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推荐采用CVT换档速度控制的一种算法来改进金属推块无级变速器车辆的燃油经济性.重新调整CVT换档动力学方程式,可以找到CVT换档速度与工作油压以及初始油压有关,绘制换档速度图估算工作油压对换档速度的影响,以求出换档速度为目标,提出工作油压计算的一种算法.为了估算换档速度和液体的损耗,采用考虑CVT换档动力学的试验证实求得工作油压控制阀和比例控制阀的动力学模型.根据仿真的结果,尽管由于工作压力增加液体损失增加,发觉燃油经济改进为2%. 相似文献
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CVT虚拟样机的实现方法 总被引:1,自引:0,他引:1
简要介绍了虚拟样机及其支撑技术.针对虚拟样机动力学仿真软件ADAMS建模功能的特点,采用UG与ADAMS结合的三维建模与动力学仿真的通用方法.在CVT的虚拟样机构建中,对于其技术难点钢带的柔性化和接触力的添加,分别使用了ADAMS提供的无质量梁和冲击函数,并进行了仿真分析. 相似文献
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并联混合电动车辆采用无级变速器速比控制对燃油经济性的改进 总被引:1,自引:0,他引:1
H Lee H Kim 《传动技术(上海)》2006,20(3):29-36,48
考虑到并联混合电动车辆(HEV)动力系响应滞后,建议采用无级变速器(CVT)速比控制方法来实现HEV的燃油经济性的改进.在该方法内,由估算于动力系响应滞后之后根据车辆速度来修正目标CVT速比,并推荐一个加速图谱来估算响应滞后的车辆速度.该CVT速比控制方法采用HEV台架试验机试验证实.根据试验结果,可以看到用修正速比控制方法发动机工作迹线比用常规CVT速比控制对于适度加速模式可以有更有效换档范围,故能给出最佳的燃油经济性.此外,还采用HEV动力系模型对联邦城市驱动计划性能仿真进行估算响应滞后对燃油经济性的影响.仿真结果表明作为响应滞后采用修正CVT速比增大可以实现最佳的燃油经济性.但在实际应用中,要求最佳燃油经济性和加速性能之间进行折衷. 相似文献
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This paper presents a CVT line pressure control strategy for the increased shift speed. Firstly, an algorithm to increase the CVT shift speed is suggested based on a modified CVT shift dynamics and shift speed maps are constructed. In addition, simplified dynamic models of the line pressure and the ratio control valve are derived by considering the CVT shift dynamics, and low level control algorithms for the ratio and the line pressure control are proposed. Using the shift speed maps and the simplified dynamic models of the CVT system, shift performance is investigated. It is found from the experimental and simulation results that improved shift speed can be achieved by increasing the line pressure. 相似文献
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T.Kim H.Kim 《传动技术(上海)》2003,17(4):19-26
本文考虑由于CVT速比变化引起动力系功率损失和惯性转矩推荐了一种集成发动机一无级变速器(CVT)控制算法。此外还提出了减少CVT速比响应滞后对驱动转矩影响的补偿算法。实验结果表明,最佳发动机速度补偿算法给出最佳发动机工作点在最佳工作线附近。当加速度响应接近相等时和最佳转矩补偿比较。建议把集成发动机-CVT控制算法的特点和传统CVT相比较,加速时采用集成控制来实现在最佳工作线上找到最佳发动机工作点。 相似文献
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介绍了液压传动的类型,重点对液压无级变速传动系统的工作原理做了详细的分析,对匹配设计过程做了详细的推导.利用MATLAB/Simulink软件建立了液压无级变速系统的仿真模型.在此模型中对变量泵、变量马达的排量匹配进行了优化,使行走速度和驱动力的发挥达到最佳状态,并将仿真结果应用在轮式挖掘机行走系统的设计中.经样机测试完全满足设计要求,取得了较好的结果. 相似文献
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In this paper, low level control algorithms of a metal belt CVT are suggested. A feedforward PID control algorithm is adopted for line pressure based on a steady state relationship between the input duty and the line pressure. Experimental results show that feedforward PID control of the line pressure guarantees a fast response while reducing the pressure undershoot which may result in belt slip. For ratio control, a fuzzy logic is suggested by considering the CVT shift dynamics and on-off characteristics of the ratio control valve. It is found from experimental results that a desired speed ratio can be achieved at steady state in spite of the fluctuating primary pressure. It is expected that the low level control algorithms for the line pressure and speed ratio suggested in this study can be implemented in a prototype CVT. 相似文献
