MPC-based Torque Distribution for Planar Motion of Four-wheel Independently Driven Electric Vehicles:Considering Motor Models and Iron Losses

The most critical obstacle for four-wheel independently driven electric vehicles(4WID-EVs)is the driving range.Being the actuators of 4WID-EVs,motors account for its major power consumption.In this sense,by properly distributing torques to minimize the power consumption,the driving range of 4WID-EV can be effectively improved.This paper proposes a model predictive control(MPC)-based torque distribution scheme,which minimizes the power consumption of 4WID-EVs while guaranteeing its tracking performance of planar motions.By incorporating the motor model considering iron losses,the optimal torque distribution can be achieved without an additional torque controller.Also,for this reason,the proposed control scheme is computationally efficient,since the power consumption term to be optimized,which is expressed as the product of the motor voltages and currents,is much simpler than that derived from the efficiency map.With reasonable simplification and linearization,the MPC problem is converted to a quadratic programming problem,which can be solved efficiently.The simulation results in MATLAB and CarSim co-simulation environments demonstrate that the proposed scheme effectively reduces power consumption with guaranteed tracking performance.

Decentralized Dynamic Event-Triggered Communication and Active Suspension Control of In-Wheel Motor Driven Electric Vehicles with Dynamic Damping

This paper addresses the co-design problem of decentralized dynamic event-triggered communication and active suspension control for an in-wheel motor driven electric vehicle equipped with a dynamic damper. The main objective is to simultaneously improve the desired suspension performance caused by various road disturbances and alleviate the network resource utilization for the concerned in-vehicle networked suspension system. First, a T-S fuzzy active suspension model of an electric vehicle under dynamic damping is established. Second,a novel decentralized dynamic event-triggered communication mechanism is developed to regulate each sensor's data transmissions such that sampled data packets on each sensor are scheduled in an independent manner. In contrast to the traditional static triggering mechanisms, a key feature of the proposed mechanism is that the threshold parameter in the event trigger is adjusted adaptively over time to reduce the network resources occupancy. Third, co-design criteria for the desired event-triggered fuzzy controller and dynamic triggering mechanisms are derived. Finally, comprehensive comparative simulation studies of a 3-degrees-of-freedom quarter suspension model are provided under both bump road disturbance and ISO-2631 classified random road disturbance to validate the effectiveness of the proposed co-design approach. It is shown that ride comfort can be greatly improved in either road disturbance case and the suspension deflection, dynamic tyre load and actuator control input are all kept below the prescribed maximum allowable limits, while simultaneously maintaining desirable communication efficiency.

Design optimization of a slotless PM brushless motor with helical edge wound laminations for rim driven thrusters

This paper discusses the analysis and design of a very thin slotless permanent magnet （PM） brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral （like a ＂Slinky＂） and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis （FEA） are used to determine the con- strained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fit- ted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance results are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive （prototype cost） than the slotted machine.

Dual-steering mode based on direct yaw moment control for multi-wheel hub motor driven vehicles:Theoretical design and experimental assessment

One of the main challenges for multi-wheel hub motor driven vehicles is the coordination of individual drivetrains to improve mobility and stability in the steering process.This paper proposes a dual-steering mode based on direct yaw moment control for enhancing vehicle steering ability in complex environ ments.The control system is designed as a hierarchical structure,with a yaw moment decision layer and a driving force distribution layer.In the higher-level layer,the objective optimization function is con-structed to obtain the slip steering ratio,which represents the degree of vehicle slip steering in the dual-steering mode.Ayaw moment controller using active disturbance rejection control theory is designed for continuous yaw rate control.When the actual yaw rate of the vehicle deviates from the reference yaw rate obtained by the vehicle reference model and the slip steering ratio,the yaw moment controller isactuated to determine the yaw moment demand for vehicle steering.In the lower-level layer,there is a torque distribution controller based on distribution rules,which meets the requirement of yaw moment demand without affecting the total longitudinal driving force of the vehicle.For verifying the validity and feasibility of the dual-steering mode,simulations were conducted on the hardware-in-loop real-time simulation platfomm.Additionally,corresponding real vehicle tests were carried out on an eight-wheel prototype vehicle.Test results were generally consistent with the simulation results,thereby demon-strating that the proposed dual-steering mode reduces steering radius and enhances the steering per-formance of the vehicle.

