动车组防滑控制特性分析

列车在制动过程中,如果轮轨间制动力超过了最大粘着力,车轮就会产生滑行,轮轨之间的滑动会延长制动距离并使车轮踏面擦伤。踏面擦伤后不仅降低乘车的舒适性,也会给转向架零部件带来附加的冲击力,使其寿命缩短;为避免这种现象的产生,使用微机控制的防滑器,对制动、即将滑行、缓解、再粘着的全过程进行动态检测与控制。通过使用Simulink建立模型对动车组制动时防滑过程进行模拟仿真,通过检测车体、车轮速度的变化来控制制动缸压力的变化,进而达到防止车轮打滑的目的。     

铁道车辆防滑控制仿真

列车的可靠制动是其安全运行的必要保证,而制动过程中的防滑控制又是安全制动和缩短制动距离的有效途径.建立车辆制动动力学模型和单轮对制动动力学模型,车辆系统自由度为42,建模中考虑车辆系统悬架力非线性、轮轨接触几何关系非线性和轮轨蠕滑力非线性.考虑到盘型制动系统的摩擦特性和制动缸压力变化特性,建立了制动系统力学模型.采用P控制方法,用数值仿真方法研究准高速列车制动过程的防滑控制.计算结果表明,P控制能有效防止车轮在轮轨粘着力较低时的滑行,从而提高制动的可靠性和缩短制动距离,并减小制动过程中车辆的纵向振动.     

带式输送机盘式制动系统控制特性的数值模拟研究

为研究带式输送机盘式制动系统的控制特性,建立了盘式制动系统的AMEsim仿真模型,并进行了仿真分析,研究了液压缸进口压力和位移随时间的变化规律,突然停电时节流阀不同开度、蓄能器不同充气压力对制动性能的影响,正常制动时的正压力与速度变化规律,以及采用开环和闭环控制时的速度控制特性。结果表明采用开环控制时系统虽然稳定,但响应速度较慢,稳态误差较大。要获得较理想的控制效果,就要采用闭环控制策略。     

基于ESC的电动汽车再生制动策略及能量回收

为了提高电动汽车制动过程的节能效果,构建了可以对电机回馈制动以及液压制动过程进行协调控制的方案,能够满足对车轮轮缸的协调控制效果。通过仿真测试发现,随着制动强度的变化,可实现电机回馈制动力与液压制动力间的良好协调,以此满足制动过程的控制要求,实现制动能量的高效回收。以电子稳定控制器(Electronic Stability Controller,ESC)实现的制动能量回收方案效率更高,并且随着制动减速度的降低变得更加显著。当车辆减速度为5m/s²时,液压与电机制动力同时发挥作用,实现协调控制的效果,且轮缸压力的调节功能,避免车轮发生抱死的情况。本方案可以达到更优的车辆控制性能,实现车辆制动能量的高效回收。可以使NDEC工况下的续驶里程提升9.35%,WLTP工况下上升37.2%,ECE工况下上升15.2%。     

负制动技术在电动叉车设计中的应用

电动叉车的制动系统一般分为行车制动和停车制动,其作用是对行驶中的叉车前轮施加制动力,使车辆减速或停车,车辆可靠停放。停车制动实现叉车在平地或坡道可靠停放,也可用于紧急刹车。本文主要介绍一种更安全可靠的负式停车制动方案,它通过机械弹簧力压紧制动摩擦盘实现制动,通过电控适时有效地控制电磁阀和油路的开启,在制动器油腔产生压力以克服作用在摩擦片上的弹簧力,达到停车制动的释放。     

拖车制动性能两种控制方式仿真对比研究

本文通过运用MATLAB/SIMULINK建立拖车制动控制系统的仿真数学模型,并对其进行仿真计算,在制动力增长方式、制动减速度、制动距离、牵引杆受力等方面,分析比较两种控制方式下拖车制动性能的优劣,为汽车电磁制动器控制系统的设计提供一定的理论依据。     

