Advanced Materials Research Vol. 709

Abstract: Two new blind estimation schemes based on decorrelation LMS（DLMS）and time-domain orthogonal LMS（TDO-LMS） algorithms are proposed to solve the problem of convergence in the estimation scheme based on LMS algorithm in wireless mobile communication OFDM systems. These schemes are improved on the traditional LMS algorithm.The factor of TDO-LMS algorithm changes along with the power of signal ,and the decorrelation LMS removes the correlation of the signal.Two methods can get faster convergence and better estimation performance combining with alterable step in the channel estimation of OFDM systems.Simulation shows that the convergence of the schemes proposed is better than that in the channel estimation based on the traditional LMS algorithm obviously.

Abstract: Based on MIMO-OFDM systems,an adaptive modified factor EM channel estimation algorithm was proposed to improve the performance of channel estimation.Comparad to MEM,the adaptive modified factor was introduced in the algorithm,which reflected the impact of noise on signal more accurately and improved the estimation performance.The result of simulation showed that the algorithm proposed had better estimation performance.

Abstract: In order to measure the actuation time of low voltage electrical apparatus, this paper designs an intelligent timing device triggered by single and double circuits. The device adopts the system structure of the upper and lower computer so that the action signals will be collected and measured by lower computer through conditioning, and the measurement results will be shown on the digital tube. Through communication with lower computer by RS232 serial port, the upper computer can display the real-time status and results of the measurement and issue commands to control the operation of the device. Utilizing modular programming, and targeted for the action characteristics of different components, this paper puts forward adaptive optimization testing algorithm, which can achieve single / double circuit timing, digital display, upper computer monitoring, manual / programmed control, the positive and negative transition trigger of the adaptive input signal and other functions. After the tests on actual functionality and reliability, the device is successfully applied in aircraft power supply system. The results suggest that the function of the timing device is complete, its structure is simple, easy to maintain, and it can meet the measurement requirements of the actuation time for low voltage electrical components.

Abstract: As the fourth generation light source，LED lamp has the following advantages：energy- saving,environment- protection,flexible installation,and long service life.Using programmable logic device as the controller of LED landscape lamp, the system has the advantages of simple design,convenient update,high reliability; at the same time , easy to configuration of background music without adding any hardware .

Abstract: A new marine monitoring system is introduced in this paper. This study is based on a taut single point mid-water mooring instrument which is packaged into a two-float assembly, with the lower float containing several times as much buoyancy as the upper float. During the system working in ocean water, an energy conserving transmission is designed under energy-balance principle. Battery pack and motor can supplement the energy dissipation which was engendered during the movement of observation vector in water. From this research, single sensor fixed on platform can meet the requirements of vertical profile measurement. Compared with other single-point marine monitoring system, the proposed system has the benefits both in technique and economy.

Abstract: In this paper, we study the thermostat controller of the fish tank controlled by STC89C52. We use DS18B20 to measure the temperature. We control the relay to control the heating wire to whether heat or not. We can control the temperature at the setting value and display the value in LED.

Abstract: When aeroplane ground power supply is supplying electric power to aeroplane, due to the large difference in electricity needs of aeroplanes, there may be phenomenon of inadaptation in the electricity use mutation process. In order to test the online power supply quality of ground power supply and check the problem of mutual adaptability, this paper designed an online testing system of aeroplane ground power. The system determines the content of test with reference to national military standard on characteristics of aeroplane ground power supply, of which the hardware is embedded system formed by PC/104 architecture-based computer, high-speed parallel AD data acquisition card and so on; the software is programmed using Labview; the test algorithm is designed based on the “GJB 5189 -2003 Test Methods for Determining Parameters of the Characteristics of Aeroplane Power Supply”. The actual test on a certain type of ground power unit proved that the system is easy to operate, accurate in measurement and has good portability, meeting the design requirements and the urgent need of maintenance, thus is of high practical value and economic significance.

Abstract: Vehicle navigation plays an important part in intelligent transportation. The optimal route of navigation was selected based on the optimization of the algorithm of Dijkstra in topology storage structure, node storage order in topology network and route weight of Dijkstra, thus reducing participating nodes, advancing optimization speed and improving efficiency in optimization process.

Abstract: In this paper, we study the temperature control system of thermoelectric cooler controlled by MSP430F149 microcomputer. The system achieves automatic temperature control by using PID algorithm and voltage-controlled steady flow circuit. Using the keyboard and LCD, we can set the temperature, display the working status and draw real-time temperature curve.

Abstract: Abstract. A mid-frequency magnetron sputtering (MFMS) power supply based on TL494 and MCU was introduced. A Buck Chopper and full bridge inverter were applied to the main circuit. The PWM controller TL494 was used in the Buck voltage-regulation control circuit to realize closed loop control. The drive signal of the IGBT in full bridge inverter was based on precise digital pulse width modulator (DPWM) signal produced by the MCU M30290. The DPWM can be set by potentiometer so the power supply can output the square wave with adjustable frequency and duty cycle. The power supply was operated in constant current mode. For micro or strong arcing of the target, different safeguards were adopted by the control circuit. At last, the system test and experimental results show that the stability, reliability and tuning range of the MFMS power supply can meet the requirements of the magnetron sputtering coating.