共查询到20条相似文献，搜索用时 156 毫秒
1.
《实验室研究与探索》2015,(11):86-89
描述了一种新的控制异步电机驱动系统设计方法。这种控制方法是一种基于自适应变结构的设计。自适应变结构控制器是基于遗传数学算法模型的优化方法系统模型。这种方法简单,易于实现。仿真和实验结果表明,该自适应变结构控制器在性能的动态特性方面,有较强的鲁棒性,改变了电机转速和负载的扰动。 相似文献
2.
目的：在强磁场持续运行下,高速磁悬浮列车悬浮系统的执行器容易发生部分故障,使得悬浮控制问题具有挑战性。为了降低容错的成本和能耗,提升高速磁悬浮列车悬浮系统对执行器故障的容忍度,本文从实用的角度出发,提出一种新型的高速磁浮列车悬浮系统自适应补偿非线性容错控制策略。创新点：1.无需知道执行器的故障信息,自适应补偿控制律随系统故障的发生而变化,并自适应地进行重构,降低系统的保守性;2.在没有任何线性化近似的情况下,证明控制器的设计和稳定性。方法：1.通过数学推导,建立基于连接结构的悬浮系统的动力学模型（图2和公式(12)）;2.通过理论分析,描述执行器故障的类型（公式(14)）;3.通过数学分析,设计一种具有自适应更新律的非线性容错悬浮控制律,以实现针对部分执行器故障的稳定悬浮（公式(19)和(20)）。利用Lyapunov理论和扩展的Barbalat引理来严格证明闭环渐近稳定性（公式(23)）;4.通过在高速磁悬浮车辆-轨道磁耦合实验平台进行硬件实验,验证所提方法的可行性和有效性（图4～17）。结论：1.提出的具有自适应补偿的非线性容错控制策略在无故障诊断和隔离的情况下,实现了部分执行器故... 相似文献
3.
4.
针对一类具有饱和非线性输入的混沌系统,基于RBF神经网络的逼近能力提出一种控制方案。该方法利用自适应控制和鲁棒控制,使系统可在模型函数和外扰未知下,设计出结构简单有效的控制器,有效消除了现实中由于饱和非线性输入的存在而引起的控制器抖动的不良控制效果。仿真结果表明了所提控制方法的可行性。 相似文献
5.
6.
针对受限环境下四旋翼无人飞行器在参数不确定及外部扰动影响下的高性能高度控制问题,设计一种基于复合非线性反馈（CNF）和自适应非光滑轨迹跟踪控制的高度控制方法。通过四旋翼无人飞行器的垂直通道动力学模型分析和变换,将高度轨迹规划问题转换为输入受限的线性系统控制问题,设计CNF控制器实现轨迹生成;建立参数不确定及外部扰动影响下的垂直通道动力学模型,设计一种自适应非光滑轨迹跟踪控制器,并理论证明了闭环系统稳定性。最后,通过仿真实验验证所提出方法的有效性。结果表明,所设计方法能够有效提高参数不确定及外部扰动下的高度控制品质,且简单实用。 相似文献
7.
为了消除双关节机械手系统中存在的摩擦、外界扰动及负载变化等问题,得到高精度的快速位置跟踪轨迹,可采用保证系统稳定性的滑模控制来实现,但在控制过程中系统会存在抖动问题.为此,引入了自适应模糊系统,实现系统滑模控制中切换增益的自适应逼近,完成控制区间范围内的抑制抖动.仿真结果表明:该方法通过选取控制律和李雅普诺夫函数,证明了系统具有渐进稳定性;并且实现了系统位置及速度等参数的高精度轨迹跟踪控制,又很好抑制了滑模控制中存在的抖动问题,满足了系统高精度的轨迹跟踪控制. 相似文献
8.
针对一类具有未知饱和模型的单输入单输出非线性系统的控制问题,根据滑模控制原理和多层神经网络的逼近能力,提出了一种直接自适应神经网络控制器的设计新方案。该方法将控制增益推广到未知函数,通过补偿饱和模型方法取消了饱和模型各参数已知的条件。鲁棒项的引入消除了建模误差和参数估计误差的影响。理论分析证明了闭环系统是半全局一致终结有界,跟踪误差收敛到零的邻域内。仿真结果进一步表明所提控制方法的有效性。 相似文献
9.