高速列车钢质制动盘锻造技术研究与发展

进入21世纪以来,随着列车速度的提高,列车动能的不断增加,为保证列车安全运行,高速列车需要有强大的制动力及黏着的复合制动系统,来保证良好的制动性能。纵观国内外高速列车技术,盘形制动装置是其基础制动方式的最佳选择。盘形制动装置依靠制动盘与闸片之间的摩擦获得制动力。国内外制动盘的种类繁多,曾应用过普通铸钢、普通铸铁及低合金铸铁等制动盘,由于列车速度的不断提高和轻量化要求,又相继研发了合金铸钢、钢质锻造、蠕墨铸铁和碳／碳纤维复合材料等制动盘。     

基于制动稳定性要求的ADVISOR再生制动模块的开发

利用ADVISOR软件,分析满足制动稳定性条件下的电动汽车再生制动系统的制动能回收能力,在其再生制动模型基础上,从动力学角度建立了各制动力制动份额随制动减速度变化的模型,仿真结果表明,此模型有效地拓展了ADVISOR的仿真范围,方便了评估电动汽车再生制动系统.     

基于SIMULINK的矿井提升机盘式制动器性能研究

基于JKB-2.5×2.3P型提升机盘式制动器的恒压减速回路制动系统与制动过程数学模型,建立SIMULINK仿真模型,获得盘式制动器制动加速度、速度、闸瓦位移随时间的变化关系.分析其仿真结果,得到"制动器制动迅速,响应时间较短,在制动过程中加速度值变化较小,其制动力可随负载变化而变化"的结论.该研究结论有助于掌握不同工况下盘式制动器的制动过程.     

鼓式制动器制动力矩监测方法研究

鼓式制动器在门式起重机、卸船机、门座式起重机、电梯等特种设备上具有广泛的应用,文中针对鼓式制动器制动力矩监测的迫切需要,对鼓式制动器的制动原理进行研究,提出一种不依赖固定的摩擦系数、不需要空载运行的全新的制动力矩监测方法,在鼓式制动器制动时,连接2个制动闸瓦的制动力臂形成1对制动力偶,通过监测制动臂对制动器底座的力得到制动器的制动力矩。该方法能随着施加在制动轮上的正压力以及摩擦系数的变化对制动力矩进行实时的监测。文中基于该方法研发一套传感器,完成制动力矩的标定工作,发现该传感器的可重复性高,且具有较高的精度和灵敏度,相比于常规的通过监测制动力,乘以固定的摩擦系数相比,有效地解决了无法监测摩擦系数改变而导致的制动力矩的问题。     

Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

The accurate estimation of road friction coefficient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coefficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coefficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode surface. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels.The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time andresist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.     

基于AMT的轻度混合动力系统再生制动控制

分析制动强度、ISG电动机制动力、发动机制动力以及电池充电功率的相互关系,得到电动机实际制动力随期望制动强度和车速变化曲面。提出基于电动机实际制动力的前后轮制动力分配策略。在此基础上考虑变速器挡位对传动系统工作点的影响,提出制动过程中能量最大化回收的换挡控制策略。台架试验结果表明,采用所提出的再生制动控制策略比传统控制策略能更有效地回收制动能量。     

Adaptive robust motion trajectory tracking control of pneumatic cylinders with LuGre model-based friction compensation

Friction compensation is particularly important for motion trajectory tracking control of pneumatic cylinders at low speed movement. However, most of the existing model-based friction compensation schemes use simple classical models, which are not enough to address applications with high-accuracy position requirements. Furthermore, the friction force in the cylinder is time-varying, and there exist rather severe unmodelled dynamics and unknown disturbances in the pneumatic system. To deal with these problems effectively, an adaptive robust controller with LuGre model-based dynamic friction compensation is constructed. The proposed controller employs on-line recursive least squares estimation（RLSE） to reduce the extent of parametric uncertainties, and utilizes the sliding mode control method to attenuate the effects of parameter estimation errors, unmodelled dynamics and disturbances. In addition, in order to realize LuGre model-based friction compensation, the modified dual-observer structure for estimating immeasurable friction internal state is developed. Therefore, a prescribed motion tracking transient performance and final tracking accuracy can be guaranteed. Since the system model uncertainties are unmatched, the recursive backstepping design technology is applied. In order to solve the conflicts between the sliding mode control design and the adaptive control design, the projection mapping is used to condition the RLSE algorithm so that the parameter estimates are kept within a known bounded convex set. Finally, the proposed controller is tested for tracking sinusoidal trajectories and smooth square trajectory under different loads and sudden disturbance. The testing results demonstrate that the achievable performance of the proposed controller is excellent and is much better than most other studies in literature. Especially when a 0.5 Hz sinusoidal trajectory is tracked, the maximum tracking error is 0.96 mm and the average tracking error is 0.45 mm. This paper constructs an adaptive robust controller     

