复合式汽车变速器最佳经济性速比优化算法研究

复合式汽车变速器,由金属带式无级变速器(continuously variable transmission,CVT)和有级变速传动装置组成,可根据汽车工况的需要分别实现无级变速传动和有级变速传动。综合考虑了发动机效率和CVT效率对汽车油耗的影响,提出了一种复合式汽车变速器最佳经济性速比优化方法。首先建立了动力传动系统的数值模型,为系统优化匹配和仿真分析奠定了基础。其次,建立了CVT最佳经济性速比匹配优化目标函数模型。基于simulation X软件,建立了装有复合式变速器的汽车仿真模型,对CVT的最佳经济性速比进行了优化,并对比分析了速比优化前后汽车的动力性和燃油经济性,证明了本文算法的有效性和实用性。     

车用摆销链式CVT速比控制参数优化策略研究

速比控制是变速器控制领域的关键技术之一。通过分析摆销链式CVT的结构及工作原理,采用模糊PID控制方法对汽车行驶循环工况进行仿真;搭建CVT传动系统数学模型和速比模糊控制器子模型,基于Simulink/Cruise联合仿真软件平台对模糊控制进行仿真研究;最后,引入遗传算法对速比控制器控制规则进行参数优化,分别对汽车起步工况和循环工况速比跟踪控制策略进行验证。结果表明,基于遗传算法的速比模糊控制对目标速比的跟随效果及误差变化均优于传统的模糊PID控制方法,可满足摆销链式CVT速比控制的要求。     

液力变矩器-机械无级变速器自动变速汽车综合控制策略研究

针对采用液力变矩器作为汽车起步和低速行驶时的调速装置,金属带无级变速传动为高速行驶时调速装置的双状态无级自动变速汽车,在液力变矩器台架试验的基础上,建立了双状态无级自动变速汽车的动力学仿真模型和金属带无级变速传动系统的综合控制策略,分析了分段加速行驶过程中,汽车液力变矩器和金属带无级变速器速比的变化规律,为开发设计双状态无级自动变速汽车提供理论依据。     

回流式无级自动变速传动系统设计方法研究

提出了新型回流式无级自动变速传动系统的设计方法。该设计方法以传动系统效率和速比变化范围为设计指标，确保汽车在各种行驶工况下传动系统效率在80％以上，在不同节气门开度下发动机稳态工作点均能位于最佳燃油经济线上。以长安羚羊SC7101轿车为例，完成了回流式无级自动变速传动系统关键参数的设计，为新型无级自动变速传动系统的研制开发奠定基础。     

基于发动机转速调节特性CVT速比模糊控制仿真研究

针对发动机的负荷特性和转速调节特性,建立了发动机的稳态转矩模型并确定了发动机的最佳动力性和经济性曲线,然后使用经济性加权系数法计算得出发动机的目标转速。将动力传动系统简化成双旋转质量模型,通过整车的数学模型利用Simulink建立物理模型,提出基于发动机转速调节特性的速比模糊控制方法,并分别对起步工况、制动工况和循环工况进行仿真。仿真结果显示:可以实现实际速比对目标速比很好的跟随效果,说明基于发动机转速调节特性的速比模糊控制方法能够很好的应用于速比控制。     

基于模糊免疫PID的CVT速比控制研究

针对装备金属带式无级变速器的某款车型,确定了发动机的目标转速调节特性曲线和无级变速器的目标速比,建立了CVT液压控制执行机构的数学模型。考虑到CVT速比控制的时变非线性和时滞耦合性的特点,借鉴生物免疫系统中的免疫反馈原理,结合模糊控制和PID控制各自的优点,设计了模糊免疫PID速比控制器,并在Simulink环境下对CVT整车模型起步、急加速和上坡工况进行了仿真分析。结果表明,模糊免疫PID速比控制能够很好地跟踪目标速比,具有良好的动态响应性能和较高的稳态控制精度。     

基于传动集成控制的锥环无级变速方法的研究

本文研究了一种新型汽车无级变速机构,其由两个圆锥体和一个金属锥环组成,锥环式无级变速器利用锥环本身的机械特性,实现变速器速比的转换。在Matlab/Simulink环境下建立了整车动力传动系一体化控制仿真模型,根据PID控制器的控制原理及特点对传统的PID控制器进行了改进,并对几种典型行驶工况进行了仿真分析,仿真结果表明,设计的调速控制策略能适应车辆各种行驶工况的要求,实际速比能很好地跟随目标速比。     

考虑CVT效率的无级变速车辆最佳经济性控制

传统的无级变速传动系统最佳经济性控制策略只考虑使发动机工作在其效率最高的工作点,并没有考虑无级变速器(Continuously variable transmission,CVT)效率对系统燃油消耗量的影响,而实际上无级变速器效率随其工况的变化在70%到95%之间变化,对系统燃油消耗量的影响是不可忽略的。在分析系统燃油消耗量与发动机效率和无级变速器效率之间关系的基础上,提出综合考虑发动机与无级变速器效率的最佳经济性控制策略,设计算法,以系统效率最高为优化目标,对各需求功率和车速下下发动机与无级变速器联合高效工作的目标转速和转矩进行计算。建立系统仿真模型,对优化前后的控制规律进行仿真对比分析,并在定车速工况下对优化前后的控制规律进行了对比试验。仿真及试验结果表明,综合考虑发动机与无级变速器效率的最佳经济性控制可以实现节油2%左右。     

基于模糊PID控制的CVT速比仿真研究

针对装备金属带式无级变速器的某款具体车型,建立了其发动机的转矩模型和油耗模型,基于此得出了目标转速调节特性曲线.之后,确定了无级变速传动的目标速比,并按照质量集中法简化了传动系统的模型.结合模糊PID的控制原理,提出了以CVT速比变化率为控制对象的模糊PID控制算法.在SIMULINK平台下对包含该控制算法的CVT整车...     

机电式CVT混合动力系统工况过渡控制

针对搭载机电式无级自动变速(Electric-mechanic continuously variable transmission,EMCVT)混合动力传动系统结构,采用枚举法分析了系统工作模式,将系统模式切换过渡工况归纳为发动机介入传动系统和退出传动系统两种情况。分别制定了两种情况下的控制逻辑和各阶段的控制目标,提出了发动机、电机、EMCVT和离合器综合协调控制的过渡工况控制策略。根据系统结构,建立了各关键部件的动力学模型,在MATLAB/SIMULINK仿真平台上,搭建了系统过渡工况控制仿真模型,分别针对发动机介入传动系统和退出传动系统两种情况进行了仿真。仿真结果表明,采用所提出的控制策略能大大降低系统冲击,提高模式切换品质,为机电控制CVT的应用提供理论参考。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.