OPTIMAL CONTROL OF AN ACTIVE SUSPENSION SYSTEMEMPLOYING HIGH SPEED ON/OFF SOLENOID VALVE

Conventionalpassivesuspensionistypicallycomposedofcoilspringandhydraulicdampers.Toimproveridecomfort,thesepassiveelementsmustbesetonthesoftside,buttoimprovehandling,springsanddampersmustbemadestiffertodampwheelvibrationandreducebodyrollingandpitchingmotions.Thesecontrarypurposesformtheclassicsuspensiondesigncompromise.Differingfromapassivesuspension,anactivesuspensionhasitsownpowersource,andcancontinuallysupplyandmodulatetheflowofenergyandgeneratethecontrolforcewhichcanbeafunctionsofanyvariabl…     

LQ Speed Control of Pump Controlled Motor System

A linear quadric (LQ) optimal speed control algorithm is proposed for the speed control of a pump controlled motor hydraulic system. The control theme consists of optimal state feedback and disturbing compensation based on observation. The optimal state feedback bases on LQ cost function. The disturbing compensation is realized through reconstructing the state of load torque. A series of simulation are performed, and the results show that the control performance is satisfactory and can be maintained under changes of load torque.     

汽车ABS制动压力抖动仿真与控制

建立复杂的非线性ABS系统与四分之一车数学模型,对不同参数下ABS的性能进行仿真,发现在传统控制方式下,ABS的制动压力抖动与滑移率波动存在一定的矛盾性。提出利用PWM方式控制高速电磁阀的开关,实现制动液流量的连续控制方法,有效地防止了汽车制动主缸压力抖动与滑移率的波动,提高了制动舒适性与安全性。     

基于智能脉宽调制的车辆牵引力控制系统驱动轮制动控制

为实现车辆牵引力控制系统(TCS)驱动轮制动控制的精细调节,对车辆液压制动系统的高速开关阀控制进行了分析,试验确定脉宽调制(PWM)控制规则,基于神经网络PI设计了TCS驱动轮制动控制的智能PWM控制器。利用面向TCS的AMESim与MATLAB联合仿真平台进行了仿真分析,结果表明,基于智能PWM的TCS驱动轮制动控制方法能够实现对制动压力的精细调节,有效地提高了车辆的加速性。     

H∞ Theory and its Application to the Position of Rolling Mill Control System

The controller designed according to classical or modern control theory will not satisfy the performance requirements when the controlled object in industrial field can not be described by exact mathematical model or the disturbance of the controlled system. In order to make the controlled system stable and having good performance, H∞ control theory was put forward to solve this practical problem. Taking the position of a rolling mill as the controlled object, it was rectified by optimal engineering way. Then, three different plans were put forward according to Bang-Bang control, LQ control and H∞ control, respectively. The result of the simulation shows that the controller designed according to H∞ method whose robust performance and ability to restrain colors disturbance is satisfactory.     

基于单片机的无刷直流电动机脉宽调速系统

针对以往无刷直流电动机多由单片机附加许多种接口设备构成,难于实现从位置环到速度、电流环的全数字控制问题,设计了采用SPCE061A型16位单片机的脉宽调速系统.该单片机主要完成位置传感器信号的采集、电动机换相信号的输出、电动机转速的测量以及数字PWM 调速信号的输出等功能.电动机驱动电路采用开关速度快、功耗低的MOSFET管全桥方式.实验证明,该系统响应速度快,动静态特性良好,适用于对小功率无刷直流电动机的速度调节.     

线控制动系统踏板感觉模拟器设计与改进

设计开发一种线控制动（EHB）系统样机,选取不同过流孔径的踏板模拟器常闭电磁阀进行踏板行程-踏板力对比试验.结果表明：当将单个电磁阀直接接入踏板感觉模拟器回路时,随着制动力加载速度的提高,会产生实际制动踏板行程-踏板力关系曲线偏离目标曲线的问题,并且电磁阀孔径越小,偏离越大,借助于数学推导得出电磁阀过流孔径与踏板速度响应之间的理论关系.设计一种液压先导阀加入到踏板模拟器回路中,以提高系统通流能力和踏板速度响应,液压先导阀由原回路中的电磁阀控制.对改进的踏板模拟器回路进行仿真及试验,结果均表明：改进过的回路可较好地实现踏板行程-踏板力曲线精度,曲线受踏板力加载速度变化影响小,同时可使模拟器常闭电磁阀工作功耗更低,提高了系统的可靠性.     

