基于驱动力控制的双电机独立驱动电动汽车DYC系统研究

DYC(Direct Yaw moment Control,直接横摆力矩控制)能够提高汽车的操纵稳定性。提出一种采用分层控制结构的DYC控制系统,上层为横摆力矩决策层,采用滑模变结构控制,计算保持整车稳定所需要的附加横摆力矩;下层为横摆力矩分配层,将决策层得出的附加横摆力矩分配到每个驱动电机,并输出相应转矩。通过建立Car Sim和Simulink联合仿真平台,在双移线工况下,验证控制策略能够提高整车的操纵稳定性。     

基于LQR的汽车横摆力矩控制研究

针对汽车极限工况稳定性控制问题,论文基于最优控制理论LQR进行了汽车横摆力矩控制研究.建立了整车七自由度动力学模型,设计了LQR附加横摆力矩控制算法.为了提高制动稳定性,相对于传统单轮制动研究了单侧两轮附加横摆力矩分配方法.最后选择增幅正弦转向低附着路面行驶工况对控制算法进行了验证.仿真结果表明所研究的控制算法能够有效提高汽车极限工况行驶稳定性.     

直接横摆力矩控制车辆稳定性研究概述

针对直接横摆力矩如何实现汽车的稳定性,与其他一些汽车稳定性控制系统进行了比较。概述了国内外采用的一些直接横摆力矩控制策略及力矩分配方法,并介绍了直接横摆力矩控制在实车上的应用,最后分析了直接横摆力矩的发展趋势。     

汽车主动转向与直接横摆力矩协调控制

为了提高汽车的操纵稳定性和行驶稳定性,分别对主动转向及直接横摆力矩控制进行了研究。根据汽车线性二自由度模型获得汽车稳态工况下的期望横摆角速度和期望质心侧偏角,设计了上层控制器和下层控制器,其中上层控制器为主动转向与直接横摆力矩功能分配的协调控制,下层控制器采用单神经元自适应PID算法设计了主动转向控制器和直接横摆力矩控制器。基于汽车行驶稳定性指标设计了调度参数,以实现主动转向和直接横摆力矩的协调控制。分别选取高附着系数路面和低附着系数路面进行了正弦输入试验和阶跃输入试验,结果表明所设计的控制系统能够很好地提高线控转向汽车的操纵稳定性和行驶稳定性。     

基于模糊技术的汽车稳定性控制的研究

汽车稳定性是汽车安全性的一个重要指标,传统的稳定性控制方法难以满足控制系统的性能要求,本文采用鲁棒性较强的模糊控制方法对汽车稳定性进行控制。建立了整车七自由度汽车稳定性系统模型及Matlab/Simulink仿真模型,采用"魔术公式"轮胎模型,以横摆角速度的误差及误差变化率作为输入、横摆力矩作为输出设计了模糊控制器,并进行仿真。通过分析仿真结果,验证了模糊控制在汽车稳定性控制中的有效性。     

基于动态门限值的分布式驱动电动汽车驱动力矩控制研究

为改善分布式驱动电动汽车高速行驶稳定性，避免频繁驱动控制操作对汽车行驶安全性的影响，提出了一种适应不同驾驶工况的参数动态门限值算法，设计了汽车附加横摆力矩滑模控制策略和驱动力矩二次规划优化分配控制策略，并进行了角阶跃输入工况和双正弦输入工况的仿真分析。结果表明，所设计的控制策略能有效控制汽车的质心侧偏角与横摆角速度，在保证汽车行驶稳定性的前提下，使质心侧偏角与理想值偏差减小了3.6%以上，轮胎附着利用率减少19.5%以上，有效地降低了轮胎附着利用率，提高了汽车的行驶安全性。     

分布式驱动电动汽车操纵稳定性控制仿真

本文研究通过直接横摆力矩控制来提高分布式驱动电动汽车稳定性问题。针对充分发挥四轮独立驱动电动汽车各电机独立可控的特点来提高车辆稳定性的问题,提出了基于滑模变结构控制原理的车辆稳定性分层控制策略。其中,以横摆角速度和质心侧偏角为控制变量,设计了上层附加横摆力矩层。考虑地面附着条件和电机外特性约束,设计了下层动态转矩分配层。通过Simulink与Carsim联合仿真表明,所设计控制策略提高了车辆的稳态行驶能力,增强了车辆的横向稳定性,控制策略行之有效。     

