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To deal with the nonlinearity and high order in compression refrigeration system, a seven-order dynamic model including chilled water cycle is proposed. Based on analysis of the mechanism of the refrigeration system, this model which is described by two-phase lumped parameter method uses main parameters of the refrigeration system as state variables. The steady-state and dynamic performance of the model is confirmed well with simulation and experiment data. Compared with experimental model, this dynamic model can maintain better accuracy under different working conditions.

In this paper, a novel sliding mode control (SMC) method is proposed for the small-scale unmanned helicopter with mismatched disturbance. The novel SMC method is developed by designing a new sliding surface with the output of nonlinear disturbance observer (NDO). The proposed method is robust with both matched and mismatched disturbance. Moreover, it can attenuate the chattering problem significantly. Finally, simulation results illustrate the effectiveness and robustness of the proposed flight control scheme.

A novel sliding mode nonlinear proportional-integral control (SMNPIC) scheme is proposed for driving a class of time-variant chaotic systems with uncertainty to arbitrarily desired trajectory with high accuracy. The SMNPIC differs from the previous sliding mode techniques in the sense that a nonlinear proportional-integral action of sliding function is involved in control law, so that both the steady-state error and the high-frequency chattering are reduced and meanwhile, robustness and fastness are guaranteed. In addition, the proposed SMNPIC actually acts as a class of nonlinear proportional-integral-differential (PID) controller, in which the tracking error and its derivatives up to (n-1)th order as well as the integral of tracking error are considered, so that more useful information than traditional PID can be implemented and better dynamic and static characteristics can obtained. Its good performance for chaotic control is illustrated through a Duffing–Holmes system with uncertainty.

Helicopter dynamics system is a strongly coupled multi-variable nonlinear system, and the actual maneuvers in the presence of many uncertain factors. Therefore, in the design of helicopter flight controller, in order to ensure the safety of helicopter flight, improve the efficiency of completing the mission and reduce driver's work burden, it is not enough to make the helicopter for anti-jamming capability, while the internal parameters of the helicopter model perturbations have a strong robustness. This paper describes the mathematical model of a helicopter first, providing a basis for making for the relevant control methods; Then, this article describes the state feedback pole assignment based on decoupling control and robust H∞ control theory's concept and mathematical foundations; Finally, it proposes a design method of robust H∞ controller, designs concrete H∞ controller for the helicopter model specifically, and builds a complete decoupling of robust H∞ control system.

The phase-to-ground fault occurs frequently in power system, Fault Location is a knotty problem for a long time. This paper presents a novel method to get Fault Current between Adjacent Nodes according to the characteristic of transient current based on WSN (Wireless Sensor Networks). It is used to identify and locate the current fault. The power system is divided into pieces by WSN nodes that could sense the transient three-phase current and identify the fault information based on communication between adjacent nodes. The principle of arranging WSN nodes is also presented. Through the simulation in Matlab, it shows that the method could extract the fault component correctly bypass the influence of variant load and harmonic.

The LED is used for the tunnel lighting. And a tunnel lighting system is presented based on 485 bus. While a variant illumination curve is constructed through inference rules of expert system according to the out illumination of the tunnel, car flow in traffic and car speed. And the tunnel illumination is controlled by the given illumination curve. Under the control of the method, the illumination in tunnel made the bright and dark adaptation process more natural and safeguarded the driving in tunnel. Also the variant curve based on the real illumination of the out of a tunnel, car flow and car speed, meets the real driving demand. Finally, a feedforward and feedback control strategy based on the relationship between light flux and brightness in tunnel is presented. As well as the power energy of tunnel lighting system is saved.

The paper studies the sliding mode control of nonlinear, distributed parameter system described by partial differential equations. The nonlinear system is approximated by a sequence of linear, time-varying system which, under very mild conditions, globally converges in the limit to the nonlinear systems considered. This reduces the nonlinear control problem to linear, time-varying control problems. For each iterative approximation, an infinite-dimensional time-varying sliding surface and the corresponding control input is designed. The converged control input could exponentially stabilizes the nonlinear system. Here we give an example of nonlinear wave equation to illustrate the theory.