轻巧的机械手──真空吸附移载系统

轻巧的机械手──真空吸附移载系统纪远升（天津工程学院二分院）该技术目前在世界发达国家已得到广泛应用，而且在理论和技术上获得迅速的发展。该系统的关键是真空发生器。我国在吸收消化国外产品的基础上，已研制出该项产品，广泛应用于汽车、彩电、空调器、冰箱、建材...

真空气动移载系统——轻物料搬运的未来之星

在轻物料运搬领域，人力已不再是想当然的搬运工具，气动移载系统提供了安全、高效和人性化的解决方案。

吊篮跟踪移载系统

在两条相向运动的吊篮间实现完全移载作业 ,建立一智能跟踪移载系统 ,解决设计中的关键技术 ,提出各种不利因素下的完全移载方法。

塔式停车设备中移载系统的设计计算

重点介绍了垂直升降式(塔式)停车设备的基本情况,并对该设备中的移载系统进行了设计计算。

移载跟踪系统模糊控制器的仿真及其动态模拟

近年来 ,模糊控制器应用取得了广泛的成功。但是 ,模糊控制器的设计和分析理论却远没有经典控制理论那样完美。因此 ,模糊控制的设计很大程度上还依赖于对实际系统的反复实验、调整。针对这一普遍现象 ,本文结合一个设计实例 ,介绍了利用较先进的 MATLAB软件中的 SIMULINK仿真工具 ,来实现模糊控制器的设计、分析、仿真的方法。并结合 S函数 。

旱地蔬菜移栽机研究综述

主要综述了国内外蔬菜移栽机的种类,移栽机的工作原理、工作效率、适用的移栽范围以及蔬菜移栽机存在的问题。探讨了国内蔬菜移栽机目前存在的问题和今后的研发重点,应大力研发旱地全自动蔬菜移栽机,研发适用范围广、效率高、故障发生率低的全自动旱地蔬菜移栽机。

面向翼身对接的移载定位系统全驱动调姿算法

飞机大部件对接工艺在使用移载定位系统时需要快速标定坐标系并且采用全驱动调姿算法,目前国内学者针对该领域的研究较少。文中建立了移载定位系统的运动学模型,提出了一种翼身对接移载定位系统的全驱动调姿算法。通过测量设备获取数据计算得到定位系统坐标系;设计了调姿轨迹,根据调姿轨迹求解出驱动量;结合激光雷达误差检测实时对轨迹进行优化,保证了调姿过程的安全性与准确性;对运动误差进行了仿真分析。结果表明该全驱动调姿算法驱动量计算准确,在移载定位系统存在运动误差或球头位置误差时能实现调姿轨迹的实时修正,使机翼姿态达到对接工艺要求。

Non-Orthogonal Multi-Carrier Transmission for Internet via Satellite

As the important complementary to terrestrial mobile communications, Internet via satellite can extend the coverage of communication and improve the continuity of data services. To build a space-terrestrial integrated communication system is the inevitable trend in the future. Taking into account combination of 5th generation(5G) terrestrial mobile communication system and satellite communication system, it is necessary to evaluate the promising 5G air interface waveform which can be adopted by satellite. In this paper, several non-orthogonal multi-carrier transmission schemes are evaluated and generalized frequency division multiplexing(GFDM) is advised as potential scheme of space-terrestrial integrated communication system. After the overview of GFDM, the implementation of GFDM transceiver is discussed respectively in time-domain and in frequency-domain. By deriving and comparing implementation complexity, GFDM modulation in time-domain is more suitable for satellite communication system. Then the properties of demodulation algorithms are specified. Based on designed pilot subcarriers, a new improved receiving algorithm is proposed in the end of the paper. The improved algorithm solves the problem of inter subcarriers interference(ICI) in matched filtering(MF) receiver and improves the re-ceiving symbol error rate(SER) obviously. The simulation and analysis prove that the proposed algorithm is effective.

Evaluation of Signaling Loads in NO Stack 5G Mobile Network

Present mobile communication system suffers from the exponentially increased mobile traffic and research on the fifth generation(5G) mobile network architectures is ongoing to solve this problem. We investigate the feasibility of the proposals used for the network architecture evolution from 4G to 5G and first propose a compatible network architecture, which decouples the management plane, the control plane and the user plane based on NO Stack framework proposed in our previous study. We mainly design detail procedures including UE attachment, service request and dedicated bearer activation/deactivation for our proposal network architecture. Finally, we establish a clear analytical mode of the application and system states to evaluate the signaling loads of new architecture. Simulation results show that our proposal network architecture with elaborated signaling procedures has much impact on the total signaling loads of system and could obviously decrease the signaling overhead compared with LTE.

