Earticle

This thesis develops efficiency optimization control strategies for three phase induction motors with Hall sensor. This thesis compares the different control strategies include open-loop voltage-mode control of hard-commutation scheme, open-loop voltage-mode control of soft-commutation scheme, and closed-loop current-mode control scheme, and analyzes the current response and overall efficiency. This thesis also develops a low-cost and high efficiency sensorless control for three phase induction motors drives. The proposed scheme detects the back-EMF zero-crossing-point (ZCP) to realize current commutation without Hall sensor. An adjustable blanking time control method is used to ensure correct detection of the ZCP. When using sensorless commutation control, the fan motor can start-up smoothly and operate under wide speed range, moreover, the overall efficiency is almost the same to the results of control scheme with Hall sensor.

The linear quadratic regulator based autopilot is premeditated for level flight of unmanned aerial vehicle (UAV) which has been achieved lucratively. Diverse modes are utilized for controlling the rates of UAV. The pitch rate is controlled by utilizing the phugoid mode, the roll rate is controlled by utilizing the roll mode and the spiral mode is utilized for yaw rate. The linear quadratic regulator proposes sturdiness at the rate of accomplishment to subjugation over the turbulences and instabilities in order to conquer the favored performance. The FlightGear simulator is utilized for the authentication of the performance of the autopilot. The level flight has been conquered successfully and has been legitimated by utilizing the FlightGear simulator. The simulated results as well as the FlightGear simulator results or the legitimated results are presented in this paper. Microsoft Visual Studio has been employed as a conduit between the MATLAB and FlightGear Simulator.

This paper proposes a hardware/software partitioning algorithm which can be applied to the dynamically reconfigurable system. Firstly, based on reconfigurable system structure, this paper brings forward a kind of system model and its task description ,then use genetic/tabu search (GATS) integration strategy, in the condition of resource constrain of the reconfigurable systems, specific applications will be mapped to software and hardware platform. Secondly, using configuration prefetching and scheduling strategy it will be found out that the shortest time assignment and the execution order of the entire task flow diagram in the partition result. The experiment results have shown that this method can effectively map the task graph to reconfigurable system, and is a kind of method with high performance.

In this study, to resolve flood damage in flood-prone areas around Incheon Bridge landfill, numerical analysis was performed according to change of coefficient of runoff considering underground rainfall storage in surrounding parks and facilities to reduce non-point source pollutants. Use of rainfall retention facility to improve urban flooding reduced peak flow and effectively prevented flooding in the subject areas. In the result according to change of coefficient of runoff considering facilities to reduce non-point source pollutants, control of initial rainfall led to reduce peak water level and secure delay time. Based on the study result, to properly install underground retention storage and apply coefficient of runoff according to facilities to reduce non-point source pollutants within the subject areas, providing accuracy of various parameters necessary for future analysis and measurement data will help design effective multi-functional parks with minimized flood damage and prepare measures to prevent disaster.

Sensitivity field distribution of the sensor in ECT system is affected by the distribution of the mixture, The "soft field" property of sensitive field bring great difficulty in image reconstruction, on the basis of analyzing capacitance tomography sensitive mechanism, by analyzing that sensor structure parameters in ECT system have influence on the uniformity of the sensitive field, this paper proposed a structural parameters optimization algorithm based on the ant colony algorithm. The algorithm first determines the parameter optimization design evaluation function, and then rapidly identifies several suboptimal paths by using particle swarm optimization and initializes the pheromones in the path, Ant colony algorithm finds the optimal solution according to the initialization pheromones and using the characteristics of rapid convergence. The experimental results show that, compared with the orthogonal algorithm, the performance of the sensor designed by using the structure parameters obtained by ant colony optimization algorithm is obviously improved, Alleviate the difficulty of data acquisition circuit design and improve the accuracy and uniformity of the sensitive field, the quality of image reconstruction is improved, the relative error of image reconstruction is reduced.

