Earticle

Multisensor distributed fusion Wiener deconvolution estimator is presented in this paper. It does not need to solve the Diophantine equation, and the steady-state Kalman filter gain of the augmented system. It can handle processing of nonstationary signal. White noise estimator and Astrom predictor are used in the algorithm. Gevers-Wouters (G-W) algorithm is also used in this paper. In order to improve the estimation precision, multisensor information fusion Wiener deconvolution estimator for multichannel system is proposed in this paper by using the modern time series analysis method. The information fusion algorithms included matrix weighted, diagonal matrices weighted, scalar weighted and covariance intersection fusion in this paper. Under the linear minimum variance optimal information fusion criterion, the calculation formula of optimal weighting coefficients have be given. The algorithm analyzes the relationship between the accuracy and the computation complexities of four fusion algorithms. Compared with the single sensor case, the accuracy of the fused filter is greatly improved. It can be applied in signal processing, communication, control field and other fields. A simulation example for multichannel ARMA signal shows its correctness and effectiveness.

This paper addresses the control problem of an electrohydraulic velocity servo-system (EHVSS). Two control schemes are proposed for the stabilization of the system. The first scheme is a dynamic sliding mode controller (SMC), and the second scheme is a linear quadratic regulator-like control law which is based on the state-dependent Riccati equation (SDRE) approach. When applying the SMC technique, the mathematical model of the system is transformed into the controller canonical form via a nonlinear transformation to facilitate the control design. When applying the SDRE technique, the EHVSS dynamics are parameterized to produce a system with a state-dependent coefficient matrix; then the linear quadratic controller technique is carried out to produce a sub-optimal state feedback control law that regulates the system trajectories to their desired values. The effectiveness of the proposed controllers is validated through computer simulations.

Switched reluctance motor drive system has greatly practical value in electric vehicle applications. For the characteristics of switched reluctance motor and electric vehicle application requirements, how to reduce the torque ripple effectively and ensure its average output torque, all these become a hot spot of research. Based on this, first of all, the nonlinear model of switched reluctance motor is established and then the function relation between optimal turn-off angle and rotational speed is established based on the dynamic model simulation data, in the end, the optimization torque controller is designed successfully based on variable turn-off angle strategies. The simulation results show that the optimization torque controller can effectively restrain the torque ripple and improve its average torque and realize the torque dynamic characteristics optimization of switch reluctance motor, all these advantages meet the operation performance requirements of electric vehicle.

Aimed to ventilation system of large air-cooled turbine generator, using the principle of CFD and following characteristics of the stator cooling system, mathematical and physical models of three-dimensional flow and heat ventilation systems built, and two schemes proposed. One was only changing the thickness of the iron core lamination with stableness total effective length of the core, total ventilating ducts, and every duct constant axial length, the other was changing the number of ducts with stableness total effective length of the core. Corresponding basic assumptions and boundary conditions selected, fluid field and temperature field coupled solutions solved, flow field and temperature field of the original and variation structure and the spatial distribution characteristics of each part of the motor analyzed, as well the performance of the stator under different structure was compared. More effectively Structure selected.

IEEE 802.16-series are expected to provide broadband wireless access for a variety of multimedia services. The WiMAX Forum has defined a two-tiered mobility management to minimize handover delay and packet loss. The standards only define the Access Service Network Gateway ASN GW relocation procedures without specifying when the ASN GW relocation should be performed. So to address it previously Gateway Relocation Admission Control (GRAC) was developed, which combines ASN GW relocation and Admission Control (AC) algorithm to maximize system capacity. GRAC incorporates traditional Admission Control (AC) and Wiener Process (WP)-based prediction algorithms to determine when to carry out ASN GW relocation. Unfortunately, it is suitable only for Inter-ASN communications because of the inability to support vertical hand off communications (heterogeneous networks). The decision for vertical handover depends on many factors (cost, load, network bandwidth, coverage, security speed, power consumption etc.) that need to be considered together with the signal strength in the complex heterogeneous wireless environment. Therefore, we propose to use a vertical handover decision algorithm based on the user’s speed and session’s priority (non-real-time or real-time service) of the mobile nodes. Delivers had better channel utilization and preserves QoS requirements of the mobile subscribers and a practical implementation validates our claim.

In this paper, a new structured switch based on photon crystal is designed, whose structure is notable in enhancing RF system performances. Experiment demonstrates that the new structure switch is of excellent transmission characteristics relative to average structures. In the end, the switch S parameters' analysis and some design rules are given. When T=50μm, the inserting wave loss is reduced by 20%, and the signal transmission efficency can be improved greatly.

