模块化和柔性化的机载数据记录系统设计

 目前一般的机载数据记录系统通道数量与存储容量固定,不能灵活适应被测对象数据通道数量、存储容量的变化. 针对机载数据记录系统被测对象要求多变的问题,采用模块化和柔性化的设计方法,构建一种以基板为中央逻辑控制的插槽式数据记录系统,实现接口与存储模块的灵活扩展,提高了记录系统的灵活性和通用性. 对数据记录系统的关键模块进行测试与分析. 通过多次现场试验,验证记录系统的可实现性和可靠性. 模块化和柔性化的设计方法具有较高的可行性,值得推广到车辆、船舶等数据记录领域.     

Laser Ultrasonic Nondestructive Testing Based on Nonlinear Ultrasonic Coefficient

Russian Journal of Nondestructive Testing - Laser ultrasonic nondestructive testing technology can effectively detect the location of cracks and other information, it is easy to realize the...     

Non-stationary power signal processing for pattern recognition using HS-transform

A new approach to time-frequency transform and pattern recognition of non-stationary power signals is presented in this paper. In the proposed work visual localization, detection and classification of non-stationary power signals are achieved using hyperbolic S-transform known as HS-transform and automatic pattern recognition is carried out using GA based Fuzzy C-means algorithm. Time-frequency analysis and feature extraction from the non-stationary power signals are done by HS-transform. Various non-stationary power signal waveforms are processed through HS-transform with hyperbolic window to generate time-frequency contours for extracting relevant features for pattern classification. The extracted features are clustered using Fuzzy C-means algorithm and finally the algorithm is optimized using genetic algorithm to refine the cluster centers. The average classification accuracy of the disturbances is 93.25% and 95.75% using Fuzzy C-means and genetic based Fuzzy C-means algorithm, respectively.     

罗氏线圈与隧道磁阻复合的电流测试方法

针对车载微电网中电流频率成分丰富和电磁环境复杂的环境特征,为了实现车载微电网电流测试的问题,利用隧道磁 阻传感器低频特性好和罗氏线圈中高频特性好的优点,研究了罗氏线圈与隧道磁阻复合的全封闭式电流测试方法。 采用 Ansoft Maxwell 对屏蔽壳体的屏蔽效能进行了仿真分析,利用罗氏线圈和隧道磁阻传感器进行工频测试实验,并以钳形电流探 头作为基准完成标定,将标定后的传感器及测试系统进行微电网储能并/ 离网过程中的尖峰脉冲电流测试实验,进行了数据复 合处理。 实验结果表明,复合后的电流测试信号与钳形电流探头测量信号一致性好,特别是尖峰处误差减小,复合后脉冲电流 峰值相对误差减少到 3. 67%。 罗氏线圈与隧道磁阻两种传感器数据复合的电流测试方法对于装备的电气化测试具有重要 意义。     

Adaptive restricted trajectory tracking for a non-minimum phase hypersonic vehicle model

The design of a nonlinear robust controller for a non-minimum phase model of an air-breathing hypersonic vehicle is presented in this work. When flight-path angle is selected as a regulated output and the elevator is the only control surface available for the pitch dynamics, longitudinal models of the rigid-body dynamics of air-breathing hypersonic vehicles exhibit unstable zero-dynamics that prevent the applicability of standard inversion methods for control design. The approach proposed in this paper uses a combination of small-gain arguments and adaptive control techniques for the design of a state-feedback controller that achieves asymptotic tracking of a family of velocity and flight-path angle reference trajectories belonging to a given class of vehicle maneuvers, in spite of model uncertainties. The method reposes upon a suitable redefinition of the internal dynamics of a control-oriented model of the vehicle dynamics, and uses a time-scale separation between the controlled variables to manage the peaking phenomenon occurring in the system. Simulation results on a full nonlinear vehicle model that includes structural flexibility illustrate the effectiveness of the methodology.