质量偏心对裂纹转子系统振动特性的影响研究

将叶轮转子系统简化为Jeffcott转子,在非线性油膜力和流体激振力作用下建立了带有裂纹的转子系统的动力学模型,并推导了系统的无量纲运动方程.运用数值积分法研究了系统响应的分岔特性,分析了质量偏心对裂纹转子分岔特性的影响.结果表明:质量偏心越大,对裂纹转子系统响应的影响也越大.     

基于Petri网考虑中介状态的机械系统失效相关可靠性分析

机械系统因其各子系统、各部件、各单元之间的相互复杂关系,容易受到自身结构与人为因素的影响,导致其发生失效,严重影响了机械系统的可靠性.在利用Petfi网模型对机械系统分析的基础上,并引入"安全-中介-失效"3级工作模式,从安全、中介、失效3个方面来反映机械系统的可靠(完全正常工作)、可靠与失效的中介过渡、失效(完全不能...     

电力电子变压器多指标非线性控制研究

电力电子变压器是一种通过电力电子变换实现电力系统能量传递的新型变压器.以微分几何理论为基础,实现非线性系统的多性能指标控制,提出基于跟踪偏差的非线性控制器,以实现改善电力系统控制性能的目的,从而可在统一的非线性控制设计框架下同时对系统中多个状态量的性能指标提出要求.所提控制策略解决了系统的非线性问题,改善了系统的动态性能,仿真结果表明设计的控制方法在电力电子变压器输出稳定性控制.     

非线性滤波器在动力定位船位估计中的应用

针对动力定位船舶在作业过程中因丢失GPS位置测量信号,从而导致动力定位系统不能正常工作,而使船舶偏离作业点的问题,设计了一种非线性滤波器,它可以利用以前保存的历史数据进行船舶位置的实时估计,从而使船舶在一定的时间内可以维持在作业点附近,当重新获得GPS信号后,又可以快速地进入正常工作状态。为了使历史数据能够更准确地反映船舶的实时位置,利用历史数据相对于作业点的平均偏差对历史数据进行了补偿。最后给出了此非线性滤波器在船舶仿真系统中的仿真曲线,分析表明在有滤波器的情况下,船舶真实位置估计的准确度比没有滤波器的情况下有明显的改善。     

2500m车道/2300客位客滚船消防灭火系统设计

客滚船作为一种既能载运车辆,又同时载运旅客的特殊船型,实现船舶的消防安全目标和功能的要求至关重要。简要介绍2500m车道／2300客位客滚船全船消防灭火系统的设计。重点介绍全船水灭火系统、固定式高压二氧化碳灭火系统、车辆舱固定式压力水雾系统、舱室自动水喷淋系统、机舱局部水雾灭火系统和直升机泡沫灭火系统。     

Scheduled paratransit transport systems

In this paper we focus on ways to provide individualized services to people with mobility challenges using existing modes of public transport. We study the design of an interesting case, in which a bus operating in a public transport route may diverge from its nominal path to pick-up passengers with limited mobility and drop them off at their destination. We have modeled the design problem by a mixed integer-linear program, and we developed an exact Branch and Price approach to solve it to optimality. The proposed approach includes a labeling algorithm in which we introduced appropriate dominance rules, which do not compromise optimality. We have compared the efficiency of our approach with that of related algorithms from the literature. Furthermore, we have used the proposed approach to study key aspects of the system design problem, such as the effect of various constraints on the service level, and the tuning of the system’s parameters to address different transport environments.     

地铁通风小系统风机送电调试的探讨

通过6个案例分析,从不同调试故障的处理方法,归纳出3类常见调试问题,进而提出分3步进行的送电调试,为快速、高效地完成通风小系统风机送电调试任务提供了一条可行的便利途径。     

Asynchronous n-step Q-learning adaptive traffic signal control

Ensuring transportation systems are efficient is a priority for modern society. Intersection traffic signal control can be modeled as a sequential decision-making problem. To learn how to make the best decisions, we apply reinforcement learning techniques with function approximation to train an adaptive traffic signal controller. We use the asynchronous n-step Q-learning algorithm with a two hidden layer artificial neural network as our reinforcement learning agent. A dynamic, stochastic rush hour simulation is developed to test the agent’s performance. Compared against traditional loop detector actuated and linear Q-learning traffic signal control methods, our reinforcement learning model develops a superior control policy, reducing mean total delay by up 40% without compromising throughput. However, we find our proposed model slightly increases delay for left turning vehicles compared to the actuated controller, as a consequence of the reward function, highlighting the need for an appropriate reward function which truly develops the desired policy.     

Multivariable speed synchronisation for a parallel hybrid electric vehicle drivetrain

In this article, a new drivetrain configuration of a parallel hybrid electric vehicle is considered and a novel model-based control design strategy is given. In particular, the control design covers the speed synchronisation task during a restart of the internal combustion engine. The proposed multivariable synchronisation strategy is based on feedforward and decoupled feedback controllers. The performance and the robustness properties of the closed-loop system are illustrated by nonlinear simulation results.