Construction of improved rigid blocks failure mechanism for ultimate bearing capacity calculation based on slip-line field theory

Based on the slip-line field theory, a two-dimensional slip failure mechanism with mesh-like rigid block system was constructed to analyze the ultimate bearing capacity problems of rough foundation within the framework of the upper bound limit analysis theorem. In the velocity discontinuities in transition area, the velocity changes in radial and tangent directions are allowed. The objective functions of the stability problems of geotechnical structures are obtained by equating the work rate of external force to internal dissipation along the velocity discontinuities, and then the objective functions are transformed as an upper-bound mathematic optimization model. The upper bound solutions for the objective functions are obtained by use of the nonlinear sequential quadratic programming and interior point method. From the numerical results and comparative analysis, it can be seen that the method presented in this work gives better calculation results than existing upper bound methods and can be used to establish the more accurate plastic collapse load for the ultimate bearing capacity of rough foundation.

Engine Noise Prediction by Using Multi-body Simulation

Abstract： This paper presents a coupled multi-body and FEM （finite element method）-BEM （boundary element method） methodology used to carry out a comprehensive NVH （noise, vibration and harshness） investigation of a four-cylinder internal combustion engine prototype. Firstly, a MBDS （multi-body dynamic simulation） of the internal combustion engine has been carried out, at a defined operating condition, in order to determine the excitation force of the powertrain exciting the cylinder block. In this way, the dynamics of the engine powertrain have been described taking into account both the effects of the gas forces of the combustion process and the inertia forces of the moving parts. Afterwards, the cylinder block excitation forces have been used to evaluate the engine block vibrations and to predict the external noise radiated with both the well-known ATV （acoustic transfer vectors） and MATV （modal acoustic transfer vectors） methodologies at a distance of 1 m from the engine, according to the standard ISO 3744. The dynamics of the engine powertrain and its vibro-acoustic behaviour have been described using LMS （learning management system） Engineering Innovation Virtual.Lab tools.

Carrier frequency offset estimation for a generalized OFDMA uplink

A residual carrier frequency offset （CFO） estimation scheme is proposed for the uplink of orthogonal frequency division multiple access （OFDMA） systems. Multiple access interference caused by CFOs in the uplink is investigated, as it severely affects the performance of a classical maximum likelihood （ML） frequency estimator. By the use of the estimated CFOs of the active users, the linear maximum mean square error （LMMSE） equalization is performed before the ML frequency estimator for the interference cancellation, which can help to sufficiently improve the estimation accuracy for the residual CFO of the incoming user. Analysis and simulations show that the modified ML estimator provides a tradeoff between estimation accuracy and computational complexity caused by the LMMSE interference cancellation, and the proposed method allows OFDMA systems flexibly allocating subcarriers to users.

Frequency Offset Compensation for Satellite Communication System with CE-OFDM

Constant envelope orthogonal frequency division multiplexing(CE-OFDM) is a waveform that can achieve 0d B peak-to-average power ratio and avoid the signal distortion caused by the nonlinear power amplifi er. However, the carrier frequency offset(CFO) in CE-OFDM systems can cause errors at phase unwrapper module. In this paper, a CFO estimation scheme is proposed for CEOFDM in satellite communication system. As the null subcarrier is inherent in the conjugate symmetric symbol structure at the transmitter, the proposed scheme uses the null subcarrier as prior information to estimate the CFO at the receiver. The ideal estimation range of normalized CFO is obtained by mathematical analysis. Simulation results show that the proposed scheme can estimate the CFO accurately under additive white Gaussian noise(AWGN) channel and multipath fading channel, especially for moderate and high signal-to-noise ratio(SNR).

ProSync： A protective synchronization scheme for NC-OFDM based opportunistic spectrum sharing system

A protective synchronization scheme （ProSync） for the non-contiguous orthogonal frequency-division multiplexing （NC-OFDM） system is proposed in this paper, aiming to minimize the impact of cross-band interference in opportunistic dynamic spectrum sharing networks. ProSync partly shrinks the preamble at the transmitter and exploits two multi-band filters at the receiver. By doing so, the potential interference suffered by NC-OFDM users, including both the cross-band interference and self interference, can be greatly reduced. Simulation results verify the effectiveness of ProSync, which is able to lower the carrier frequency offset （CFO） estimation error by up to 50%, compared with the traditional method.

基于物联网的高速货运列车智能装卸系统研制

针对传统快递物流业务存在时间长、劳动强度大、效率低等不足,研制了基于物联网的高速货运列车智能装卸系统。该系统基于时速350 km高速货运动车组平台开发,由横向移载、纵向移载、地锁、电气控制等子系统组成,实现了集装器自动装载、卸载,以及在车厢内部的锁固、解锁、移载等功能。经过冲击振动、静载等型式试验验证,结果符合设计要求。通过装车初步验证,该系统可以有效缩短装卸时间,降低人工成本,减轻人工装卸强度,提高装卸效率。