Advanced Materials Research Vols. 317-319

Abstract: In order to break through the traditional flow change way of the variable plunger pump, a kind of micro-flow variable plunger pump with stepper motor is designed; and on this basis, the main control electric circuit of the pump is developed by taking AT89C52 single-chip microprocessor as MCU and making use of the keyboard and display circuit and three internal timers of AT89C52; the driving circuit is developed by using chapped wave driving model implemented by the chips of L297 and L298N; the software of the system is also developed. The joint debugging results of hardware and software indicate that the developed embedded control system not only implements the numerical driving of the pump, but also carries out the frequency control of the pump by changing the input frequency and duty ratio, additionally, the control of the whole system is flexible and the operation is simple.

Abstract: This paper comes up with an algorithm and application for velocity measurement based on RFID technology. This measurement can reduce the cost of velocity-measuring system to a great degree, and improve the accuracy of velocity measurement on the basis of the algorithm.

Abstract: Safety is one of the key issues of future automotive development. With the trend of increasing functionality and complexity in automotive embedded system, there are increasing risks of functional failures. It is necessary to perform the functional safety process throughout the safety lifecycle of these systems. The appearance of the new functional safety standard ISO WD 26262 also makes the consideration of functional safety as part of the design and implementation process for these systems. This paper introduces the new standard ISO WD 26262 and analyses its features. The safety life cycle according to the new standard, activities necessary for the achievement of functional safety during the development phase are shown. An example application according to ISO WD 26262 is given and the process and methods of functional safety analysis in this example are proposed.

Abstract: Ethernet Passive Optical Network (EPON) has been widely used in the Smart Grid. However, the overlay radius of EPON system is generally a 20 km, which has become the obstacle of application of EPON in Smart Grid.This paper introduces the advantages of EPON and analyzes the need for long-distance EPON of t Transmission Lines Monitoring System. And also this paper analyzes the factors affecting the long-distance transmission of EPON. Then this paper discusses the implementation of long-distance EPON and proposes a scheme of achieving communication network of Transmission Lines Monitoring System based on long-distance EPON.

Abstract: Fall is a risky event in the elderly people’s daily life, it often cause serious injury both in physiology and psychology. An inertial and magnetic sensor based system is designed for fall detection in real time. This paper presents the design and test of this system. The system consists of three attitude measurement units fixed on the human legs and waist. Each unit contains orthogonally mounted triads of accelerometers, magnetometers and gyros. With an integrated microcontroller for attitude calculating and flash for data storage, the size of the unit is 32mm×23mm×12mm. An extended Kalman filter based on quaternions is designed for attitude measurement. The digital angle output rate is 100Hz. Human lower limb kinematic model is presented. The position of the gravity center is tracking by the inertial and magnetic sensing system.

Abstract: The control arms, as an important part of automobile components, are widely used in auto assemblies. The ball joint sealing of control arms is a key process to chassises assembly and the sealing quality directly determines the lifespan of steering systems of automobiles. In this paper, based on the aluminum control arms, a precise control system of revolving-riveting equipment spindle displacement was developed and the effect of riveting equipment spindle displacement on torque of ball joint sealing was studied through experiments method. The results showed that the torque of ball joint is directly related to the displacement of spindle, and a better sealing quality can be achieved when the displacement of spindle was in a reasonable range. The research will provide elementary technical support to the ball joint sealing of automobile control arms.

Abstract: Aiming at the disadvantage of slicing STL model in rapid prototyping, a method of slicing CAD model directly is proposed to advoid the precision damage during converting CAD model to STL file. The effect of the staircase error to the part surface is analyzed, and an algorithm of compensating the section contour is proposed to eliminate the layers’ volumetric difference and improve the part surface precision. The test shows that the methods can obtain the accurate sections of CAD model and improve the part’s shape and size precision.

Abstract: Flexible hinge is a typical flexible element in compliant mechanisms. But in the micro area, the design of flexible Hook hinge is rare. Compared with the traditional gap-type flexure hinges, flexure hinges with curve leaf are more prone to large deformation in functions direction under the load. And through the rational design, overall error of whole body with flexure hinges with curve leaf would be reduced to a minimum. So this article uses the curve leaf as the basic unit to construct a distributed multi-leaves and large-deformation flexible Hooke hinge. In view of the hinge structure is complex and very difficult to get accurate model, the model of flexible hinge Hook is establish by pseudo-rigid method to analysis the deformation of flexible hinge Hook under pure torque load. Theoretical analysis and nonlinear finite element analysis results are very close, proved that the construction of pseudo-rigid body model is correct. The results also show that this new type of distributed multi-leaves and large-deformation flexible Hooke hinge can provide the larger two-dimensional rotating schedule, and center drift of rotation is small. So this flexible Hooke hinge is a new type of large deformation flexible Hook hinge and line with the basic rotation characteristics of Hooke hinge.

Abstract: Micropump is the key component in the micro total analytical system. The major technical impediment in improving the performance of this micro-device lies in the lack of understanding the physical phenomena and their interactions of electric, mechanical, and fluidic fields for performing their intended functions. Because of the complexity of the micropump, the full coupled numerical analysis is extremely needed. This paper presents for the results of such fully coupled simulations. CFDRC® was used for the transient analysis of an electrostatically actuated micropump. The results show that the dynamic characteristics of fluid in the micropump and the vibration of flexible diaphragm are highly interactive each other. The flow rectification of the nozzle/diffuser will work only after the pressure difference between the two ends of valve have reached at a critical value. In the pump chamber, the fluidic press distribution almost independent of the space variation. Due to the increasing demands for accuracy, the nonlinear features of viscous loss of the fluid can no longer be neglected or simplified, but have to be taken into account in detail.

Abstract: This paper mainly studies the microstructure and strengthening mechanism of ferritic stainless under laser shock. the mechanical properties and microstructure were observed through the X-ray diffraction and TEM. The results showed that laser induced shock wave peak pressure is higher than the yield strength of stainless steel, the plastic deformation occus under the impact of the role of stress and high strain rate. when the laser power increases, ferritic stainless steel will have an obvious phase transition from the body-centered cubic into hexagonal system.