乔维德 《番禺职业技术学院学报》2009,(4):50-53,59
交流伺服系统是一个非缌陛、多变量、强耦合的系统,采用传统的PID控制和普通模糊控制方法,难以达到理想的控制效果。通过设计一种模糊PID控制器,应用模糊算法在线自动整定PID参数的方法,将其应用于交流伺服系统位置调节器。仿真结果表明：模糊自适应PID控制方法具有较强的自适应能力和抗负载扰动能力,动态响应速度、稳定性等均优于常规PID控制和普通模糊控制,从而满足了交流伺服系统较高的控制要求和控制效果。 相似文献
10.
针对存在未知时变惯量不确定性、外部干扰力矩和执行机构衰退故障的非刚体航天器系统,研究了非刚体航天器自适应优化容错控制问题。首先,为了根据误差变量优化控制增益,设计一种动态增益调整函数实时优化控制增益;然后,基于非线性鲁棒控制方法、动态增益函数调整方法、自适应方法、容错控制理论与参数估计方法,提出一种新颖的自适应优化姿态跟踪容错控制器。所设计的控制器克服了执行器故障、惯量不确定性以及外界干扰的影响,保证航天器姿态及角速度能够跟踪时变的参考轨迹,实现跟踪误差系统最终一致有界稳定;最后,数字仿真结果验证了所提出方法的有效性,而且与已有控制方法相比,该方法具有更高的控制精度和稳定性。 相似文献
11.
ZOU Jun FU Xin YANG Hua-yong 《浙江大学学报(A卷英文版)》2007,8(9):1429-1434
The highly nonlinear behavior of the system limits the performance of classical linear proportional and integral (PI) controllers used for hot rolling. An active disturbance rejection controller is proposed in this paper to deal with the nonlinear problem of hydraulic servo system in order to preserve fast response and small overshoot of control system. The active disturbance rejection (ADR) controller is composed of nonlinear tracking differentiator (TD),extended state observer (ESO) and nonlinear feedback (NF) law. An example of the hydraulic edger system case study is investigated to show the effectiveness and robustness of the proposed nonlinear controller,especially,in the circumstance of foreign disturbance and working condition variation,compared with classic PI controller. 相似文献
12.
A new chaos control method is proposed to take advantage of chaos or avoid it. The hybrid Internal Model Control and Proportional Control learning scheme are introduced. In order to gain the desired robust performance and ensure the system's stability, Adaptive Momentum Algorithms are also developed. Through properly designing the neural network plant model and neural network controller, the chaotic dynamical systems are controlled while the parameters of the BP neural network are modified. Taking the Lorenz chaotic system as example, the results show that chaotic dynamical systems can be stabilized at the desired orbits by this control strategy. 相似文献
13.
14.
INTRODUCTIONOneoftheoldestresearchesofchaosincon trolfieldscanbeseeninthepaperbyKalman(1956) ,whofirstfoundnon synchronousoscil lationsinatwo dimensionalsampled datacontrolsystem .IntheOGYmethoddevelopedbyOttetal.(1990 ) ,chaoticphenomenawaseliminatedbyadjustingparametersofthesystemswhenthechaoticorbitcomesnearaperiodicalorbit.ButtheOGY’smethodrequiresmonitoringthesys temlongenoughtodeterminealinearizationmodeintheneighborhoodofthedesiredunstableperiodicorbitbeforeitcanbeapplied .Besi… 相似文献
15.
This paper reviews recent developments in nonlinear control technologies for shape memory alloy (SMA) actuators in robotics and their related applications. SMA possesses large hysteresis, low bandwidth, slow response, and non-linear behavior, which make them difficult to control. The fast response of the SMA actuator mostly depends upon, (1) type of controller, (2) rate of addition and removal of heat, and (3) shape or form of the actuator. Though linear controllers are more desirable than nonlinear ones, the review of literature shows that the results obtained using nonlinear controllers were far better than the former one. Therefore, more emphasis is made on the nonlinear control technologies taking into account the intelligent controllers. Various forms of SMA actuator along with different heating and cooling methods are presented in this review, followed by the nonlinear control methods and the control problems encountered by the researchers. 相似文献
16.
