排序方式: 共有33条查询结果,搜索用时 140 毫秒
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以南水北调北京段大宁水库防渗墙加高施工工程为背景,基于小波包变换去噪法和小波变换阀值去噪法,对现场监测数据进行了消噪处理,比较了两者在工程实际中的应用效果。研究表明,对防渗墙工程安全监测数据,小波包的处理结果更为理想,能够更有效地去除噪音突变信号,保留原始有用信号的突变点,使重构信号能够更光滑地重现原始信号,其去噪法性能比小波变换阀值去噪法更佳,具有更好的实际应用价值。研究结论为后期更加准确地评价防渗墙施工期间的变形和进行墙体长期稳定性分析提供重要依据,研究方法可为类似工程提供参考。 相似文献
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前置组合式转向梯形机构具有布置灵活、传动可靠等优点,但机构复杂、设计困难。本文从运动分析入手,建立了优化数学模型及算法,开发地优化设计软件系统。并给出了设计分析实例 相似文献
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冲压成形件毛坯设计的曲面展平截面剖分算法 总被引:1,自引:0,他引:1
分析了复杂参数曲面的展开原理,采用了截面剖分算法实现自由曲面的近似展平,推导了曲面和截面线的展开算法,开发了C++语言应用程序,给出了应用实例。该方法对中等复杂曲面零件展开毛坯有良好的适应性。 相似文献
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In the paper, crashworthiness of the S-shaped rail extracted from the frontal frame in a car is studied. In order to reduce the peak impact force while increasing the total absorbed energy, the hybrid materials are employed in that rail, where aluminum alloy is used for its front part and advanced high strength steel (AHSS) for its back part. By designing 16 experiments based on orthogonal experiment, the effect of five influence factors with four levels on the crash performance of the steel–aluminum hybrid S-shaped front rail is emphatically investigated. These influence factors include the different material types of aluminum alloy and AHSS, the sheet thicknesses of the two parts, and length proportion for the aluminum part. The AHSS includes dual-phase (DP) steel, transformation induced plasticity (Trip) steel and Mart steel; the aluminum alloy series include 5000 and 6000 series. The research result shows that the use of steel–aluminum hybrid materials can reduce the peak impact force and the total weight for the S-shaped front rail, while the total absorbed energy can be greatly increased, so the crashworthiness and lightweight of the S-shaped front rail are significantly improved. 相似文献
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Coasting in gear is a common driving mode for the conventional vehicle equipped with the internal combustion engine (ICE), and the assistant braking function of ICE is utilized to decelerate the vehicl... 相似文献
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Currently, many research from domestic and foreign on improving anti-rollover performance of vehicle mainly focus on the electronic control of auxiliary equipment, do not make full use of suspension layout to optimize anti-rollover performance of vehicle. This investigation into anti-rollover propensity improvement concentrates on the vehicle parameters greatly influencing on anti-rollover propensity of vehicle. A simulation based on fishhook procedure is used to perform design trials and evaluations aimed at ensuring an optimal balance between vehicle's design parameters and various engineering capacities, the anti-rollover propensity is optimized at the detailed design stage of a new SUV model. Firstly a four-DOF theoretical kinematic model is established, then a complete multi-body dynamics model built in ADAMS/car based on the whole vehicle parameters is correlated to the objective handing and stability test results of a mule car. Secondly, in fishhook test simulations, the Design of Experiments method is used to quantify the effect of the vehicle parameters on the anti-rollover performance. By means of the simulation, the roll center height of front suspension should be more than 30 mm, that of rear suspension less than 150 mm, and the HCG less than 620 mm for the SUV. The ratio of front to rear suspension roll stiffness should be ranged from 1.4 to 1.6 for the SUV. As a result, at the detailed design stage of product, the anti-rollover performance of vehicle can be improved by optimizing chassis and integrated vehicle parameters. 相似文献
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开关磁阻电机结构性转矩脉动抑制方法 总被引:5,自引:0,他引:5
开关磁阻电机具有结构简单、成本低和调速范围广等优势,但其双凸极结构和控制器的开关特性,导致存在转矩脉动现象,使得抑制转矩脉动成为焦点问题。首先从开关磁阻电机的结构和运行机理出发,针对线性解析方法难以分析转矩特征的问题,建立电机有限元模型求解出转矩特征并进行样机验证试验。分析样机结构参数对转矩脉动的影响,针对结构参数耦合问题,选择NSGA-Ⅱ算法在参数优化平台上对样机结构参数进行多目标寻优,在保证优化后样机的转矩脉动系数和平均转矩均优于初始电机的条件下,最终获得样机最优化结果。结果表明,不同结构参数对电机转矩的影响有较大的差异,对结构参数的优化能有效地抑制转矩脉动,该参数优化方法可以为开关磁阻电机结构性转矩脉动抑制提供参考。 相似文献
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Xia Hongyang Chen Jiqing Lan Fengchong Liu Zhaolin 《International Journal of Control, Automation and Systems》2020,18(6):1510-1517
International Journal of Control, Automation and Systems - In this paper, a novel motion control scheme with guaranteed prescribed performance is proposed for autonomous vehicles with consideration... 相似文献
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