车用转筒式电涡流缓速器设计和试验研究

介绍了车用转筒式电涡流缓速器的结构和工作原理,研究了车用转筒式电涡流缓速器制动力矩的计算方法,设计了一种额定制动力矩为1400N.m的转筒式电涡流缓速器,并且在试验台上测试了该缓速器有关性能参数。试验结果表明,该车用转筒式电涡流缓速器符合设计要求,设计实践为转筒式电涡流缓速器的优化设计和系列化设计提供了依据。     

车用电涡流缓速器转子盘流场有限元分析

简要介绍了车用电涡流缓速器的工作原理,建立了6191HS型电涡流缓速器转子盘叶片二维有限元模型,确定适当的边界条什件并对流场进行了数值分析,显示了叶片上的压力和叶间速度分布,其数值分析结果有利于叶片结构的改进设计,以达到降低转子盘温升,提高电涡流缓速器制动稳定性的目的。     

Hydraulic retarders for heavy vehicles: Analysis of fluid mechanics and computational fluid dynamics on braking torque and temperature rise

Hydraulic retarders are auxiliary braking devices that reduce the velocity of a vehicle, particularly when a vehicle is driven downhill. Such velocity reduction could reduce the potential risk caused by brake failure caused by the service brake working for a long time and the temperature of the brake shoe becomes extremely high. This paper introduces the construction of the hydraulic retarder and proposes two mathematical models for the hydraulic retarder. The first mathematical model is deduced by using fluid mechanics, which is used to analyze the mechanism of how braking torque is produced and the key factors that can influence the value of the braking torque. The second mathematical model is deduced by using thermodynamics, which is used to quantify the heat produced by the hydraulic retarder. This research emphasizes that the flow rate and the average velocity of the working fluid in the working chamber mainly determine the braking torque of the hydraulic retarder. The flow rate into and out of the working chamber determines the temperature rise of the working fluid. Computational fluid dynamics (CFD) simulations are conducted with the Reynolds-averaged Navier-Stokes (RANS) and Shear Stress Transport (SST) turbulent models. Experiments are carried out to justify the two mathematical models and the CFD simulations. The results show that the mathematical models are capable of describing the force analysis and energy conversion of the hydraulic retarder and SST is more accurate for CFD simulation and the error is within 6 %.     

Torque characteristics analysis for optimal design of a copper-layered eddy current brake system

An enhanced parametric model for a copper-layered eddy current electric machine (retarder) is introduced in this paper. The modeled torque characteristics of the copper-layered electromagnetic retarders are based on the results from a detailed electromagnetic finite element analysis (FEA) of these eddy current machines. The model uses a parameterized double-exponential function to model the steady state speed-torque characteristics of the retarder. The parameters are adjusted for optimal braking performance in conjunction with predicted speed-torque characteristics of a copper-layered retarder. A full vehicle model, along with the proposed retarder speed-torque model has been used to simulate a series braking events. The simulation results show that the peaks of the retarder speed-torque curves must be designed to occur within a specific range of speeds for optimal braking performance.     

电涡流缓速器制动力矩的计算方法

运用电磁场理论推导了电涡流缓速器的电流密度和制动力矩计算公式，这些计算公式反映了电涡流缓速器各设计参数的相互关系．可用于指导电涡流缓速器的产品开发。     

能量回收式电涡流缓速器制动策略研究

文章结合电涡流缓速器和再生制动能量回收技术的优点,提出了能量回收式电涡流缓速器制动补偿策略。利用再生制动系统提供的制动力矩为电涡流缓速器在持续制动过程中的制动力矩热衰退予以补偿。以GB12676-2014政策法规为验证标准,车辆在满载情况下在7%的坡道上保持以30km/h的车速匀速行驶5km为仿真目标,对某商用车型进行仿真分析。验证了该策略使得实际产生的总制动力矩始终能满足驾驶员的制动需求,可以延缓电涡流缓速器温升,保障车辆行车安全。     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

汽车电涡流缓速器的使用与维修

电涡流缓速器是一种辅助制动系统，是在现有的制动系统中增加一套作用于车辆传动系统中使车辆减速的安全辅助制动装置，它能够很容易地使乍辆缓速和恒速行驶，大大提高了汽车行驶的安全性与舒适性。介绍了汽车电涡流缓速器的性能特点、结构与工作原理、正确使用、维护及常见故障诊断等。     

Investigation of influential factors of a brake corner system to reduce brake torque variation

This paper investigates the brake corner system to reduce brake torque variation in the brake judder problem. A numerical model for determining brake torque variation was constructed using the multi-body dynamics model. Using this model, the brake torque variation for a given disc thickness variation was obtained in the time domain. The multi-body dynamics model was verified by a dynamometer test via the comparison of brake torque variation and load distribution patterns of the pad. To reduce the simulation time and cost required to determine factors that influence the reduction in brake torque variation, a simple mathematical model was constructed and used to determine both the brake torque variation and influential factors. The multi-body dynamics model and dynamometer test were modified on the basis of the results of the simple mathematical model and deformed shape of the multi-body dynamics model. These influential factors were verified to reduce the brake torque variation.     

