Research of dynamics of a gated balanced comparator

The results are presented of the research of the dynamics of a gated balanced comparator on tunnel diodes in the mode of sampling signal transformation. A tunnel diode has been used as a shaper of the gating voltage drop. The dynamic properties of the comparator are characterized by the step response time of the sampling converter built on this comparator. A modification of the comparator circuit is also investigated that extends the range of the allowed values of the resistance in the circuit of the clock signal. The model of the tunnel diodes takes into account the p-n junction capacitance, the spreading resistance, and the parasitic inductance of the diodes. The research was conducted using the SPICE simulation program. The simulation results are compared with the theoretical calculations.     

A biologically inspired spiking neural network for sound source lateralization.

In this paper, a binaural sound source lateralization spiking neural network (NN) will be presented which is inspired by most recent neurophysiological studies on the role of certain nuclei in the superior olivary complex (SOC) and the inferior colliculus (IC). The binaural sound source lateralization neural network (BiSoLaNN) is a spiking NN based on neural mechanisms, utilizing complex neural models, and attempting to simulate certain parts of nuclei of the auditory system in detail. The BiSoLaNN utilizes both excitatory and inhibitory ipsilateral and contralateral influences arrayed in only one delay line originating in the contralateral side to achieve a sharp azimuthal localization. It will be shown that the proposed model can be used both for purposes of understanding the mechanisms of an NN of the auditory system and for sound source lateralization tasks in technical applications, e.g., its use with the Darmstadt robotic head (DRH).     

Robot phonotaxis in the wild: a biologically inspired approach to outdoor sound localization

Cricket phonotaxis (sound localization behavior) was implemented on an autonomous outdoor robot platform inspired by cockroach locomotion. This required the integration of a novel robot morphology (Whegs) with a biologically based auditory processing circuit and neural control system, as well as interfacing this to a new tracking device and software architecture for running robot experiments. In repeated tests, the robot is shown to be capable of tracking towards a simulated male cricket song over natural terrain. Range fractionation and gain control were added to the auditory control circuit in order to deal with the substantial change in amplitude of the signal as the robot approached the outdoor sound stimulus. We also discuss issues related to acoustic interference from motor noise, the need for a motor feedback mechanism to better regulate the drive signal and plans for future work incorporating additional sensory systems on this platform.     

基于传声器阵列的声源定位算法与误差分析

基于传声器阵列和互相关算法的时间延迟技术对声源进行定位,互相关算法对宽频带信号（扫频信号）定位比较准确,对窄带信号（风琴信号）定位不显著,分析了影响声源定位精度的因素,并改进声源定位系统.通过实验验证了影响风琴信号声源定位的因素,实现了风琴信号的声源定位,并在NI CompactRIO系统上开发了一个实时声源定位系统.     

虚拟环境中的空间立体声显示

介绍了虚拟环境中面向扬声器的空间立体声生成和定位的研究现状、矢量基幅值相移算法，讨论了有关声音仿真的若干问题。针对某大型分布式虚拟战场环境，构造并实现了DIS/HLA体系结构下实时3维空间立体声系统，分析了该系统中空间扬声器阵列声音显示的若干问题。提出了声觉信息显示包围球的概念，进而提出了一种以虚拟观察者／听者为中心的包围球内声源目标快速检索算法，解决了分布交互仿真中感兴趣区域大量实体声源的实时显示问题，该方法用于实际系统，效果良好。     

Simple analog-digital motion detection circuit and its application to target tracking systems

We propose an analog-digital circuit for detecting the movement of an object. The proposed unit circuit is a simple structure since the digital part of the circuit is constructed with only one NOT circuit and one NOR circuit. The measured results on a constructed test circuit showed that the proposed circuit can output the pulsed voltage (motion signal) when an object moves on the circuit. We proposed and constructed the system in this study in order to track target. Since the array in the proposed circuits was introduced at the first stage of the system, the circuit for tracking the target became a simple structure. It was clear from the measured results of the test system that it can track and capture a target in the center of the input section.     

一种新型BUCK变换器控制电路的系统建模与分析

基于传统峰值电流模式的控制结构,提出了一种新型的峰值电流模式同步整流BUCK变换器的控制结构。在输出回路串入检测电阻形成电压采样电路,并将采样电压直接输入到PWM电流比较器,使得电路结构更加简单,反应速度更陕。文中利用经典控制理论方法对控制电路进行了系统建模与分析,并通过Matlab仿真验证了本方案的可行性。     

Selection of the Closest Sound Source for Robot Auditory Attention in Multi-source Scenarios

Robotic auditory attention mainly relies on sound source localization using a microphone array. Typically, the robot detects a sound source whenever it emits, estimates its direction, and then turns to that direction to pay attention. However, in scenarios where multiple sound sources emit simultaneously, the robot may have difficulty with selecting a single target source. This paper proposes a novel robot auditory attention system that is based on source distance perception (e.g., selection of the closest among localized sources). Microphone array consists of head- and base-arrays installed in the robot’s head and base, respectively. The difficulty in the attention among multiple sound sources is solved by estimating a binary mask for each source based on the azimuth localization of the head-array. For each individual source represented by a binary mask, elevations of head- and base-array are estimated and triangulated to obtain distance to the robot. Finally, the closest source is determined and its direction is used for controlling the robot. Experiment results clearly show the benefit of the proposed system, on real indoor recordings of two and three simultaneous sound sources, as well as real-time demonstration at a robot exhibition.     

