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To extract the weak fault feature of the accelerating process from a gearbox, a fractional energy gathering band time–frequency aggregated spectrum (FETFAS) is proposed to achieve a fast time–frequency analysis of a large signal and to highlight target components. The best order of the fractional Fourier transform (FRFT) is determined according to the rotating speed signal and transmission ratio....
For the non-stationary characteristics of diesel vibration signals, a method of connecting rod bearing based on EMD and Gabor transformation is proposed for fault feature extraction. The EMD method was used to decompose engine acceleration vibration signals into multiple empirical mode components > than using Gabor transformation to the first to the fourth correlation IMF. Effective fault features...
In order to monitor technical status of vehicle-born rotational device, it is necessary to power monitoring unit wirelessly. The transmission and receiving module of wireless energy-transmission device are designed and smallest system of monitoring unit is devised by using low-power. Determine optimum resonant frequency of the transmission module through testing the strength of the received signal...
The vibration signal of transmission bearing is decomposed by empirical mode decomposition, and fractal dimensions of decomposed intrinsic mode functions are calculated to extract fault characters of transmission bearings of different conditions. The results show that empirical mode decomposition method is able to separate signals of different frequency bands effectively, and the fractal dimension...
The above ground marker system (AGM) is an important part of pipeline internal inspection instrument, which can reduce the mileage error and improve the positioning precision. A AGM based on geophone array was proposed aiming at increasing depth problem of the pipeline. It can record and amplify the sound of an approaching pipeline pig's cups striking the welds of a pipe to an easily discernible level...
In order to solve some scheduling problems about multi-mission, multi-restriction and re-entrant multi-machine, model of timing Petri net is built, combination of technique on discrete event simulation and simulation algorithms based on dual code is proposed by using genetic algorithms,the optimized scheduling planning about technological process is computed. Maintain technological process of BJ2020...
The principle and algorithm of Empirical mode decomposition (EMD) and ensemble empirical mode decomposition (EEMD) is introduced, and two methods are respectively used to analyze simulated signal and engine's vibration signals. Based on EEMD, the signal can be efficiently decomposed into a finite number of intrinsic mode functions (IMFs) by adding white noise, and the problem of mode mixing in frequency...
To diagnose faults in engine accurately, technology on unsteady vibration signal acquisition(UVSA) from engine is studied. Measure principal, software and hardware composition of UVSA system at fixed rotary-speed is discussed and method of frequency bond energy accumulation(FBEA) is introduced. Based on short term Fourier transform (STFT), the repeatability and stability of acquired unsteady signal...
In order to monitor technical information in vehicle, monitoring system is designed based on CAN Bus. The hardware of data acquisition ECU is designed. By scheduling priority and send cycle, every node is optimized by considering bus average load rate and maximum delay time limit. Experimental results show that maximum delay time of node with lowest priority is reduced by 30% after modify, and CAN...
In video surveillance system, in order to classify vehicles, every region of moving target can be labeled by single linking region growing algorithm, so the area and degree of shape complex can be gotten for every target, and can be used as input eigenvalues, then fuzzy clustering algorithm is adopted to classify moving targets. In this course, euclid distance with weights is used as criterion, and...
According to the characteristics of unstable vibration signals, this paper proposes a combined approach to detect engine crank bearing mechanical faults by using cyclostationarity and support vector machine theory. The unstable vibration signals of engine accelerating process are analyzed by cyclostationarity theory. The fault diagnostic rules are generated by combining signal acquiring process and...
The vibrant signal of diesel engine is analyzed by the method of bispectrum, and bispectral feature planes are searched along diagonal and parallel lines of diagonal at certain step in the bispectral modulus field, and the mean breadth value in bispectral feature planes are calculated as signal feature which is capable of describing the fault. The support vector machines is used to diagnose the fault...
In this paper, empirical mode decomposition (EMD) denoising is applied in audio signals location when speech signals are received at several spatially separated sensors in the presence of noise. Firstly, Prior to cross correlation, each of the sensor outputs is separated into several intrinsic mode functions (IMFs) using EMD. Then, we compute normal energy of each IMFs and denoise IMFs according to...
Videos in an intersection were taken synchronously by panoramic camera and close-range camera, the image was sampled by close-range camera in calibrated location of panoramic camera, car license plate is located in this close-range image. Aiming to some features of car license plate, edges are detected by using improved color Sobel operator, and the binary image is processed by adopting the method...
In order to compute the exact position of default in vehicle's transmission shaft, the cyclostationary of vibration signal in vehicle's transmission shaft is analyzed, and the method about extracting imbalance vibration signal characteristic of transmission shaft by using SOCS(second order cyclostationary) is proposed, then through comparing the SOCS-peaks in different imbalance conditions, the imbalance...
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