基于同侧车轮制动力优化分配的汽车稳定性控制

针对汽车复杂行驶工况下的稳定性问题,提出了基于同侧车轮制动力优化分配的汽车稳定性控制方法。整体控制分为上层横摆力矩控制与下层制动力优化分配两部分,上层横摆力矩控制以跟踪参考横摆响应为目标,输出保持车辆横向稳定性的修正横摆力矩;下层制动力优化分配采用最优化分配算法计算需要施加在各制动车轮上的制动力,实现上层横摆力矩控制器输出的修正横摆力矩。利用MATLAB/Simulink与Carsim联合仿真验证控制效果,结果表明,基于同侧车轮制动力优化分配的汽车稳定性控制在多种复杂运行工况下均能较好地跟踪汽车参考横摆响应,减小质心侧偏角,改善汽车的操纵稳定性。     

独立驱动电动汽车模型参考自适应稳定性控制

为提高四轮独立驱动电动车(EV)辆行驶中侧向稳定性和安全性,设计了一种基于模型参考自适应(MRAC)直接横摆力矩稳定性控制算法.上层控制器通过Lyapunov数设计并对系统轮胎侧偏刚度、车身质量参数进行实时估计以获得额外横摆力矩;下层控制器利用二次规划法优化所得力矩分配至各轮,以保证控制器动态响应的实时性.在双移线工况...     

四轮独立驱动电动汽车驱动控制策略研究

电动化、智能化是汽车未来的发展趋势,分布式电动汽车近年来发展迅速,四轮独立驱动电动汽车作为其中的一种形式,在很多方面具有有优于传统汽车的控制优势。文章对四轮独立驱动电动汽车的驱动控制策略进行研究,采用神经网络PID控制设计横摆力矩控制器保证汽车的侧向稳定性,以保持车轮的最佳滑移率为目标研究了驱动防滑控制,通过实验验证驱动防滑策略能够有效防止车轮打滑和严重失稳现象。研究表明:该驱动控制策略能够对四轮驱动汽车的驱动力矩进行合理分配,能确保车轮在附着系数不均路面上具有足够的驱动力。     

不同混合动力驱动系统和工作模式

对串联式、并联式和混联式三种典型的混合动力系统的结构进行研究;在此基础上,对三种混合动力系统的工作模式进行分析和比较。     

某型蓄电池叉车状态监测器设计

设计了基于C8051F020的蓄电池叉车状态监测器,讨论了蓄电池组的电量测量方法和叉车载货量测量方法,分析了监测器的硬件组成,并给出了单片机的软件流程图。在叉车驾驶员培训中的应用,表明该监测器达到了既定目的。     

Energy efficiency optimization of electric vehicle driven by in-wheel motors

Electric vehicle is considered to be the solution for energy and environment crisis, but it’s still not competitive enough with conventional vehicles because of the limited energy density and high cost of the power battery. So the energy efficiency is of the most importance for the control of electric vehicles. This paper looks into the energy efficiency optimization problem of electric vehicle driven by four in-wheel motors by developing a comprehensive energy efficiency model of the permanent magnet synchronous motor including the inverter. The calculated efficiency agrees with the measured data quite well. Based on the power loss analysis, the conclusion is drawn that in all driving or braking conditions the total torque requirement should be distributed evenly to all the motors in order to maximize the energy efficiency for electric vehicles driven by permanent magnet synchronous in-wheel motors. Vehicle test results show that the energy efficiency of the evenly distributed torque control is higher than the control strategy proposed by control allocation in literature.     

三轴客车随动转向轿随动转向原理分析

针对目前市场所用13．7米客车随动转向桥,重点分析随动转向原理,转向半径的减小,锁止控制装置的工作原理。     

Reconfigurable fault-tolerant controller synthesis for a steer-by-wire vehicle using independently driven wheels

In this paper, a synthesis method for a reconfigurable fault-tolerant control system for use in a steer-by-wire vehicle is proposed. The vehicle considered in this paper is also assumed to have independently driven wheels. The control objective in this work is to enable the vehicle yaw rate to track the reference signal even when the steering actuator breaks down. Since the vehicle yaw rate can be controlled with either the front wheel turn angle or the yaw moment generated by the independently driven wheels, this system has actuator redundancy. We attempt to design a control system that manages this actuator redundancy so that the performance degradation due to the actuator failure is minimised. We utilise a control allocator based on on-line optimisation for managing the actuator redundancy. The fault-tolerant control system with a control allocator has several excellent properties. For example, the method can handle various failure situations. Also, since the control allocation problem is reduced to a convex quadratic programming problem, the on-line computational effort is relatively little. However, so far, it has been unclear whether the stability of the control system with the control allocator is guaranteed when the actuator failure occurs. Therefore, we propose a design method of a fault-tolerant controller based on on-line optimisation that guarantees the stability of the overall system. The effectiveness of the method is established through numerical examples.     

