Wheel slip control with torque blending using linear and nonlinear model predictive control

Modern hybrid electric vehicles employ electric braking to recuperate energy during deceleration. However, currently anti-lock braking system (ABS) functionality is delivered solely by friction brakes. Hence regenerative braking is typically deactivated at a low deceleration threshold in case high slip develops at the wheels and ABS activation is required. If blending of friction and electric braking can be achieved during ABS events, there would be no need to impose conservative thresholds for deactivation of regenerative braking and the recuperation capacity of the vehicle would increase significantly. In addition, electric actuators are typically significantly faster responding and would deliver better control of wheel slip than friction brakes. In this work we present a control strategy for ABS on a fully electric vehicle with each wheel independently driven by an electric machine and friction brake independently applied at each wheel. In particular we develop linear and nonlinear model predictive control strategies for optimal performance and enforcement of critical control and state constraints. The capability for real-time implementation of these controllers is assessed and their performance is validated in high fidelity simulation.     

基于建筑信息模型(BIM)的城市轨道交通设施设备分类与编码研究

城市轨道交通涉及多专业的设施设备,建设项目从设计、施工到运营维护,各阶段的设施设备信息采用不同的分类编码体系,难以开展设施设备的统一化管理。调研上海轨道交通既有的设施设备分类编码体系,基于建筑信息模型(BIM)技术研究,建立城市轨道交通全生命周期的设施设备分类编码体系。该分类编码体系是以城市轨道交通资产管理的分类编码为基础进行编制的,划分了21类,具有唯一性、稳定性、可扩展性等特点,可兼容既有的设施设备分类编码体系,并能够满足城市轨道交通运营维护管理的需求。     

基于Timed RAISE的高速列车RBC切换协议形式化建模及验证

在CTCS-3(Chinese Train Control System Level 3)级列控系统中,RBC(Radio Block Center)切换是影响列车安全高效运行的重要环节,现阶段对RBC切换协议进行验证分析所使用的形式化方法还存在状态爆炸或描述性质单一等问题。基于Timed RAISE的形式化方法,结合域的模型,在对RBC切换流程分析的基础上,构建状态转移图,得到切换协议的形式化模型,使用等价和推断的推理规则对模型的正确性和实时性进行推理验证,得到的结果表明,RBC切换协议满足规范标准对正确性与实时性的要求,将验证结果与其他文献的结论进行比较分析,说明该方法具有通用性,对于推广其在列控系统场景验证中的应用有一定的实际意义。     

基于Berger码的故障-安全信号转换模块设计

设计1种基于Berger码状态分配的故障-安全信号转换模块,采用固定频率的交替信号作为输出,目的在于与铁路广泛应用的继电器保护电路合用,构成具有高故障-安全保险系数的控制信号输出端。     

从知识对象到"生活形态":皮尔士实在理论中的中介性原则

一切传统的二元性的认识论必然导致最后一个形而上学式的“自在之物”。由此，皮尔士对传统认识论的批判也必然促使他建立全新的实在理论。在阐述实在概念的过程中，皮尔士逐步建立起了较为完整的实用主义理论构架，并且对实在、真理、意义等普遍性概念给出了独特的理解和全新的意义。     

A Concatenated ML Decoder for ST／SFBC-OFDM Systems in Double Selective Fading Channels

This paper presented a concatenated maximum-likelihood (ML) decoder for space-time/space-frequency block coded orthogonal frequency diversion multiplexing (ST/SFBC-OFDM) systems in double selective fading channels. The proposed decoder first detects space-time or space-frequency codeword elements separately. Then,according to the coarsely estimated codeword elements, the ML decoding is performed in a smaller constellation element set to searching final codeword. It is proved that the proposed decoder has optimal performances if and only if subchannels are constant during a codeword interval. The simulation results show that the performances of proposed decoder is close to that of the optimal ML decoder in severe Doppler and delay spread channels. However,the complexity of proposed decoder is much lower than that of the optimal ML decoder.     

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研究在具有过去的统计信息及实时信息条件下的交通网络上的路径生成问题 我们假定路段通行时间具有一定的概率分布，这一分布从过去的统计数据得到，而当旅行者到达某一节点时，以该节点为起点的路段的通行时间作为实时信息被告知。在以上条件下，我们给出一种自适应算法来实时地生成一条路经，使得在某一预定时刻以前到达目的地的概率最大这个概率是衡量路径的时间可靠性的尺度，因而我们称相应算法为reliable routing algorithm。与之对应，我们注意到在以往的研究中，衡量路径优劣的有平均通行时间长短等等尺度。     

Closed Loop Space-Time Block Coding for Wireless Downlink Transmission

In order to improve the poor performance of Space-Time Block Coding (STBC) in a downlink correlated fading environment, a closed loop scheme is proposed. With the known channel fading statistics fed from the receiver, eigenbeamforming is utilized to improve the performance of STBC at the transmitter. The new system achieves the array and diversity gain simultaneously. Because reduced dimension processing is adopted, the proposed system has a relative simple structure compared with the traditional beamforming system. The validity of the scheme is verified in several situations by simulation experiments.     

STC-OFDM系统的post-IDFT多波束形成技术

提出了适用于空时编码-正交频分复用(OFDM)系统的后-逆离散傅立叶变换(post-IDFT)多波束形成技术.该技术通过对空频信道相关矩阵进行特征分解获得多个特征模式,再利用空时分组码(STBC)各发射分支信号的正交性使OFDM系统形成多个post-IDFT波束.接收端根据STBC传输矩阵的正交性对多波束解码.系统获得的空间分集增益为空频信道相关矩阵的特征值之和,最大空间分集增益与子载波波束形成方案相同,误码率比STC-OFDM的低.该技术将复杂度降低到子载波波束形成方案的1/S(S为OFDM系统的子载波数目),而且当波束维数(m)小于发射天线数目(M)时,可进一步减少M-m个IDFT模块     

Bounded Real Lemma for Generalized Linear System with Finite Discrete Jumps

Introduction In the past decade, research interests on sam-pled-data systems are increasing with the wide ap-plication of digital control in the industry. Tradi-tional discretization technique is limited since failedto take into account intersample behavi…