Applied Mechanics and Materials Vols. 568-570

Abstract: Based on computer simulation, a new measurement pipe design with locally shrunk cross section is proposed for electromagnetic flow transducer. The efficiency of the magnetic field excitation circuit is effectively enhanced. The sensitivity of the transducer is increased. The transducer design is adopted in a battery powered electromagnetic flow meter prototype to reduce the power consumption. The prototype was tested. The feasibility of the proposed design was proved.

Abstract: A new CCD camera calibration method based on the translation of Coordinate Measuring Machine (CMM) is proposed. The CMM brings the CCD camera to produce the relative translation with respect to the center of the white ceramic standard sphere along the X, Y, Z axis, and the coordinates of the different positions of the calibration characteristic point in the probe coordinate system can be generated. Meanwhile, the camera captures the image of the white ceramic standard sphere at every position, and the coordinates of the calibration characteristic point in the computer frame coordinate system can be registered. The calibration mathematic model was established, and the calibration steps were given and the calibration system was set up. The comparing calibration result shows that precision of this method is equivalent to that of the special calibration method, and the difference between the calibrating data of these two methods is within ±1μm.

Abstract: Cloud particle image playback is the supporting software of cloud particle measurement system. It completes image playback and analysis, facilitates cloud and precipitation physics research. It has been implemented by JKI state machine and the queuing mechanism of LabVIEW, and includes three core functional modules, data decompression, 2D image data display and the number of particles statistics. The test pattern data and the real data testing results show that the design meets functional requirements completely.

Abstract: Steel rolling occupies a very important position in the iron and steel industry. The thickness of the steel plate is a crucial index of the quality, so the automatic detection system for high-precision thickness of the steel industry has a vital significance. The traditional thickness instruments have X-ray thickness gauge and ultrasonic thickness meter while the X-ray thickness gauge has radiation which is harmful to human body and ultrasonic thickness has a lower precision. For these shortcomings, a high precision thickness gauge by laser sensor was designed. Presented the differential measurement method based on laser displacement sensor. Then using TMS320F2812 as main control chip designed the hardware of the system. Finally, software programming was completed based on the hardware design. By experiment research, the results show that the laser thickness gauge has advantages of high precision and high reliability. It has a high practical value.

Abstract: To measure frequency stability of 10.23MHz signal, a 10.2299MHz frequency source based on AD9854 was developed. The performance of frequency source was tested using a phase noise and Allan deviation test set 5125A. According to the experiment results, the following conclusion can be drawn that the Allan deviation of the 10.2299MHz frequency signal is about 2.6E-14 at 1s when the 10MHz reference signal was generated by a frequency and phase offset generator HROG-10. The 10.2299MHz frequency source can be used as a common source in dual mixer time difference and as a reference signal in beat frequency method when measuring the frequency stability of 10.23MHz signal.

Abstract: To obtain dual high-precision and high-resolution numerical control signal source, and accurately adjust the signal frequency, the paper proposed a method based on AD9854 direct digital frequency synthesis technology, design and implementation the dual high-precision and high-resolution frequency synthesizer. FPGA controlled AD9854 registers to achieve frequency modulation, and after amplification processing output by THS3001, increasing the output signal drive capability. Comprehensive consideration the anti-jamming measures, the system is stable and reliable, the output signal frequency range from 500Hz to 30MHz relative error is less than 10ppm, and can numerical adjust the sine and square wave frequency and has a sweep output mode. Compared with previous equipment, it reduces the system power consumption and volume.

Abstract: To obtain the dual high-precision numerical control signal source, and could be accurately adjusted the dual signals frequency and phase and increase the output signal power, the paper presented a method based on direct digital synthesis technology and parallel push-pull output, designed and implemented the dual channel high-precision and high power signal generator. MSP430 controlled AD9854 registers to realize frequency and phase modulation, after low-pass filter to adjust the square wave duty cycle by the DAC7612, amplitude was integrated optimization adjustment by AD9854 AD603 and power amplifier. Consideration the anti-jamming measures, the system is stable and reliable, and can output high-precision and high power sine and square wave in the 5-150kHz frequency band, signal frequency, phase, amplitude and duty cycle can numerical control. In addition, it has sweep output mode.

Abstract: A kind of Linux-based embedded stroke rehabilitation system is studied by aiming at the problems concerning the motor functions of patients with stroke. A new rehabilitation platform is provided by combining the cognitive relearning therapy, myoelectrical visual feedback and sEMG-triggered-NMES therapy. The system is stable and simple in operation. According to the clinical test, the system is efficient for the rehabilitation of motor function of patients with stroke.

Abstract: Principle of vernier caliper is a reference of the working principle of high voltage cable head positioner for scribing and cutting (HVCHPSC), considering the HVCHPSC is suitable for 35kV and below grade high voltage cable termination, the desired measurement range and position is 0-600mm and the measurement accuracy is 0.1mm of HVCHPSC are determined. According to the characteristics of production and installation process during 35kV and lower grade high voltage cable termination, identified the desired number of vernier on HVCHPSC is six, the required measuring span is 20mm. Designed and produced HVCHPSC, mainly constructed of a set of main scale and six sets of deputy ruler, each of which have a snap ring structure match with high voltage cable. Tests proved that the tool is easy to use, precise in positioning, well in performance.

Abstract: To improve the muscle function handicap and enhance the body movement function of the stroke patients, a new medical instrument, based on audio-visual feedback, is developed. The designed stimulator regards sound (voice) and light signal (flash lamp) as the command signals. With remind of both voice and visualization signal, trainers can take the initiative to participate in training and try their best to generate a weak electromyographic signal. It provides a new treatment platform for stroke patients, which can play a positive role in the rebuilding of cerebral nerve net, the rehabilitation of body movement function diseases, the protection of brain function and psychological rehabilitation. The real-time monitoring and regulating function for the stimulating current was innovatively achieved. With the above functions, it’s easy for doctors to set up different stimulating intensities for different patients. This stimulator also has advantages of safer noninvasive, easy to carry and advanced human-computer interaction function, all of these make contributions to building up the muscle strength and the rehabilitation of body movement.