scheme and feedback control method. The compared results illustrate that the proposed MPC method has better performance when the proportion of vehicle types changes drastically.

This paper presents a thorough literature reviews of control methods to improve transient response in switch mode power supply (SMPS). A fast transient response to a step load change is very essential in a power supply. The transient response can be improved by means of feedback control method. There are two feedback control methods widely used for SMPS that are, voltage mode control (VMC) and peak current mode control (PCMC). A simulation study on these feedback control methods has been done using Matlab/Simulink. It is found that the PCMC helps the SMPS for a faster transient response compared to the VMC. Based on all the reviews a new method is being investigated known as "Voltage Injection Switching Inductor" (VISI) method. This feedback control method provides a better transient response to PCMC. The comparison of these simulation results validates the proposed idea.

In this paper, a novel control method that combines passive, linear feedback, and dislocated feedback control methods is proposed and applied to the control of the four-dimensional hyperchaotic finance system which has been introduced and controlled with the linear feedback and speed feedback control methods by Yu, Cai, and Li (2012). The stability of the hyperchaotic finance system at its equilibrium points is ensured on the basis of a Lyapunov function. Computer simulations are used for verifying all the theoretical analyses visually. In the simulations, the proposed control method is also compared with the speed feedback and linear feedback control methods to observe its effectiveness and the results are discussed. DOI: http://dx.doi.org/10.5755/j01.itc.47.1.16898

In this paper we provide a review of the state of the art for active vibration control of axially moving materials (string and beam, etc.) in the past ten years, with particular regard to the subjects of some important active control methods of axially moving strings. First, an introduction is given to explain the aims and scope of this paper. This is followed by a comprehensive discussion of the active wave control methods presented by many investigators in the past ten years, including feedback control methods (such as the modal control method, the direct velocity feedback control method and the control method via transfer function formulation), active wave control methods combining transfer function, boundary control methods using the Lyapunov function, the variable structure control method, the adaptive control method, the vibration control of an axially moving beam and the active control of a moving material with arbitrarily varying length, etc. Finally, we conclude with a discussion of several issues for future research in this area.

Reconstruction of controls in exponentially stable linear systems subjected to small perturbations

One of the authors had previously proposed an adaptive nonstationary control (ANSC) method and described its applications for the positioning control of vibration systems. In that control method, the time-varying feedback gains were obtained by online computations of a time-varying Riccati equation taking the parameter variations of the controlled object into account. However, the previous paper discussed the state feedback control method. The improvement of this method to enable output feedback control is one of important issues for actual applications. Generally, the output feedback controller of the optimal control includes a Kalman filter as the observer. However, the use of the Kalman filter for the ANSC method implies a heavy computational load in actual implementations because the Kalman filter is designed by another time-varying Riccati equation. Therefore, this paper proposes a practical output feedback control method for ANSC that does not include Kalman filter. The proposed method corresponds to a two-degree-of-freedom control system; the system consists of an online simulator and a sliding mode controller. This structure enables us to reduce the computational load. The effectiveness of the method is verified theoretically as well as experimentally.

This paper investigates the problem of robust passive control for networked fuzzy systems, where randomly occurring uncertainties, variable sampling intervals, and constant network-induced delay are taken into account. A discontinuous Lyapunov functional is introduced for the closed-loop systems, which takes full advantage of the sawtooth structure of the time-varying interval delay induced by sample-and-hold and signal transmission. A sufficient condition is proposed to ensure the closed-loop system to be robustly stochastically passive. Then, the problem of robust passive control is solved. Two examples are utilized to illustrate the advantages and effectiveness of the results that are proposed in this paper.

This paper provides an overview of modern feedback control methods for the voltage regulation in DC/DC converters of DC microgrids. Control objectives and practical restrictions are defined and used as indicators for the analysis and performance assessment of the control methods. After presenting the concept of each control method, the advantages and limitations in the converter applications are discussed. The main conclusions of this overview can be used as recommendations for the selection of the suitable control method according to the control requirements in the DC microgrid. The low robustness against disturbances is a major issue in all control methods. For the enhancement of the robustness of the feedback control methods, three approaches are reviewed. Applications of these approaches in DC/DC converters are compared with regard to the achieved disturbance rejection and the related cost of nominal performance degradation. The disturbance/uncertainty estimation and attenuation (DUEA) framework appears to be the most promising approach to compromising these opposing control objectives. This overview is presented for a general DC/DC converter, without any additional control design requirement imposed by a specific converter plant. This allows the generalisation of the conclusions of the performance assessment, which can facilitate the application of the control methods in similar systems, such as in AC/DC converters or motor drives.

Feedback control methods for stabilizing unstable equilibrium points in a new chaotic system

In this paper, stability and Hopf bifurcation analysis of a novel hyperchaotic system are investigated. Four feedback control strategies, the linear feedback control method, enhancing feedback control method, speed feedback control method and delayed feedback control method, are used to control the hyperchaotic attractor to unstable equilibrium. Moreover numerical simulations are given to verify the theoretical results.

The problem of dynamic reconstruction of the variable input of a linear system is considered. In the case when observations of some characteristics of the phase trajectory of the system are subject to uncertainty, an algorithm for solving this problem, based on control method with a model, is specified. The algorithm is robust to information noise and computational errors. General constructions are illustrated by an example.

A generalized robust decentralized control methodology for a class of interconnected nonlinear systems subject to uncertainties and disturbances

In high power applications, proper gate control strategy for insulated gate bipolar transistors (IGBTs) can increase their efficient and reliability. As to the feed-back control strategy, the key issues are the control speed and control stability. This paper proposed a new feed-back control method integrated in digital gate driver for high power IGBT. It aims for controlling the current and voltage slope suppressing the voltage overshoot and electromagnetic interference (EMI) in switching transient. The digital gate driver for large power IGBT detects the collector current and voltage in real time. Then the detected analog signal is digitally sampled and sent to the digital core on board. An algorithm similar to bang-bang control is deployed in forward control loop to adjust the gate drive resistance. The control stability and robustness can be guaranteed as a result. The whole detection and control process is accomplished in real time with only hundreds of nanoseconds. Thus, the proposed control method can optimized the IGBT switching transient with high reliability and time effectiveness. Experimental results validate the feasibility of the proposed feed-back digital control method.

Ball handling and dribbling are basics soccer techniques. Therefore, handling and dribbling mechanism becomes important component for MSL (Middle Size League) robot soccer. The implementation of active handling and dribbling systems aims to enable the robot to perform dribbling mechanism when maneuvering, while in idle position use handling mechanism. Feedforward and feedback applied as control method in active ball handling and dribbling system. Feedforward control method will give a response to the dribbler wheel based on the motion of robot movement against x , y , and θ axes. Whereas, Feedback control method applied fuzzy inference system by reading the displacement of the arm angle from sensor databased on angle reference of dribbler arm to keep the ball in an ideal position. Implementation geometric calculation for feedforward control toward x , y , and θ axes movement of the robot that it has resulted RMSE value for left motor is 5.75 and for right motor is 7.01. Fuzzy inference system method is used as a feedback control to manipulate the speed and direction of wheel’s rotation as a result ball remains in the ideal position. The value of arm angle displacement and the combination of the two-dribbler arms are used as input for fuzzy inference system. The results of this research show that the application of the combined feedforward and feedback control methods in active handling and dribbling systems can provide robot-dribbling capabilities. Consequently, the robot has a good ability in handling and dribbling mechanism.