Abstract An accurate pad parameters measurement method for printed circuit board (PCB) is proposed in this paper. Firstly, the measured pad is selected by drawing a circle around it, then the processing image is de-noised and segmentation. After that, the teardrop in connected area of the pad and line is excluded. Secondly, all the possible edge points around the pad are detected by Sobel... An accurate pad parameters measurement method for printed circuit board (PCB) is proposed in this paper. Firstly, the measured pad is selected by drawing a circle around it, then the processing image is de-noised and segmentation. After that, the teardrop in connected area of the pad and line is excluded. Secondly, all the possible edge points around the pad are detected by Sobel operator and Zernike moment is used for localization of the edge points on a sub-pixel level. Finally, the detected circle edge of the pad is fitted by a least-square algorithm and the pad diameter and center position are derived. Experimental results reveal that the proposed method is precise, quick and stable, and it has already been applied in our selfdeveloped “automatic optical measurement instrument (AOM1.1)”system. Read More Read Less

Abstract Power spectrum estimation method refers to vibration or random signal power spectrum calculation method, The power spectrum analysis is an important part of the signal analysis, can be used to detect the periodic component and the percentage of the signal. And it has important implications for the diagnosis of mechanical failure.... Power spectrum estimation method refers to vibration or random signal power spectrum calculation method, The power spectrum analysis is an important part of the signal analysis, can be used to detect the periodic component and the percentage of the signal. And it has important implications for the diagnosis of mechanical failure. Read More Read Less

Abstract Vehicle dynamic safety warning system based on data fusion is researched and designed in this paper. Dynamic information of vehicle, road and environment can be collected in real time. By analyzing and processing these data, active safety warning information is achieved for individual vehicle on different work condition. Security characteristic parameter, road conditions and traffic meteorological information can be detected automatically by the... Vehicle dynamic safety warning system based on data fusion is researched and designed in this paper. Dynamic information of vehicle, road and environment can be collected in real time. By analyzing and processing these data, active safety warning information is achieved for individual vehicle on different work condition. Security characteristic parameter, road conditions and traffic meteorological information can be detected automatically by the vehicle dynamic security supervision system. Active warning and supervision of comprehensive vehicle safety performance are achieved. The warning system owns the function of data acquisition, operation, wireless data transmission, information distribution and parameter preserving. Warning information is transferred by wireless network in real time. Research work in this paper is applied to road traffic control area. This vehicle warning system is of value to removing incipient fault of running vehicle, improving reliability, rational maintaining and proper inspection. Read More Read Less