Fault diagnosis of rotating machinery driven by induction motors has received increasing attention. Current diagnostic methods, which can be performed on existing inverters or current transformers of three-phase induc...
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In this paper, a novel scene 3D reconstruction algorithm based on optical flow was proposed. This algorithm doses not require any initialization of the scene' bounding volume and the whole reconstruction process i...
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In this paper, a novel scene 3D reconstruction algorithm based on optical flow was proposed. This algorithm doses not require any initialization of the scene' bounding volume and the whole reconstruction process is completed automatically. The keys to its performance are dense pre-matching between two adjacent images and refining the matching using tri-linear constraints by an additional image. The reconstruction process is as follows. First, SIFT keypoints were detected from multiple images of a scene and used as control points to calculate interior and exterior orientation parameters for each image. Then, optical flow algorithm was adapted to get pre-matching points between two images. In order to reduce the influence of uneven illumination on matching, image textures were applied to create data item in the optical flow model. After that, tri-linear constraints were adopted to eliminate false matches;finally, the 3D coordinate of each object point was obtained by their trigonometric relations. Both indoor and outdoor scenes were tested with the proposed method, the results showed the proposed algorithm was effective.
Thrust prediction of a tunnel boring machine(TBM)is crucial for the life span of disc cutters,cost forecasting,and its design *** factors affect the thrust of a *** rock pressure on the shield,advance speed,and cutter...
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Thrust prediction of a tunnel boring machine(TBM)is crucial for the life span of disc cutters,cost forecasting,and its design *** factors affect the thrust of a *** rock pressure on the shield,advance speed,and cutter water pressure will all have a certain *** addition,geological conditions and other random factors will also influence the thrust and greatly increase the difficulty of modeling it,seriously affecting the efficiency of tunnel *** overcome these challenges,this paper establishes a thrust prediction model for the TBM based on the combination of on-site quality record data and surrogate model ***,the thrust composition and influencing factors are analyzed and the thrust is modeled using a surrogate model based on field *** main factor screening based on the Morris method,the accuracy of the surrogate model is greatly *** Kriging model with the highest accuracy is selected to model the thrust and predict the thrust of the unexcavated *** results show that the thrust model has better thrust prediction by selecting similar conditions for modeling and reasonably increasing modeling *** thrust prediction method of TBM based on the combination of field data and surrogate model can accurately predict the dynamic thrust of the load and can also accurately estimate its statistical characteristics and effectively improve the excavation plan.
An important requirement for assessing technology for wireless applications is to have an accurate description of the wireless channel. Rayleigh and Rice are the most popular models for wireless channels. In this pape...
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This paper brief describes FIR anti-aliasing filters with equiripple pass bands and stop bands. We designed equiripple linear-phase FIR filters with one stage, two stages and three stages. The simulation results of th...
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This paper explores the conditions under which second and third order dynamic systems can be reduced to systems of lower order. The performance criterion chosen is the 2% settling time in response to a step input to t...
This paper explores the conditions under which second and third order dynamic systems can be reduced to systems of lower order. The performance criterion chosen is the 2% settling time in response to a step input to the system. Graphical results are presented which depict the conditions for the valid reduction of (1) second order systems to first order dominant, (2) third order systems to first order dominant, and (3) third order systems to second order dominant.
This paper deals with the high performance force control of hydraulic load simulator. Many previous works for hydraulic force control are based on their linearization equations, but hydraulic inherent nonlinear proper...
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This paper deals with the high performance force control of hydraulic load simulator. Many previous works for hydraulic force control are based on their linearization equations, but hydraulic inherent nonlinear properties and uncertainties make the conven- tional feedback proportional-integral-derivative control not yield to high-performance requirements. In this paper, a nonlinear system model is derived and linear parameterization is made for adaptive control. Then a discontinuous projection-based nonlin- ear adaptive robust force controller is developed for hydraulic load simulator. The proposed controller constructs an asymptoti- cally stable adaptive controller and adaptation laws, which can compensate for the system nonlinearities and uncertain parame- ters. Meanwhile a well-designed robust controller is also developed to cope with the hydraulic system uncertain nonlinearities. The controller achieves a guaranteed transient performance and final tracking accuracy in the presence of both parametric uncer- tainties and uncertain nonlinearities; in the absence of uncertain nonlinearities, the scheme also achieves asymptotic tracking performance. Simulation and experiment comparative results are obtained to verify the high-performance nature of the proposed control strategy and the tracking accuracy is greatly improved.
In this paper, we proposed a novel hidden Markov model (HMM) to approximate the characteristic of the Nakagami Fading channel. Our study is based on a Hidden Markov Model (HMM). The channel switches between 'good&...
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