With the fast development of robot technologies, robots are increasingly operating in complex and unknown environments. Thus, the robotic software systems need to be online reconfigurable to fast meet users’ new demands or environment requirements. In order to improve the online reconfiguration, an innovative way to combine runtime software architecture and robotic development is proposed, and then use model-driven techniques to establish a rigorous and useable abstract architecture meta-model and robotic system meta-model. In order to improve the bidirectional transformation, model difference and merge operations are constructed and proposed. And meanwhile we extending an existing synchronization engine generation tool and makes it adapted to the robot system. Finally, our platform is test with a concrete case study on top of the Microsoft Robotics Developer Studio to further verify its correctness. The result proves this study can effectively improve online reconfiguration of robotic software systems, and architecture model-based online configure makes it can effectively improve the development of different types of robot software architectures, and improves the reusability of the entire development process.

A MANET is an autonomous collection of mobile nodes that communicate all the other nodes within their radio ranges. Where the nodes that are not in the direct communication range use intermediate node to communicate with each other. In MANET each mobile node has mobility and move according to the specified locations in the network. Therefore the verification of node locations is an important issue in mobile adhoc networks, and it becomes particularly challenging in the presence of adversaries aiming at harming the system. In this research work proposed a protocol called Neighbor position verification (NPV), in order to verify the position of its communication neighbors and detect the adversaries in the mobile adhoc network, This protocol is used to exchanges the messages and verifies the position of communicating nodes in the network. The first scheme is deals with the identification of nodes with which a communication link can be established or that are within a given distance. This distance calculation is based on message exchange between the verifier and its communicated neighbors. After the distances are calculated verifier verifies the position of communicating nodes in networks by following three tests that to be done, they are: 1) Direct symmetry test 2) Cross symmetry test 3) The Multilateration Test. This protocol is implemented over the MANET network and simulated using Network Simulator (NS2). This research work carry out QOS based forwarding node selection scheme to reduce the delay and achieve the high throughput. Performance of the proposed system evaluated based on the parameters such as delay and throughput.

Autonomous Navigation Vehicle (AUV) navigates to the specified longitude and latitude on water surface by means of Global Positioning System (GPS), Inertial Navigation System (INS) and Electronic Compass (EC), then dives to the specified depth according to the measurements of Depth Gauge (DG). To overcome the low location accuracy of existing navigation technologies in AUV, an integrated navigation method based on multi-sensor data fusion of GPS/INS/EC/DG has been proposed. Since the systematic stability and high precision in short-term measurement of INS, it takes the INS as common reference system. The problem which measurement error accumulates with time is solved by the combination of four sub-filters and a main filter. The sub-filters output the measured velocity, position, orientation and depth error to the main filter, which fuse the data to obtain the global optimal estimation and feedback to the INS system. Realistic environment parameters are simulated in MATLAB to verify the rationality of the navigation algorithm. The feasibility of method is proved by the comparison of position errors with and without combined navigation.

The main objective of this work is to design and construct a PoE switch based system: to control electric appliances such as light, fan, heater, washing machine, motor, TV, etc. and simultaneously data communication facility. Especially PoE switch can manage power and data separately by a splitter which motivated the need to research into it not only for industrial application but also for domestic use or home use. Power is use for controlling devices and data is for communication purpose. This system will play an important role for the elderly and physically disabled people to control their home appliances in intuitive and flexible way through Wi-Fi and internet. This system is password protected so only authorized person can control any sensitive electrical appliances. Most commercially available home automation systems are used only for control purpose. But by our proposed PoE based system we can control electrical appliances as well as data communication by the same switch port.

There are many mathematical models or chemical models available to describe the avascular tumor growth. However, few of them take into account the necessary physical growth for the avascular tumor. In this paper, we proposed a multiscale finite element model that spans three distinct scales for the avascular tumor growth. At the extracellular microenvironment level, we proposed a new set of piecewise reaction diffusion equations to describe the extracellular microenvironment of the tumor growth. At the intracellular cycle level, we proposed a cell cycle control factor to model the key role that played by the G1-S phase transition. At the cellular level, we introduced the proposed cell cycle control factor to combine the extracellular microenvironment, the intracellular cycle and the cellular cycle into the total energy equations to form our finite element cellular model. Experiments were performed to simulate the growth of EMT6/Ro mouse mammary cell under three different kinds of initial chemical concentrations. Results showed that the proposed approach outperformed the baseline approach in terms of tumor cell number and tumor cell volume.