The human face is among the most significant objects in an image or video, it contains many important information and specifications, also is required to be the cause of almost all achievable look variants caused by changes in scale, location, orientation, pose, facial expression, lighting conditions and partial occlusions. It plays a key role in face recognition systems and many other face analysis applications. We focus on the feature based approach because it gave great results on detect the human face. Face feature detection techniques can be mainly divided into two kinds of approaches are Feature base and image base approach. Feature base approach tries to extract features and match it against the knowledge of the facial features. This paper gives the idea about challenging problems in the field of human face analysis and as such, as it has achieved a great attention over the last few years because of its many applications in various domains. Furthermore, several existing face detection approaches are analyzed and discussed and attempt to give the issues regarding key technologies of feature base methods, we had gone direct comparisons of the method's performance are made where possible and the advantages/ disadvantages of different approaches are discussed.

This paper introduces a design and realization method of battery management system about emergency light based on time division multiplexing and balanced charging technology. Through Calculating state of electric charge by detecting the battery charge and discharge current and monitoring of a single voltage, the system achieves a balanced charge control methods and strategies, avoided battery overcharge and over-discharge, and further improves the efficiency of the battery, extending the battery life.

After discussing analysis of photovoltaic (PV) cell characteristics, and the study of existing PV system maximum power point tracking (MPPT) methods, a MPPT technology based on combination of incremental conductance (INC) and fuzzy control (FC) is proposed to improve the tracking behavior of the single method. The algorithm based on MATLAB 7.6 is developed. The simulation results show that combination algorithm can make the photovoltaic generation system quickly and accurately track the maximum power point (MPP), and its fast response and steady-state performance achieve expectation. Finally, the correctness and effectiveness of the algorithm is verified via power generation statistical data of PV system experimental platform.

The problem of estimating motions of a mobile robot has been studied extensively in the past. In this paper, a new Vision-Aided Motion Detection Algorithm (VAMD) for orientation sensing in an unknown environment is proposed. This algorithm aims to estimate a mobile vehicle orientation, based on a single camera pose, while reducing accumulation error. The VAMD makes use of feature points, detected in a 2D scene, to recognize any rotational motion of a camera, placed on a mobile platform, and estimate the orientations in 3 Degree of Freedom (pitch, yaw, roll angles) from its initial position. The robustness, accuracy and flexibility of this algorithm will be put through several experiments on real scenarios aided with mobile robot, and the results are compared with data obtained from the mobile robot optical encoder.

The cascaded H-bridge (CHB) multilevel converter with energy feedback device has been proved beneficial in a motor drive system to improve system dynamic performance and efficiency. This paper presents a power distribution strategy in energy source, cascaded multilevel converters, transformer and electric motor based on CHB-transformer configuration in different motor drive operation modes. In this strategy, a design trajectory for energy flow distribution is proposed. This power management strategy not only giving a trace for each part to fellow in operation modes, but also show the energy flow working, An energy flow control method is developed to perform power transition smoothly between different operation modes and make sure to the whole system working steady. Simulation results are provided to demonstrate the effectiveness of the proposed motor drive system.

This paper emphasizes on proposing a cost effective photovoltaic (PV) fed 3 phase Induction motor drive which serves for rural pumping applications. Generally in a standalone system, the solar panels generate direct current energy which is then stored in rechargeable batteries and the battery set up in turn will serve as a source for the inverter. But here in this proposed work a new single stage battery-less power conversion is employed by designing a maximum power point tracker (MPPT) embedded boost converter which revolutionizes the present tradition and makes the overall cost of the setup to go down considerably. The proposed work is realized as a prototype consisting PV array of 500watts, MPPT aided boost converter, three phase inverter and a three phase squirrel cage induction drive of 357 watts. An efficient and low cost micro controller dspic4011 is used as the platforms to code and implement the prominent perturb and observe MPPT technique. Sinusoidal pulse width modulation (SPWM) is the control technique employed for the three phase inverter. To validate the experimental results simulation of the whole set up is carried out in Matlab/Simulink environment. Simulation and hardware results reveal that the system is versatile.

In recent years, researchers found that the complex dynamical network is an effective tool to describe and understand the complex nonlinear systems. Because of the difficulty in establishing accurate mathematical models for nonlinear systems, the classical linear control methods are difficult to be applied to them. T-S fuzzy model has been proved to be an all-purpose approximation for nonlinear system, and has ability to combine linear control theory with fuzzy theory. In this paper, a scheme for synchronization between two fuzzy networks based on output signals under pinning control is proposed. Unlike other common methods,it only requires output signals to be transmitted from driving network to response network, and part of nodes in response network to be controlled. The synchronization criteria is given by using Lyapunov stability theory and linear matrix inequality technology, and the number of pinning nodes can be calculated by using the proposed synchronization theorem. Finally, a simulation example is given to verify the effectiveness of this scheme.

