共查询到20条相似文献,搜索用时 152 毫秒
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为实现更加精准的时滞非线性切换系统滑模控制,应用干扰观测器设计一种新的系统滑模控制方法。构建时滞非线性切换系统模型,针对系统在发生结构变化时会产生复合干扰变化的情况,设计了一种非线性切换干扰观测器,实施系统不连续干扰的估计。通过 Backstepping 方法结合干扰观测器,设计一种切换滑模控制器,依据标量非线性特性打造一个滑模面,通过滑模控制器算法使时滞非线性切换系统能够满足滑模面的实际可达性条件,完成切换滑模控制器设计,实现系统的滑模控制。对设计的滑模控制方法进行测试,实验中选择的时滞非线性切换系统为一种变后掠翼 NSV 。实验结果表明,该设计方法能够实现较为准确地切入信号跟踪,表现出了很好的切换复合干扰估计性能。 相似文献
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建立车辆转向动力学模型,运用滑模变结构控制理论设计了变结构控制器,由于控制器中参数的选取对控 制器的品质起关键作用,本文介绍系统切换超平面和控制器中其它参数的选取方法。通过仿真和实验验证了控制 器对于模型中时变和不确定参数具有很好鲁棒性,使车辆导航具有良好的跟踪性能。 相似文献
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电液伺服系统的滑模变结构控制仿真研究 总被引:1,自引:0,他引:1
针对典型电液伺服系统,用存在条件及到达条件确定切换函数和变结构控制律,设计了滑模控制器。仿真结果表明,基于比例切换控制方法设计的滑动模态变结构控制系统,优于传统的PID控制系统。 相似文献
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伺服系统的模糊智能协调控制 总被引:3,自引:0,他引:3
综合了神经控制与模糊控制的各自优点,运用模糊隶属规则设计了一种基于模糊规则的多控制器协调控制伺服系统,同常规变结构控制相比,它把前者的点切换拓宽为区间相对平滑的切换,仿真和实验结果表明了控制的有效性。 相似文献
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ABS的模糊滑模变结构控制方法及仿真研究 总被引:3,自引:0,他引:3
分析了车辆防抱死制动系统的滑模变结构控制,提出了防抱死制动系统的模糊滑模变结构控制方法,根据滑模切换函数及其导数对滑模控制量进行模糊划分,形成二维模糊控制规则表。对切换函数及其导数采用动态模糊划分,以提高系统控制的敏感度。对单轮系统车辆的仿真表明,模糊滑模变结构控制方法既能缩短响应时间,也能抑制系统颤振。 相似文献
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人工心脏泵磁悬浮转子非线性特性及控制方法研究 总被引:1,自引:0,他引:1
引入滑动模态变结构控制,对转子转速大于6000r/min时转子产生的颤振及转子在强干扰下产生的新的平衡位置等非线性效应进行控制。以轴向为例取切换函数,滑动模态按指数律趋向原点,推导出了等效控制方程。用电锤给轴向磁悬浮转子施加冲击干扰,观察变结构控制的结果,发现系统在短暂调整后即恢复平衡位置,渐近稳定,说明采用变结构控制的适应性较好。利用变结构控制对内部参数变动和外部扰动作用不变这一显著特点,可有利于控制血液应力及粘弹性等非线性因素造成的转子扰动,从而使得系统数学模型的不准确性、实际系统的不确定性及镇定的复杂性得以解决。 相似文献
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Moharam Habibnejad Korayem M. Zakeri 《The International Journal of Advanced Manufacturing Technology》2010,50(5-8):579-589
The AFM system, which is used as a nanomanipulator, includes a probe consistent of a cantilever and a tapered tip. In cantilevers, the tip can be located in different distances from the cantilever free end. This causes to change in stiffness of the cantilever and therefore changing in pushing force of the nanomanipulation. In this paper, the effect of the tip distance on the cantilever stiffness is studied using the equations of Hazel, and Neumeister and Ducker (ND), and a new equation to correct the torsional stiffness of V-shaped cantilevers (VSC) is proposed, which is based on the ND equation. Then, the effect of distance on pushing force of AFM-based nanomanipulations with rectangular cantilevered (RC) and VSC AFMs is simulated. The obtained results using proposed equation show that increasing of distance causes to non-linear increment of torsional stiffness of VSC. Error of the proposed equation is achieved less than 3% in comparison with result of torsional stiffness equation of ND. Moreover, it is observed that the torsional stiffness of VSC predicted by Hazel’s equation is considerably inaccurate. In nanomanipulation studies, the necessary pushing forces of nanoparticle motion are increased by increment of distance, for both types of cantilevers (RC and VSC). Moreover, critical time for RC AFM increases, but in the case of VSC AFM, the critical time decreases at first, then it is almost constant at a limited range of d, and finally it starts to increase by increasing the distance. 相似文献
