工程平面控制网置平平差的方法研究

提出一种将秩亏自由网平差和三参数坐标转换相结合的平面控制网平差方法,其特点是在平差过程中控制网整体网形不因上级控制点点位的改变而变化。首先介绍秩亏自由网平差及其精度评定的原理,推导进行控制网三参数坐标转换及对置平后的控制网进行精度评定的数学模型。仿真计算结果证明了对传统边角控制网而言,置平平差较约束平差具有更强的抗原始数据误差的能力,是一种工程平面控制网平差的新方法。     

钢管混凝土拱桥力学特性试验研究

武汉江汉三桥、江汉五桥和南宁永和桥均为钢管混凝土拱桥。通过3座实桥的计算分析与静、动载试验,对钢管混凝土拱桥的力学特性做了研究。结果表明:目前钢管混凝土拱桥所用设计理论和方法可靠,施工方法可行且质量优良。     

Study on Real-time Look-ahead and Adaptive Parametric Curve Interpolator

The principle of real-time look-ahead was introduced and analysed. An adaptive parametric curve interpolator with a real-time look-ahead function was developed for non-uniform rational B-spline (NURBS) curves interpolation, which considering the maximum acceleration/deceleration of the machine tool. In order to deal with the acceleration/deceleration around the feedrate sensitive corners, the look-ahead function was designed and illustrated. It can detect and adjust the feedrate adaptively. With the help of real-time look-ahead, the acceleration/deceleration can be limited to the range of the machine tool capacity. Thus, feedrate fluctuation is reduced. A NURBS curve interpolation experiment was provided to verify the feasibility and advantages of the proposed interpolator with a real-time look-ahead function.     

城轨车辆称重调载系统测力装置的误差补偿

为保证城轨车辆称重调载系统的测量准确性,研究便捷高效的载荷传感器校准方法,文章提出了系统测力装置的误差补偿方法。针对系统特点搭建了专用的载荷校准硬件设备,并通过软件方法配合硬件实现了系统传感器的误差修正和补偿。经系统载荷传感器校准应用实例证明,文章提出的方法误差补偿效果显著,且操作简便,适合现场实现。     

PC连续刚构桥施工控制系统参数识别

系统参数误差是引起PC连续刚构桥悬臂施工控制误差的主要因素之一,因此消除系统参数误差是施工控制的关键所在.酉水河大桥施工监控系统参数识别过程表明,参数识别有利于施工参数的重点监测与调控.     

长大隧道贯通误差估算方法

结合大伙房水库输水工程长大隧道,介绍施工测量控制系统的设计思路及其误差所引起的横向、纵向、竖向贯通误差的估算方法,精度预计结果说明本设计方案能满足横向、纵向、竖向贯通误差控制的要求。     

某出口米轨动车组(Tc车)车体设计及试验对比研究

介绍了使用大型通用计算机辅助工程软件ANSYS和有限元方法,对某出口米轨动车组(Tc车)进行了分析计算的过程,并通过实际物理样机试验数据与计算数据的比对,分析车身强度的可靠性。     

Non-fragile multi-objective static output feedback control of vehicle active suspension with time-delay

This paper presents an approach to design a delay-dependent non-fragile H_∞/L₂–L_∞ static output feedback (SOF) controller for active suspension with input time-delay. The control problem of quarter-car active suspension with actuator time-delay is formulated to a H_∞/L₂–L_∞ control problem. By employing a delay-dependent Lyapunov function, new existence conditions of delay-dependent non-fragile SOF H_∞ controller and L₂–L_∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities (BMIs). Then, a procedure based on linear matrix inequality optimisation and a hybrid algorithm of the particle swarm optimisation and differential evolution is used to solve an optimisation problem with BMI constraints. Design and simulation results of non-fragile H_∞/L₂–L_∞ controller for active suspension show that the designed controller not only can achieve the optimal performance and stability of the closed-loop system in spite of the existence of the actuator time-delay, but also has significantly improved the non-fragility characteristics over controller perturbations.     

轨道交通换乘枢纽交通信息服务分析

从乘客的角度出发,针对目前轨道交通换乘枢纽交通信息服务方面存在的问题展开分析.在此基础上,探讨静态信息与动态信息相结合的优化设计方法,力求实现轨道交通换乘枢纽交通信息服务的人性化、系统化.     

先进电力电子技术在超高压输电网中的应用

简要介绍了先进电力电子技术在输配电中的应用,主要包括高压直流输电、柔性交流输电和定制电力技术三个方面.在叙述电力电子技术的发展和应用情况的基础上,重点阐述了由中国电力科学研究院自主集成的可控串补和静止无功补偿器成套设备的关键技术,强调了自主开发的重要性.