Advanced Materials Research Vols. 765-767

Abstract: Based on the vehicle-track coupled dynamic theory, a new method was developed to monitor the state of heavy-haul train, this method can dynamically monitor the wheel/rail dynamic safety performance of heavy-haul train in the dangerous operation condition. The results show that: wheel/rail dynamic action is obvious whether the wheel flat is new or old, and wheel flat could lead to mutational vertical force.

Abstract: This paper introduces the principle of capacitive detection and specific method of signal detecting based on a triaxial micro-accelerometer. The corresponding detecting circuit is designed, and a suitable test system is set up. The sensitivity and accuracy test results of the triaxial micro-accelerometer show that all the masses sensitivity has nice consistency, the micro-accelerometer is feasible in theory and practice, and with the capability of precisely measuring the input acceleration in three directions.

Abstract: Nuclear Magnetic Resonance (NMR) can provide information about pore and fracture structures, porosity and permeability of reservoirs. It can deep into materials without destroying samples, with advantages such as rapid, accurate and high resolution. This paper introduced the experimental principles and carried out a series of NMR experiments based on high rank coal and low rank coal samples. Results show that: the T₂ spectra of high rank coal samples have an independent trimodal distribution with the main peak located at the low T₂ value section, indicating that high rank coal is dominated by micropores and transition pores; while the T₂ spectrum of low rank coal samples show a continuous trimodal distribution with the main peak located at the high T₂ value section, demonstrating the dominance of macropores, mesopores and fractures. The pore and fracture structures of low rank coals are significantly favorable than those of high rank coals.

Abstract: To accurately monitoring the subsidence of similar material simulation test in coal mining, a static deformation measurement system is proposed based on the digital image processing and photogrammetry techniques. Firstly pastes reference points and observation points on model frame and working face respectively. Before exploitation, calculates the 3D coordinates of those artificial points, transfers the default coordinate system to user defined coordinate system using 3-2-1 transformation method, and defines this stage as basic stage. Then start mining, records enough images from different position and angle, and calculates the 3D coordinates of the deformation stage. Finally aligns the single deformation stage to the basic stage, by tracking and comparing the 3D coordinates of the homonymous points, the subsidence of observation points are obtained. One similar material simulation tests were conducted which prove good performance of the proposed measurement system.

Abstract: As the only power source of electric vehicles (EVs), power battery pack is also the main fault source in EVs. The faults of power battery affect its performence and life, and even endanger vehicle security in extremly situation. Early fault diagnosis of power batteries can reduce losses, minimize maintenance, guarantee vehicle performence, security and realibility. In this study, the faults of power batteries are summarized, four fault diagnosis methods are concluded and analyzed, and the applicability of each method is compared and discussed. The principle of choosing the diagnosis method is that choosing according to the diagnostic condition.

Abstract: The paper starts from from the rotor unbalance fault, and analyze the reasons of unbalanced rotor are improper design, material defects, process and assemble error, process problem; Summarizes the frequency spectrum characteristics of rotor unbalance, its features, frequency components of speed have protruding peak on spectrum diagram of detection in radial direction;Puts forward the diagnosis methods of Unbalanced vibration, the first step is to analyze vibration signal frequency components, then analyze its characteristics of vibration in the direction of the change of amplitude and phase. Proved by examples, this paper summarizes the rotor unbalance analysis and diagnosis method is simple and practical, and has reference significance for other vibration problem.

Abstract: The development of industrial automation has urged the vibratory feeding system to become an efficient automation equipment. With vibration as the operating mode of the vibratory transmission system, the moving mass has a crucial impact on transmission rate and efficiency of the material. Therefore, it is necessary to carry out real-time vibration measurement of the vibratory feeding system and get feedback to the control system, so that the vibratory feeding system works more efficiently. The paper provides two vibration measuring techniques which separately uses the displacement sensor and the acceleration sensor. Through comparing the two methods, it provides a strong basis for choosing better measuring technique for vibratory feeding system.

Abstract: The research of vehicle dynamics performance on the flat road has been more perfect at present. Around the world ,for lack of simulation environment, the analysis of vehicle driving and handling performance on non-level road is on an explorative stage. The paper established tire road detection model by using of open source code OPCODE. The ray given off from the wheel center intersects with the road model, and obtains the precise contact point and the road normal vector. Then wrote computer program based on the established detection model and embedded it into the complex vehicle model to simulate on longitudinal and lateral slope road. The simulation results show that: each detection time reach microsecond level and in the 1ms vehicle dynamics calculation step, road detection model meet the real-time simulation, and also the detection accuracy satisfy the requirements of the whole vehicle simulation.

Abstract: In order to meet the development of shock absorber on-line detection, a new method of indicator diagrams recognition for shock absorber based on support vector machine (SVM) is proposed. Different fault patterns of shock absorber indicator diagram are discussed, including their main causes. The recognition model is constructed each with Linear, Polynomial and Radial Basis Function (RBF) kernel function. The experimental results show that the best average recognition rate is 96.4%. This method is effective in indicator diagram fault recognition of shock absorber.

Abstract: A visual tracking system based on ultrasonic motors is designed in view of shortcoming of traditional video surveillance system, which has a large volume, complicated structure. The pan-tilt can rotate in horizontal and vertical directions by using two ultrasonic motors served as the driving units. The image from video camera is processed and the target is identified and real-time tracked by rotating the pan-tilt which is controlled by ultrasonic motor. Compared with electromagnetic motor, the ultrasonic motor has advantages of high torque at low speed, quick response, high precision and self-locked, which makes the structure simpler and control more convenient. Experimental results show that the system can be stably tracking the selected target with fast response speed and relatively high tracking accuracy.