In this paper, a high-precision flat gasket thickness measuring and classifying system based on line-structured light is presented. The system consists of a part feeding device, a measurement platform, a measurement and control subsystem and a classifying subsystem. The measurement system is based on the optical trigonometry measurement principle. Different from other common measurement system, a line-structured light instead of a beam is projected to the surface of the measured object. From a stripe the measured result will get more confirmation than a single beam spot. More than one frame of image are grabbed and averaged to reduce the random error. The gravity center algorithm is used to extract the center-point of the stripe in one column. According to the least squares method, a straight line can be fitted from gravity center-points extracted. A virtual grate is designed to improve the resolution of the measurement system. The calibration of the measurement system is designed and realized. An experiment is built and the measurement result is analyzed. The result shows that the uncertainty of the measurement system is limited in ± 0.003<i>mm</i>. And this system can be used for classifying the gaskets by thickness.
The vibration signal of a rotor bearing system is usually nonlinear and non-stationary. Fourier transform is hard to
analyze these signals. A new method based upon empirical mode decomposition (EMD) and Hilbert spectrum is
proposed for fault diagnosis of roller bearings. We get vibration signals from 6205-type ball bearings with inner-race
faults and with outer-race faults, then analyzing its local Hilbert spectrum and local Hilbert marginal spectrum.
Comparing the results with theory value, we can diagnose the fault of rotary machinery fault. In this study, we find that
local Hilbert spectrum and local Hilbert marginal spectrum are very useful. Hilbert Transformation is introduced to
confirm the HHT method is fit to process nonlinear and non-stationary signals.
Accurate and rapid 3D position measurement is required in many industrial applications. Traditional 3D position measurements is usually applied in laboratories using coordinate measuring machine(CMM). CMM can achieve a high accuracy, but efficiency is low. Machine vision is a new technology in position measuring. Measurement based on machine vision has non-touch, high speed, high accuracy and other prominent advantages. Because depth information is lost during the process of image formation, synthesizing operation become more complicated, direct 3D position measurement based on machine vision has hardly been used in online industry application. In this paper, an indirectly online 3D position measurement system is discussed. This system is consisted with an assistant gauge, one set of machine vision system and a computer. Through the assistant gauge, 3D position measurement is transffered to 2D measurement. Thus, making full use of existing 2D image processing theory and method, accuracy and speed of measurement of 3D position measurement may be promoted effectively.
In this paper, a missed needle rollers inspecting device and a missed needle rollers recognizing algorithm, which are
based on mechanical vision technology, are introduced. The cores of this system are image acquisition devices and image
processing. The image acquisition system is composed of a CCD, lens, low angle light resource, image acquisition card,
and mechanical position. The image processing procedure includes conditioning module, image partition module, image
searching module and the number of needle rollers recognizing module. According to the results of dynamic and static
testing, a method synthesizing the static and dynamic image acquisition is selected. Meanwhile, the specific parameters
of image acquisition and steps of image processing are established. The machine vision technology is used to find the
missed needle rollers, the speed of inspecting is promoted, and an automatically, non-touched and online inspecting
system is realized.
In this paper, a fast 3D reconstruction method based on structured light for the raceway groove of bearings is presented. As to our method, digital parallel grating stripes distributed with sine density are projected onto the raceway groove by a DLP projector, and distorting of stripes is encountered on the raceway groove. Simultaneously, aided by three-step phase-shifting approach, three images covered by different stripes are obtained by a high-resolution CCD camera at the same local location of the raceway groove, thus a more accuracy local topography can be obtained. And the bearing is then rotated on a high precision computer-controlled rotational stage. Three images are also obtained at next preprogrammed location through the trigger of the motor. After one cycle, all images information is combined to get the 3D information in form of a full 360° raceway groove. According to the assemble simulation and running result, the bearing windage can be obtained, especially, the raceway of bearing balls centers can be calculated. Thus, most bearing running parameters can be got before being really assembled. The one of our goals is to simulate the state of bearings with more exacter prototyping during assembling and running. As a result, a simulation based on the obtained 3D topography of the raceway groove is discussed.
Proc. SPIE. 5757, Smart Structures and Materials 2005: Modeling, Signal Processing, and Control
KEYWORDS: Digital signal processing, Signal processing, Control systems, Telecommunications, Data communications, Computer architecture, Binary data, Data centers, Computer programming, Systems modeling
An idea about software PnP (Plug & Play) is put forward according to the hardware PnP. And base on this idea, a virtual flexible digital signal processing system (FVDSPS) is carried out. FVDSPS is composed of a main control center, many sub-function modules and other hardware I/O modules. Main control center sends out commands to sub-function modules, and manages running orders, parameters and results of sub-functions. The software kernel of FVDSPS is DSP (Digital Signal Processing) module, which communicates with the main control center through some protocols, accept commands or send requirements. The data sharing and exchanging between the main control center and the DSP modules are carried out and managed by the files system of the Windows Operation System through the effective communication. FVDSPS real orients objects, orients engineers and orients engineering problems. With FVDSPS, users can freely plug and play, and fast reconfigure a signal process system according to engineering problems without programming. What you see is what you get. Thus, an engineer can orient engineering problems directly, pay more attention to engineering problems, and promote the flexibility, reliability and veracity of testing system. Because FVDSPS orients TCP/IP protocol, through Internet, testing engineers, technology experts can be connected freely without space. Engineering problems can be resolved fast and effectively. FVDSPS can be used in many fields such as instruments and meter, fault diagnosis, device maintenance and quality control.