Blank Holder Force Control System Driven by Servo-Motor

Blank holder force (BHF) control is used to prevent wrinkles of sheet metal in deep drawing process. Based on a novel conception of BHF control technique driven by servo-motor, a new BHF device with six-bar linkage mechanism has been designed and manufactured. Whole control system of the new BHF technique was developed, and the basic structure of the hardware configuration of the system was given. Software analysis, implementation and division of the functional modules have been done. Also, the control software in data acquisition and processing module has been developed in the relevant technology of the BHF control system for the requirements of real-time, stability and accuracy. By the new BHF device combined with the hardware and the software system, the BHF can be regulated accurately variation with the predefined BHF profile in deep drawing process.

双并列转子永磁直驱电机转子不平衡力分析与优化

双并列转子永磁直驱电机受轴间距限制,设计时会切掉部分定子铁心和绕组,造成转子电磁力不平衡。为最大限度地抑制转子所受的不平衡电磁力,该文从双并列转子结构出发,分析了电机绕组电感参数不对称的原因,提出通过合理设计线圈跨距和分布平衡三相电感。在此基础上,构建转子所受总电磁力的数学模型,理论分析各个分力的来源及影响因素,研究各个分力对转子所受总电磁力的影响,提出了优化占空角、优化耦合间距、采用定子端部不对称结构、采用转子偏心结构和切除部分单元电机五种优化方法,实现对转子所受电磁力的优化,探讨了不同方法的优化效果,以及其对转矩脉动的影响,总结了不同优化方法的优缺点。

基于长周期暂态信号分析的电机驱动变换器直流母线电容在线状态监测

直流母线电容作为电机驱动变换器中最薄弱的元件之一,其老化会导致系统故障的概率增大,因此对电容老化进行在线监测至关重要。针对现有监测方法存在经济性差、采样频率高、影响系统正常运行等问题,提出一种基于长周期暂态信号分析的电容在线监测方法,用于估计电机驱动变换器直流母线等值串联电容(equivalent series capacitance,ESC)。首先,根据系统负载切换过程建立共节点感-容等值暂态模型,分析长周期暂态信号特点。其次,推导基于长周期暂态信号的在线监测模型,确定监测程序启动判定条件。然后,提出一种基于多项式重构的电容电流基线校准方法,消除传感器零漂影响,提高监测精度。最后,仿真和实验表明所提出方法的监测精度满足电容监测的要求。

基于自联想核回归算法的数据驱动电机控制

在电机控制领域,基于模型驱动的控制方法已经广为研究,随着计算机运算能力的提升,给大量数据计算带来了可能性。为进一步提升电机控制性能,研究了一种基于自联想核回归法算法的控制补偿策略,基于运行过程中的大量数据来校正补偿电机控制过程,以提升电机控制性能,平抑运行过程中的波动。通过理论以及仿真分析,该方法能较好完成电机运行控制,加上补偿后的控制策略能减小电流波动以及转矩脉动,有一定的控制补偿效果。此控制算法同样适用于其他电机控制策略的优化过程,有一定的参考价值。

船舶轮缘推进器关键技术研究现状和发展趋势

采用电力直驱模式来完成电能与机械能的无传动转化是高端交通动力装备领域的未来战略性技术之一。轮缘推进器(RDT)作为一种高度集成的电力直驱推进,是近年来研究的热点。文章梳理了船舶轮缘推进器的6项关键技术,包括水力部件设计及优化、电机设计及控制、水润滑轴承的设计和性能强化、系统集成与测试、船体匹配及联合控制以及可靠性评估与智能运维;阐述了各项技术的研究现状和趋势,总结了国内外RDT产品和实船应用情况。研究和应用表明,节能、环保、灵活的轮缘推进器是绿色智能船舶电力推进形式的重要选择,高性能轮缘推进器专用化设计、效能提升和状态监测以及智能运维是轮缘推进器未来重要发展趋势。

AA3连续流动分析仪驱动马达带动转轴旋转模块设计及土壤中总氮测试

针对连续流动分析仪检测土壤中总氮时遇到的问题,研制了驱动马达带动转轴旋转模块.该模块可使混合的样品、试剂和空气保持在合适的温度区间进行中和反应,以利于后期利用连续流动分析仪在最优化条件下对样品进行检测分析,可将总氮的检出限从16.4µg/L降低至10.0µg/L,从而提高连续流动分析仪对样品的分析精度.

