Applied Mechanics and Materials Vol. 344

Abstract: For the physiological signal monitoring applications, as a micro-controller based on field programmable gate array (FPGA) physiological parameters intelligent acquisition system is given, which has the advantages of low cost, high speed, low power consumption. FPGA is responsible for the completion of pulse sensor, the temperature sensor, acceleration sensor data acquisition and serial output and so on. Focuses on the design ideas and architecture of the various subsystems of the whole system, gives the internal FPGA circuit diagram of the entire system. The whole system is easy to implement and has a very good promotional value.

Abstract: At present, quantities of similar spurious signals have been found in the reconnaissance and there are electromagnetic leakage problems when each department of work does scientific experiment using varieties of signals that put forward new challenges to national defense and scientific research information security. Aiming at these situations, a new type of the regional environmental electromagnetic monitoring and signal identity system emerges to meet the practical need of electromagnetic environmental monitoring. This system monitors signals over small areas by using newest mixed domain signal analysis method and combining with virtual instrument, which let the desired research goal more convenient to be realized. The system with the characteristic of accuracy, usability, portability and expansibility can do efficiently electromagnetic environmental monitoring job and are practical and worthy of using abroad.

Abstract: Frequently, voltage reference stability and noise define measurement limits in instrumentation systems. In particular, reference noise often sets stable resolution limits. Reference voltages have decreased with the continuing drop in system power supply voltages, making reference noise increasingly important. The compressed signal processing range mandates a commensurate reduction in reference noise to maintain resolution. Noise ultimately translates into quantization uncertainty in A to D converters, introducing jitter in applications such as scales, inertial navigation systems, infrared thermography, DVMs and medical imaging apparatus.

Abstract: The performance of radar anti-jamming (ECCM) to become an important parameter in modern radar, how objective and comprehensive assessment of the performance of radar equipment development and use are of concern, this paper analyzes the radar-jamming environment, build a radar evaluation index systemestablished anti-interference assessment models, the results of the assessment, and finally a brief analysis of the results.

Abstract: A rigorous mathematical analysis of cross-eye jamming in a radar system scenario and an expression for the induced angular error due to the cross-eye jammer are presented. The simulation results show that there is a Doppler difference between jamming and target return. The Doppler difference increases with the decrease of the distance between the monopulse radar and the platform protected by cross-eye jammer. When the power of target return is not small enough with respect to the power of jamming transmitted by one of the two sources, maybe the sign of the indicated angle is uncontrollable. The simulation results also show that although the cross-eye gain is maximized if two jamming signals are equal amplitude and antiphase, it is not a reasonable choice.

Abstract: Giant Magnetoimpedance (GMI) sensor is the hot research topics in sensor engineering. In this paper we setup a double channel acquisition system for MGG signal. Then FastICA algorithm is applied in the raw data and We get the spectrum after ICA processing. The results show that ICA is powerful tool for MGG signal processing to separate the noise signal.

Abstract: The natural frequency is the inherent characteristics of the objects which would be reflected during the vibration. Firstly, obtained the calculation results of the natural frequency of the cantilever sheet, and then obtained cantilever sheet experimental values through experiments based on hammering method . According to real data and imaginary data of the experimental frequency response curve , used levy method in order to fit the natural frequency. The results show little difference among finite element values, experimental values and the values based on levy method.

Abstract: The two-cylinder drive is one of many commonly used mechanical drive forms. Its synchronous control accuracy determines the movement accuracy of the working machinery. The paper established the mathematical model for the two-cylinder electro-hydraulic servo synchronous drive system, and revealed that the two-cylinder horizontal electro-hydraulic synchronous drive system has the cascade form of the linear system with the nonlinear system. Taking the band sawing machine and the broaching machine as the application object, the paper analyzed their compositions and synchronization CNC systems. Aiming at the dual-cylinder drive form for the broaching machine, the IPSO-PID synchronous controller of the two-cylinder system was designed. Through the digital simulation and actual testing, the results show that the IPSO-PID synchronous controller is faster in the tracking response speed and better in the synchronization performance than the conventional PID synchronization controller.

Abstract: This objective of this work is to design and implement the magnetic-control soft-start controller for the motor starting at rated current. The motor is accelerated smoothly, the starting current is reduced and motor starting performance is improved by this soft-starting technology. For eliminating the harmfulness of the starting current of the three-phase AC motor, the DSP controller is used as the controller in this magnetic-control soft-starter. The design of the DSP controller for the magnetic-control soft-starter is first proposed. The hardware and software designs are realized in this paper, and it is subsequently verified experimentally. Experimental results show that the DSP controller for the magnetic-control soft-starter has extensive applicability, high reliability and high performance price ratio.

Abstract: In tradition, one underactuated robotic finger with two or three joints always utilizes only one actuator for self-adaptive grasp, which results in quite weak grasping force because there is only one motor and the motor is so small in size so that it can be embedded into the phalange of the robot finger or the palm of the robot hand. Aiming to overcome the weakness, this paper proposed a novel robotic finger with redundant driving, called RD finger, which can produce sufficient grasping force through increasing a redundant motor and keep original characteristic of self-adaptive grasp. A special single direction transmission mechanism is designed in the finger to make two motors seem like one motor and prevent interference between the first motor and the second motor. The grasping process of the RD finger is close to traditional underactuated finger but there is up to double grasping force. One kind of the RD finger is designed in detail with coupling and self-adaptive grasping mode, which is composed of two motors, bevel gears, a pulley-belt transmission, a single direction transmission and a spring. In addition, the RD finger is compact, easy to control, low in energy consumption, is able to provide wide range of grasping force, and is therefore suitable for humanoid hands.