Applied Mechanics and Materials Vol. 577

Abstract: The blisk is an important component of aviation engine and its level of machining and measurement will directly affect the application properties of the engine. This paper investigates the on-line measurement of single blade of the blisk. The section lines and the points to be measured are determined by using the empirical formula based on B-spline theory and feature point extraction algorithm. The probe-blade interference problem is solved by dividing the measurement area into different sectors and the posture angle of the probe in different inference-free sector domain is determined. The CATIA simulation is conducted to validate the correctness of the path planning algorithm for measurement. The measuring path planning plays an important role in improving the efficiency and reducing the cost of measurement.

Abstract: In recent years, the use of submarine pipeline trajectory detection has become more and more widespread, and it not only can improve the efficiency of laying pipelines, but also can detect the state information of pipelines in time. However, most of it has the low detection efficiency and it can not have a good reaction of the specific state. In this paper, we design a detection system of submarine pipeline trajectory which is based on MEMS sensors and Kalman filter that is for date fusion. It can monitor and display the status of the pipeline to ensure the safety production and to avoid pipe damage and security risks.

Abstract: Aiming at the target detection technique is time-consuming, noise and other issues, improved the application of FSVM in target detection, a piecewise fuzzy membership function is proposed based on LDA algorithm. The algorithm projected the original high-dimensional samples onto a one-dimensional space by LDA ,the original sample’s fuzzy weights is segment calculated based on the distribution of the projection point, reduce the impact of noise and outliers on classification results. In the simulation experiments, this method can effectively reduce the impact of unbalanced data to FSVM, improve the classification accuracy.

Abstract: Aiming at indoor harmful gas pollution of residents, a real-time online monitoring system is designed based on the detecting and control of harmful gases. The lower computer system make the STM32F103 microcontroller as the core and make each module been designed which included the sensor temperature and humidity acquisition, gas concentrations acquisition, sensor interface circuits, signal amplification circuit, liquid crystal display circuit, alarm circuit and so on. The upper computer make the microcomputer as the monitoring center which make on-line display of temperature, humidity and gas concentration in real-time, then people can get the indoor harmful gas data for collection and management with the upper computer. CAN bus is adopted for information transfer between the master computer and the slave computer.

Abstract: Exoatmospheric IR detector is an effective means of space debris detection. In order to achieve the goal of an effective detection for low-orbit space debris, study the detection range for exoatmospheric IR detector. Studied the infrared detection technology, as well as the specific characteristics of the low-orbit space debris and other related aspects. First of all, introduce the method of detection process and determine the characteristic parameters of the space debris and infrared detectors. Then, calculate the space debris’ own infrared radiation energy and the background radiation energy. Then, by the infrared detector receives the photon number, refer to the engineering practice, the detecting range for exoatmospheric IR detector enhanced in evidence. The ground-based experiment demonstrates the calculation is preciseness and credibility. The space debris’ orbital height is 550KM and its size is 8m × 1.2m × 0.025m. Under such conditions, the detecting range for exoatmospheric IR detector is 48KM .This method can provide a certain referential significance for pace debris detection, imaging, and attacks.

Abstract: In this paper, a new method to realize online wear detection of micro-milling cutters based on length fractal dimension is proposed. On the basis of expression derivation of length fractal dimension, experiments are conducted. First, several cutters with different wear condition are chosen as reference samples. Their multi-section vibration signals in time-domain are collected and the clustering domain δ of each sample are obtained based on length fractal dimensions. Then, the vibration signals of tested cutters are monitored and analysed in time domain, thus their length fractal dimension are abstracted. Comparing the length fractal dimension of tested cutters with the clustering domain δ of reference samples, the wear condition of tested cutters are detected. The experimental results show that the length fractal dimension of each tested cutter falls in the clustering domain corresponding to the actual wear condition.

Abstract: The non-invasion electrical process tomography of plant tuber or root is a new research field in the accurate cultivation of plants. Tuber Electrical Resistance Tomography (TERT) is aimed to extend the application of the technology into agriculture, which can help improving and breeding new varieties of the crops. This paper mainly studies excitation & measurement strategy. Especially the influences on distribution of sensitive field brought by the width and numbers of the array electrodes in the soil environment are analyzed. Besides, the relationship between the electrical conductivity and the measured boundary voltages is also discussed.

Abstract: The fast non-destructive inspection of plant tubers or roots is a big problem in the plant accurate cultivation. With the characteristic of non-invasion, low cost, no radiation and visualization, the electrical resistance tomography technology is applied to the research of agriculture field; therefore it can be used in the tuber growth status monitoring, new varieties nurturing and fine cultivation of plants. The main research contents include: establish the sensitive model and simulate by using COMSOL software; the affects brought by different positions and sizes of one tuber are studied in detail and the research of effects of tuber number on electrical properties is carried out. The research has crucial guidance for the further study of the TERT technology.

Abstract: Due to the special conditions of the Arctic climate, ocean observation buoys long-term work in harsh environments, such as seawater corrosion, temperature, pressure and other factors to buoy a higher sealing requirements, ocean snorkeling standard sealing system status monitoring and fault diagnosis mechanism analysis using autoregressive-moving average ARMA model for pressure measurement error problem buoy mathematical modeling can be applied to solve the pressure seal failure buoy measurement problems caused errors.

Abstract: We have designed a high resolution and dule-path optical turbidimeter. The right angle scatted light turbidimeter is mainly for water in low turbidity levels, especially for drinking water. Mechanical design of the optoelectronic receiving room and the realizing circuit for modulation and demodulation are described in detail. To achieve good linearity in the measuring range from 0 to 5 NTU, pulse width modulation (PWM) and demodulation techniques are proposed, in this way, low temperature-drift and good anti-jamming ability can be obtained without the interference of background light. To improve the precision, the ratio algorithm which measures the ratio of the scattered light and reflected light is introduced in a dule-path optical system so that the interference of light emission can be eliminated effectively. Through the analysis and comparison of the experimental results, the linearity is improved by the ratio algorithm with a correlation coefficient for about 0.99932.