直线伺服系统的鲁棒二次最优控制

针对永磁直线同步伺服电机(PMLSM)直接驱动伺服系统存在的负载扰动等不确定性因素的影响，根据鲁棒二次最优控制理论来设计速度状态反馈控制器，在保持传统控制结构不变的同时，解决了直线电机伺服系统的鲁棒性问题，能够克服系统中存在的不确定性与外部干扰对系统性能的影响，实现对系统速度的跟踪控制.仿真结果表明，该方案在保证伺服系统的快速性、精确跟踪性的同时，对系统参数变化和阻力扰动具有很强的鲁棒性.     

基于李雅普诺夫方法的阻感性负载PWM整流器控制

针对PWM整流器在控制过程中存在的问题,本文基于能量的观点研究了阻感性负载的三相电压型PWM整流器的建模与控制。建立了PWM整流器dq旋转坐标下的数学模型,根据系统的控制目标确定了期望的平衡点,并分析了系统在平衡点的稳定性,同时采用李雅普诺夫方法通过注入阻尼得到PWM整流器的控制器,并在MATLAB/Simulink环境中进行了仿真分析,仿真结果表明,该系统稳态性能较好,能够抑制负载扰动,并且具有良好的电压跟踪和单位功率因数控制性能。该控制器具有广阔的应用前景。     

基于电路仿真的高压共轨电磁阀驱动电路设计

为了缩短硬件系统的开发周期及降低开发成本,利用电路仿真软件建立精确的柴油机高压共轨喷油器电磁阀驱动电路模型.基于仿真结果分析不同驱动电压对电磁阀电流提升响应时间的影响,并设计减少其关闭响应时间的电路.在对各个因素综合分析的基础上,设计高低双电源（110 V和24 V）驱动及硬件脉宽调制（PWM）的维持电流反馈控制喷油器电磁阀驱动模块,以及电磁阀驱动回路的故障检测电路.试验结果表明,优化后的驱动模块显著缩短了喷油器电磁阀的开启延迟和关闭延迟,驱动高压在燃油喷射过程中基本保持稳定,同时证明了采用该设计方法设计高压共轨电磁阀驱动模块是切实可行且高效可靠的.     

Vehicle height and leveling control of electronically controlled air suspension using mixed logical dynamical approach

Vehicle height and leveling control of electronically controlled air suspension (ECAS) still poses theoretical challenges for researchers that have not been adequately addressed in prior research. This paper investigates the design and verification of a new controller to adjust the vehicle height and to regulate the roll and pitch angles of the vehicle body (leveling control) during the height adjustment procedures. A nonlinear mechanism model of the vehicle height adjustment system is formulated to describe the dynamic behaviors of the system. By using mixed logical dynamical (MLD) approach, a novel control strategy is proposed to adjust the vehicle height by controlling the on-off statuses of the solenoid valves directly. On this basis, a correction algorithm is also designed to regulate the durations of the on-off statuses of the solenoid valves based on pulse width modulated (PWM) technology, thus the effective leveling control of the vehicle body can be guaranteed. Finally, simulations and vehicle tests results are presented to demonstrate the effectiveness and applicability of the proposed control methodology.     

基于三电平PWM开关功放磁推力轴承控制系统

针对磁悬浮推力轴承控制系统的特点和要求,设计了三电平PWM开关功率放大器,对其输入、输出信号跟踪等特性进行分析,并对磁悬浮推力轴承转子运动控制系统进行仿真。仿真结果表明,采用三电平PWM开关功率放大器可以有效降低电流纹波,缩短电流响应时间,并显著提高转子控制系统的精度。     

直流无刷电机位置跟踪的模糊PID控制

为了设计高精度的直流无刷电机伺服控制系统,性能优良的位置跟踪控制器是其重要保障.基于直流无刷电机的工作原理.运用Matlab/Simulink建立其自动位置跟踪控制系统的计算机仿真模型,系统的电流和速度环采用PI控制,结合PID控制和模糊控制设计了系统位置环的模糊PID控制器.数字仿真结果表明,模糊PID控制的动静态特性优于传统单一的PID控制,论文的研究工作对设计性能优良的直流无刷电机控制器具有借鉴意义.     