Flexible AC Transmission Systems (FACTS)technology has been developed to control voltage and reactive power in power systems by incorporating high speed power electronic devices.The FACTS device presentedin this research work is Thyristor Controlled Voltage Regulator (TCVR) which is a novel FACTS devicethat aims to control system voltage and hence improvesvoltage regulation. This paper studies the effect of voltages injected by TCVR, whether positive or negative, on short-circuit calculations. The type of fault considered is a ground faultthat occurs at the end of a high voltage line compensated at its mid point by TCVR while maintaining a fixed fault resistance.A case study is selected for a high voltage power line in the Algerian transmission network.In this research work, the illustrated simulation results show perfect agreement with the presented theoretical analysiswhich is based on the method of symmetrical components.

As a feasible option, surface signals can be transmitted downhole by taking downhole oil pipe as channel and sound waves as medium. In this paper, a longitudinal wave transmission experiment is conducted for oil pipes with limited length, and experimental environment and equipment are prepared. The experimental objects include 10 oil pipes of three sizes, and each pipe is arranged with a set of velocity sensor. The experiments of impact signals and continuous sine signals are performed, revealing the time-domain and frequency-domain properties of sound waves during transmission through different pipe nodes. Through detailed analysis of the experimental results, it is concluded that spectral distribution of longitudinal wave in pipes presents a comb filter structure with alternating passband and stopband, which is validated in respect of frequency domain and time domain. Moreover, distortion and attenuation of longitudinal wave signals may occur within passband frequencies.

As science continues to progress, human civilization has ever enter into a new realm. Household electrification has become a symbol of progress .In southern China and some humid regions in foreign countries, clothes are still wet in several days after washing. People deeply suffered from it. The invention of clothing quick-drying device has solved this problem and has brought great convenience to people living in wet areas. According to the need of the people at home or traveling, this paper brought a new design conception which makes innovative design and research from the function and structure, materials and technology and human relationships. To let people use it at the same time feel a happy convenience life.

Water Circulation system in canal has a great importance in Songdo Waterfront. There is a need to ensure that consistent water flows occur in the canal. In this study, MIKE3 FM was setup and used to investigate the circulation system with respect to the operation of the water gates will present at the ends of the canal system. The model was computed under various tidal conditions in Incheon coastal. The numerical modeling of the water flow helped to determine the gate operation that will play an important part in the water circulation in the canal.Water gate operation was possible to maintain the specific water level. Optimal water gate operation was decided for the Songdo waterfront canal system.

In allusion to the special characteristic of longitudinal loop risk assessment in landing process of carrier-based aircraft, this paper extends the concept of decision-maker, and proposes a method of fuzzy multi-attribute decision making with normal fuzzy linguistic variables as decision-making information. Based on the establishment of carrier-based aircraft landing model, the expressions of risk evaluation indicators are ensured, and the relative attribute weight is calculated by the simulation of the safe flight area in landing process. The application of risk assessment is implemented by analogy between standard points and decision-maker. The analysis of numerical examples shows that the method is practical and the application in risk evaluation is reasonable. Multipoint decision information is complete and decision results accord with distributions of touchdown points. Comprehensive evaluation of flight safety with different pilots can be realized.

Statistical distributions are useful in predicting patterns of failure and hence, are employed in failure and reliability analysis. Reliability analysis is relatively easier when time variance is linear. However, for a non-linear progression of time such as the case in preventive maintenance, the reliability analysis becomes complex. This paper primarily investigates characteristics of exponential distribution taking into account periodic preventive maintenance. As a secondary consideration, the paper also investigates characteristics of Weibull distribution to provide a platform for comparison.

In allusion to high electricity consumption and resource wasting of college schoolroom, this paper proposes a lighting fuzzy control system based on CC2430. The deviation and transformation rate comparing ideal illumination and the practical one has inferenced by Fuzzy Model Reference adaptive system (FMRAS), and it can compensate natural light illumination stabilizing schoolroom lighting through PWM code. The system core hardware structure and adaptive fuzzy control algorithm have been expressed. Simulation results show that the control system accords with government standard, and achieves the desired effect.

