排序方式: 共有54条查询结果,搜索用时 31 毫秒
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利用移动互联网技术为汽车用户提供基于位置的服务是智能汽车的一个重要内容.当前汽车服务领域,提供的服务只是定位导航等基本服务,针对汽车用户提供更为个性化服务的系统几乎没有.为了方便汽车用户确定车辆位置,实时了解车辆内的信息状况,在深入分析基于车载端移动应用现状的基础上,提出并实现了一套基于Android的车辆服务系统的设计方案.系统由信息管理模块和地图模块组成,信息管理模块提供了用户车辆内甲醛浓度、PM2.5浓度和PM10浓度等信息的显示,地图模块实现了对用户车辆位置定位、行车导航以及附近服务搜索的功能.该系统在实际运用中运行稳定,定位精度较高、路线规划准确,和传统的地图相比可实时刷新车辆位置,其功能的设计更适用于汽车驾驶者. 相似文献
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为了改善传统滑模观测器(SMO)无传感器永磁同步电机(PMSM)高频抖振问题,提高无传感器PMSM观测性能,在传统SMO的基础上采用Sigmoid函数作为切换函数以减小抖振。同时,通过低通变截止滤波器和卡尔曼滤波器组合的级联滤波器进行滤波以去除高频信号,并降低测量噪声和测量误差,最后运用锁相环技术(PLL)提取电机转速信息和位置信息。采用MATLAB/Simulink仿真的手段来验证改进的SMO有效性和可行性。仿真结果表明,采用改进的SMO比传统SMO具有更高质量的观测信号,并且控制系统动态和静态性能较好。 相似文献
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目的研究第3代高强钢——QP钢在实际零件上应用涉及的成形特性问题。方法通过微观组织分析、单向拉伸、成形极限、V形弯曲回弹等试验,分析探讨了QP钢的力学性能、成形性能、成形极限和弯曲特性,并与广泛应用的DP钢对比。结果 QP钢HC600/980QP的成形性能好于相同强度级别的DP钢HC550/980DP,与HC420/780DP相当;QP钢弯曲回弹量比同等强度级别DP钢大。通过2个试冲零件的分析,验证了QP的成形特性,并从零件应用角度提出了QP钢的零件适用范围和零件设计要点。结论 QP钢具有综合的强度和塑性性能,有助于解决局部特征复杂的难成形零件和具有等截面特征的零件,在汽车车身结构件上有较大的应用前景。 相似文献
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《International Journal of Hydrogen Energy》2019,44(29):15511-15522
Homogeneous charge compression ignition (HCCI) is an alternative combustion strategy employed for automotive systems. It has a higher thermal efficiency with lower nitric oxides and particulate matter emissions that are below current emission requirements. However, owing to difficulties associated with combustion control, HCCI engines have disadvantages in terms of combustion instability, such as low-speed-low-load or high-speed-high-load conditions.This study investigates the effects of different parameters on HCCI engine combustion using numerical methods. The parametric study is carried out at low loads (25% part load), and a reference intake temperature of 550 K is used to preheat the air–fuel mixture. The GRI-3.0 chemical reaction mechanism involving 53 species and 325 reactions is used for 1-D simulations describing the combustion process fueled with methane and hydrogen added methane. By changing the variables, including compression ratio, excess air ratio, and hydrogen content, the combustion behavior is investigated and discussed. The results show that an increase in compression ratio resulted in a faster start of combustion and caused higher in cylinder pressure and heat-release rate. When the excess air ratio was increased, the start of combustion was delayed and lower in-cylinder pressure and heat release rate were observed. The results were similar for varying compression ratios. 相似文献
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刘爱东 《柴油机设计与制造》2020,(1):19-22
对新开发的活塞冷却喷射装置进行试验评估,评估其流量特性及油束速度与落点是否达到设计要求。评估结果表明,活塞冷却喷射装置油束速度与落点符合技术要求,但其流量特性不符合要求。对此,提出设计规范和改进意见,并对改进后的活塞冷却喷射装置进行验证试验。结果表明,改进后的活塞冷却喷射装置的流量和喷束速度达到技术要求,使活塞温度场分布和梯度都达到发动机强化设计的要求。 相似文献
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An adaptive gain sliding mode observer (AGSMO) for battery state of charge (SOC) estimation based on a combined battery equivalent circuit model (CBECM) is presented. The error convergence of the AGSMO for the SOC estimation is proved by Lyapunov stability theory. Comparing with conventional sliding mode observers for the SOC estimation, the AGSMO can minimise chattering levels and improve the accuracy by adaptively adjusting switching gains to compensate modelling errors. To design the AGSMO for the SOC estimation, the state equations of the CBECM are derived to capture dynamics of a battery. A lithium-polymer battery (LiPB) is used to conduct experiments for extracting parameters of the CBECM and verifying the effectiveness of the proposed AGSMO for the SOC estimation. 相似文献