共查询到18条相似文献,搜索用时 328 毫秒
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与传统内燃机汽车相比,电动汽车缺少真空助力制动系统所需的真空源,需增加一个具有足够排气量的电动真空发生系统。现以某型纯电动轿车为例,给出了完整的制动系统的计算参数,对真空助力制动系统的性能进行了分析计算,并根据计算结果,设计了间歇性工作的真空发生系统。整车道路试验表明,所设计的电动真空助力制动系统合理。 相似文献
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本文给出了某型电动轿车完整的制动系统的计算参数,并对真空助力制动系统的性能进行了分析计算,并根据计算结果,设计了电动真空助力制动系统。通过整车道路试验验证,所设计的电动真空助力制动系统合理。 相似文献
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<正>电动汽车使用驱动电机代替发动机驱动车辆,其制动系统无法像传统内燃机汽车制动系统那样,可以从发动机处获得真空源,从而让真空助力器为驾驶员提供辅助。为了弥补这一不足,电动汽车使用电动真空泵来产生车辆制动时所需的真空,从而达到助力的目的。制动系统真空助力效果的优劣直接影响到汽车的行驶安全。在汽车制动助力系统中,如果真空助力器不能获得真空或获得的真空不足,将导致制动系统制动效果差,且制动踏板发硬。整车控制器利用真空度传感器采集真空助力器或真空管道中真空压力变化,并作出电动真空泵是否运转的决策,来确保在各种工况下都能提供足够的助力效果。 相似文献
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制动系统的真空助力效果关系到汽车的行驶安全。在汽车制动助力系统中,由于真空助力器不能获得真空或获得的真空不足,将导致制动系统助力效果差。电动真空泵能通过真空度传感器监测助力器内的真空度变化,进而保证驾驶者在各种工况下,都能提供足够的助力效果。现代车辆大多采用真空助力器作为制动系统的辅助助力方式;真空助力器通过单向阀与发动机进气歧管相通;当发动机运转时,产生负压,进而在助力器膜片两端形成压力差,从而达到减轻制动踏板操作力的作用,真空度的大小直接影响制动效果。可见真空度对于制动系统的重要作用。随着发动机排放及用户对于汽车性能的要求日益提高, 相似文献
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通过对某液压制动车型真空助力系统设计,研究制动、离合真空系统的参数匹配设计,优化真空助力系统控制管路,实现在离合真空失效工况下,保证制动的安全性;实车验证,真空助力系统可以作为改善制动、离合操纵舒适性的有效措施,为新车型开发提供了改进方向及设计方法。 相似文献
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Functions of anti-lock braking for full electric vehicles (EV) with individually controlled wheel drive can be realized through conventional brake system actuating friction brakes and regenerative brake system actuating electric motors. To analyze advantages and limitations of both variants of anti-lock braking systems (ABS), the presented study introduces results of experimental investigations obtained from proving ground tests of all-wheel drive EV. The brake performance is assessed for three different configurations: hydraulic ABS; regenerative ABS only on the front axle; blended hydraulic and regenerative ABS on the front axle and hydraulic ABS on the rear axle. The hydraulic ABS is based on a rule-based controller, and the continuous regenerative ABS uses the gain-scheduled proportional-integral direct slip control with feedforward and feedback control parts. The results of tests on low-friction road surface demonstrated that all the ABS configurations guarantee considerable reduction of the brake distance compared to the vehicle without ABS. In addition, braking manoeuvres with the regenerative ABS are characterized by accurate tracking of the reference wheel slip that results in less oscillatory time profile of the vehicle deceleration and, as consequence, in better driving comfort. The results of the presented experimental investigations can be used in the process of selection of ABS architecture for upcoming generations of full electric vehicles with individual wheel drive. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):1372-1388
Because of the damping and elastic properties of an electrified powertrain, the regenerative brake of an electric vehicle (EV) is very different from a conventional friction brake with respect to the system dynamics. The flexibility of an electric drivetrain would have a negative effect on the blended brake control performance. In this study, models of the powertrain system of an electric car equipped with an axle motor are developed. Based on these models, the transfer characteristics of the motor torque in the driveline and its effect on blended braking control performance are analysed. To further enhance a vehicle's brake performance and energy efficiency, blended braking control algorithms with compensation for the powertrain flexibility are proposed using an extended Kalman filter. These algorithms are simulated under normal deceleration braking. The results show that the brake performance and blended braking control accuracy of the vehicle are significantly enhanced by the newly proposed algorithms. 相似文献
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Jiawang Yong Feng Gao Nenggen Ding Yuping He 《International Journal of Automotive Technology》2017,18(4):603-612
This paper presents a novel electric booster (E-booster) that exibits superior performance advantages over traditional vacuum boosters. The proposed E-booster, consisting of an electric motor and a ball screw assembly, is designed for electro-hydraulic brake (EHB) systems to meet relevant requirements for electric vehicles and active safety technologies. A mathematical model for an EHB system is generated to determine the desired values of the parameters for the E-booster prototype using numerical simulation in MATLAB. Simulation results of the EHB system with the virtual E-booster demonstrate the feasibility and effectiveness of the innovative technique. Built upon the results derived from the numerical simualtions, an integrated algorithm based on the Kalman filter and a sliding mode control technique is designed to control the E-booster motor and to implement the brake booster function. A hardware-in-the-loop (HIL) real-time simulation system equipped with the E-booster prototype is developed. HIL real-time simulations are conducted to evaluate the proposed algorithm. The HIL real-time simulation results demonstrate that the proposed algorithm generates booster brake forces fast, and forces the ball nut to track the push rod well to ensure comfortable brake pedal feel. 相似文献
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为了提高滑行能量回收经济性和踏板制动安全性、舒适性,基于交通信息,提出了电动汽车(EV)制动协调策略。分析了滑行制动的经济性,由交通信息和汽车行驶状态确定滑行制动强度;由道路信息和前方车辆信息建立汽车安全距离模型和碰撞预警策略,利用预警信息对滑行制动和踏板制动强度进行协调。对本策略进行仿真验证。结果表明:利用交通信息的滑行策略,在通行良好工况下综合能耗减少1.1%,拥堵工况下减轻驾驶员的制动疲劳;预警和协调策略避免了频繁预警,减小了紧急避撞触发几率。因此,利用交通信息能够辅助驾驶员进行更加合理的制动。 相似文献
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对电动汽车真空助力系统进行建模仿真,分析了踏板行程与真空度消耗关系、不同真空度条件下助力器的输出性能关系、真空泵响应是否满足助力器等问题,仿真结果显示,助力器输出力与踏板输入力相协调,符合制动要求。真空泵抽速、启停真空度、罐体大小与真空助力器的需求搭配合理。制动主缸液压压力满足制动强度需求。在连续制动时,真空罐内真空度变化规律性好,每次制动前真空罐真空度环境一致。 相似文献
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Liang Li Xujian Li Xiangyu Wang Jian Song Xu Ran 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(2):231-257
Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV. 相似文献
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EQ1060F轻型载货汽车的制动系统最初采用单腔制动总泵加单真空增压器及安全缸的半双管路结构。为了提高安全性,后采用双膜片真空助力器的双管路结构。为了适应使用要求,又改为两个真空增压器的方案,但仍存在结构复杂、接头环管多、易泄漏、自由行程过大,超载行驶时,感到制动力不足等问题。现采用一种新设计方案,以双腔制动总泵输出油压为控制源,用真空动力缸为增压机构,以双进、双出、双活塞的泵体为辅助缸,实现单真空增压器的双管路系统。 相似文献