Decoupling control of two-motor dual three-phase permanent-magnet synchronous motor (PMSM) series-connected system can be realized by using proper phase transposition rules with a single supply from a six-phase voltage source inverter (VSI), which solved the control problem of two motors in series. Since the traditional two-vector SVPWM strategy, which is commonly used in three-phase system, exists 5th and 7th harmonics in x-y plane, making it hard to realize decoupling control of two-motor dual three-phase PMSM series-connected system. Meanwhile, the DC bus voltage utilization of carrier-based PWM strategy is lower. Thus one method, which adopted a TBTSB-SVPWM strategy with two modulators, was proposed in this paper. It ensures the inverter output voltage only contains two kinds of fundamental components required by the two series-connected motors with a single VSI, making it possible to realize decoupling control of two-motor dual three-phase PMSM series-connected system. Simulation results indicate that there is no influence on the other motor while the speed/load of any one motor changed, achieving the decoupling control of series-connected system, and the feasibility and validness of the proposed approach are verified.

Recently the importance of the management technologies for prevention increases. There are many kinds of pipelines under the ground of cities which have pipelines for waterworks, wastewater, oil, gas, electronic power, communications, heat energy, and so on. And these underground pipelines have different roles in supply the essential resources for citizens of cities and will be more important for citizens increasingly. So we call these pipelines as "LifeLine." By the way, these pipelines do not support their core roles to citizens and we can easily see that pipeline accidents have given inconvenient facts or serious man-made disasters to modern citizens as well. For examples, road settlement and sinkholes, waterworks leaks, pollutions by wastewater and oil, explosions by gas, and so on. Nowadays, we live in times using ICT - sensor technologies. So these environments have been advanced and are probably possible to resolve pipeline management problems using them beforehand in real time. Thus, ICT convergences will encourage us to make new technologies and paradigms on the field of pipeline management.

In this work principles of modern algorithm construction of detection acoustic emission impulses and preliminary classification of there are sources danger degree are given. Given algorithm is worked out taking in to account modern digital systems of acoustic information processing. It is based on the adaptive changing principle of the discovering level of detection of the useful signal while performing non-standard parameters valuation of danger degree of acoustic emission impulse sources.

Flowshop scheduling problems with a work shop or group shop in which the flow control shall enable an appropriate sequencing for each job and for processing on a set of machines are very significant for production control. HFS (Hybrid Flowshops) is a typical mass-customization with large product series which is widely used in the current production companies. However, as the increasing customization requirements from large number of customers, the control of HFS is really difficult. This paper introduces a Petri net-based adaptive scheduling model for easing the qualitative analysis of the production system and reducing the complexity. Resource-oriented Petri Net (ROPN) is used to establish the relation in terms of logics and behaviors of various resources, converting the dynamics control of manufacturing system into resources aspects. After the model analysis and a real-life case illustration, this model can perform good interpretation of various objective functions and real case considerations. That could be used for guiding production schedules control and automation.

The use of wireless sensor networks in agriculture is anticipated to revolutionalise its operational mechanism. Many activities like moisture deficit monitoring, crop yield estimation and soil erosion can be automated using sensors. However, we need to develop deployment strategies, routing schemes appropriate for such applications. This paper focuses on special case of irrigated agriculture in gravity and pressurised irrigation. We have formulated a deployment strategy and developed an efficient routing protocol LATHAR (Location aware Threshold Based Hierarchical and Adaptive Routing) for transmitting the data packets from sensor node to the access point. The protocol has been tested on simulation model developed in ns2 simulator and it has been found to perform best in almost all the matrices used to evaluate the performance of WSN.

