基于稳态数据的逻辑积分PI切换控制北大核心CSCD

基于过程稳态数据,为无源系统设计快速跟踪控制器,所设计的控制器不要求被控系统具有解析数学模型。对于无迟延的一阶无源非线性系统,能够从理论上确保系统的响应快速性和无超调性能。对于有输入迟延的情况,给出了线性系统超调和控制参数之间的关系。所设计的积分逻辑在避免积分对超调影响的同时,确保了系统在扰动下的无差性能。单容非线性水箱的仿真实验验证了所提方法的正确性和有效性。     

燃料电池输出电压的非方控制

研究质子交换膜燃料电池(PEMFC)输出电压控制问题,该问题输入个数大于输出个数,是个典型的非方系统,控制起来较为困难。使用一种新方法对非方系统进行控制。该方法可以对静态解耦引起的缺陷进行动态补偿,也可以克服由于模型近似而对系统性能造成模型误差的影响。将这种方法用于PEMFC非方系统的动态控制,并进行仿真研究,结果表明,可以提高控制系统的动态特性和鲁棒性,有较强的抗干扰能力,并且算法简单,调试容易。     

多变量非方系统集中式PI 控制器设计

针对工业过程中含有多时滞的高维多变量非方系统,基于等价传递函数理论,研究其集中式PI控制器设计问题.利用等价传递函数(ETF)与非方被控对象传递函数广义逆之间的关系,提出一种精度更高的ETF参数化算法,并推导出ETF模型的解析通式.所提出的ETF算法既避免了求广义逆的复杂运算,又提高了控制性能,且适用于高维非方系统.仿真实例验证了所提出的ETF算法的有效性和优越性.     

DSP控制的3kW非隔离型并网逆变器研究

提出了一种基于DSP控制的非隔离型并网逆变器的实现方案。介绍了该并网逆变器结构及原理,给出了基于DSP控制的硬件和软件的总体设计,实现了基于电压扰动观察与控制的最大功率点跟踪(MPPT)和无差拍控制的并网控制策略,并测试了其孤岛保护,完成了3 kW的实验样机及相关实验,对实验波形的分析证明了该控制策略和方案的有效性。     

高速网络多模式相似数据串隔离式传输仿真

针对传统数据串隔离式传输方法模式单一,数据串相似度不高的问题,为有效提升数据传输成功率以及网络吞吐量,提出了高速网络多模式相似数据串隔离式传输方法.评估不同链路信道上相似节点的可用性,判断链路相互干扰情况,利用信道干扰电平的路由指标函数,计算相似节点链路的网络干扰电平,组建高速网络多模式干扰无向图.在多模式干扰无向图中...     

一类不确定网络切换模糊系统的非脆弱控制

针对一类参数不确定的网络切换模糊系统,在控制器增益存在摄动以及状态不可测的情况下,研究系统的非脆弱控制问题.采用平均驻留时间法、Lyapunov函数法以及线性矩阵不等式技术等,给出网络切换模糊系统指数稳定的平均驻留时间条件以及系统切换律设计,并给出基于观测器的反馈控制器设计方法和使系统指数稳定的矩阵不等式条件,并将此条...     

单轴联结式并联混合动力汽车分层切换控制设计

为提高整车燃油经济性,降低尾气排放,本文针对单轴联结式并联混合动力汽车(parallel hybrid electric vehicle,PHEV)提出了一种分层切换控制方法.首先,在分析发动机稳态效率和电池充放电内阻变化规律基础上,采用分层切换思想,制定了PHEV各运行模式间切换规则.然后,研究了不同目标运行模式下的能量分配策略,针对单一驱动模式和3种制动模式,设计了基于规则的转矩分配策略;针对混合模式,分别设计了行车充电/混合驱动模式下的Lyapunov优化功率分配策略以及驻车充电模式下的Willans line模型极值法功率分配策略.最后,仿真结果表明,所提出方法可确保发动机和电池工作在高效区.在UDDS+HWFET工况下,与电辅助策略相比,百公里油耗降低了40.82%,CH,CO和NOx的排放量分别减少了2.86%,4.41%和8.02%;与基于庞特里亚金最小值原理(Pontryagin’s minimum principle,PMP)的全局优化策略相比,百公里油耗降低了9.37%.     

