Advanced Materials Research Vols. 468-471

Abstract: Its advantage to use DDS chip is output signal frequency bigger, and precision higher, But users can't change the output signal waveforms. The MCU can produce the required arbitrary waveforms, but its program execution of the order limit the speed.So we use their Synergy to design the digital controlled signal generator. The System has the advantage of output good quality waveform, frequency of precision and stability ,and high frequency, empty, amplitude and phase is to step into the need.

Abstract: The intensity and direction of the geomagnetism vector is a function of geography position. The roll attitude of flying ammunition can be calculated by detecting geomagnetism. In the paper, the chief scheme and implement method of roll attitude detection system are suggested. The result of the geomagnetic detection unit can be used to resolve attitude by inertial trajectory. After experiments on 2-axis turntable are implemented, the results show that by the geomagnetic solution the angle error is of no cumulative characteristics, and the absolute error at different rotating speeds are controlled within 2 deg.

Abstract: Low power loss is the key of loop powered transducer design. The methods for reducing power loss are discussed in this paper. By selecting the appropriate device, and ultimately achieve the purpose of reducing energy loss. By the measured, the design fully meets the system requirements.

Abstract: This paper describes the designing and producing of a multi-direction tiny force switch, which is based on the technology of micro-surface processing on privative silicon. The switch is mainly formed by shore, overhanging spring, movable electrode and fixed electrode. Its’ structure material is Ni. The parameters of switch are confirmed by doing finite-element analysis with ANSYS. And rigidities of structure both on horizontal direction and vertical direction are analyzed by using ANSYS to ensure that the uniformity of switch rigidity is qualified. After producing the switch, the rigidity of switch is tested by using bonding tester. The test result shows that the rigidity is almost qualified with requirements.

Abstract: In this paper, a handheld terminal is designed which has encryption and decryption function to solve the problems of relatively lower security level of the traditional terminal equipment’s transmission data in electrical communication. This handheld terminal not only can implement the screct key update and recovery, load switch controlling, charge adding, parameter setting, data reading function and so on , but also through introducing advanced encryption and decryption techniques and using security unit,, , can ensure that the transmission data was not altered in the communication and transmission data’s integrity and confidentiality was not destroyed. This handheld terminal has great practical value.

Abstract: Design of width measuring instrument for drawn cup bearing without inner ring.The instrument used inductive displacement sensor converting width variation into voltage output of sensor. The measuring system which used AT89S52 as control chip excellently adapted to the requirment of fast production beat and the human-computer interface was developed by using VB. The instrument was practical that can accurately measure width of the bearing, and meet the production requirment.

Abstract: Based on the asymmetry characteristic of 33 coupler output signal, the improved demodulation arithmetic of 3x3 coupler was studied and deduced. To satisfy the requirement of fiber-optic sensor for real time, high accuracy and net work processing, a design method for embedded signal processing based on dual-core microprocessor OMAP is provided. The results of the experiments show that the system can meet the requirements of processing accuracy and real-time property and it has very high practical value.

Abstract: This paper focuses on the problem of robust fault detection for a class of nonlinear time-delay systems. The system under study involves distributed time delay, unknown inputs and nonlinear fault distribution functions which is dependent on the inputs, outputs and states of the system. By applying Lyapunov stability theory and free-weighting matrix methods, a novel delay-dependent sufficient condition, which is in terms of linear matrix inequality (LMI) and ensures existence of the desired robust fault detection observer for the nonlinear systems, is proposed. When the LMI is feasible, an explicit expression of a desired observer gain is given. Based on the observer technique, desired approach to robust fault detection is presented

Abstract: This paper introduced a fast fingerprint identification system based on TMS320VC5416 DSP chip and MBF200 solidity fingerprint sensor. It precipitates fingerprint identification device developing into the direction of miniaturization, embedded and automatic.It recommends fingerprint identification system hardware and software design and the main system processing flow, aim at fingerprint identification arithmetic, the influence of system operation speed is being researched at the same time. High-speed data acquisition system is been built in order to achieve a DSP fingerprint identification system with high efficiency and low cost.

Abstract: Through the research of domestic and international aviation engine seal pieces, this paper have described the structure and technological design of electrical discharge grinding honeycomb torus. Based on experimental analysis of processing precision and processing efficiency under different electrical parameters, machining sections were designed according to the processing requirements of different parts. The results indicate that the machining precision and efficiency can be enhanced greatly.