氦气风机驱动电机转子径向通风结构研究

氦气风机驱动电机是高温气冷堆一回路唯一能动设备,其安全性直接影响到高温气冷堆的安全稳定运行。针对高温高压环境及氦气传热工质对驱动电机风路结构设计及相关参数影响引发的新问题,通过建立双侧转子铁心三维风路结构流固耦合传热模型,计算分析了高温高压环境下传热工质氦气在转子径向风沟内的流动特性,研究了转子分别在动态和静态情况下,通风结构内流体流动规律及转子铁心和导条的温升变化规律。同时,对不同种类传热工质的对应规律进行了对比研究,搭建了模拟实验测试装置,实测数据与数值计算结果吻合较好,验证了计算分析结果的合理性和正确性,为氦气风机驱动电机转子风路结构优化、冷却性能的有效提升提供一定的理论参考。

深硅刻蚀晶圆位置偏移分析与研究

晶圆位置偏移过大是导致深硅刻蚀设备发生传片报警问题的主要原因之一,尤其是在采用静电卡盘的设备中。阐述了晶圆位置发生偏移原因,重点研究了解吸附配方、顶针驱动和片间清洗方案。研究表明,静电吸盘的表面聚合物残留是导致静电释放不充分的主要因素,表面聚合物的清除有助于优化晶圆位置偏移。电动三针在固有残留静电力的情况下,通过缓慢连续升针方案缓解了跳片现象。优化片间清洗方案大幅减小表面聚合物残留。实验结果表明:优化后的解吸附配方为工艺时长90 s、电极功率1000 W、气压20 mTorr(1 mTorr≈0.133 Pa)、氩气体积流量250 mL/min,电动三针接触晶圆前、接触中、脱离静电吸盘后的升针速度分别为3、2和6 mm/s,在上述工艺条件下,通过进一步优化片间清洗方案,使得晶圆位置偏移量从初始的2~6 mm降至0.2 mm以内。

基于路面影响因子的轮毂电机驱动车辆自适应转矩控制

为实现轮毂电机驱动越野车辆在附着条件多变、路面起伏不定的复杂环境中动力性和稳定性的多目标优化,提出一种基于路面影响因子的自适应转矩控制策略。以滚动阻力差异、空气阻力归一化比例、坡度阻力归一化比例、路面附着差异方差以及最小路面附着系数5个特征参数作为输入,并基于模糊理论方法搭建路面影响因子五参数辨识模型。基于辨识出的路面影响因子,开发整车动力性和稳定性多目标优化自适应转矩控制策略,构建了三层式控制架构:顶层引入路面影响因子对加速度紧迫程度进行判定,采用模型预测控制算法得到期望总驱动力;中层为目标决策层,以最优滑转率为目标决策驱动防滑力矩,并基于路面行驶阻力,决策期望前馈补偿力矩;下层为转矩分配层,以需求总驱动力及轮胎利用率作为控制目标,引入路面影响因子优化两者权重系数,以多约束条件的混合优化算法对转矩进行自适应控制。利用Matlab/Simulink-CarSim联合仿真平台进行仿真,基于实车进行验证。结果表明,在低附着路面,在0.2s内快速完成滑转率抑制;在对开路面,侧向位移接近0;在大扭曲路面,避免腾空车轮出现大滑转率,滑转率最高0.2。

轮毂电机驱动电动汽车4WS和DYC协调控制

为了提高轮毂电机驱动电动汽车的路径跟踪能力和操纵稳定性,本文针对主动四轮转向系统(4WS)和直接横摆力矩控制系统(DYC)提出一种新型的协调控制策略。首先,综合考虑车辆的路径跟踪性能和操纵稳定性,建立一种共享转向控制模型,并在此基础上提出基于非合作Nash博弈的4WS控制策略。其次,为了提高危险行驶工况下的车辆侧向稳定性,基于质心侧偏角相平面将车辆状态划分为稳定区域、过渡区域和失稳区域,并分区域建立DYC控制器。再次,为了实现后轮转向与直接横摆力矩的协同控制,建立基于模糊神经网络的ARS/DYC协调控制器。最后,利用CarSim/Simulink联合仿真平台和硬件在环平台,分别进行双移线工况下的试验验证。研究结果表明,所提出的控制策略能够有效地提高车辆在极端行驶工况下的路径跟踪精度和操纵稳定性能。

