导弹数字舵机多通道信号转换及传输系统设计

针对全数字电动舵机无法直接使用传统的模拟信号及数据传输过程中丢帧、串帧、等待时间过长等问题,设计了一种基于DSP的多通道信号转换及传输系统,该系统采用片外AD及DA转换器实现信号转换,并针对传统通信算法存在的弊端,提出新的方法,实时配置FIFO中断等级,实现存在扰动情况下的无丢帧、无串帧通信,且执行时间37μs,提高了系统的稳定性、实时性。     

压电谐振驱动三足机器人的平面运动

设计并实现了一类利用压电陶瓷片作动,由三条曲梁足支撑的振动驱动机器人.建立了在一条足共振驱动下机器人水平运动的动力学方程,数值计算解释了摩擦作用下的运动机理,寻找到异性摩擦对运动方向、速度的影响和压电激励频率与运动速度间的关系.通过建立圆弧曲梁控制方程求解圆弧型足面内振动的固有频率及振型,设计了三组不同频率的圆弧曲梁足参数,实验制作了机器人模型,利用压电控制三足间振动的共振切换,实现了预想的三个方向的运动以达到平面运动的效果,实验测量了机器人的运动速度与理论计算吻合得较好.     

Building on the past to help prepare the workforce for the future with automated vehicles: A systematic review of automated passenger vehicle deployment timelines

A variety of stakeholders have put forth automated vehicle (AV) deployment timeline predictions over the past decade. To synthesize these predictions, we performed a systematic literature review of past and current AV deployment timeline predictions in the United States from different stakeholder groups, including private stakeholders, government organizations, and research organizations. Our analysis revealed that none of the AV mass deployment timelines from any stakeholder group have been met. It also shows discrepancies between timelines put forth by private and public stakeholders, with the private sector being more optimistic in their predictions. Accurate timelines are needed so regulators are able to create appropriate public policies and comprehensive budgets, and private stakeholders can make better informed decisions. More specifically, the mass deployment of AVs is anticipated to affect many transportation-related jobs which reinforces the importance of accurate AV deployment timelines to prepare the workers who may be displaced and for the development of workforce education and training initiatives.     

一类非线性飞行控制系统鲁棒故障诊断

针对一类仿射非线性飞行控制系统的执行器故障,提出了一种基于微分几何方法的鲁棒故障诊断方案.各个输入通道相应的不可观分布满足条件时,可以通过分别在状态空间和输出空间进行同胚变换,将原系统化为多个只受单一通道故障输入影响的能观商子系统.原系统的残差生成器设计问题转化为对其各通道能观商子系统的观测器设计,实现残差与其他通道故...     

Automated breast cancer detection and classification using ultrasound images: A survey

Breast cancer is the second leading cause of death for women all over the world. Since the cause of the disease remains unknown, early detection and diagnosis is the key for breast cancer control, and it can increase the success of treatment, save lives and reduce cost. Ultrasound imaging is one of the most frequently used diagnosis tools to detect and classify abnormalities of the breast. In order to eliminate the operator dependency and improve the diagnostic accuracy, computer-aided diagnosis (CAD) system is a valuable and beneficial means for breast cancer detection and classification. Generally, a CAD system consists of four stages: preprocessing, segmentation, feature extraction and selection, and classification. In this paper, the approaches used in these stages are summarized and their advantages and disadvantages are discussed. The performance evaluation of CAD system is investigated as well.     

ISS feedback control redesign for continuous stirred tank reactors

In this paper a new nonlinear feedback control law for continuous stirred tank reactors, obtained by exact Input/Output (I/O) linearization and Sontag's input‐to‐state stability feedback control redesign methods, is studied. By the new feedback control law, a significant attenuation of the disturbance effect is guaranteed, with evident improvement with respect to control laws obtained by the exact I/O linearization method. The performed simulations validate the theoretical results. Copyright © 2010 John Wiley & Sons, Ltd.     

A job grouping approach for planning container transfers at automated seaport container terminals

This paper proposes a practical job grouping approach, which aims to enhance the time related performance metrics of container transfers in the Patrick AutoStrad container terminal, located in Brisbane, Australia. It first formulates a mathematical model of the automated container transfers in a relatively complex environment. Apart from the consideration on collision avoidance of a fleet of large vehicles in a confined area, it also deals with many other difficult practical challenges such as the presence of multiple levels of container stacking and sequencing, variable container orientations, and vehicular dynamics that require finite acceleration and deceleration times. The proposed job grouping approach aims to improve the makespan of the schedule for yard jobs, while reducing straddle carrier waiting time by grouping jobs using a guiding function. The performance of the current sequential job allocation method and the proposed job grouping approach are evaluated and compared statistically using a pooled t-test for 30 randomly generated yard configurations. The experimental results show that the job grouping approach can effectively improve the schedule makespan and reduce the total straddle carrier waiting time.     

双伸位堆垛机系统调度的优化设计

以某机务段段修配件自动化立体仓库(AS/RS)为例,通过分析影响双伸位堆垛机系统运作的重要因素,提出一种基于作业时间最短的优化设计,建立相应的数学模型,并采用分区平均搜索初始种群的遗传算法对其进行验证。结果证明该优化设计有利于提高双伸位堆垛机AS/RS系统的运作效率。     

电静液作动器的设计与仿真

针对飞机作动系统的发展状况,设计了一种一体化电静液作动器(EHA)。在分析EHA的工作原理和设计特点的基础上,对电机、泵和作动缸的选用及系统性能的设计进行了优化。分析了EHA各个模块的数学模型,并在Matlab/Simuink环境下对各个部件的模型进行了仿真和结果分析,讨论了结构参数对整个系统性能的影响,设计了合理有效的控制算法,建立了整个系统的数学模型,给出了系统在不同输入信号下的仿真结果。结果表明,设计的EHA系统模型合理,满足性能指标。