In order to reduce the permanent magnet (PM) volume and combine the advantages of in-wheel motor, a novel modular-stator outer-rotor flux-switching permanent-magnet motor (MSOR-FSPM) whose PM volume is half of that in...
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In order to reduce the permanent magnet (PM) volume and combine the advantages of in-wheel motor, a novel modular-stator outer-rotor flux-switching permanent-magnet motor (MSOR-FSPM) whose PM volume is half of that in conventional outer-rotor flux-switching permanent-magnet (COR-FSPM) motor is proposed. However, cogging torque and torque ripple of MSOR-FSPM motor are especially worse due to the inherent double salient effect and the back-EMF harmonics caused by module stator structure. In this paper, structure and operation principle of MSOR-FSPM motor are described simply. Secondly, cogging torque and torque ripple are reduced by using traditional rotor two-step skewing method, but the result is unsatisfactory. Thirdly, a new rotor two-step skewing method is adopted since the ratio of back-EMF period to cogging torque period is the odd. Compared with traditional rotor step skewing method, the new method eliminates the even harmonics of back-EMF and remains the amplitude of fundamental waveform;the odd harmonics of cogging torque and electromagnetic torque are eliminated. Finally, the results of the new rotor step skewing method is verified by 3D finite element method (FEM) and further improved by embedding non-magnetic blocks in the middle of the stator and rotor.
Digitally controlled PWM inverters are interfered by quantization errors caused by A/D converters(ADC) and Digital Pulse-Width Modulators(DPWMs),which may result in undesirable limit-cycle oscillations(LCO).In t...
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Digitally controlled PWM inverters are interfered by quantization errors caused by A/D converters(ADC) and Digital Pulse-Width Modulators(DPWMs),which may result in undesirable limit-cycle oscillations(LCO).In this paper,static and dynamic models that include the quantization effects are derived and used to explain the origins of *** to a brief analysis of the limit cycle oscillation period and amplitude,a new method to improve digital PWM resolution is introduced in the *** this method,the limit cycle can be avoided with the proposed integral part so that it will not propagate to the output *** the digital PWM resolution is improved *** the end,the conclusions are illustrated by simulation and experimental examples.
For personalized design it is important to be able to collect, measure and evaluate individual properties of human beings. This paper proposes registration for the point clouds during foot 3D scanning. In the experime...
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Traditional bridge inspection methods require lane closures, inspection equipment, and most importantly the experiences and knowledge of the inspectors. This increases not only the inspection cost and time, but also t...
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In this paper, in order to replace a conventional electric linear actuator which is consist of rotary PM machine and ball screw, a novel double-sided five-phase modular linear permanent magnet synchronous machine (MLP...
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In this paper, in order to replace a conventional electric linear actuator which is consist of rotary PM machine and ball screw, a novel double-sided five-phase modular linear permanent magnet synchronous machine (MLPMSM) is proposed and designed with the same volume. The basic structure of the machine is firstly described and the major dimensions of one module are then optimized to acquire the largest thrust force. Through these methods, the average force of the MLPMSM reaches 206N, which is 58.4% larger than the conventional linear actuator. After that, the 5 th order harmonic in thrust ripple is analyzed and diminished by adjusting the distance between slot openings of the module. As the result the 5 th order harmonic is diminished greatly by 57%.
Data mining is one hot orientation in today’s research *** activity recognition is meaningful in our daily living and is a significant aspect in data *** previously research is almost based on tri-axial *** paper pre...
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ISBN:
(纸本)9781509009107
Data mining is one hot orientation in today’s research *** activity recognition is meaningful in our daily living and is a significant aspect in data *** previously research is almost based on tri-axial *** paper presents a novel method to collect data from both accelerometer and gyroscope using *** daily activities including Walking,Running,Upstairs,Downstairs,Standing,Sitting and Cycling,a total of seven categories are *** raw data from MEMS are recorded by smartphone according to different daily *** improve the accuracy of classification for daily activities,this paper combines time-series features with wavelet coefficients to extract *** recognize these activities,the support vector machine is used to finish this ***,we compare the accuracy with other machine learning methods,such as k-nearest neighbor algorithm and neural network or decision *** result indicates that our method can achieve nearly 96%classification accuracy for the seven kinds of daily activities.
Research of Unmanned Aerial Vehicle (UAV) formation is a hot spot in the field of UAV applications. Based on the fountain code, an encoding communication scheme using unequal level coding Lu by Transform (ULC-LT) code...
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Research of Unmanned Aerial Vehicle (UAV) formation is a hot spot in the field of UAV applications. Based on the fountain code, an encoding communication scheme using unequal level coding Lu by Transform (ULC-LT) code and stepwise unequal error protection Lu by Transform (SUEP-LT) code are proposed for the UAV formation communication. Simulation results reveal that the proposed coding scheme can reduce the decoding bit error rate and provide strong unequal error protection property across sources.
In this paper,the adaptive robust control(ARC) algorithm is proposed for tracking control of the electric cylinder *** to the analysis of the working principle of the electric cylinder servo system,the model of the ...
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In this paper,the adaptive robust control(ARC) algorithm is proposed for tracking control of the electric cylinder *** to the analysis of the working principle of the electric cylinder servo system,the model of the system is established on the modified Lugre friction model,and single observer is designed for calculating friction as *** the ARC controller and adaptive law are designed for on-line parameters estimation,frictional compensation and the suppression external *** the Lyapunov approach,the stability of this system can be obtained in this *** simulation result shows that ARC can suppresses external disturbances effectively and realize real-time online parameter estimation.
The problem of adaptive optimal control for a class of nonlinear uncertain systems with saturating actuators and external disturbance is investigated in this paper. Considering the saturating actuators, a non-quadrati...
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ISBN:
(纸本)9781509015740;9781509015733
The problem of adaptive optimal control for a class of nonlinear uncertain systems with saturating actuators and external disturbance is investigated in this paper. Considering the saturating actuators, a non-quadratic cost function is adopted. The key of this optimal control problem is to find the solution to the Hamilton Jacobi Bellman equation (HJB). An online intergral reinforcement learning (IRL) algorithm based-Neural Network (NN) is given to approximate the solution. Unlike traditional integral reinforcement learning algorithms, data onto a period of time stored together with current data are used to update the neural network weights in place of persistence of excitation (PE) condition. This method overcomes the shortcomings of the PE condition which is not easy to be checked online. Finally, numerical examples are given to show the effectiveness of the proposed methods.
In this paper, the model of a novel liquid-circular angular accelerometer is studied. Due to the absence of theoretical model of liquid-circular angular accelerometer, a subspace identification method(SIM) based on Ak...
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ISBN:
(纸本)9781509009107
In this paper, the model of a novel liquid-circular angular accelerometer is studied. Due to the absence of theoretical model of liquid-circular angular accelerometer, a subspace identification method(SIM) based on Akaike Information Criterion(AIC) is chosen for model identification of angular accelerometer. The proposed identification method is tested on a liquid-circular angular accelerometer prototype. The experimental results indicate that SIM could obtain a more accurate model than least square method, with a degree of fitting above 90%. In addition, SIM possesses good repeatability and stability. The experimental model identified by SIM in this paper can be applied in engineering practice.
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