应用模型预测控制的混合动力汽车模式切换动态协调控制

利用传统协调控制策略或模型预测控制(MPC)方法能够解决离合器模式切换的平顺性,但其改善效果不显著,且缺乏深入的细化研究.因此,为了改进混合动力汽车有离合器结合的模式切换过程中的平顺性,本文基于MPC制定有离合器模式切换过程的动态协调控制策略.在对混合动力系统有离合器模式切换模型进行简化的基础上,开展MPC在模式切换动态协调控制过程的原理描述,以减小有离合器模式间切换的冲击度进行基于MPC动态协调控制策略设计,并对不同权重下的冲击度进行了详细的对比.通过实验验证,其结果表明采用MPC的模式切换协调控制最大冲击度从26.3 m/s³下降至9.26 m/s³,降低了64.8%,明显的抑制了模式切换过程中的冲击度,有效的改善了模式切换的平顺性.     

多变量非方系统多环PI控制器设计

基于等价传递函数（ETF）理论,提出含有多时滞的高维多变量非方系统多环PI（preportional-integral）控制器设计方法．首先,利用等价传递函数与被控过程传递函数的广义逆之间关系推导出ETF的求解通式．接着,基于已获得的ETF,利用IMC-PID（internal model control-proportional integral derivation）原理设计控制器,再利用Maclaurin级数展开获得多环PI控制器参数．所提ETF算法不仅具有更高的精度且适应于高维非方系统．最后通过仿真实例验证了所提算法的简单性和有效性．     

一类线性不确定切换系统的非脆弱控制器设计方法

针对一类线性不确定切换系统,在控制器增益存在加性摄动的情况下,给出了非脆弱状态反馈控制器的两种设计方案：方案1是利用多Lyapunov函数方法,通过子系统之间的切换,使系统对所有可允许的不确定性保持渐近稳定;方案2是基于平均驻留时间方法,给出了非脆弱状态反馈控制器存在的一个充分条件．相应的结果都是以线性矩阵不等式的形式给出．最后以一个数值例子说明了上述两种方法的有效性.     

Operation mode control of a hybrid power system based on fuel cell/battery/ultracapacitor for an electric tramway

This paper focuses on describing a control strategy for a real tramway, in Zaragoza (Spain), whose current propulsion system is to be replaced by a hybrid system based on fuel cell (FC) as primary energy source and batteries and ultracapacitors (UCs) as secondary energy sources. Due to its slow dynamic response, the FC needs other energy sources support during the starts and accelerations, which are used as energy storage devices in order to harness the regenerative energy generated during brakings and decelerations. The proposed energy management system is based on an operation mode control, which generates the FC reference power, and cascade controls, which define the battery and UC reference powers in order to achieve a proper control of the DC bus voltage and states of charge (SOC) of battery and UC. The simulations, performed by using the real drive cycle of the tramway, show that the proposed hybrid system and energy management system are suitable for its application in this tramway.     

Passivity and robust PI control of the air supply system of a PEM fuel cell model

Fuel cells are electrochemical devices that convert the chemical energy of a gaseous fuel directly into electricity. They are widely regarded as potential future stationary and mobile power sources. The response of a fuel cell system depends on the air and hydrogen feed, flow and pressure regulation, and heat and water management. In this paper, the study is concentrated on the control of the air subsystem that feeds the fuel cell cathode with oxygen—whose dynamics is described with a widely accepted nonlinear model. Due to the complexity of this model, the model-based controllers that have been proposed for this application are designed using its linear approximation at a given equilibrium point, which might lead to conservative stability margin estimates for the usually wide operating ranges of the system. On the other hand, practitioners propose the use of simple proportional or proportional–integral controllers around the compressor flow, which ensures good performance in most applications. In this paper we provide the theoretical justification to this scheme, proving that this output variable has the remarkable property that the linearization (around any admissible equilibrium) of the input–output map is strictly passive. Hence, the controllers used in applications yield (locally) asymptotically stable loops—for any desired equilibrium point and all values of the controller gains. Ensuring stability for all tuning gains overcomes the inherent conservativeness of linearized dynamics analysis, and assures the designer on the current use of robust, high performance loops. Instrumental to prove the passivity property is the exploitation of some monotonicity characteristics of the system that stem from physical laws.     