“汽电双驱”引风机驱动方案的电气原理与应用

介绍某火力发电厂中“汽电双驱”的引风机驱动方案的配置、结构以及各运行工况。阐述该系统的电气原理、介绍异步电机的参数选取和边界条件;并分析系统工作的稳定性,以及在各种不同工况下,电机、汽轮机和引风机如何配合以实现功率的自平衡。计算该异步电机对降低厂用电率的作用,及其对中压母线电压降和短路电流的影响。

自驱动关节臂测量机多电机同步控制系统

为了解决自驱动关节臂坐标测量机的多电机同步转动问题,设计了一套多电机同步控制系统。该系统选用以TMS320F28335为核心的DSP处理器,依次设计了双CAN通信电路、功率逆变电路、电机驱动电路等驱动板接口电路;利用Simulink建立了六电机同步转动控制仿真模型,将电机控制模型转化为工程代码,对六电机设定不同的位置角度进行点到点位置同步实验,以及多电机轨迹跟踪实验。实验结果分析得到同步控制时间精度在10ms以内,验证了六电机的同步控制有效性,为提高测量机的运动平稳性和测量效率提供参考依据。

多台电动给水泵并列运行控制策略分析

电动给水泵作为电厂关键设备,对保证机组经济性具有重要作用,其启停直接关系机组安全稳定运行。针对某电厂350 MW直接空冷机组电动给水泵配置方式,提出多台电动给水泵之间联锁启动、备用状态下和备用泵联启及自动并泵时勺管跟踪、失去给水泵时Runback的各工况控制策略。经过静态试验和实际运行验证,符合生产要求,可为同类配置方式的电动给水泵控制策略提供参考。

基于滑膜观测的FOC无刷电机控制系统设计

针对目前全驱动型机器人的高工作精度以及高稳定性需求,设计全驱动型机器人关节驱动控制系统。基于无刷电机数学模型,电机驱动方案采用矢量电机控制算法FOC,电机角速度位置采用有感、无感相结合获取,即在启动以及低速转动下采用位置传感器,在中高速转动下切换使用滑模观测器。观测器对电机反电动势观测值进行运算处理,获得电机位置和速度。在MATLAB/Simulink搭建控制模型,验证算法可行性。仿真结果表明:在负载情况下,中低转速下,控制精度低,低成本位置传感器足以满足控制需求;在中高转速下,位置获取方法切换为滑模观测器,此时无位置传感器控制,无需使用高精度位置传感器,根据电机运行的电流观测到的位置,足以满足中高转速需求。且观测器监测内部运行状态,无视外界影响,大大提高控制系统的响应性与稳定性。

掘锚机用电机驱动行走减速机设计

掘锚机行走机构需配置减速机来增大扭矩,合理地拟定行走减速机的传动方案是保证行走机构设计质量的基础。传统掘锚机的行走减速机采用液压马达驱动,由于掘锚机自重大、接地比压大,对于机重100 t左右整机所需的驱动力,使用效果并不好。为了增大行走部驱动力,使其具有良好的通过性能,阐述一种变频电机驱动的低速大扭矩行走减速机的设计。

基于仿射超局部的交流电机无模型预测控制策略

在复杂工况和运动状态下,交流电机系统因磁场耦合、铁心饱和等因素导致物理参数非线性时变,电机控制性能和系统鲁棒性弱化。针对上述问题,无模型预测控制策略利用交流电机变量之间的内在关系,构建数据驱动模型,从而摆脱对物理参数的依赖,并消除参数失配的影响。文中结合永磁同步电机驱动系统,提出一种仿射超局部模型,并设计无模型预测电流控制策略。该方法采用最小二乘算法对仿射算子进行在线估计,并设计状态补偿机制,通过ε-近似思想选取状态补偿增益,以实时反映系统运动特性。方法稳定性通过系统零极点分析进行验证,并通过实验验证对其有效性以及在模型适配性、电流质量和系统鲁棒性等优势进行验证。