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电压源换流器直流侧短路故障特性分析 总被引:3,自引:0,他引:3
电压源换流器直流侧发生故障时,其故障电压电流变化迅速,对系统造成了严重威胁。针对这一问题,从电力电子层面深入分析了电压源换流器直流侧短路故障中最为严重的两极短路故障过程。将故障过程分为3个阶段,推导了电容放电阶段直流电压、电流表达式,分析了不控整流初始阶段存在的两种情况,对不控整流稳态阶段提出了采用开关函数计算短路电流的方法。最后通过PSCAD/EMTDC环境下±10 kV直流线路两极短路故障模型的仿真计算,对理论分析进行了验证。研究结果表明,两极短路故障后电路的响应情况与短路阻抗大小相关,短路阻抗较小时需要直流断路器在极短的时间内切除故障,短路阻抗较大时则可以利用交流侧的保护装置对直流侧电压、电流进行动态监测,实现直流侧短路故障的后备保护。 相似文献
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YAO Jianjun School of Mechanical Electrical Engineering Harbin Institute of Technology Harbin China WANG Xiancheng Department of Electromechanical Engineering Ningbo Institute of Technology Zhejiang University Ningbo China WU Zhenshun HAN Junwei School of Mechanical Electrical Engineering Harbin Institute of Technology Harbin China 《机械工程学报(英文版)》2006,19(1):32-36
The variable structure control (VSC) theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control (APC) algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking. 相似文献
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《Mechanical Systems and Signal Processing》2007,21(6):2515-2522
In this paper, a variable structure control (VSC) design for a chaotic symmetric gyro with linear-plus-cubic damping is considered. The results show that the stable or unstable (chaotic) nonlinear gyros can be controlled and asymptotically driven the system orbits to arbitrarily desired trajectories. Numerical simulations demonstrate the validity and feasibility of the proposed VSC design method. 相似文献
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针对变结构控制的抖振问题,设计了双模态“变结构-模糊变结构”控制器,并用于变工况的铣削加工过程控制中。仿真实验结果表明,这类混合控制器能较好地削弱系统抖振,并且对不确定加工过程的控制具有很强的鲁棒性能。 相似文献
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Vehicle Stability Control (VSC) system prevents vehicle from spinning or drifting out mainly by braking intervention. Although
a control threshold of conventional VSC is designed by vehicle characteristics and centered on average drivers, it can be
a redundancy to expert drivers in critical driving conditions. In this study, a manual adaptation of VSC is investigated by
changing the control threshold. A control threshold can be determined by phase plane analysis of side slip angle and angular
velocity which is established with various vehicle speeds and steering angles. Since vehicle side slip angle is impossible
to be obtained by commercially available sensors, a side slip angle is designed and evaluated with test results. By using
the estimated value, phase plane analysis is applied to determine control threshold. To evaluate an effect of control threshold,
we applied a 23-DOF vehicle nonlinear model with a vehicle planar motion model based sliding controller. Controller gains
are tuned as the control threshold changed. A VSC with various control thresholds makes VSC more flexible with respect to
individual driver characteristics. 相似文献
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