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The current research on pulse continuously variable transmission(CVT) is mainly focused on reducing the pulse degree and making pulse degrees a constant value. Current research mainly confined to find out new design parameters by using the method of optimization, and reduce the pulse degree of pulse CVT and its range of variation. But the fact is that the reduction of the pulse degree is not significant. This article presents a new structure of mechanical pulse CVT-the rotational swashplate pulse CVT with driven by helical gear axial meshing. This transmission is simple and compact in structure and low in pulsatile rate (it adopts 6 guide rods), and the pulsatile degree is irrelevant to the transmission ratio. Theoretically, pulsatile rate could be reduced to zero if appropriate curved surface of the swashplate is used. Compared with the connecting rod pulse CVT, the present structure uses helical gear mechanism as transmission part and it avoids unbalanced inertial force in the former model. This paper analyzes the principle of driving of this transmission, presents its mechanical structure, and discusses its motion characteristics. Experimental prototype of this type of CVT has been manufactured. Tests for the transmission efficiency(when the rotational speed of the output shaft is the maximum) and the angular velocity of the output shaft have been carried out, and data have been analyzed. The experimental results show that the speed of the output shaft for the experimental prototype is slightly lower than the theoretical value, and the transmission efficiency of the experimental prototype is about 70%. The pulse degree of the CVT discussed in this paper is less than the existing pulse CVT of other types, and it is irrelevant to the transmission ratio of the CVT. The research provides the new idea to the CVT study. 相似文献
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提出一种针对电动汽车中集成电磁直线驱动装置的电磁直驱变速器DAMT(Direct-Driving Automated Mechanical Transmission),利用仿真与实验分析其换挡性能。该变速器联合了直驱技术与机械变速器的优势,利用电磁直线驱动装置直接驱动两挡一体式接合套完成换挡。以换挡力与换挡力衰减率为目标,通过退火粒子群-有限元算法对换挡执行机构参数优化;研究电磁直驱变速器换挡机理对换挡过程分阶段建模仿真;搭建DAMT样机与试验台,进行了典型工况换挡实验。实验结果表明,电磁直驱变速器在转速差220 r/min、被同步端转动惯量0.04 kg?m2工况下换挡时间为148 ms,同步时间为109 ms。实验结果验证了建模的准确性和电磁直驱变速器的可行性。 相似文献
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车用无级变速器性能研究 总被引:1,自引:0,他引:1
本文作出了装配无级变速器(CVT)汽车动力特性图,同时通过一系列试验结果,对CVT汽车与配备其它变速器汽车在动力性、燃油经济性、传动效率、寿命、排放、可靠性、传递扭矩、成本、操纵性和舒适性等方面进行了详细的对比研究,详述了CVT与AT和MT之间的优缺点. 相似文献
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为了提高配有金属带式无级变速器车型燃油经济性,提出基于滑模极值搜索理论的控制算法和基于滑模极值搜索控制与传统夹紧力控制相结合的一体化式联合控制方法;设计了滑模极值搜索控制和传统液压控制合为一体化的联合控制系统。建立具有非线性、离散性的数学模型;分析无级变速器传动效率和金属带滑差率在一定速比下存在特殊曲线关系;测试主/从动轮夹紧力比值系数,完成了速比跟踪控制器及变化率控制流程设计。依据滑模极值搜索算法原理,完成了滑模极值搜索控制器设计。在具有环境仓的转鼓试验台上进行整车试验,试验结果表明:采用一体化式控制的金属带式无级变速器车型油耗为7.18L/100km,比传统控制系统的油耗降低约5.64%;主、从动压力安全系数倒数指标均小于1。满足整车提高燃油经济需求的可靠性、稳定性及优化性能。 相似文献
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车辆CVT液压系统功率匹配控制与仿真 总被引:3,自引:1,他引:3
以金属带式无级变速器(V-belt continuously variable transmission,CVT)液压系统为研究对象,建立了系统压力、流量和功率特性的仿真模型;对车辆行驶循环下的CVT功率特性进行了仿真和功率匹配分析,提出了减小液压系统功率损失、实现系统功率匹配的方案;进行了双联泵供油的CVT液压系统功率匹配控制的方案设计、动态建模和仿真分析。计算表明,采用的双联泵功率匹配系统能有效提高CVT液压系统效率。研究结果为CVT液压系统的节能控制提供了理论依据。 相似文献