为了消除桥式起重机吊重摆动和实现小车精确定位,提高起重机工作效率,国内外很多学者对防摆控制方法做了大量研究。在建立起重机非线性数学模型的基础上,完成基于模糊自适应PID防摆控制器的设计,其中角度环采用模糊控制器,位置环采用模糊PID控制器。通过与线性二次型最优控制（LQR）仿真结果比较,表明该方法的可行性,其控制过程更加平稳,稳态精度更高,并且当吊重质量和绳长发生改变时,系统仍有较强的鲁棒性。 相似文献
17.
This paper presented a control design methodology for a proton exchange membrane fuel cell （PEMFC） generation system for residential applications. The dynamic behavior of the generation system is complex in such applications. A compre- hensive control design is very important for achieving a steady system operation and efficiency. The control strategy for a 60 kW generation system was proposed and tested based on the system dynamic model. A two-variable single neuron proportional-integral （PI） decoupling controller was developed for anode pressure and humidity by adjusting the hydrogen flow and water injection. A similar controller was developed for cathode pressure and humidity by adjusting the exhaust flow and water injection. The desired oxygen excess ratio was kept by a feedback controller based on the load current. An optimal seeking con- troller was used to trace the unique optimal power point. Two negative feedback controllers were used to provide AC power and a suitable voltage for residential loads by a power conditioning unit. Control simulation tests showed that 60 kW PEMFC generation system responded well for computer-simulated step changes in the load power demand. This control methodology for a 60 kW PEMFC generation system would be a competitive solution for system level designs such as parameter design, performance analysis, and online optimization. 相似文献
18.
The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening,friction,etc. Aside from the nonlinear nature of hydraulic dynamics,hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues,a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well,and all signals in the closed-loop system remain bounded. Moreover,a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers,this paper's robust controller based on backstepping recursive design method is easier to design,and is more suitable for implementation. 相似文献
19.
For a single-motor parallel hybrid electric vehicle, during mode transitions （especially the transition from electric drive mode to engine/parallel drive mode, which requires the clutch engagement）, the drivability of the vehicle will be signifi- cantly affected by a clutch torque induced disturbance, driveline oscillations and jerks which can occur without adequate controls. To improve vehicle drivability during mode transitions for a single-motor parallel hybrid electric vehicle, two controllers are proposed. The first controller is the engine-side controller for engine cranking/starting and speed synchronization. The second controller is the motor-side controller for achieving a smooth mode transition with reduced driveline oscillations and jerks under the clutch torque induced disturbance and system uncertainties. The controllers are all composed of a feed-forward control and a robust feedback control. The robust controllers are designed by using the mu synthesis method. In the design process, control- oriented system models that take account of various parameter uncertainties and un-modeled dynamics are used. The results of the simulation demonstrate the effectiveness of the proposed control algorithms. 相似文献
20.
LU Guang WANG Yong-chao ZHU Miao-liang 《浙江大学学报(A卷英文版)》2007,8(6):849-856
The Internet evolves to incorporate very-high-bandwidth optical links and more large-delay satellite links. TCP faces new challenges in this unique environment. Theory and experiments showed that TCP becomes inefficient and is prone to be unstable as the per-flow product of bandwidth and latency increases, regardless of the queuing scheme. Variable-structure congestion Control Protocol (VCP) is proposed to address these problems. However, VCP has problem in terms of convergence time, i.e., it takes a long time for a new VCP flow to achieve fair bandwidth allocation if the existing VCP flows have large con- gestion windows. This paper proposed an Extended Variable-structure congestion Control Protocol (EVCP), which adopted a convergence controller. The basic idea of convergence controller is that if a flow has larger window than its fair window, its congestion window should be decreased more aggressively than usual in Multiplicative Decrease (MD) phase. Simulations showed that EVCP has better performance in terms of convergence time while keeping the advantages of VCP. 相似文献