Applied Mechanics and Materials Vols. 701-702

Abstract: The measurement system adopts linear CCD as photographic element. Through the optical amplification system, the images of oil-water and oil-air interfaces were clearly imaged onto CCD chip. CCD transforms optical signals into electronically signals, and then submits data to PC through USB channel. After Savitzky-Golay smoothing on light intensity data, the software analyzes the data and calculate out the positions of oil-water-air interfaces. By calculating the difference between two positions, the oil layer thickness is gotten. The experiment results that the measurement system given in this paper is reasonable, stable, effective and accurate. This measurement system has wide application in the physical and chemical industry field.

Abstract: The paper presents a synergistic approach for height tracking within a blast furnace (BF). The Frequency Modulated Continuous Wave (FMCW) radar has been employed to measure the height and surface profile of the burden surface. However the radar signal is easily disturbed, by the radar anomalies, during the process of continuous measurement. The data from rotating chute and charging switch provide information on contextual relevance with radar anomalies. An anomaly detection models has been developed to increase the measurement accuracy by utilizing contextual information. The approach has been validated on real BF. The root mean squared (RMS) error in the measured height is reduced by 17% when using the proposed approach compared to the case without it. The results suggest that the proposed approach successfully adapts to changes in the pattern and characteristics of the burden surface.

Abstract: The design introduced in the ARM9 Linux embedded system using USB camera for remote video surveillance. Using TCP / IP protocol as a transport medium and routers connected via video stream ordinary unshielded twisted pair, combined with peanut shell DDNS (Dynamic Domain Name System) using remote video surveillance, improve usability and adaptability of the system.

Abstract: For the linear discrete time multisensor system with uncertain model parameters and measurement noise variances, the centralized fusion robust steady-state Kalman filter is presented by a new approach of compensating the parameter uncertainties by a fictitious noise. Based on the Lyapunov equation, it is proved that for given fictitious noise variance, the variances of the actual filtering errors have a less-conservative upper bound when the uncertainty of parameters is limited in a sufficiently small region which is called as robust region of the parameter uncertainties. Further, a simulation example demonstrates how to search the robust region. It is also proved that the robust accuracy of the centralized fusion robust steady-state Kalman filter is higher than that of each local robust Kalman filter. A simulation example shows its effectiveness.

Abstract: For the multisensor time-invariant system with uncertainties of both the noise variances and parameters, by introducing a fictitious white noise to compensate the uncertain parameters, the uncertain system can be converted into the conservative system with known parameters and uncertain noise variances. Using the minimax robust estimation principle, and the Lyapunov equation approach, a robust weighted measurement fusion Kalman predictor is presented based on the worst-case conservative system with the conservative upper bounds of noise variances. A Monte-Carlo simulation example shows its effectiveness.

Abstract: Aim to quantificational evaluation of capability of countering oppressive active jamming for Sky-wave Over-The-Horizon Radar (SWOTHR), main oppressive jamming types for SWOTHR and measures of countering oppressive jamming of SWOTHR are analyzed minutely. Based on idea of power countermeasure, evaluation index of detection probability loss is put forward. Based on signal-to-interference ratio equation including the main measures of anti-jamming, simulation models of detection probability loss are established. Simulation results show that SWOTHR has strong capability of countering oppressive active jamming and capability of countering main lobe interference stronger than side lobe interference. And simulation results also confirm feasibility and validity of evaluation index and models.

Abstract: Density three dimensional plant canopy structure data has numerous applications in agriculture, but many existing 3D data collection approaches are time-consuming. In this paper, we present a measurement system based on structured-light for plant canopy structure data collection. The structured-light projector projects laser beam reflected by dual-oscillating mirror, arrives to the plant canopy, which is captured by a camera. We propose a new scanning mode, that is, during one exposure time of CCD camera, one mirror keeps moving in high frequency and small angle, while the other one maintains the same position, so that we can get a laser stripe rather than a spot in each image, from which about 100 sub-pixel centers of laser stripe can be extracted. Experiments show that the measurement system can rapid collect three dimensional information of the plant.

Abstract: Tooth pitting in gears is one of the most critical fault modes in gearboxes, and monitoring the increase of tooth pitting damage can avoid great risk to gearboxes. The optimal selection of monitoring parameters in gearboxes can reduce the monitoring cost and improve the reliability on the basis of meeting monitoring requirements. To better track the increase of pitting damage, monitoring parameters should include abundant information of pitting growth in its evolution process. Hence, this paper proposes a novel approach to select optimal monitoring parameters based on fault trend analysis of pitting growth. With the analytical formulations of tooth pitting, the dependencies between damage levels of tooth pitting and the reduction of mesh stiffness can be obtained, then the damage dynamics of the gearbox system due to tooth pitting can be built. Afterwards, the dynamic responses of generalized parameters in the models of pitting levels can be simulated, and their condition indicators can be obtained by using effective signal processing methods. Then, the sensitivities of each generalized parameter to tooth damage can be calculated, and the optimal monitoring parameters can be determined according to the size of sensitivities. The simulation results show that monitoring the acceleration of gear and calculating its kurtosis can effectively track tooth pitting growth.

Abstract: This paper describes an automatic line detection system which is based on mechanical vision technology to detect the defects of the nitrile gloves’ surface, and mainly discusses the extraction methods and the recognition algorithms about the gloves image features. Finally, the last part gives the methods to design an easy-operation, friendly-interface, full-functions interface software system. The automatic line detection system about nitrile gloves surface defects not only lets the gloves detection line to be automated, but also improves the production efficiency and the quality of the products.

Abstract: This paper proposed a welding quality detection method with the computer vision technology for PCB of IC chip. This method is better than the normal one by human examines in the precision and in speed. It is suitable for welding quality automatic detection in the printing process of the SMT solder paste for IC chips mount on PCB board. This method is implemented in lab. Theoretical analysis and experimental results show that the accuracy of this method is high; the capture error is small and is easy to operate.