Non-Synchronous Deformation Effect of Particle in Sheet Metal Forming Process

A new concept referred to the non-synchronous deformation effect of particle in sheet metal forming is proposed. The results of finite element analysis show that the flow resistance of sheet metal can be effectively reduced and thus the forming property can be greatly improved if the moving and deformation state of the neighboring elements with equal perpendicular distance to the entrance contour of die is non-synchronous. Experiment tests are presented and the results agree well with FEA simulation. In addition, the mechanism of the non-synchronous effect is analyzed in detail.

Phase synchronization processing method for alternating bistatic mode in distributed SAR

In the distributed synthetic aperture radar （SAR）, the alternating bistatic mode can perform phase reference without a synchronization link between two satellites compared with the pulsed alternate synchronization method. The key of the phase synchronization processing is to extract the oscillator phase differences from the bistatic echoes. A signal model of phase synchronization in the alternating bistatic mode is presented. The phase synchronization processing method is then studied. To reduce the phase errors introduced by SAR imaging, a sub-aperture processing method is proposed. To generalize the sub-aperture processing method, an echo-domain processing method using correlation of bistatic echoes is proposed. Finally, the residual phase errors of the both proposed processing methods are analyzed. Simulation experiments validate the proposed phase synchronization processing method and its phase error analysis results.

A master-slave generalized predictive synchronization control for preheating process of multi-cavity hot runner system

As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the leading cause.Hence,the solution may rest with the synchronization of those heating processes in MCHR system.This paper proposes a’Master-Slave’generalized predictive synchronization control(MS-GPSC)method with’Mr.Slowest’strategy for preheating stage of MCHR system.The core of the proposed method is choosing the heating process with slowest dynamics as the’Master’to track the setpoint,while the other heating processes are treated as‘Slaves’tracking the output of’Master’.This proposed method is shown to have the good ability of temperature synchronization.The corresponding analysis is conducted on parameters tuning and stability,simulations and experiments show the strategy is effective.

A Fault Feature Extraction Model in Synchronous Generator under Stator Inter-Turn Short Circuit Based on ACMD and DEO3S

This paper proposed a new diagnosis model for the stator inter-turn short circuit fault in synchronous generators.Different from the past methods focused on the current or voltage signals to diagnose the electrical fault,the sta-tor vibration signal analysis based on ACMD(adaptive chirp mode decomposition)and DEO3S(demodulation energy operator of symmetrical differencing)was adopted to extract the fault feature.Firstly,FT(Fourier trans-form)is applied to the vibration signal to obtain the instantaneous frequency,and PE(permutation entropy)is calculated to select the proper weighting coefficients.Then,the signal is decomposed by ACMD,with the instan-taneous frequency and weighting coefficient acquired in the former step to obtain the optimal mode.Finally,DEO3S is operated to get the envelope spectrum which is able to strengthen the characteristic frequencies of the stator inter-turn short circuit fault.The study on the simulating signal and the real experiment data indicates the effectiveness of the proposed method for the stator inter-turn short circuit fault in synchronous generators.In addition,the comparison with other methods shows the superiority of the proposed model.

Collaborative Simulation Method with Spatiotemporal Synchronization Process Control

When designing a complex mechatronics system, such as high speed trains, it is relatively difficult to effectively simulate the entire system＇s dynamic behaviors because it involves multi-disciplinary subsystems. Currently, a most practical approach for multi-disciplinary simulation is interface based coupling simulation method, but it faces a twofold challenge： spatial and time unsynchronizations among multi-directional coupling simulation of subsystems. A new collaborative simulation method with spatiotemporal synchronization process control is proposed for coupling simulating a given complex mechatronics system across multiple subsystems on different platforms. The method consists of 1） a coupler-based coupling mechanisms to define the interfacing and interaction mechanisms among subsystems, and 2） a simulation process control algorithm to realize the coupling simulation in a spatiotemporal synchronized manner. The test results from a case study show that the proposed method 1） can certainly be used to simulate the sub-systems interactions under different simulation conditions in an engineering system, and 2） effectively supports multi-directional coupling simulation among multi-disciplinary subsystems. This method has been successfully applied in China high speed train design and development processes, demonstrating that it can be applied in a wide range of engineering systems design and simulation with improved efficiency and effectiveness.