Aiming at the defects of traditional variable focal length relative orientation algorithm, such as strong dependence on initial value and poor convergence, the paper proposes a variable focal length relative orientation method based on p-h algorithm. In order to solve the defects caused by rotation matrix formed by trigonometric function, this method uses unit quaternion instead of trigonometric function to describe rotation matrix, solving algorithm parameters iteratively according to the least square principle. New method is optimized by p-h algorithm, and it established the corresponding solution model. The experimental results showed that the improved algorithm has the following characteristics: initial value weak dependence, fast convergence, adaptability for large angle, which solved multivaluedness and singularity problems.

According to the software ANSYS, Rigid-Flexible coupling model of drum washing machine is built with parameterized characteristics. Based on ADAMS/View and ADAMS/Vibration platform, the simulation of the system in time domain and frequency domain is respectively achieved, and the effect of the key variables parameters (spring stiffness, damping coefficient) of vibration system is studied. Based on ADAMS/Durability module, the flexible body dynamic response is analyzed which obtains structure hot spots and provide a basis for optimal design of body structure.

Distance measurement is essential for autonomous mobile robot. In this paper, development of a structured-light image based ranging system is addressed. In order to obtain omnidirectional distance data, the ranging sensor units are deployed in ring structure on a mobile robot. The omnidirectional distance information to surrounding objects is useful for making a local distance map and the self-localization of a mobile robot by matching the local map with a given global map. An efficient image processing algorithm, i.e., integration of difference images with structured-light modulation is proposed, which results in robust extraction of the structured-light pixels from a camera image against environmental ambient light. Experiments for the structured-light pixel extraction, distance computation, matching and localization are conducted to verify the performance of the proposed ranging system.

Fault prediction is the precondition of Condition Based Maintenance (CBM), accurate prediction for equipment can not only make warning before failure occurs, but also reduce the cost of maintenance of complicated equipment and system. Therefore, it is of profound importance to make research on fault prediction of electronic equipment. This paper analyses some typical fault prediction method of electronic equipment, and presented improvement measures for the practical problems, finally proposed a combination of fault prediction model, and it was applied to the electronic equipment with complex structure verification.

In this paper, the fractional order motion control is designed basing on the Leader I-DX service robotic platform, where the implementation of robust fractional order controller is introduced in details. The fractional order PDμ control is analyzed in frequency domain by using an FIR/IIR method. The system model of the motor of Leader I-DX is established in MATLAB so that the influence of μ to the whole control system can be verified, and the comparisons of PD and PDμ controllers are shown as well. Motivated by the better performance of fractional order controllers, a digital implementation of fractional order PDμ controllers using PRONY technique is applied so that the incremental fractional order controllers can be realized. The real experiments on Leader I-DX platform are illustrated to validate the above concepts.

The continuous track system with the hull disturbances has 6 degrees of freedom (dof) motion in the pitching, yawing and rolling directions of two independent axes. The controller in such a system must satisfy the requirements in disturbance rejection ratio, position accuracy, speed and acceleration magnitude. The paper presents PID controller with disturbance rejection function, low sensitivity and notch filter against the bending frequency by the disturbances. The dynamic analysis of mechanical load and servo-valve flow has been performed by considering the kinetic, potential and dissipation energies. The control scheme has been certified by the MATLAB simulation using practical disturbances. The performance of a designed system has been certified by the simulation and experiment and experiment results, which indicates the improvement of the system performance in case of the existence of external disturbances.

Based on investigation on basis of physical process of the motor running under different negative sequence, calculation simulation model for steam turbine generator field was established on a 1266 MW half speed steam turbine generator for nuclear power generation, and according to time-step finite element electromagnetic theory, the 2-d finite element mathematical model is established. According to the numerical method, the magnetic field distributions inside the motor at the rated running state, with 1%IN, 2%IN, 3%IN, 4%IN and 5%IN negative sequence current were calculated. Based on the comparison and analysis of the magnetic fields inside the motor, influence of the negative sequence component proportion on the magnetic field distribution was investigated. The results could provide the reference for the design of operation and protection scheme of the generator.

Systematic exercise is required for patients with degenerative joint conditions and the elderly in need of others' help. In this study, the authors developed 30 bed rehabilitation exercises for the elderly to conduct easily on a bed using their upper extremity muscles and fine motor muscles. However, the rehabilitation exercises are effective only if those who do them have the will to continue them. Many people are taking advantage of ICT, such as on their smartphones, for constant exercise management. In this paper, the authors suggested five different motions for bedside rehabilitation exercises and obtained experimental results from the motion patterns using a three-axis acceleration sensor of the smart phone. Each motion of the rehabilitation exercises has a specific pattern, which is composed of x, y, and z-coordinates from acceleration sensor of the smart phone. Further studies on the development of motion detectors/guides for assisting bedside rehabilitation exercises are needed.