Application of rack type motor driven power steering control system for heavy vehicles

The Electric Power Steering (EPS) or Motor Driven Power Steering (MDPS) mechanism proves to be a bright prospect among passenger vehicles ensuring better vehicle safety and fuel economy. The car manufacturers are focusing on the production of Rack type EPS system (REPS). This paper describes the development of concurrent simulation technique using TruckSim and control strategy for analysing RMDPS control system with a dynamic vehicle system. A full Truck vehicle model interacting with RMDPS control algorithm was concurrently simulated on a sinusoidal steering input. The dynamic responses of vehicle chassis and steering system resulting were evaluated and compared with proving ground experimental data. The comparisons show reasonable agreement on steering wheel torque, lateral acceleration and yaw rate. This concurrent simulation research leads the possibility of RMDPS performance evaluation of Truck and Semi-bonnet cars.     

Study on a four wheel steering vehicle driven at an objective side slip angle

At the center of gravity of a vehicle, the control function for rear steering can cancel the side slip angle which varies as the running speed is changed. An instantaneous center of vehicle motion is controlled, employing rear steering. Even though the running speed of the vehicle is changed, the side slip angle remains as it was, if a relation of the position of the instantaneous center of vehicle motion to the vehicle does not change. Furthermore, taking account of an instantaeous center of yaw motion will enable us to select how much the side slip angle should be.     

沉管灌注简桩在高速公路软基处理中的应用

介绍了沉管灌注筒桩（简称筒桩）加固高速公路软基的原理、施工设备、工艺、设计和质量检测。通过在杭-宁高速公路的工程实例表明，筒桩承载力大，处理软基总沉降量小，且易于稳定，土体侧向变形小，填筑速度快，施工周期短，是一种适用于软基处理的优质新桩型。     

沉管灌注筒桩在高速公路软基处理中的应用

介绍了沉管灌注筒桩(简称筒桩)加固高速公路软基的原理、施工设备、工艺、设计和质量检测.通过在杭-宁高速公路的工程实例表明,筒桩承载力大,处理软基总沉降量小,且易于稳定,土体侧向变形小,填筑速度快,施工周期短,是一种适用于软基处理的优质新桩型.     

System power loss optimization of electric vehicle driven by front and rear induction motors

Power loss optimization aiming at the high-efficiency drive of front-and-rear-induction-motor-drive electric vehicle (FRIMDEV) as an effective way to improve energy efficiency and extend driving range is of high importance. Different from the traditional look-up table method of motor efficiency, power loss optimization of the dual- motor system based on the loss mechanism of induction motor (IM) is proposed. First of all, based on the power loss characteristic of FRIMDEV from battery to wheels, the torque distribution optimization model aiming at the minimum system power loss is put forward. Secondly, referring to d-q axis equivalent model of IM, the power loss functions of the dual-IM system are modeled. Then, the optimal torque distribution coefficient (β _o) between the two IMs is derived, and the theoretical switching condition (T _sw) between the single- and dual-motor-drive mode (SMDM and DMDM) is confirmed. Finally, a dual-motor test platform is developed. The derived torque distribution strategy is verified. The influence of motor temperature on β _o and T _sw are tested, and the correction models based on temperature difference are proposed. Based on the system power loss analysis, it can be confirmed that, under low load conditions, the SMDM takes priority over the DMDM, and the controller of the idling motor should be shut down to avoid the additional excitation loss. While under middle to high load conditions, even torque distribution (β _o = 0.5) is preferred if the temperature difference between the two IMs is small; otherwise, β _o should be corrected based on dual-motor temperatures. The theoretical T _sw derived without dealing with temperature difference is a function only of motor speed, while temperature difference correction of it should be conducted in actual operations based on motor resistance changing with temperature.