Pressurized Synchronous Extraction of Volatile Oils, Total Flavonoids and Tannic Acid from Artemisia argyi

[Objectives] This study aimed to optimize the conditions for pressurized synchronous extraction of volatile oils, total flavonoids and tannic acid from Artemisia argyi .[Methods] Single factor experiments and orthogonal experiments were conducted.[Results] Pressurization had a significant effect on the extraction rate of chemical constituents of A. argyi . The optimal conditions for pressurized synchronous extraction of volatile oils, total flavonoids and tannic acid from A. argyi were as follows: solvent concentration of 70%, solid to liquid ratio of 1∶ 30 (g/mL), extraction pressure of 0.9 MPa, extraction time of 40 min and extraction temperature of 90 ℃. Under the optimal extraction conditions, the yields of volatile oils, total flavonoids and tannic acid were 0.852%, 4.66% and 6.79%, respectively.[Conclusions] Compared with other extraction methods, the pressurized assistant solvent extraction method can achieve the synchronous extraction of volatile oils, total flavonoids and tannic acid from A. argyi . The process is stable, short in extraction time, high in solvent utilization rate and ideal in extraction effect of the three components from A. argyi .

Applicability of Phase Synchronization Clustering to Detect the Process of Climate Events

Phase synchronization clustering method is used to detect the process of extreme weather events rather than extreme values events mathematically. The applicability is discussed from the aspects of noise intensity and sequence length and the observed data are applied practically. The detection process shows that clustering measure difference can detect the temporal process objectively to a certain degree and it has certain application to detect the temporal process of extreme weather events.

RL and AHP-Based Multi-Timescale Multi-Clock Source Time Synchronization for Distribution Power Internet of Things

Time synchronization(TS)is crucial for ensuring the secure and reliable functioning of the distribution power Internet of Things(IoT).Multi-clock source time synchronization(MTS)has significant advantages of high reliability and accuracy but still faces challenges such as optimization of the multi-clock source selection and the clock source weight calculation at different timescales,and the coupling of synchronization latency jitter and pulse phase difference.In this paper,the multi-timescale MTS model is conducted,and the reinforcement learning(RL)and analytic hierarchy process(AHP)-based multi-timescale MTS algorithm is designed to improve the weighted summation of synchronization latency jitter standard deviation and average pulse phase difference.Specifically,the multi-clock source selection is optimized based on Softmax in the large timescale,and the clock source weight calculation is optimized based on lower confidence bound-assisted AHP in the small timescale.Simulation shows that the proposed algorithm can effectively reduce time synchronization delay standard deviation and average pulse phase difference.

苦荞和燕麦同步熟化工艺及抗氧化活性研究

为提高苦荞的利用率,改善苦荞的口感,该试验以苦荞和燕麦为原料,采用微波熟化工艺进行同步熟化研究,运用响应面分析法探讨苦荞与燕麦同步熟化物料比例、微波时间、微波功率3个因素对总黄酮含量的影响,优化苦荞与燕麦同步熟化工艺。结果表明,最优熟化工艺条件为物料比例1∶1、微波时间3.5 min、微波功率700 W,在此条件下苦荞与燕麦同步熟化的总黄酮含量为0.568 mg/g,微波熟化后苦荞燕麦的总黄酮含量降低,苦味消失,酥脆可口,籽粒膨化均匀且饱满,香味浓郁。同时,其具有一定的抗氧化活性和抑制α-淀粉酶作用,为杂粮加工生产中以同步熟化苦荞燕麦为原料提供了一定的参考。

Enhanced Synchronization of Intercellular Calcium Oscillations by Noise Contaminated Signals

We consider the dynamics of locally coupled calcium oscillation systems,each cell is subjected to extracel-lular contaminated signal,which contains common sub-threshold signal and independent Gaussian noise.It is found thatintermediate noise can enhance synchronized oscillations of calcium ions,where the frequency of noise-induced oscilla-tions is matched with the one of sub-threshold external signal.We show that synchronization is enhanced as a result ofthe entrainment of external signal Furthermore,the effect of coupling strength is considered.We find above-mentionedphenomenon exists only when coupling strength is very small.Our findings may exhibit that noise can enhance thedetection of feeble external signal through the mechanism of synchronization of intercellular calcium ions.

