Advanced Materials Research Vols. 760-762

Abstract: In this paper, a novel BiCMOS current steering bandgap is presented, which includes reference core, start-up circuit, and output circuit, of which the reference core is used to produce the temperature-stable current, the start-up to start up the reference core when powered on, and the output circuit to proportionally transport the reference current to other cells on the same chip. Compared to the traditional voltage-mode bandgap reference, because of the adoption of the current-steering mode, the reference proposed in this paper, has the merits of being immune to variation of the power supply, minimum transport consumption, better matches, temperature stability, smaller area, auto-startup, and so on, which are specially needed in AD/DA application. The simulation shows that the proposed current-mode reference circuit has full temperature range coefficient of 8.9ppm, which is better than that of the traditional voltage-and current-mode reference circuits.

Abstract: Traditional frequency-tracking technique of ultrasonic power often adopts analog phase locked loop circuit. But it has some defects, such as the narrow locked-inrange and the tendency to lose phase locked with a sudden change in load, etc. Therefore, this paper proposes a composed control strategy which combines a digital fuzzy controller with phase locked loop in DSP, and the working principle and design method are gived. The experimental results show that the ultrasonic power using Fuzzy-DPLL can realize quick and accurate frequency tracking, and it can make the vibrate system work stably and efficiently, and it improves the efficiency of the power supply.

Abstract: In order to improve the robot path planning speed and accuracy, this paper combined cloud theory and rough sets in path planning. First initial path group can be gained by using rough set training, then a series of feasible path group can drawn by the minimum decision rule training, finally the population based on cloud model optimization can also gained and further the best route can be acquired. The simulation results verified the effectiveness of the proposed algorithm.

Abstract: In this paper, a fault diagnosis method for spacecraft based on telemetry data mining and fault tree analysis was proposed. Decision trees are constructed from the history telemetry data of the spacecraft, and are used to classify the current data which is unknown whether it is fault. If there is a fault, the fault tree method will be used to analyze the fault reason and the impact on the spacecraft system. This method can effectively solve the problem of diagnostic knowledge acquisition. We design and construct a fault diagnosis expert system for spacecraft based on this diagnosis method. An experiment is presented to prove the effectiveness and practicality of the expert system.

Abstract: To realize online automatic measuring of total sugar content in chlortetracycline fermenter, we developed an online automatic measuring system based on MSP430 microcomputer. We designed the automatic sampling, filtering and washing of fermented liquid by controlling the I/O of MSP430 and the relay. The data of total sugar content was sampled and processed by MSP430. The data of total sugar content can display clearly and easily on host computer with the RS232 serial port connection between MSP430 and host computer. The software of this system was programed with C language based on IAR for MSP430 environment. The experiment results show that the online automatic measuring system of total sugar content in chlortetracycline fermenter can be met the demand of practical application.

Abstract: In order to achieve the automatic measurement of the total sugar content in Chlortetracycline fermentation kettle, MSP430 is designed as the hard core of the automatic measurement system. Based on MSP430 MCU, opening and closing valves of the automatic measurement system can be controlled, and the total sugar content can be acquired by measuring dope from filter. Wind turbine and valves of automatic measuring system are controlled in order to prepare for the next measurement of total sugar content. MSP430 software environment is developed using C language, and upper computer display system is developed using LabVIEW. The system motion state can be observed through the upper computer system. MSP430 can be connected upper computer through the RS232 protocol for data communications. Experimental results show that the automatic measurement system can meet the requirements of the actual application.

Abstract: This paper introduces several PID control algorithms and their discretization expression. Compare the performance of positional PID algorithm with incremental PID algorithm, integration separate PID algorithm, incomplete differential PID algorithm and PID algorithm with dead zone. The experiment results show that different digital PID control algorithm could achieve different using.

Abstract: A good fuzzy control table is the key to a fuzzy control system, and the systems performance mainly depends on the quality of the table. Based on analyzing fully the principles of a typical fuzzy control systems and the procedures of building a fuzzy control table, this paper presents a new method of applying the boolean association rule data mining techniques to mining of fuzzy control table directly from the database of manual operating records.

Abstract: Software testability parameter system was constructed by parameters that extracted from software testability influence factors. It established relationships between these parameters and software testability through a target layer which may reflect software inner attributes. In order to carry out the design of software testability in engineering ways, principles of software testability requirements and software testability requirement factor were presented in this article, as well as analysis method for software testability requirement. This method considered software characteristics and software test types as selection criteria to specify the target layer, and then tried to acquire software testability requirement factors with the help of software testability parameter architecture built before. Next, software testability requirement could be obtained by following the steps of software requirement engineering.

Abstract: The Multi-signal Flow Graph (MFG) is a simple and effective system modeling methodology, widely used in testability analysis and fault diagnosis field. In order to shorten the maintenance time and reduce the influence of human factors, the MFG method was introduced, and it was used to set up the testability model of aircraft Audio Management Unit (AMU) and found the fault-testability dependency matrix and the fault-fault dependency matrix. Based on dependency matrix and real unit fault message, the trapezoidal fuzzy number algorithm was introduced, thus the new fault diagnosis method was generated. Finally, an example proves that the fault diagnosis algorithm can not only locate the fault more accurately, but also improve the maintenance efficiency.