纯电动汽车用永磁同步电机空间矢量控制系统建模与仿真

在分析小型纯电动汽车动力学方程和永磁同步电机PMSM数学模型的基础上,建立PMSM驱动汽车的数学模型,并利用空间矢量脉宽调制技术和模糊PID控制算法设计了车速-电流双闭环控制系统,以驱动汽车变速运行。在Matlab 7.6/Simulink环境下搭建了纯电动汽车车速-电流双闭环控制系统动态仿真模型,依据行驶需求对电动汽车在某档位的车速与转矩进行了仿真分析,并对控制策略进行了静、动态性能验证。仿真结果表明:该系统具有响应速度快、精度高、抗干扰能力强等优点,为实际纯电动汽车驱动控制系统的分析与设计提供了新的思路。     

永磁屏蔽式耐高压高速开关电磁铁

为了提高电磁力、加快响应速度,提出一种永磁屏蔽式耐高压高速开关电磁铁,采用NdFeB稀土永磁材料作为磁屏蔽元件,减少漏磁并加快了动态响应.基于有限元方法建立电磁铁的动态数学模型,并通过实验进行验证,实验与仿真基本吻合,响应误差为3.2%,验证模型的有效性.在此基础上,对该高速开关电磁铁进行动态仿真,探讨永磁体长度、厚度、激磁方向,盆口高,耐压环厚度,隔磁片长度,前隔磁角和后隔磁角等结构参数对响应时间的影响规律.结合实际设计要求,结果表明,采用优化后的结构参数研制的永磁屏蔽式耐高压高速开关电磁铁在0.6 mm行程时的响应时间为2.20 ms.     

基于PWM整流技术的高功率因数串级调速系统

阐述了PWM整流技术引入串级调速的背景和意义,并对其拓扑结构和原理进行了介绍.在此基础上,分析了PWM整流技术提高串级调速功率因数的调节原理.最后给出了仿真及相关结论.     

基于FPGA的直流电机转速控制系统设计

设计了一种基于现场可编程门阵列（FPGA）数字电子系统的直流电机控制系统。系统主要由FPGA与外围电路组成,其中FPGA作为整个电路的控制核心,通过VerilogHDL硬件编程语言设计FPGA内部硬件电路以完成增量式PID控制算法,以及直流电机脉宽调制PWM控制器设计。外围电路包括位置光电编码器和功率驱动模块,可实现电机的驱动和速度反馈,并将速度通过LED实时显示。Modelsim仿真和控制结果表明,该系统可以有效地产生PWM控制信号控制电机转速。     

永磁同步电机传动系统能量成形控制仿真研究

针对功率变换器和永磁同步电机（PMSM）构成的传动系统,基于能量成形和端口受控哈密顿（PCH）系统理论,研究其速度控制问题。建立了PMSM的PCH非线性数学模型,在负载转矩恒定已知和恒定未知情况下,设计了系统的速度控制器。根据最大转矩／电流（MTPA）控制原理确定了系统的期望平衡点,分析了平衡点的稳定性。利用PWM信号变换方法控制功率变换器各开关器件的导通占空比,实现隐极PMSM的速度调节。利用Matlab／Simulink仿真,结果表明,系统具有很好的负载扰动抑制能力和转速跟踪性能。     

Optimization of Waste Gate Drive Circuit of Two-Stage Turbocharging System

A two stage turbocharging control system was proposed, in which the pressure regulator valve with a close-loop pressure adjusting function instead of a high speed on-off solenoid valve, is used as a driving mechanism of waste gate. A digital-analog (DA)conversion circuit based on pulse width modulation (PWM) generates one analog voltage signal required by the pressure regulating valve control. The principle of the DA conversion circuit was analyzed, meanwhile, the performance of the conversion circuit was improved by adopting a speed-up capacitor, which helps to increase the stability and responsiveness of the control voltage generated by the conversion circuit; the structure parameters of the circuit was optimized by simulation. After the optimization, the ripple wave of circuit output voltage was kept within 16.mV under the 12.bit conversion accuracy, the conversion time of the circuit could be reduced to 4.ms. The engine bench test show that the turbocharging boost pressure control system which adopted the circuit had a rather good stable control accuracy(the steady state within 0.8%) and dynamic response(the regulation time is less than 4.s).     

一种基于规则采样法的新型PWM逆变器

以单片机为最小控制单元,设计了一种新型变频系统。系统采用一种新的ＰＷＭ控制策略,它是通过对原规则采样法进行改造而获得的,这种新型ＰＷＭ控制策略地实现,适合于实时控制。试验结果表明其性能优越。