层次分析法的电子音乐音质评估模型

为准确评估电子音乐音质,提出了基于层次分析法的电子音乐音质评估模型。首先将电子音乐音质评估作为目标层,将声源特性、信号特征、声场特性、听觉特性和立体感作为准则层,将十音质评估元素作为方案层,从而电子音乐音质评估指标体系结构,然后根据各层次间元素的从属关系或并列关系,构建电子音乐音质判断矩阵,通过判断矩阵的最大特征值归一化后特征向量分量,获取电子音乐音质评估指标体系各层元素的权重,最后采用电子音乐音质评估元素权重和专家评分,得到电子音乐音质评估结果。仿真测试结果表明,这种方法能获取各电子音乐音质评估元素对音质的影响权重,得到准确的电子音乐音质评估结果。     

基于盖革APD阵列的单通道激光雷达信号读出电路设计

随着测量技术的发展,激光雷达技术成为研究的热点,选取工作在盖革模式下的集成APD阵列雪崩二极管作为激光雷达的光电探测器,在探测距离为100-200m范围内,选择上升沿为5ns的激光脉冲,则接收带宽在70MHz~88MHz范围内,在此范围内APD探测器将接收到的回波信号转化为电信号,用TIA跨阻放大器反向放大模式将电流信号转化为电压信号,并将信号有效放大,输入至时刻鉴别电路,时刻鉴别电路用电压比较器来实现,最终可输出COMS逻辑电平信号;用TINA仿真软件进行仿真,仿真结果表明在接收带宽范围内TIA放大器的增益动态范围达到了54dB,总体电路延迟约为10ns。     

基于CPLD的相控声发射系统设计与实现

提出一种新的增强声源指向性的电路设计方法,设计了基于复杂可编程逻辑器件(CPLD)的相控声发射系统.该系统由滤波采样、信号延时、按键显示、D/A转换等电路组成,通过控制声波在空气中波阵面的耦合,实现声波的相控发射.试验表明,该系统能够较明显地增强声源指向性.     

基于机器人听觉的自主声源搜索策略

提出了融合机器人听觉和超声避障的自主声源搜索策略．搜索策略按优先级分成3个模块：声源确认、超声避障、声源定位搜索, 通过优先级的判断确定当前执行模块．声源定位基于改进的时延估计定位方法实现,机器人在搜索并接近声源过程中利用超声避障． 在室内环境下测试系统,实验结果证明在混响环境下机器人可以定位声源并且可以绕过障碍物接近并确认声源,该方法具有实时实现的有效性和应用性．     

基于平均分割阻容延时时间的短时间间隔测量方法

提出一种基于平均分割阻容延时时间的短时间间隔测量方法。先将被测时间间隔与基准信号之间的前后时间差信息存储在阻容延时电路,再利用比较器对其进行平均分割和比较,这样测量误差可以降低1~2个数量级。理论分析和实验测量数据表明,通过增加比较器数量,可以使测量误差大幅降低。该方法实现简单、成本较低,实用性较好。     

Using bat-modelled sonar as a navigational tool in virtual environments

Bats are able to use active sonar as a mechanism for locating object in three dimensions and for generating spatial maps of their environments. Humans use passive sound cues to detect features of the space they occupy, as well as react to the spatial location of objects which generate sound. The system described in this paper allows free-ranging humans to locate a virtual sound location using active sonar. An emitted pulse, centred on the users head, serves as an intensity and time marker. The return pulse is rendered at the virtual target location and emitted after a time delay corresponding to the two-way path from sender to target and back again. The sonar system is modelled on those of bats, using ultrasonic frequency-modulated signals reflected from simple targets. The model uses the reflectivity characteristics of ultrasound, but the frequency and temporal structure used are scaled, with the speed of sound being set to 8.5 ms⁻¹ to bring the frequency range and temporal resolution within the capabilities of the human auditory system. Orientation with respect to the ensonified target is achieved by time-of-flight time delays to give target range, and binaural location information derived from interaural timing differences, interaural intensity differences, and head-related transfer functions. Subjects performed significantly better at a localization task when given temporal data based on echo delays with an outgoing reference pulse than without a reference pulse. Frequency-modulated signals sweeping from 1.5 kHz–100 Hz over 500 ms provide the best localization cues, and users found them significantly easier to locate than continuous sounds.     