Agent-based Collaborative Design Framework Supporting Synchronization and Asynchronization on Internet

On the basis of analysis of the research issues and requirement of collaborative design, we propose the overall framework of agent based collaborative design on Internet. Then, we describe the implementation of synchronous and asynchronous collaborative design process based on standardized design activities under the overall framework. In order to realize design message passing, the DMP Protocol is proposed as well in this paper and described in detail.

Detection of the Process about Extreme Weather Events

In view of extreme values events mathematically rather than the process about extreme weather events, phase synchronization clustering method is introduced and the applicability of the method is discussed from the aspects of noise intensity and sequence length. At last the observed data is applied. The results show that clustering measure difference can detect the temporal process objectively to a certain degree and it has certain application to detect the temporal proc- ess of extreme weather events.

Wireless Infrared Pyrometer with Fiber Optic: Construction and Processing Algorithms

In this paper, developed wireless portable infrared pyrometer with dual channel fiber optic is described. The pyrometer measures surface temperature in wide infrared spectral range of 2 - 25 um. A data processing algorithm based on the methods of synchronous detection providing

Hybrid Segment Approximate Multiplication for Image Processing Applications

It is critical in terms of approximate computation errors in VLSI multiplier circuits are increasing with technology scaling. The most common method for fast and energy efficient execution of multiplication result is approximation of operands. But this traditional approximate result is not suitable for image processing applications. This paper proposes the two architectures of high accurate hybrid segment approximate multiplier (HSAM) and enhanced HSAM for image compression. Existing static segment method based approximate multiplier is not suitable for certain accurate applications and dynamic segment method based approximate multiplier is not suitable for cost efficient applications. The proposed work combines the advantages of both static segment method and dynamic segment method to drive the efficiency in accuracy and cost. The proposed approximate multipliers HSAM8 × 8 and EHSAM8 × 8 provide 99.85% and 99.999% accuracy respectively for various inputs. The proposed HSAM consumes less energy with small increase of area overhead. The proposed EHSAM consumes less energy without any area overhead. The proposed HSAM and EHSAM is improved the speed by 40% and 85% compared to the existing SSM8 × 8 technique.

Real-time Parallel Processing System Design and Implementation for Underwater Acoustic Communication Based on Multiple Processors

ADSP-TS101 is a high performance DSP with good properties of parallel processing and high speed.According to the real-time processing requirements of underwater acoustic communication algorithms,a real-time parallel processing system with multi-channel synchronous sample,which is composed of multiple ADSP-TS101s,is designed and carried out.For the hardware design,field programmable gate array(FPGA)logical control is adopted for the design of multi-channel synchronous sample module and cluster/data flow associated pin connection mode is adopted for multiprocessing parallel processing configuration respectively.And the software is optimized by two kinds of communication ways:broadcast writing way through shared bus and point-to-point way through link ports.Through the whole system installation,connective debugging,and experiments in a lake,the results show that the real-time parallel processing system has good stability and real-time processing capability and meets the technical design requirements of real-time processing.

顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法

BDS-3高稳定星载原子钟作为北斗星座的显著技术优势,在GNSS数据处理中尚未得到充分利用。针对严格时效性限制下GNSS超快速轨道钟差参数精度受限问题,本文提出顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法。首先,以GNSS轨道钟差参数间相关性为基础,构建顾及BDS-3星钟参数特性的GNSS定轨模型;然后,基于GNSS精密钟差产品,分析星钟约束对GNSS轨道钟差参数精度的影响规律;最后,为克服预报钟差精度与约束筛选对定轨影响,建立BDS-3星钟建模与GNSS超快速轨道钟差估计的同步处理方法。试验结果表明,在BDS-3星钟参数最优约束下,BDS-3与GPS轨道钟差精度可分别提升27.5%、5.1%和20.2%、5.2%;且较传统BDS-3星钟单历元处理策略,基于BDS-3星钟建模与GNSS超快速定轨同步处理方法,GNSS超快速轨道钟差精度可分别提升至4.8%与34.2%,轨道精度实现了毫米级改善。因此,顾及BDS-3星钟约束的GNSS超快速轨道钟差解算方法可有效对BDS-3高稳星钟信息模型化,并实现GNSS超快速轨道钟差精度的优化处理。

南荻纤维素分批补料同步糖化发酵产乙醇工艺优化及其结构表征

文章以南荻纤维素为原料,采用分批补料同步糖化发酵工艺生产生物乙醇,分析了底物初始质量分数、底物最终质量分数、补料次数对乙醇产量的影响,并在此基础上采用正交试验进行工艺优化,获得最佳工艺参数:底物初始质量分数为17.5%,分批补料2次至底物最终质量分数为32.5%。在此条件下,乙醇含量最高可达70.15 g/L,较未补料同步糖化发酵过程获得的最大乙醇含量提高23.36%。在分批补料同步糖化发酵最佳工艺的基础上,做了物料平衡分析,并采用扫描电镜、傅里叶变换红外光谱、X-衍射对发酵前、后的南荻纤维素结构进行表征,结果显示,酶解糖化及发酵过程会改变南荻纤维素的内部结构,使氢键或共价键断裂,底物结晶度提高。

饱和砂土地层盾构隧道同步注浆浆液填充-渗透扩散过程研究

为研究盾构隧道多阶段注浆过程,研发填充-渗透多阶段注浆试验装置,开展一维浆液填充-渗透扩散试验,并基于体积平均法将微观多孔介质孔隙边界效应简化为阻力项,构建宏观耦合注浆填充和渗透过程的浆液扩散模型;利用COMSOL有限元平台实现方程的求解以及浆液扩散情况的可视化,结合室内试验以及实例分析验证模型的适用性,最后建立同步注浆模型,通过控制变量分析不同工况对浆液最终扩散的影响。研究结果表明:1)本文提出的模型可以较好地反映浆液的填充-渗透过程,试验与模型误差控制在5%以内;2)注浆孔数量的增加会减少注浆所需时间,但会增加盾尾空隙内最大压力以及空隙上下部压力差,同时浆液的选取对注浆过程有极大的影响。

永磁同步电机FOC控制下相电流直流分量影响与抑制策略研究

永磁同步电机在矢量控制时需要对电机相电流进行采样,采样过程中参考电平波动等诸多因素都会造成相电流中包含直流分量,此外直流电压注入法等永磁同步电机参数在线估计方法,也会在相电流中引入直流分量。本文详细分析了不同情况下直流分量的产生机理,研究了直流分量对控制效果、转矩脉动、效率等性能的影响。提出一种可滤除三相交流信号中直流分量的数据处理方法,该方法对不同因素引入的直流分量均能起到良好的抑制作用,从而增加控制稳定性,降低转矩波动,仿真和应用实践验证了算法有效性。

基于力引导的空间舱外双臂机器人遥操作同步过程优化

为提高空间舱外双臂机器人遥操作同步过程中操作效率,提出了一种基于力引导的遥操作同步过程优化方法。通过改进的蒙特卡洛法对双臂机器人协作的工作空间进行分析,提出了一种最优协作位置预测方法,并通过力引导方式,辅助引导遥操作双臂到达最优协作位置。实验结果表明:相比于只有视觉反馈的遥操作过程,同步过程优化后到达同步工作状态的时间减少了84.26%,同步过程通过的路径长度缩短了35.43%;对比运动学引导方法,各项指标方差更小,稳定性更强。