Stability of vehicle handling is of great importance for measuring the safety of vehicles. According to the current evaluation method, this crucial property is usually determined by technicians using existing impact factors and the evaluation is always generated by subjective judgments because there are no united criterion that can simplify the evaluation. However, this evaluation process is very hard to achieve because of the large scale of independent variables. Here, we aim at presenting a novel method based on artificial neural networks (ANNs) to aid the evaluation process for the tests of stability of vehicle handling. We set different impact factors of the tests as the independent variables, while the scores of the tests were set as the dependent variables. Using the existing data, we trained it using linear predictor, general regression neural network (GRNN) and multi-layer feedforward network (MLFN) during the machine learning process. Results show that ANN models can be used for aiding the subjective evaluation of stability in vehicle engineering. Our research can offer a novel insight for the vehicle evaluation in future studies.

In view of the limitations that the optimal examining items do not have dynamic and real-time performance in the traditional Preventive Maintenance (PM) model of repairable devices, a dynamic and real-time control strategy that selecting checking rate as control variable to control the dynamic behaviour of maintenance system is proposed based on the actual state of devices. The mathematical model of maintenance system is established, some performance indexes of maintenance system including the steady-state availability and the Mean Time To Failure (MTTF) are calculated. And then the control laws on the checking rate are designed. In the end, devices state evaluation is performed and the control errors and the selection of control timing are analyzed and given out. The essence of the strategy proposed in this paper is to achieve the expected steady-state behaviour by controlling the dynamic behavior of maintenance system and reduce the possibility of corrective maintenance by modifying MTTF of maintenance system, which will guarantee reliable completion of target task and reduce maintenance cost. Researches indicate that the strategy proposed in this paper is very effective to improve the utilization of devices and guide the maintenance practice activities of enterprises.

This paper presents a novel method to generate an index word for the topological map in robot localization. Previous studies extract only appearance features from an input image to match the visual words of the model images. However, the localization performance is much affected by the miss or false matches. First, we segment a robot navigation environment into the structural planes using 3D depth data. We obtain both the surface normal vectors of the structural planes and visual features in the model image, which are compared with those of an input request image in the voting approach. The experimental results show the voting performance is improved by taking into account the spatial distribution of the features.

The previous study of PM motor torque ripple is generally considered that the current distortion is the root cause of torque ripple of PMDC motor, and it is AC motor or brushless motor, not considered the effect of EMF and PMDC motor. To solve the problem, using the voltage harmonic injection method to suppress the PMDC motor torque ripple, considered the effect of EMF and PMDC motor. Base on the theory model of round square PMDC torque ripple suppression method, apply the FEM method to analyze the current and torque ripple, the improvement target is the minimum of torque and current ripple, compare the injection voltage harmonic with different optimization targets, The study provide theoretical and simulation basis to make round square torque ripple suppression sample and achieve the torque ripple suppression target.

The abstract is the technology of spinning has developed for more than 40 years. Especially in recent years, contributed a lot to Chinese equipment manufacturing industry and various kinds of spinning equipment have been developed, but it is blank in the light industry and civil industry. Due to the high cost and programming complexity of NC machine tools, we have no dedicated spinning machine and mostly rely on simple manual in the lampcover production. As to the above problems, we developed the lampcover NC spinning machines that can generate the track automatically and complete automatic control in the machining process.

The cache coherency protocol guarantees the validity of the cache block by keeping it with the latest updated contents. In multi-level cache memory hierarchy, the inclusion property enforces the lower layer cache to maintain the superset of its higher layer cache contents. The inclusion property has its benefits for cache coherence, but it may waste valuable cache blocks and bandwidth by invalidating the duplicated contents in the higher level cache. In this paper, a new cache contention management scheme is presented with modified inclusion property to avoid unnecessary cache block invalidation.

Wind power prediction accuracy is important for assessing the security and economy when wind power is connected to the grid, and wind speed is the key factor. This article presents a future four hours prediction scheme that combined chaos phase space reconstruction with NWP method. Historical wind speed data are reconstructed as phase space vectors, which are used as the first input part of prediction model, and the NWP data at the prediction time as the second input part. Wind speed at the height of turbine hub is derived from neural network model output. To test the approach, the data from a wind farm are used for this study. The prediction results are presented and compared separately to the chaos neural network model, NWP ANN model and persistence model. The results show that the method presented in this paper has higher prediction precision.