倾转旋翼机过渡飞行模式的有限时间切换控制

基于有限时间切换控制方法,研究倾转旋翼机过渡模式,即短舱倾角从$0^{\circ     

Adaptive sliding mode control of interleaved parallel boost converter for fuel cell energy generation system

This paper deals with the problem of controlling energy generation systems including fuel cells (FCs) and interleaved boost power converters. The proposed nonlinear adaptive controller is designed using sliding mode control (SMC) technique based on the system nonlinear model. The latter accounts for the boost converter large-signal dynamics as well as for the fuel-cell nonlinear characteristics. The adaptive nonlinear controller involves online estimation of the DC bus impedance ‘seen’ by the converter. The control objective is threefold: (i) asymptotic stability of the closed loop system, (ii) output voltage regulation under bus impedance uncertainties and (iii) equal current sharing between modules. It is formally shown, using theoretical analysis and simulations, that the developed adaptive controller actually meets its control objectives.     

Experimental results applying second order sliding mode control to a PEM fuel cell based system

A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. A Super Twisting controller is designed using a nonlinear model of a laboratory fuel cell test station, even a Lyapunov based stability discussion is included. Subsequently, the proposed control strategy is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, oxygen stoichiometry regulation and robustness against uncertainty.     

基于滑模控制的充液航天器燃料晃动抑制研究

考虑一类带液体燃料的航天器,由于航天器控制自身姿态的同时,还需要抑制液体燃料的晃动,使得系统整体表现为一个欠驱动系统.针对给出的物理模型,将其转化为一定形式的标准型,并对模型的特性进行了分析验证,最后采用一种适用于一类欠驱动系统的滑模控制方法来进行控制器的设计.由系统的稳定性分析可以看出,设计的控制器可以使系统的一些状态量达到平衡点,而剩下的状态量在系统自身特性的作用下,也能够达到平衡点,进而使整个航天器系统渐近稳定.仿真结果证明了控制器的有效性和可行性.     

带有副边电流过零检测的双模式AC/DC开关电源

当反激式变换器在副边电流减小至零时,原边电感和功率开关管的寄生电容会发生耦合振荡作用,针对此现象提出了一种带有副边电流过零检测功能的双模式AC/DC驱动电路,有效地确定了副边电流过零时刻。根据副边电流持续的时间判断负载情况,实现了输出端负载短路或者断路保护,并避免了芯片应用系统从电流断续模式突然进入电流连续工作模式,使开关电源驱动电路更加稳定,并且结合反激式原边反馈技术实现了恒流和恒压的双模式驱动。     

Sliding mode control of uncertain switched delay systems via hysteresis switching strategy

This paper investigates the robust sliding mode control (SMC) problem for a class of uncertain switched systems with time-varying delay. The sliding surface is constructed such that the sliding motion is completely invariant to all admissible uncertainties. For the case of the known delay-derivative upper bound, by using the multiple Lyapunov functions method, the Hysteresis switching law dependent on the state and the previous value of switching signal are designed to stabilize the sliding motion and avoid the chattering. Variable structure controllers are developed to drive the state of switched systems to reach the sliding surface in finite time and remain on it thereafter. For the case of the unknown delay-derivative upper bound, based on the single Lyapunov function method, the conditions of stabilization are obtained. Finally, a numerical example is given to illustrate the effectiveness of the proposed methods.     

Design of piecewise-linear switching functions for relay control systems

The design of piecewise-linear switching functions is investigated for linear, constant, lumped systems with a single ideal relay controller with respect to a transient response (minimum-time) performance criterion. A design method is presented which consists of a series of steps leading finally to the optimization of parameters by a gradient or other search technique suitable for computer implementation. The preliminary steps are devoted to reducing the dimensionality of the parameter space which must be searched, defining the criterion function so as to yield a surface which is reasonably smooth and free of relative minima, and insuring that the search is started with a feasible parameter set. It is concluded that easily implemented piecewise-linear switching functions can be designed so as to yield improved performance, both in terms of settling times and region of stability in the state space, over that attainable with linear switching functions. The complexities of the performance surface are such, however, that it is felt that frequently the determination of a switching function by the heuristic guides described, constitutes an adequate design without the refinement of parameter optimization.