基于主动式静电探测技术的目标定位方法

针对被动式静电探测技术无法对不带电目标进行探测的问题,提出了一种基于主动式静电探测技术的目标定位方法。在对带电和不带电目标分析的基础上,得到了相应的通过检测电流实现目标定位的探测方程,并在Maxwell 3D中进行了仿真。仿真结果表明:基于该方法的探测距离与目标的带电量、主动静电场的强弱以及电流检测电路的灵敏度有关。     

A model of co-saliency based audio attention

Inspired by biological perceptual characteristics in human auditory systems and the mechanisms of saliency detection, we study the relevance constraint between time-frequency characteristics of sound signals and the multiple spectrogram and propose a co-saliency detection method for multiple sound signals in this paper. Then, according to the auditory characteristics of the human ear, the distinctive saliency features from the acoustic channel and the image channel are fused. Finally, an auditory saliency map is obtained to complete the detection of significant sounds. The saliency features of the acoustic channel include the features calculated in the in the temporal and spectral domains of signal, which the temporal saliency features could be represented by the local maximum points in the Power Spectral Density (PSD) curve, and the spectral features could be represented by local maximum points in Mel Frequency Cepstrum Coefficient (MFCC) curve of sound signal. The saliency features of acoustic channel and cross-scale fusion with the contrast cue of spectrogram, whose result is more in line with the human auditory attention mechanism. Finally, combined with the corresponding cue which could reflect the distribution between multiple spectrograms, it could reflect the characteristics of global repeatability, and reflect high frequency of occurrence. Experimentally, the auditory Co-Saliency map verifies the accuracy and robustness of proposed method in this paper. It shows that the proposed method is superior to other traditional detection methods for auditory saliency, and can implement intelligent automatic detection to sound signals.

     

多阈值神经元电路设计及在多值逻辑中的应用

分析了多阈值神经元工作原理,并提出设计多阈值神经元电路的方法．首先,用两个MOS晶体管组成电压型突触电路,然后又提出一种基于BiCMOS工艺的判别转换开关电路,这种电路以压控电流作为阈值信号,并实现电压到电流的转换．在此基础上,结合限幅电压开关理论提出多阈值神经元阈值判别函数电路的开关级设计方法．最后,从开关级设计了实现三值逻辑中文字、与、或三种基本运算的多阈值神经元电路,用这三种基本运算的多阈值神经元电路可实现任意三值函数的多阈值神经网络．文章还对设计出的电路用PSPICE进行模拟,测量相关参数．模拟结果表明,该文设计的电路不仅实现了正确的逻辑功能,而且速度较快。     

针对头佩式麦克风阵列的声源定位算法研究

头佩式麦克风阵列在单兵便携反狙击声探测定位系统和机器人声定位系统中具有实际的应用价值。一般的声源定位方法是基于无遮挡的线性或非线性麦克风阵列。采用头佩式麦克风阵列,考虑到背向声源麦克风的低频声波由于头盔遮挡而发生的衍射作用,针对低频波段的声音信号进行定位算法的设计和研究。该算法利用低频声波的绕射路径计算时延,采用联合可控功率响应（SRP-PHAT）框架进行时延补偿搜索定位。实验表明,相比于普通的无遮挡定位算法,基于绕射路径的头佩式麦克风阵列定位方法通过综合利用背向声源的麦克风数据,明显地提高了定位的精度,这种精度的提升在选择1 kHz以内的信号频率窗口时达到最佳效果。     

一种鲁棒的双耳声源方位角定位方法

在噪声和混响的声学环境中,基于双耳时间差的声源方位角定位性能会严重降低。针对这个问题,提出了一种基于子带选择和DBSCAN的双耳声源定位算法,首先,采用 Gammatone 滤波器将双耳声源信号分解为若干个子带信号;其次,根据子带能量大小进行子带通道数压缩;然后,根据子带信噪比大小获取最优子带,降低无关子带干扰;接着将子带信号进行分帧,根据互相关算法获取峰值处的数据点;最后,引入DBSCAN算法消除噪声点的影响,获取最优数据点,从而根据ITD定位模型判断目标声源方位角,实验结果表明,该算法在复杂的声学环境中,相较于传统的互相关算法,可显著提高双耳声源方位角定位性能。     

Threshold‐voltage‐compensation methods for AMOLED pixel and analog buffer circuits

Abstract— New pixel‐circuit designs for active‐matrix organic light‐emitting diodes (AMOLEDs) and a new analog buffer circuit for the integrated data‐driver circuit of active‐matrix liquid‐crystal displays (AMLCDs) and AMOLEDs, based on low‐temperature polycrystalline‐silicon thin‐film transistors (LTPS‐TFTs), were proposed and verified by SPICE simulation and measured results. Threshold‐voltage‐compensation pixel circuits consisting of LTPS‐TFTs, an additional control signal line, and a storage capacitor were used to enhance display‐image uniformity. A diode‐connected concept is used to calibrate the threshold‐voltage variation of the driving TFT in an AMOLED pixel circuit. An active load is added and a calibration operation is applied to study the influences on the analog buffer circuit. The proposed circuits are shown to be capable of minimizing the variation from the device characteristics through the simulation and measured results.