Applied Mechanics and Materials Vol. 577

Abstract: A switched reluctance motor drive (SRD) is designed in this paper. This system has the characteristics of simple structure and reliable performance. It is designed based on 3 phase, 12/8 pole, 2.2 KW switched reluctance motor (SRM). The TMS320LF2407A is chosen as the core controller. The type of half bridge is adopted in the main power converter circuit, and IGBT is used as the main power switching component and discrete components is used as the main power switch converter device driver circuit. Experimental results show that the designed system can be run steadily under rated load conditions. Moreover, the speed regulation of this system has satisfactory performance.

Abstract: A new powertrain system was developed for electric vehicle driving application with adoption of one electric motor and one set of planetary gear set. With the control of fork, the sleeve of synchronizer can mesh two different parts on the left and right side; the system can provide pure electric driving, hybrid driving and regenerative braking operation modes to meet vehicle practical conditions. It can reduce both power train structure size and cost with fewer parts.

Abstract: In order to improve the performance of the existing On-The-Move system, this paper studied a kind of step tracking technology based on the traditional algorithm. For the contradictions between the capture speed and precision performance on the initial acquisition, re-acquisition and auto tracking and controlling algorithm, this technology improved the initial acquisition stage. In the initial acquisition stage, the beacon AGC is distinguished. When the beacon AGC is below the specific threshold, there is a uniform rotation in the azimuth direction. When the AGC is above the threshold, the system turns to the step tracking stage based on variable step algorithm. Research showed that this technology has faster acquisition speed and higher tracking accuracy, maintains low computational complexity, and improves the system performance.

Abstract: The key part of the deep sea product system has high demand for the detecting system. The paper makes deep research in extracting the detection feature information of the facilities, path planning, data processing. Improve the detecting efficiency and the detecting precision.

Abstract: According to the communication principle of 840D numerical control (NC) system and internal data structure, the PLC program is developed to make 840D system state data transmit to the PC with the MPI channels; production status data real-time monitoring system based on 840D NC machine tools is developed, meanwhile, the monitoring and data management for NC machine tool production process status is realized.

Abstract: ECM aiming at fire control radar is an effective method for improving ship-to-ship missile penetration capability. Based on the analysis of Doppler fire control radar working principle, Doppler fire control radar countermeasures strategy is brought up. The repeater jamming technology applied to the ship-to-ship missile, aiming at Doppler fire control radar, and its application conditions are lucubrated. The research has positive significance to the weapon equipment development and operational application.

Abstract: Electric power steering (EPS) uses an electric motor to assist the driver when he or she is driving, and the amount of assistance to be applied depends on steering wheel torque and driving conditions. So steering wheel torque is one of the most important signals which keep the EPS system working properly, and a steering wheel torque fault could be a disaster for whole vehicle security. The aim of this paper is to design a calibration and evaluation system of torque signal, which is utilized for function detection of steering wheel torque module in EPS systems. Firstly, the detection procedure is proposed according to detection requirement; Then hardware structure and software design of the detection system are introduced. Finally, an EMC (Electromagnetic Compatibility) problem is analyzed and a solution for the EMC problem is proposed to make the detection system working properly.

Abstract: The solar direction is an important clue for satellite autonomous navigation. A new method for obtaining the solar direction from skylight polarization for satellite navigation is discussed. The new method is using two E-vector polarization sensors to get solar direction, and the view field of the polarization sensor is discussed.

Abstract: A fault diagnosis approach of hydraulic system based on Hybrid Particle Swarm Optimization (HPSO) algorithm and Wavelet Packet Energy Entropy (WP-EE) is presented. A heuristic algorithm is adopted to give a transition from particle swarm search to gradient descending search. A HPSO algorithm is formed with the heuristic algorithm, which is used to optimize BP neural network weights and threshold. Then an application of fault diagnosis with HPSO and WP-EE based on a valve-controlled hydraulic motor system is presented. After wavelet packet decomposition of the acquired hydraulic pressure signal, the WP-EE is extracted; the eigenvector of wavelet packet is constructed. Taking this eigenvector as fault sample, the neural network based on HPSO algorithm is trained to implement the fault diagnosis for the hydraulic system. The test result shows that the fault recognition accuracy and the efficiency in the hydraulic system are improved by this method.

Abstract: Because of the microgravity environment of the space and mobility restriction by pressurized spacesuit, astronaut extravehicular operation is quite different from that in the ground. For ensuring high reliability of extravehicular operations, the astronauts need to do a great deal of training in simulated environments. A 3-dof of micro-gravity operation training system is designed in the paper, and the kinematics and dynamics of the interaction between the space station system and spacesuit system were simulated. Pressure and flow velocity distributions in the air orifice and air cavity were calculated by FLUENT. Experiments on the bearing capacity characteristic were carried out. The carrying capacities of the air bearing in different air pressures were achieved. Experiments validated the simulation analysis. The research provides the basis for the development of multi-degree of freedom space microgravity ground simulation technology, provides a basis for further development and application of flotation technology as well.