Position control of a rodless cylinder in pneumatic servo with actuator saturation

In this paper, positioning control of a rodless cylinder in pneumatic servo systems with actuator saturation is investigated via an active disturbance rejection control. A linear extended state observer is designed to estimate and compensate strong friction force and other nonlinearities in the pneumatic rodless cylinder system. An actuator saturation linear feedback control law is developed to further improve the control performance. Furthermore, a linear matrix inequality-based optimization algorithm is employed to estimate a strictly invariance set for the closed-loop system. Experiment results with response time 0.5 s and accuracy 0.005 mm for a 200 mm step signal demonstrate the effectiveness of the proposed control strategy.     

Regenerative braking control strategy in mild hybrid electric vehicles equipped with automatic manual transmission

The actual regenerative braking force of an integrated starter/generator (ISG), which is varied with desired braking deceleration and vehicle speed, is calculated based on an analysis of the required deceleration, maximum braking force of ISG, engine braking force and state of charge (SOC) of battery. Braking force distribution strategies are presented according to the actual regenerative braking force of ISG. To recover the vehicle’s kinetic energy maximally, braking shift rules for a mild hybrid electric vehicle (HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered. A test-bed is built up and regenerative braking tests are carried out. The results show that power recovered by the braking shift rules is more than that recovered by the normal braking control rules. __________ Translated from Chinese Journal of Mechanical Engineering, 2006, 42(10): 156–160 [译自: 机械工程学报]     

关于提升机紧急制动的探讨

钢丝绳在摩擦衬垫上滑动是提升机安全运行的最根本问题。针对提升机在紧急制动时采用二级制动的特点,对提升、下放载荷时,如何正确地确定紧急制动力矩及滑动极限减速度进行了分析探讨。     

优化制动转矩分布以提高四轮驱动混合电动车辆的稳定性

四轮驱动混合电动车辆稳定性控制逻辑建议采用后马达能量回收制动和一个电液制动器（EHB）。采用一个通常的算法,求得能量回收制动和EHB转矩之间最佳的转矩分布。根据已知输入的所要求的偏转转矩和道路摩擦系数,用该通常算法计算出最佳能量回收制动转矩和最佳的EHB转矩。基于最佳的制动转矩分布,相应驾驶员转向角和车辆速度,用模糊控制算法,车辆稳定控制逻辑建议形成所要求的偏转转矩,去补偿侧滑角和偏转率的误差。对单车道变更机动性用比较固定能量回收制动和最佳能量回收制动,判断车辆稳定性控制逻辑的性能。由仿真结果可以看到,在满足车辆稳定性的情况下,最佳能量回收制动可以比固定的能量回收制动增大能量回收。     

汽车制动力学特性分析及其控制技术

通过对汽车制动力学特性进行分析，提出了理想的制动力分配方式。根据车轮实际运动及受力情况，探讨了制动防抱死系统的控制逻辑，为进行汽车制动性能研究提供了一定的理论支持。     

复合滑模控制在精密PMLSM激光切割运动平台的应用

针对永磁直线同步电机激光切割运动平台的位置伺服控制低抖振、高精度、强鲁棒的要求,在传统双幂次滑模趋近律的基础上,提出一种变边界层的双幂次滑模趋近律带滑模扰动观测器的复合趋近律滑摸控制方法。变边界层方法是对控制系统的控制精度要求和降低抖振的权衡,而所提出的方法又继承了传统双幂次滑模趋近律方法的有限时间收敛特性。为了降低控制系统设计的保守性,设计了一种基于超螺旋算法的滑模扰动观测器对系统的未知扰动进行估计,并在此算法中添加一个幂指数,通过仿真实验证明了提高幂指数的数值可加快未知扰动的估计值的收敛速度。结合Lyapunov稳定性理论,证明了闭环系统的稳定性。最后,搭建了用于激光切割的永磁直线同步电机平移试验台对所提出的控制器进行测试。实验结果表明:本文所提出的控制器的位置跟踪误差不超过1μm,且误差波动较小,能够满足伺服控制系统的要求。