The fracturing technology has been widely applied to break up the formation in oil & gas industry. The flow dynamics and erosion phenomenon of frac sleeve in fracturing process is important but has not been studied previously. In this paper, the dynamics is studied numerically with special reference to the effect of sand mass flow rate. The simulation is conducted using a coupled approach of Computational Fluid Dynamics and Discrete Element Method. The influence of port parameters such as shape, size and number arrangement on the erosion rate was investigated. Based on this study, motion characteristics of fracturing fluid and sand particles are obtained, the structure parameters can be optimized. The frac sleeve after structural optimization obtains better erosion resistance. This study shows that Computational Fluid Dynamics could be a useful tool to study the dynamics and internal flow of fracturing tool.

Combined with our aircraft combat capability, this paper aims at the unmanned aerial vehicles automatic attack process of single target, in accordance with the principle of maximum killing the enemy and establish the model of target threat based on the situation of two sides. According to the importance of our members, defense model, and the enemy motion trajectory with the threat model and the cooperative attack and defense model of pseudo tracking site, our cooperative tracking of pseudo trace point to obtain the best accounts for the site and to fight against the target. The simulation results show that, the occupied position is a rapid and effective method which could lead to the greatest degree of destroy to enemy aircraft.

Devices existing within a wireless sensor system are small in size and their battery capacities are very limited. In addition, diverse channel environments may be configured for them. To overcome various constraints and efficiently utilize the energy of sensor nodes, transmission power control (TPC) technology may be employed. This paper describes our attempt to resolve problems with existing TPC algorithms, reduce the number of unnecessary changes in transmission power level (TPL) using the slope value of linear regressed equation, and present an algorithm for deriving TPL in a fast and appropriate manner. Through an experiment, in this study, we not only derive proper weight value of the proposed algorithm but also compare its performance with that of existing algorithms by analyzing the numbers of control packets, drop packets, and energy consumption.

To solve the problem that the traditional rapidly-exploring random tree(RRT) algorithm can not be directly applied to the path planning of Unmanned Aerial Vehicle(UAV), add the UAV turning angle constraint to the planning algorithm in the process of random point were produced, it make the path meet the capable of flying; For the problem that we could not determine the random point about the rapidly-exploring random tree(RRT) algorithm, this paper provide a improvement algorithm which combined aircraft kinematics equation, and use this algorithm to the three dimensional(3D) path planning . The simulation result proved that this algorithm could avoid the threat effectively, and the accuracy of planning is more precise, so the path planned by the algorithm proposed in this paper is more accorded the requirements of actual planning path.

This paper makes an assessment of the typical main steam temperature system in thermal power plant. Due to main steam temperature system is a cascade control system. So, it should be assessed with the performance assessment method of cascade control systems. So firstly, this paper deduces the theoretical process of performance assessment of cascade control system based on minimum variance. Then with this method assesses the performance of four typical loads in thermal power plants when using active disturbance rejection-proportion (ADRC-P) cascade control and smith active disturbance rejection-proportion (SADRC-P) cascade control respectively. Finally, makes comparison of the results. Results show that, when using the same control strategy, different loads has different performance. Load with lager inertia has better performance; When using different control strategies, performance under SADRC-P control is better than that under ADRC-P control.

In this paper, we designed and interpreted the array antennas of the aperture-coupled microstrip operating in the millimeter-wave band for radar system. The microstrip array antenna can be designed with a transmission line circuit and a matching circuit in the same substrate. Therefore it is easy to combine with the active elements of the system. We add the slots to the patch to overcome it because general microstrip patch antennas have narrow band characteristics. we have designed the U-shaped slots in the patch. The substrate of patch for an aperture-coupled is used for general dielectric layer, and the substrate of transmission line for T-junction feeding is used FR4-epoxy. At this time, the analyzed center frequencies are 17 resonance mode from 24 GHz to 77 GHz at the 4☓4 array. As a result, this paper is proposed the possibility of prototyping by design of multi-mode array antenna in the millimeter-wave.

This paper presents a design of three channel controller based on active disturbance rejection control which has a fast response, high control precision, good robustness, strongly adaptability. This design approach does not need accurate mathematics model of the small unmanned helicopter. Input-output feedback linearization is intended primarily for the system output and system control input to establish a direct relation. The final aim is to develop a robust tracking control scheme which ensures that the outputs of closed-loop system track the given expectations. There results of simulations show the satisfactory tracking performance and the great ability to suppress disturbances.