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横摆力矩和主动前轮转向结合的车辆横向稳定性模糊控制仿真 总被引:1,自引:0,他引:1
提出一种基于横摆力矩和主动前轮转向相结合的车辆横向稳定性控制方法,以横摆角速度和侧偏角为控制目标,利用前馈补偿和模糊控制产生横摆力矩和附加的前轮转角,通过控制制动力的分配以及对转向角的修正,使车辆转向行驶时的横摆角速度和侧偏角很好地跟踪参考模型.对转向轮阶跃输入和正弦输入两种工况分别进行了仿真研究,采用横摆力矩和主动前轮转向相结合控制方法,车辆转向时的瞬态及稳态响应优于单独的横摆力矩控制,表明该方法能有效地控制车辆横摆角速度和侧偏角,提高车辆转向时的横向稳定性,同时能有效地减轻驾驶员操纵负担. 相似文献
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研究汽车转向稳定性控制问题.针对线控转向系统的可变转向特性对汽车操纵稳定性的影响,为保证行驶安全,建立基于车辆横摆角速度与稳态横摆角速度之差(反馈系数F1)以及车辆侧向加速度与理想侧向加速度之差(反馈系数F2)反馈的驾驶员模型.结合整车模型和综合评价指标函数,分别对反馈系数F1(F2=0)、F2(F1 =0)和F1、F2进行优化,对线控转向系统的行驶状态进行仿真并与无反馈控制的驾驶员模型进行了比较.仿真试验结果表明:基于侧向加速度与横摆角速度共同反馈的方法,对前轮转角进行补偿,可较好的控制车辆的侧向位移、侧向加速度、横摆角速度和质心侧偏角,提高车道跟踪性能、方向稳定性能、降低驾驶员的转向负担,提高汽车的操纵稳定性. 相似文献
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李志明 《计算机测量与控制》2014,22(10):3353-3355
为了提高车辆的操稳性,提出了新型主动前轮独立转向系统,介绍了主动前轮独立转向的工作原理和结构形式,建立了系统数学模型;提出了主动前轮独立转向的控制策略,上层控制器采用PI控制,由横摆角速度偏差得出总控制转角,下层控制器负责内外侧转向轮的判断以及计算内外侧转向轮具体的转角;在仿真软件MATLAB/Simulink里进行了控制策略有效性仿真,仿真结果说明对于不足转向车辆,主动前轮独立转向系统能比传统的主动前轮转向系统更有效地提高车辆操纵稳定性。 相似文献
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无人驾驶探测车是探测行星表面和地下未知世界的重要工具。它所面临的环境非常复杂,转向机构的性能直接关系到探测任务的成败。为了研究六轮探测车的转向特性,该文建立丁它的运动模型,按照质心零侧偏角控制策略进行了合理简化。分析了其稳态响应特性;同时得到了质心侧偏角、横摆角速度、侧向加速度与前轮转角的传递函数,在此基础上,对研究的样车进行了前中后轮转角成比例控制的六轮转向车辆的运动学仿真,并与四轮转向和前轮转向进行了对比。结果表明,六轮转向小车的瞬态响应特性更为优越,对提高小车的转向性能非常有利。该结果可为结构设计提供参考。 相似文献
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为提高传统线控转向车辆转向稳定性,提出一种基于相平面预警边界的主动安全控制策略。首先,建立质心侧偏角与质心侧偏角速度■相平面图;其次,针对传统相平面稳定区域划分所用双线法在低路面附着系数时存在不足,提出“平行四边形“边界法改善相平面稳定区域的划分,并以稳定域边界建立预警边界模型。然后基于预警边界设计线控转向主动安全控制器,设计预警度PID控制器和横摆角速度滑模控制器联合决策横摆力矩,以保持车辆稳定行驶,避免失稳状态从而起到主动安全作用;最后,结合Simulink和CarSim联合仿真结果表明,控制器能够有效避免线控转向车辆失稳,提高了主动安全性。 相似文献
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4WS整车虚拟样机建模与动力学仿真 总被引:1,自引:0,他引:1
为了改善汽车在高速行驶转弯时的操纵稳定性,运用动力学仿真软件ADAMS,在其专业汽车模块ADAMS/CAR下研究了4WS汽车建模及其瞬态和稳态操纵动力学特性。以质心侧偏角和横摆角速度响应为评价指标,在角阶跃输入下高速转弯时,对前后轮转角成比例关系的4WS汽车和FWS汽车分别做了动力学仿真研究。对比分析了两者的质心侧偏角和横摆角速度响应特性,从分析结果得出,后轮主动参与转向,总体上有助于改善汽车在高速行驶转弯时的动力学响应特性,但是不同的因素也会对操纵稳定性产生不利的影响。 相似文献
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S. Shaw 《Journal of Computer Assisted Learning》1993,9(2):93-99
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained. 相似文献
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European Community policy and the market 总被引:1,自引:0,他引:1
C. Lloyd 《Journal of Computer Assisted Learning》1993,9(2):86-91
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven. 相似文献
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融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。 相似文献
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Wayne O’Brien Author Vitae 《Journal of Systems and Software》2008,81(11):1997-2013
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them. 相似文献
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This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives. 相似文献
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Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what
is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic
sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and
its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of
an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify
robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can
or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
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David Poole 《Computational Intelligence》1989,5(2):97-110
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given. 相似文献
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Watts S. Humphrey 《Annals of Software Engineering》2002,14(1-4):39-72
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical. 相似文献
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基于复小波噪声方差显著修正的SAR图像去噪 总被引:4,自引:1,他引:3
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。 相似文献
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R. NOSS 《Journal of Computer Assisted Learning》1987,3(1):2-12
Abstract This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development. 相似文献