Advanced Materials Research Vols. 301-303

Abstract: The purpose of this research was to explore the Brake Assist System of automobile overhaul competence indicators. Literature review, interviews, professional meeting, Delphi method were yielded to analyze the competence items in the automobile overhaul. Thus, to reveal the curriculum planning, instruction strategy, and teaching material for the automobile overhaul professional technology manpower cultivating, this research was conducted deep expert interview, and three times Delphi questionnaire investigation. The opinions of experts were unanimity for the competence indicators. Finally, results of this study revealed three category competence indicators for the Brake Assist System of automobile overhaul including (1) the 11 professional ethics competence indicators such as value social ethics, working ethics, time, quality, attitude, working zeal and professional dedication, really get the work done, train oneself constantly, high loyalty, plasticity, and law-abiding, and self-managerial competence. (2) the 9 competence indicators of Brake relevant knowledge of the system and analytical skills such as understanding the systematic function of ABS, knowing relevant part names of ABS, function, erection site, and understanding the principle of moving of automobile ABS, and understanding the systematic function of EBD, knowing relevant part names of EBD, function, erection site, and understanding the principle of moving of automobile EBD, and understanding the systematic function of BAS, knowing relevant part names of BAS, function, erection site, and understanding the principle of moving of automobile BAS. And (3) the 6 competence indicators of brake assist system overhaul such as skilful with ABS examine and repair; skilful with ABS relevant part procedure of renewal , and skilful with EBD examine and repair; skilful with EBD relevant part procedure of renewal ,and skilful with BAS examine and repair; skilful with BAS relevant part procedure of renewal. These results are not only offered to help curriculum planning and material development for the basis of the automobile overhaul, but help vocational industrial school and automobile industry cultivating the talent manpower.

Abstract: With the development of power system, Conventional current transformers (CTs) show a growing number of shortcomings. For better performances, Electronic Current Transformers (ECTs) are researched to replace CT. But high price, unsatisfactory life and unpredictable reliability hold back their industrializations. Employing the insulation structure of traditional inverted SF₆ transformers and the new sensing principle at the same time, using high-precision digital integration algorithm which has higher precision to extracting the power frequency signal, an innovative electronic current transformer is introduced in this paper. Test results show that the transformer has high accuracy, low price, good stability, wide frequency response and long life.

Abstract: Rigid tapping of NC Tapping center is an electromechanical control system which is strongly nonlinear, uncertain and difficult to precise modeling. It is unavoidable to be affected by some nonlinear and uncertain factors such as friction and mechanical resonance. The traditional control method could not fundamentally solve the contradiction between rapid stability and high stable precision of the system response. As an intelligent control method, fuzzy control is actually a kind of PID regulator, and it exists a strong complementary to PID control in the system dynamic and static characteristics. This paper introduced fuzzy adaptive PID control applied to NC rigid tapping in engineering practice, the control method need not to build the controlled object, using mathematical model of fuzzy reasoning method for the online PID parameters auto-tuning, it met the system well for the rapidity and smoothness of comprehensive index requirement and technical realizability, finally through test platform test, numerical control machine tool actual tapping was validated.

Abstract: Pure electric bus control strategies and methods have an important effect on performance of the bus. The pure electric buses vehicle driving system was modeled and optimized by the fuzzy control strategy. Through simulation and commissioning tests, both the dynamic performance and economy of the pure electrical bus that using fuzzy control strategy have an excellent performance.

Abstract: The basic working principle and the two-position north-seeking method based on single-axis FOG(fiber optic gyroscope) is researched in this paper. Improved north-seeking method was proposed to solve the problem in the two-position FOG north-seeking scheme. To Sample in three positions of 0º, 90ºand 180ºseparately and obtain the measurement values of angular rate in these three positions. Then according to the measurement values of angular rate in the first and the third positions to calculate the north-seeking angle, and using the positive and negative pulse outputs of the FOG in the second position to obtain the specific direction information of carrier. So that, accomplish the north-seeking in the range of 0～360° for single-axis FOG. The experiment results showed that the accuracy of the improved two-position north-seeking program based on single-axis FOG is 0.101 (1σ) within 4 minutes.

Abstract: For the problem of higher transverse sensitivity ratio of the cymbal piezoelectric vibration acceleration sensors, a mathematical model of output voltage sensitivity is established which employ orthogonal and array methods to reduce the transverse sensitivity ratio of the piezoelectric vibration acceleration sensor. Two compensation methods are designed. The results showed that the array and orthogonal methods can decrease the effect of the transverse interference of acceleration sensor effectively and control the relative error in a smaller range, improve the measurement accuracy of the sensors.

Abstract: Because the nonlinear and strong coupling characteristics of brushless DC motor, the classical PI controller can not control it easily. In order to solve the control problem of brushless DC motor, an improved control method is proposed which based on passivity-based control technology. According to a model of brushless DC motor (BLDCM) that based on Euler －Lagrange (EL) equation, designed a passivity-based controller. The simulation result shows that，compared with the PI controller，this method can not only improve the dynamic response property and anti-jamming ability of the system, but also get a better speed-adjustability.

Abstract: This paper presented an integrated measurement platform for piezoelectric transformer based on virtual instruments. Programmable signal generator was adopted to stimulate the piezoelectric transformer. Then an USB oscilloscope was used to acquire the response signal. We could get the results by analyzing the experimental data. The measurement accuracy and efficiency were greatly improved in the virtual instruments platform compared with the conventional measurement method. It was of great significance to the scientific research. Section I pointed out the problems in conventional piezoelectric transformer parameters measurement method and gave a solution of using virtual instruments technology to solve these problems. Section II described the hardware design of the measurement system. Section III described the software design of the virtual instruments measurement system. Conventional measurement methods and virtual instruments measurement method were compared in section IV.

Abstract: The pore structure of soil plays a decisive role in its engineering properties. In order to investigate the consolidation effect and pore distribution characteristic of saliniferous dredger fill after vacuum preloading, the indoor simulation experiments of vacuum preloading were carried out in two boxes, after vacuum preloading, the dredger fill was tested for its physicochemical and mechanical properties. Simultaneously, the mercury intrusion porosimetry was performed to obtain distribution of pore characteristic parameters, and analyzed its pore diameter distribution of dredger fill after vacuum preloading and the consolidation effect in the perspective of micro and macro. The research showed that the total pore volume and porosity of the No.1 box is lower than the No.2 box, and its bearing capacity and consolidation effect are much higher. When the dredger fill locates at the same distance from drainage plate, the deeper the dredger fill is buried, the smaller the porosity is, the better the bearing capacity and consolidation effect are. The pore of dredger fill in No.1 box is based mainly on meso pore, while the one in No.2 box is based mainly on meso pore and macro pore.

Abstract: This paper studies the waste heat utilization device for the coal gangue brick tunnel kiln. The heat transfer mode of the waste heat utilization device is different form the past. It recovers the physical sensible heat of the high-temperature brick. This paper builds a theoretical model to analyze the situations of the cooling section of the coal gangue brick tunnel kiln, and analyzes the temperature field numerically. The results show that the distance form the waste heat utilization device to the sintering section of the coal gangue brick tunnel kiln must be more than 2m.