Advanced Materials Research Vols. 546-547

Abstract: This paper proposes new approaches to a kind of redundant design method to control computers based on CPCI bus, which discusses the choice of redundancy model and system principle. The reliability design is the key element of the system design, as the requirement for high reliability of general users to control computer system. It introduces in detail the interlocking theory and design method, the switching control circuit design and the data sharing model. In the end we conduct reliability analysis on the redundant control computer system from the aspect of the mean time between failures (MTBF) and availability. The redundant design approach effectively improves the reliability of the control computer system, and test and application prove that the control computer can meet the requirement for reliability.

Abstract: This paper studies the problem of stability analysis for continuous-time delay systems. By introducing a free weighting parameter, combining a novel Lyapunov functional with the switching system method, a new delay-dependent sufficient stability condition is obtained in terms of a linear matrix inequality (LMI). It is shown that this new criterion can provide less conservative results than all existing ones. Numerical examples are given to illustrate the effectiveness and advantages of the proposed method.

Abstract: According to the demands of organic viticulture for small environment regulation and management automation, a grape production monitoring system based on wireless sensor networks (WSN for short) was designed, so as to solve the low management automation level, great workload and other problems that exist in traditional viticulture. The system includes a WSN and a planting management-oriented viticulture management system. The WSN consists of twelve environment monitoring nodes equipped with 168 sensors and 12 video capture cards, a sink node and a monitoring center. And it is also free to customize the functions of acquisition, processing, transmission and storage the data, such as soil moisture, soil temperature, air temperature and humidity, rainfall, solar radiation, wind direction, wind speed and so on. The communication between two nodes follows ZigBee protocol. GPRS is used to realize the communication between sink node and monitoring center. Production data collection and analysis, farming management, production decision, insect pest and disease warming are also achieved through GPRS. An experiment on data package transfer rate in grape veraison and mature stages is carried out. Six out of ten sensor nodes have transfer accuracy above 90%, and two below 35%. The reason is that the solar power supply circuit of one node has excessive energy consumption, and deployment location of the other node is influenced by environment which leads to the network instability. Through analysis, results can be got that the power supply and network environment are important factors for performance of WSN in the fields. The design and development of this viticulture monitoring system provide an effective tool for the production information monitoring and analysis decision of organic vineyard.

Abstract: In order to reduce management costs of apple orchards, improve product quality of apples, and provide detailed, comprehensive and accurate electronic information for planting works, pest warning, and production quality tracking of apples, with the application of wireless sensor technology, by applied Zigbee technology, GPRS technology and IOT technology, on the basis of realization of apple orchard environment monitoring, this paper provides a design scheme of apple orchard intelligent monitoring system based IOT, and taking the modules of dynamic monitoring, farming suggestion, planting decision making, and information push in the system as examples, it explains the specific methods of applying IOT to the realization of apple orchard monitoring management in detail. This apple orchard intelligent monitoring system provides not only detailed monitoring data of apple growth for vegetable and fruit agricultural cooperatives, but also decision making support for farming. The research of the system will be helpful in promoting the extension and application of IOT technology in agricultural production.

Abstract: This paper gives a method for static output feedback stabilization of linear time invariant systems. A general solution of a matrix equation concerning system parameter matrices is used to construct a state coordinate transformation. Then, the closed-loop system is equivalent to a transitional form, whose pivotal isolated subsystem can be stabilized via a gain matrix. This gain matrix is the free variable of the general solution. Furthermore, using this general solution of the matrix equation, the original problem is reformulated to a low dimension system, which can be easily solved. Numerical example is given to illustrate the validity of the proposed algorithm.

Abstract: This paper deals with difficulty of decentralization and presents an equivalent condition for poles assignability via decentralized static output feedback based on Kronecker product and vectorization. This condition is an equation regarding a nonsingular matrix variable and doesn't concern feedback gains. Consequently, an explanation is given for decentralized assignability, and results of centralized case are also obtained as corollaries of the proposed condition.

Abstract: This paper focuses on the regional pole placement via static output feedback. Under proper state coordinate transformation with a free matrix variable, the static output feedback gain may be obtained by solving a linear matrix inequality (LMI). The LMI is feasible only if the poles of a dummy control system are in the given LMI region. The free matrix variable can regulate the dummy system as a state feedback gain matrix. So once the free variable is determined, the static output feedback gain matrix may be obtained by an LMI-based method. The main computations do not concern any reduction or enlargement of matrix inequalities. Numerical examples show the effectiveness of the proposed algorithm.

Abstract: This paper presents a low-cost Built-In Self-Test (BIST) scheme, which is based on the principle of parity check code. The proposed circuit is consisted of a XOR network, a frequency decrease module, a BIST controller and a fault detector module. Different from the previous methods of PLL BIST, digital signals from the divide-by-N are grouped as transmission codes, and parity check codes are produced synchronously by the BIST controller. Then the results of parity checking are imported to the fault detector and final test results are generated. Purely digital design flow is adopted and hybrid faults models are used to evaluate the efficiency of the circuit. Experimental results indicates that the proposed method can provide the highest test coverage and lower area overhead, which are 98.3% and 4.2%, respectively.

Abstract: The asymmetric vortex and vortex breakdown lead to strong inter-channel coupling and non-linear characteristics when air-to-air missile flies at high angle of attack. Firstly, this essay establishes a coupling characteristics mathematical model of the missile. And then, it gives a decoupling control method based on DDFC (Direct Dynamics Feedback Compensation) theory. At last, a new decoupling controller is designed combined with sliding variable structure control theory. The simulation shows that the performance of decoupling and command responses of this designed control system is quite good.

Abstract: Cognitive Radio (CR) has been proposed as one of the most promising technologies to provide efficient utilization of the limited wireless spectrum. In this paper, we investigate the power allocation for CR system based on orthogonal frequency division multiplexing (OFDM), and an improved allocation algorithm called power-weight algorithm is proposed. This algorithm performs initial allocation via Lagrange multiplier method, and then accomplishes second allocation based on power weight obtained in initial allocation. The analytical results reveal that the total transmission rate of all subcarriers is much closer to the optimal algorithm (i.e. the greedy algorithm) than the water-level algorithm, the Krongold algorithm and adaptive water-filling algorithm, subject to transmit power constraint and bit error rate (BER) constraint. These algorithms are all based on water-filling thought. Finally, simulation results verify our analysis.