成像声呐中聚焦波束形成技术研究及实现

介绍了聚焦波束形成的基本原理,分析了一种基于半圆阵的相位补偿方法。通过Matlab仿真得出聚焦波束形成的波束图,相比远场方法,波束宽度减小,旁瓣得到抑制。设计了一种基于FPGA的数字聚焦波束形成器的实时处理结构,使用8组加权系数即可完成成像声呐近场范围内分辨力的改进。通过乒乓操作和并行结构提高处理速度,实时产生72个波束。实验结果表明,所设计的聚焦波束形成器使某型成像声呐近场分辨力得到了提高。     

Signal processor implementation of variable digital filters

The implementation of two recently introduced variable digital filter schemes using a TMS320-series digital signal processor is presented. One is a method for updating the coefficients of an FIR (finite-impulse response) filter in a simple manner such that the cutoff frequencies can be controlled through a single parameter. The other is a method for tuning the cutoff frequency of an IIR (infinite-impulse response) filter with one parameter using a series expansion of the low-pass-low-pass frequency transformation. The measured frequency responses compare well with the theory     

基于PLC的水听器回转扫描控制系统的设计及实现

基于PLC的网络控制系统因其良好的性能已经得到了广泛应用.为了实现控制系统远程操作的要求,采用网络控制和PLC相结合的方式,设计和实现了具有网络控制功能的水听器回转扫描控制系统,并详述了其系统组成及软件设计流程．     

Optoelectronic parallel watershed implementation for segmentation of magnetic resonance brain images

An optoelectronic implementation for the morphological watershed transform is proposed. Fiber-optic programmable logic arrays are used in the implementation because of their high fan factors at high clock speeds. Image segmentation is one of the main applications of the watershed transform. Based on the optoelectronic implementation, an algorithm for the segmentation of axial magnetic resonance (MR) head images to extract information on brain matter is presented. Simulation results for the different steps of the segmentation process are presented.     

White-light implementation of the Wigner-distribution function with an achromatic processor

A temporally incoherent optical processor that combines diffractive and refractive components is proposed for performing two different operations simultaneously: an achromatic image along an axis and an achromatic one-dimensional Fourier transformation along the orthogonal axis. These properties are properly employed to achieve the achromatic white-light display of the Wigner-distribution function associated with a one-dimensional real signal, with high redundancy and variable scale.     

Optoelectronic implementation of real-time control of an inverted pendulum by fuzzy-logic-control units based on a light-emitting-diode array and a position-sensing device

We have realized a novel optoelectronic implementation of an analog fuzzy-inference architecture, using the movement of the center of gravity of a far-field pattern. In the inference process Gaussianlike membership functions and a product-sum-gravity method are used. Antecedent membership functions and the grade evaluations are realized by combining light-emitting-diode (LED) arrays for sequential light emission and position-sensing devices for center-of-gravity detection. Consequent and defuzzification operations are realized by a LED array and a position-sensing device. High-speed fuzzy inference of more than several tens of mega fuzzy logical inference per second is possible with these units. The usefulness of the system is demonstrated by the real-time standing control of an inverted pendulum.     

Optical design of a 1024-channel free-space sorting demonstrator

We describe the optical design of a free-space interconnect system to be used for a 32 x 32 sorting system. The system uses 4f imaging relays to connect two hybrid optoelectronic-complementary metal-oxide semiconductor chips. These relays are used to implement a perfect-shuffle interconnect necessary for the sorting algorithm to be implemented. The relay lenses are also used with patterned mirrors and polarizing elements to combine read beams necessary for the optoelectronic chips. Issues relating to the basic system design and the detailed design of the lenses and optomechanics are given.     

12路并行光互连子系统研究

针对高速芯片间光互连的应用,利用垂直腔面发射激光器(VCSEL)列阵作为光源、PIN列阵作为探测器,采用并行光传输的方式,设计了高密度的12路高速信号的光互连子系统,并利用12芯标准多模光纤带进行了1m距离内的光传输试验测试.测试结果表明,在零误码率的条件下系统单路速率大于6Gb/s,接收端信号的上升时间(F1)为91...     

Optoelectronic approach to adaptive radio-frequency transversal filter implementation with negative coefficients by using optical spectrum shaping

A multitap negative and positive coefficient radio-frequency transversal filter is implemented by using a digital-micromirror-device spatial light modulator for weighting-factor control and a chirped fiber Bragg grating for time-delay control. The demonstrated architecture is reconfigurable, has high speed and low loss, and is robust through digital programmability for a wide variety of filtering algorithms. A design using an interleaver for differential detection realizes an ultrahigh bandwidth with a maximum processable frequency of 33.7 GHz. A multitap low-pass filter, a negative tap notch filter with 40 dB attenuation, and a multitap negative coefficient bandpass filter are experimentally demonstrated. The results are in agreement with theory.     

Electronic processor for a laser velocimeter

Translated from Izmeritel'naya Tekhnika, No. 7, pp. 38–39, July, 1989.     

Dynamic control of the batch processor in a serial-batch processor system with mean tardiness performance

Effective control of batch processors is very essential to improve on-time delivery of wafers in semiconductor manufacturing. In this paper, the focus is on mean tardiness performance of a batch processor in a two-stage processor system by including an upstream serial processor. Two new control strategies are proposed for this problem. The first strategy effectively incorporates the product information at the upstream serial station in batching decisions. The second strategy further applies a re-sequencing approach in the serial processor's queue when there is a benefit in shortening the arrival time of an urgent product. Discrete event simulation is used to test the performance of the strategies. Results are very promising as compared to benchmark control strategies.     

一种分时工作的双路声呐发射机研制

针对自容式波浪声学多普勒流速剖面仪(AcousticDopplerCurrentProfilers,ADCP)所需声呐发射机的设计要求,设计并实现了一种分时工作的双路声呐发射机。从工程实际需求出发,结合功率电路的理论、工作经验和设计方法,提出一种全新的分时工作的双路声呐发射机的设计方案,制作出样机,并进行了水池试验。实验结果表明,该分时工作的双路声呐发射机,所选择的发射机通道能准确地输出相应的发射电压,满足自容式波浪ADCP的需求。