Applied Mechanics and Materials Vols. 385-386

Abstract: Crane with its advantages is widely used in industrial and mining enterprises, but the old control system will bring a series of problems which increased the daily maintenance work. This article adopts the double machine automatic control system of dc drag, and position control method based on the standard stroke was designed, and its validity is verified by Matlab simulation.

Abstract: The problem of robustly asymptotic stability and controller design for a class of switched uncertain singular systems with time-delay is considered. By means of Lyapunov function and Matrix equivalent transformation, based on multiple Lyapunov function techniques, a delay-dependent sufficient condition is deduced, such that the solution of the switched singular system with time-delay is robustly asymptotic stable for all admissible uncertainties under an appropriate switching law. Furthermore, a convex optimization problem with LMI constraints is formulated such that the maximum bound on the admissible delay can be determined by using the LMI toolbox in MATLAB. Finally, an illustrative example is given to demonstrate the effectiveness of proposed method.

Abstract: This paper analyses the reasons of motor speed loss on variable-speed pump-control-motor governing system, and points out that the reasons are system leakage, electromotor characteristics and oil compressibility caused by system pressure change. Speed loss compensation method of variable-speed pump-control-motor governing system is put forward. Simulation analysis is carried out under constant load, variable load and variable-speed, and simulation results show that the compensation method can well compensate motor speed loss.

Abstract: A novel state error port-controlled Hamiltonian (PCH) system method is presented for speed control the direct current (DC) separately excited motor. The unity power factor regulation of three phase pulse width modulated (PWM) rectifier is also implemented. Then, the state error PCH system control theory, the PCH model of the PWM rectifier and DC motor are proposed. Moreover, the control algorithm of the duty ratio switch function is presented for the PWM rectifier. Theoretical analysis and simulation results show that the controller has good speed tracking and unity power factor control performances.

Abstract: An online monitoring system of main insulation and outer sheath of power cable is designed in this paper. The system can monitor the insulation of the power cable without change the normal power cable wiring and grid structure. Changes of the main insulation and outer sheath of power cable can be monitor and recorded. Alarm of given when the insulation of the power cable is abnormal. System managers arrange outage maintenance depends on the status of the power cable.

Abstract: Under the background of growing world energy shortage people start to realize the potentiality of renewable resources. Wind-solar hybrid power system as its stability and economy is with widespread use now. This paper according to the character of wind power and photovoltaic power generation, briefly introduces the wind-solar hybrid power system, shows the design of a remote control system based on the remote terminal unit (RTU). The control strategy of battery charging and grid-connection is carried out. There are two stages of control system which include sensors RTU communication network and terminal pc. The result of the study can be used to guide the research of this type of wind-solar hybrid power system.

Abstract: This paper presents two novel synchronization schemes for Chen chaotic system, drive-response synchronization and adaptive synchronization with unknown parameters, numerical simulation results demonstrate the effectiveness of the proposed method.

Abstract: In this paper, the full state hybrid projective synchronization (FSHPS) between two different fractional order chaotic systems is investigated. i.e., the fractional order Chen system and the fractional order Lorenz system. Based on the synchronization error system feedback linearization theory, a new method combining feedback control is proposed for the FSHPS in fractional order chaotic systems. Numerical simulations are presented to verify the effectiveness and the feasibility of the synchronization scheme.

Abstract: Research on intelligent agriculture in our country has attracted great attention of the researchers now, but it is still under discovery. According to tropical agriculture in Hainan to IT's demand, the paper studies the key technology in the development of tropical intelligent agriculture, including automatic test technology, automatic control technology, Internet of Things and so on. This paper analyzes factors that affect tropical intelligent agricultures development, which include agricultural program, agricultural policies and regulations, agricultural technology situation, infrastructure construction, field management and other factors. The thesis builds a model between the development of tropical intelligent agriculture and its affecting factors. A developmental idea of tropical intelligent agriculture in Hainan is proposed on the basis of the model. The thesis analyzes the construction of intelligent agriculture control system in Hainan from the angles of data acquisition, data transfer, data analysis and data feed.

Abstract: In order to eliminate hydraulic imbalance phenomenon of the heating network, this article briefly introduces the operation principle of the system. The remote control system uses computer information and communication technology to monitor the network flow, through the pressure curve to estimate the hydraulic condition. According to the analysis of pipe resistance properties and the hydraulic balance calculation, the system will change the valve opening intelligently, to make the heating network running in a hydraulic balance condition. The vortex flow meter and flow control valve can be used to adjust the water flow of primary and secondary network, such measure will ensure the hydraulic stability of heating system, save the thermal energy consumption.