自励式缓速器的设计与试验研究

基于转筒式电涡流缓速器与永磁发电机功能相结合的思想,提出了一种自励式电涡流缓速器的方案,并设计和制造了制动转矩为500N·m的自励式缓速器样机.最后在台架上进行了自励式缓速器的制动转矩、转筒温度和1 500r/min拖磨试验,揭示了自励式缓速器的某些特性.     

车辆液力减速制动器设计和试验研究

研究了液力减速制动器循环圆腔室内油液流动的内特性，建立了用于内特性计算的数学模型；对液力减速器空气鼓风损失进行了研究。在此基础上，设计出采用新的减损结构措施的液力减速制动器样机。并进行了相应的台架试验。结果表明，液力制动力矩的理论设计值与试验值接近；减小液力减速器空转鼓风损失的结构措施具有理想的效果。     

电涡流测功机励磁电流模糊控制的研究

发动机试验台具有多变量、时变、非线性、强耦合等特点,将模糊控制和PID控制结合起来运用于发动机试验台电涡流测功机励磁电流控制中,建立了测功机励磁电流模型,确定了模糊控制规则,对发动机的扭矩、转速进行了控制试验研究,结果表明控制精度高、动态响应快、超调量低,较好地解决了电涡流测功机控制的稳定性及测量的实时准确性问题,控制精度为4%。     

电涡流缓速器性能特性评价方法

为了掌握车用电涡流缓速器的性能特性,研究了电涡流缓速器性能特性的综合评价方法。在介绍电涡流缓速器结构、工作原理的基础上,分析了车用电涡流缓速器性能特性与使用要求,提出了以缓速器的平均制动力矩、抗热衰退性系数、制动效能、单位质量制动效能、价格作为车用电涡流缓速器性能的评价指标,并且运用价值分析的方法对车用缓速器的性能特性进行了加权综合评价。从所举实例看,加权综合评价方法对比较各种电涡流缓速器性能的优劣,有着直观的可比性,得出的结果正确、可信。     

Model-based control of an electropneumatic brake system for commercial vehicles

A properly functioning brake system is critical for ensuring the safe operation of any vehicle on roadways. Commercial vehicles such as trucks, tractors-trailers and buses are equipped with an air brake system that uses compressed air as the energy transmitting medium. This paper presents a model-based control scheme for an electropneumatic brake system for use in commercial vehicles. A mathematical model for an electropneumatic brake system was developed and corroborated with experimental data. A control scheme was developed based on this model and was used to regulate the pressure of air inside the brake chamber according to a desired pressure trajectory. This control scheme was implemented on an experimental test bench, and its performance was studied for various values of the controller parameter. The control scheme was tested for various desired pressure trajectories reflecting actual brake operation.     

宇通客车电涡流缓速器原理及性能检测

结合宁通客车电涡流缓速器的结构及工作原理,分析了电涡流缓速器的性能特点,进行丁性能测试及常见故障的诊断与排除。     

具有迟滞模拟记忆功能的奥迪盘式制动器可变线性模型

本文以奥迪１００盘式制动器为研究对象，建立了一种可模拟制动压力－力矩响应迟清点特性的可变线性模型，首先，介绍在ＪＦ－１３２型汽车制动器试验台上进行防抱制动器模拟试验的方法，其次，在获得大量试验数据的基础上，运用曲线拟合和优化技术，建立制动压力－力矩关系的线性模型，心滞模型为线笥模型，最后，在相同制动压力输入的前提下，把模型的理论计算民试验结果进行对比分析了模型的有效性和精确性。     

Brake Valve Timing and Fuel Injection: a Unified Engine Torque Actuator for Heavy-Duty Vehicles

A unified engine torque actuator for heavy-duty vehicles is developed in this paper. Based on averaging and identification of the instantaneous torque response for changes in brake valve timing and fuel flow, we derive a control oriented engine model of a six cylinder, 350 Hp turbocharged diesel engine, equipped with a compression brake. This work bridges the gap between the detailed compression crank angle based models developed in the engine design community, and the first order lag representation of diesel engine torque response used in the vehicle dynamics community. Moreover, we integrate the compression brake actuator with the service brakes and design a PI-controller that emulates the driver's actions during long descends on grades. The controller simply uses the engine speed measurement to activate the service brakes only when needed.     

缓速器：制约与重视并存

为一种高效的汽车制动辅助装置,俗称"电刹"的电涡流缓速器是国际流行的第三制动系统,可以通过驾驶员手动或脚动实现制动。伴随着中国客车行业的不断发展,如今,以特尔佳缓速器为首的国内产品正在日益获得客车企业和用户的认可。     

Brake Valve Timing and Fuel Injection: a Unified Engine Torque Actuator for Heavy-Duty Vehicles

A unified engine torque actuator for heavy-duty vehicles is developed in this paper. Based on averaging and identification of the instantaneous torque response for changes in brake valve timing and fuel flow, we derive a control oriented engine model of a six cylinder, 350 Hp turbocharged diesel engine, equipped with a compression brake. This work bridges the gap between the detailed compression crank angle based models developed in the engine design community, and the first order lag representation of diesel engine torque response used in the vehicle dynamics community. Moreover, we integrate the compression brake actuator with the service brakes and design a PI-controller that emulates the driver's actions during long descends on grades. The controller simply uses the engine speed measurement to activate the service brakes only when needed.