In industrial production, flaw detection in X-ray images is a crucial process to prevent defective tires from entering the market. To address the current issues of low accuracy, false positives and missed detections i...
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In industrial production, flaw detection in X-ray images is a crucial process to prevent defective tires from entering the market. To address the current issues of low accuracy, false positives and missed detections in tire surface defect detection, we propose a tire defect detection algorithm based on RT-DETR. Firstly, we replace the multi-scale feature fusion network with a more efficient feature focusing and diffusion pyramid network to enhance the network's ability to represent cross-scale features, thereby improving defect detection accuracy. Secondly, we substitute the GIoU loss function with the Inner-WiseIoU loss function for optimizing bounding box regression, enhancing the generalization ability of the loss function and improving the precision of bounding box localization. Experimental results demonstrate that the improved algorithm, compared to the original model, increases the mean Average Precision(mAP)@0.5 by 10.0% and mAP@0.5:0.95 by 8.9%, while maintaining a high Frame rate Per Second(FPS). When compared with algorithms such as YOLOv8 and YOLOv9, our algorithm also achieves higher detection accuracy and competitive real-time performance, indicating its effectiveness.
An accurate and reliable turbofan engine model which can describe its dynamic behavior within the full flight envelop and lifecycle plays a critical role in performance optimization, controller design and fault diagno...
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An accurate and reliable turbofan engine model which can describe its dynamic behavior within the full flight envelop and lifecycle plays a critical role in performance optimization, controller design and fault diagnosis. However, due to the performance differences caused by the tolerance of engine manufacturing and assembly, and performance degradation during continuously stringent environmental regulations, the model accuracy is severely reduced. In this paper, an adaptive modification method of turbofan engine nonlinear Component-Llevel Model(CLM) based on Long Short-Term Memory(LSTM) Neural Network(NN) and hybrid optimization algorithm is pro-posed. First, a dynamic compensator with a combined LSTM NN architecture is constructed to compensate for the initial error between the experimental data and CLM of a turbofan engine under health condition. Then, a sensitivity analysis approach based on the entropy coefficient and technique for order preference by similarity to an ideal solution integrated evaluation is developed to choose the unmeasurable health parameters to be adjusted. Finally, a parallel hybrid optimization algorithm is developed to complete the adaptive model modification when the performance degrades. The proposed method is verified on a military low-bypass twin-spool turbofan engine, and the experimental results show the effectiveness of the proposed method.
With the proliferation of cloud services and the continuous growth in enterprises' demand for dynamic multi-dimensional resources, the implementation of effective strategy for time-varying workload scheduling has ...
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Linz Donawiz converter Gas(LDG) is a kind of important secondary energy source in iron and steel *** prediction of LDG generation may provide guidance for scheduling *** this paper,a two-stage method for predicting LD...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
Linz Donawiz converter Gas(LDG) is a kind of important secondary energy source in iron and steel *** prediction of LDG generation may provide guidance for scheduling *** this paper,a two-stage method for predicting LDG generation is *** to the characteristics of LDG generation data,an improved k-means clustering integrating dynamic time warping is proposed to divide the time series data into typical characteristic ***,an error feedback deep belief network(EF-DBN-DNN) model is established to predict the starting time of LDG generation by considering the relationship between production plan and the actual performance,Actual data of LDG system in an iron and steel enterprise are employed to verify the effectiveness of the proposed method,and the results show that the prediction accuracy of the proposed one is suitable for practical application.
This paper mainly focuses on a disturbance rejection control methodology for a series of mismatched and matched disturbed complex systems. Firstly, a novel finite-time arbitrary-order extended state observer (A-ESO) i...
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The allocation and utilization of water resources have always been the focus of social development concerns. River flow velocity is the basis for flow rate estimation and is very important hydrological information. Th...
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The allocation and utilization of water resources have always been the focus of social development concerns. River flow velocity is the basis for flow rate estimation and is very important hydrological information. The most widely used contact flowmeters require manual wading to place the instrument in water, making them difficult to deploy over large areas. In this paper, an optical flow estimation method of river surface velocity detection based on RAFT is constructed to obtain flow velocity and direction information. To solve the interference problem caused by flying insects and birds, a flow velocity and direction outlier identification method based on Gaussian Mixture Model is investigated. Results demonstrate that the method can effectively and accurately realize real-time monitoring of river surface velocity, providing important information for water allocation, flood prevention and control.
In permanent magnet synchronous motors(PMSM) drive system,it is difficult to achieve the optimal performance of command tracking and disturbance rejection simultaneously when the speed loop designed with the conventio...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
In permanent magnet synchronous motors(PMSM) drive system,it is difficult to achieve the optimal performance of command tracking and disturbance rejection simultaneously when the speed loop designed with the conventional one-degree-of-freedom(1-DOF) PI *** solve this problem,this paper proposes a speed control structure of two-degree-of-freedom(2-DOF) P-PI controller with linear extended state observer(LESO).There are two sets of parameters that can be designed independently in the controller,which improves the command tracking performance without degrading the disturbance rejection *** addition,a linear extended state observer(LESO) is designed to estimate the total disturbance in the speed *** to the estimated value,the output of the 2-DOF P-PI controller is compensated feedforward equivalently,which further enhances the disturbance rejection ***,simulations verify the effectiveness of the proposed control strategy.
Mobile edge computing, a prospective wireless communication framework, can contribute to offload a large number of tasks to unmanned aerial vehicle (UAV) mobile edge servers. Besides, the demand for server computation...
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Nonuniform Trial Length is a frequent non-repetitive factor in iterative systems. To maintain the effectiveness of iterative learning control for such systems, this paper proposes a preconditioning based iterative lea...
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Nonuniform Trial Length is a frequent non-repetitive factor in iterative systems. To maintain the effectiveness of iterative learning control for such systems, this paper proposes a preconditioning based iterative learning control scheme for initialized fractional order nonlinear systems with iteration-varying trial lengths. A generalized system tracking error based on probability distribution is applied to address the uncertain trial lengths. In addition, the system preconditioning strategy is adopted to suppress the unknown initialization responses and maintain the repeatability of system dynamics. On this basis, the convergence condition of a novel Dα-type iterative updating law is strictly derived, and the result shows that the tracking error can converge to any desired range by adjusting the preconditioning horizon. Compared with existing results, the proposed strategy has better applicability and physical interpretability. Finally, a numerical example is presented to demonstrate the theoretical results.
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