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51681.2014年6月汽车行业运行分析
[汽车制造业] [2014-08-01]
2014年6月,汽车产销环比略有下降,产量同比保持较快增长,但由于市场需求回升乏力,销量同比增长略显缓慢。乘用车产销同比继续保持快速增长势头,商用车市场依旧低迷,产销量环比、同比均明显下降。中国品牌乘用车市场占有率环比、同比均继续下降,小排量乘用车市场份额也较上月及上年同期水平略有降低。6月,我国汽车企业出口情况依然不佳,尽管出口量环比有所上升,但同比仍未摆脱下滑局面。全国汽车市场价格稳中小幅波动,其中国产汽车价格保持稳定,进口汽车价格继续小幅下行。2014年1-5月,汽车工业重点企业(集团)主要经济指标保持不同程度增长,与1-4月相比,利润总额增长速度有较为明显的回落。
关键词:汽车行业;运行分析
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51682.四轮驱动电动汽车轮毂电机上的防滑控制的研究
[汽车制造业] [2014-08-01]
This paper proposes a wheel slip control strategy for 4WD Electrical Vehicle with In-wheel Motors.In the first part of this paper,a brief introduction of sliding mode control for acceleration slip regulation is given.Consider that its control effect varies with road conditions,another algorithm which can automatically adapt to different roads is designed.This method takes advantage of the peculiarity of the longitudinal static tire force curve and regulates wheel slip ratio to the detected optimal value,aiming to maximize the traction force while preserving sufficient lateral tire force.Simulation results show that the slip rate can be regulated to a value around the optimal slip ratio,and the driving torque is very close to the maximum transmissible torque.The control strategy achieves stronger stability,shorter driving distance and hence better control performance.
关键词:电动汽车;四轮驱动;防滑控制
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51683.起重机机制优化选择问题
[汽车制造业] [2014-08-01]
Design of state-of-the art crane mechanisms involves a multi-stage and multi-criterial optimization. Depending on the specificity and intended use of the machine, the optimal structure and dimensions of its mechanisms are sought as well as optimal algorithms for drive control and regulation, which requires the application of optimization criteria. It appears, however, that the approach relying on the minimum of a specifically formulated quadratic functional enables the selection of optimal geometric parameters of the mechanism and, besides, proves effective as the method of drive control. Furthermore, the geometric parameters of the mechanism can be optimized for its entire working range. Simplicity, universality and efficiency of the method are demonstrated on the example of a slewing one-link jib crane system. The search for the optimal control strategy of drive mechanisms is illustrated in the study that investigates an asymmetrically loaded platform suspended on ropes and people moving with respect to it during the hoisting phase.
关键词:控制器;起重机;机制优化选择
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51684.并联式混合动力电动汽车动力系统匹配与优化
[汽车制造业] [2014-08-01]
The parameters matching of the hybrid powertrain system of the hybrid electric vehicle has a directly impact on the performance of the vehicle dynamic and the fuel economy.The preliminary match of the powertrain system base on analysis of Driving Cycle is done,then the software of AVL-Cruise and Matlab are integrated with Isight to optimize parameters of match,by using the Multi-Island GA and NLPQL to establish the combinatorial optimization algorithm.The results show that the fuel economy have been improved by 10.92% without sacrificing the dynamic performance and under the premise of ensuring the limits of the state of charge of battery.
关键词:电动汽车;并联式;混合动力;系统匹配;系统优化
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51685.车辆路径问题的模型和电池电动汽车物流分配算法的研究
[汽车制造业] [2014-08-01]
The battery quick exchange mode is an effective solution to resolve the battery charging problem of electric vehicle.For the electric vehicle battery distribution network with the battery quick exchange mode,the distribution model and algorithm are researched; the general mathematical model to take delivery of the vehicle routing problem with time window (VRP-SDPTW) is established.By analyzing the relationship between the main variables,structure priority function of the initial population,a new front crossover operator,swap mutation operator and reverse mutation operator are designed,and an improved genetic algorithm solving VRP-SDPTW is constructed.The algorithm could overcome the traditional genetic algorithm premature convergence defects.The example shows that the improved genetic algorithm can be effective in the short period of time to obtain the satisfactory solution of the VRP-SDPTW.
关键词:电动汽车;车辆路径问题;物流分配算法
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51686.电液制动压力控制系统的结构分析
[汽车制造业] [2014-08-01]
The structure design and pressure control of electro-hydraulic braking system (EHB) is essential for electric vehicles,which is critical to the braking energy recovery and vehicle stability control.In this paper,the overall structure of the electro-hydraulic braking system is analyzed,and classification method according to how the braking pedal is decoupled with the braking pressure is proposed.Through the PID control method to achieve pressure following control,it lays the foundation for electric vehicle stability control.
关键词:电动汽车;电液制动;压力控制系统
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51687.振荡控制回路检测
[汽车制造业] [2014-08-01]
Since a control loop may exhibit poor performance for various reasons, it is not only important to detect poor performance, but the challenge is to trace the bad performance to its root cause. Not only controller design and tuning but also other elements in the control systems, such as sensors and actuators, are often responsible for the poor performance. There are many reasons for poor control performance, which can be detected using specialised methods and indices, without requiring the knowledge of time delays or model identification.
关键词:控制器;振荡控制;回路检测
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51688.双速I-AMT驱动电动汽车的性能评价
[汽车制造业] [2014-08-01]
For a novel electric vehicle equipped with 2-speed Inverse Automated Manual Transmission (I-AMT),optimal design of the gear ratios is carried out using dynamic programming (DP) under vehicle dynamic constraints.Given multiple driving cycles,the design target is to make the electric vehicle obtain the best energy consumption economy.After the gear ratios are determined,the performance of the 2-speed electric vehicle is compared with the same vehicle with a single-speed gear box,and it is shown that the 2-speed transmission has much better performacne in terms of acceleration time,maximum speed and energy economy.
关键词:电动汽车;双速;性能评价
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51689.探头接口代理的设计和它的无线传感器网络中间件协议
[汽车制造业] [2014-08-01]
This paper presents a simple design and implementation of a transducer interface agent. The agent communicates with a middleware for wireless sensor networks, and can be installed on the PC or any small gateway devices. The agent's chief end is to replace the network capable application processor (NCAP) and wireless transducer interface module (WTIM) with the agent itself in the IEEE 1451 family of standards. In order to support various non-standardized transducers, we propose to use a variety of configuration template files instead of modifying the agent itself. While a wrapper of the transducer interface agent manages various types of sensors, the controller deals with many actuators. In order to justify the usefulness of the proposed agent and its protocol, we carried out health monitoring experiments in a mock-up railway system and verified the efficiency.
关键词:控制器;探头接口代理;无线传感器;网络中间件协议
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51690.基于电动汽车动力系统的状态反馈和扭转振动的控制建模
[汽车制造业] [2014-08-01]
Electric vehicles will longitudinally vibrate obviously under acceleration and regenerative braking conditions (because of torsional vibration of the electric vehicle powertrain).This paper includes models of motor rotor,gear reducer and differential assembly,half shafts,tire and body and nonlinear powertrain dynamic model in consideration of gear backlash and frictional characteristics between tire and ground.Real car tests confirm that it is correct under acceleration conditions.Then a two mass-spring damper linear model which is simplified from the nonlinear powertrain dynamic model is proposed to design torsional vibration control algorithm based on state feedback.The simulation results show that the algorithm can actively eliminate torsional vibration.
关键词:电动汽车;动力系统;状态反馈;扭转振动;