Hong Wei Zhao

Microstructure Evolution of Ti-6Al-4V Alloy during High Speed Cutting: An Investigation Using Finite Element Simulation

In this paper, a novel model combining the microstructure prediction model and a modified constitutive model of the Johnson-Cook (JC) model was developed and embedded into FEM software via the user subroutine. The chip formation and microstructure evolution in high speed cutting of Ti-6Al-4V alloy were simulated based on the presented model. The results indicated that dynamic recrystallization mainly happened in ASBs, where the grain size had a big decline. According to the variation of cutting temperature and grain size of microstructure, the mechanism of the adiabatic shear bands (ASBs) formation was investigated deeply and concluded that dynamic recrystallization was the root cause of the serrated chip formation.

Research on Cooperation Mechanism of Multi-Agent Grinding Control System Based on Blackboard Model

In order to solve the complex industrial control problems in grinding control,we construct multi-agent grinding control system based on the blackboard model in this paper. Through the study on the structure and control mechanism of the blackboard model, we design a framework for blackboard model in multi-agent grinding control system, divide and introduce the function model of the blackboard in detail, establish blackboard control agent to control and coordinate how the individual agent takes use of the blackboard resources centralizedly.Aiming at actual situations of the grinding control,we put forward cooperation mechanism multi-agent based on a combination of tasks sharing and results sharing, establish control decision agent to solve the conflict caused by multi-agent cooperation. The cooperation mechanism multi-agent grinding control system improves the execution ability of the individual agent, avoids the conflict caused by different goals and the competition of resources, ensures the coordinated executive of multiple tasks.

Comprehensive Evaluation on Reliability of Machine Tools Based on Extension Method to Determine Membership Degree

To solve acquired the membership degree in fuzzy evaluation. we use correlation function in extension theory to calculate the degree of association between evaluation indicators and fuzzy scales, and then the degree of association is done standers conversion and normalized processing,, getting the membership value of evaluation matrix in fuzzy comprehensive evaluation. Comprising traditional statistical methods and expert evaluation method, the membership value of evaluation matrix which is gat through correlation function method of extension theory is more simple and reasonable. Comprehensive evaluation value is got from Calculating linear weighted between evaluation matrix and the index weight coming from analytic hierarchy process. Finally, using two type of home made NC machine tools as example to do the practical application study of the proposed method, the results show that this method can give the reasonable evaluation.

Wireless Digital Display Thermometers System Design

This article describes a real-time temperature measurement system based on ARM9 and temperature sensor DS18B20. The temperature signal is collected by DS18B20 and converted into 16 bits serial digital signal. Later, ARM9 receives the signal and sends it to the wireless transceiver module PTR2000. PTR2000 sends the received signal to ARM9. At last the signal is transmitted to the LCD for a real-time display, also be sent to the printer for detailed records. Our design proposal is simple and practical.

Face Detection System Based on SIFT Algorithm

This paper consists of three chapters, first introduced the algorithm and methods of Face detection, and then focus on the SIFT algorithm, finally use SIFT achieve the face detection function.

A Study on the Design Method of the Real-Time System Software Based on RTOS

This paper combines the characteristics of real-time embedded systems and the real-time operating system to propose a software engineering method and process which bases on the function structured analysis and task structured design. First in the process of structured analysis based on the Hatley-Pirbhai method, extracting and sorting out the data flow and control flow according to the functional requirements of the system, analyzing and processing the functions of the system, the dependency among the functions and the timing sequence, and then realizing the design of the specific functions of the system, next achieving the structural design through the improving method, it also simplifies the system design processes. At this time, just need to analyze and divide the processing which is obtained from the structural analysis to get the specific task, design the interfaces among the tasks and also every task to get the new design method of the embedded real-time operating system, which also solves hard issue of the traditional method which is the weak extracting and developing iteration in the embedded real-time system.

The Design of Carbon Dioxide Detection Instrument Based on MSP430F435

Studied herein, carbon dioxide detector is based MSP430F435 microcontroller developed and designed. The instrument has two upper machine and lower machine part, the host computer by PC-based operating system and application software, has a good human-computer interaction systems, a friendly man-machine interface. Aspects through the host computer machine operator is able to control the next bit machine. Lower machine selection of the MSP430F435 microcontroller as lower core chip, the chip can efficiently execute code.

Quasi-Static Contact Analysis of an Inchworm-Type Piezoelectric-Driven Rotary Actuator via Finite Element Method

Measurement results of the output stepping rotary angle of a piezoelectric-driven rotary actuator by means of inchworm motion have been compared with results obtained from three-dimensional Finite Element Analysis (FEA). Comparison results showed a good quantitative agreement, and confirmed the validity and accuracy of the finite element method in the design and analysis of the inchworm-type rotary actuators. In addition, the effect of the gap between the stator and rotor on the working performance of the actuator was investigated by using FEA. With the increase of the gap, both the stepping rotary angle and the output torque of the rotor decrease significantly. Therefore, this factor must be taken into consideration in the design and machining of this kind of actuators.

A New Mobile Visual Search System Based on the Human Visual System

We describe a novel mobile visual search system based on the saliencymechanism and sparse coding principle of the human visual system (HVS). In the featureextraction step, we first divide an image into different regions using thesaliency extraction algorithm. Then scale-invariant feature transform (SIFT)descriptors in all regions are extracted while regional identities arepreserved based on their various saliency levels. According to the sparsecoding principle in the HVS, we adopt a local neighbor preserving Hash functionto establish the binary sparse expression of the SIFT features. In the searchingstep, the nearest neighbors matched to the hashing codes are processed accordingto different saliency levels. Matching scores of images in the database arederived from the matching of hashing codes. Subsequently, the matching scoresof all levels are weighed by degrees of saliency to obtain the initial set of results. In order to further ensure matching accuracy, we propose an optimized retrieval scheme based on global texture information. We conduct extensive experiments on an actual mobile platform in large-scale datasets by using Corel-1000. The resultsshow that the proposed method outperforms the state-of-the-art algorithms on accuracyrate, and no significant increase in the running time of the feature extractionand retrieval can be observed.

Finite Element Analysis of the Whole Machine on the Domestic Large Gantry Machine Tool

The objective of this work is to define assembly body of processing center by using the contact and node coupling combined method. The information of node displacement, stress and strain can be got by static analysis. Besides, we can check the strength of key parts through the strength theory. Modal analysis results indicate that resonance would be caused in machine tools when external drive frequency is 36.477 Hz, 41.436 Hz and the 44.796 Hz, which are serious accidents. Harmonic response analysis indicates that the certain frequency of 41Hz should be avoided in practice.