基于模糊幂次趋近律的漂浮基空间机器人快速滑模控制

针对空间机械臂轨迹跟踪控制过程中的抖振抑制问题,讨论了一种基于模糊幂次趋近律的快速滑模变结构控制方法。首先运用拉格朗日第二类方程,建立了空间机械臂系统的动力学模型。然后对机械臂的传统滑模面进行改进,设计了一种快速非线性滑模面。利用模糊控制理论,设计了一种模糊幂次趋近律,使机械臂抖振抑制的效果明显,同时也保证了系统的轨迹跟踪控制效果。通过Lyapunov稳定性分析定理,验证了系统的稳定性和收敛性。最后用仿真实验结果证明了所设计控制方法的有效性和可行性。     

基于幂次指数趋近律的电子节气门变结构控制

针对电子节气门控制中使用最多的PID算法,在参数发生漂变、存在扰动时会导致控制精度下降甚至不稳定的情况,提出了基于幂次指数趋近律的变结构算法.研究了幂次指数趋近律变结构算法的优势并将其应用于节气门控制,得出了算法控制精度高的结论.提出了通过求解微分方程来研究算法的鲁棒性,并从三个阶段对新算法进行了研究,最终通过加入扰动...     

磁悬浮系统的变速趋近律滑模控制

为了抑制常规滑模控制在磁悬浮系统控制中的抖振问题,应用一种变速趋近律方法设计磁悬浮系统滑模控制器.控制器将系统的状态范数引入滑模控制律,以自动调整变结构切换控制项的增益,控制信号抖振幅值能够逐步衰减,并引导系统渐近稳定到原点;利用Lyapunov稳定性理论验证了系统的稳定性,并给出了控制器参数设计的依据;仿真实验结果表明,基于变速趋近律的磁悬浮系统滑模控制策略具有良好的动、静态性能和较强的鲁棒性.     

基于改进自适应趋近律的弹丸协调臂滑模控制

针对某火炮弹丸协调臂电液伺服系统在传统滑模控制趋近律下存在抖振现象,收敛速度慢等问题,提出一种基于改进自适应趋近律的弹丸协调臂滑模控制。当系统状态变量距离切换面较远的时候,幂次项起主要作用;当系统状态变量距离切换面较近时,自适应变速项起主要作用,随着状态变量变化自适应调节变速项系数,直到状态变量收敛到稳定点。当系统存在参数不确定性和外界扰动时,滑模状态变量可在有限时间收敛到边界层宽度为2.6的稳定误差界内。仿真结果表明,控制策略能有效提高系统的动态精度和到位精度,提高系统的鲁棒性。     

基于趋近律离散滑模控制的柔性梁振动抑制

研究了基于趋近律的离散滑模控制在智能柔性悬臂梁振动控制中的应用.以压电陶瓷为作动器,电阻应变片为传感器,采用有限元方法和模态截断技术建立结构动力学模型.由于柔性结构系统受到不确定外部扰动和量测噪声的影响以及参数的不确定性,滑模变结构控制可以实现滑动模态与系统的外干扰和参数摄动无关,即滑动模态的不变性.结构振动控制在系统状态由于外部干扰的影响偏离平衡状态,在控制器作用下能使系统趋于零状态.采用趋近律离散滑模控制方法设计状态调节器.由于状态量不能直接测量,故利用离散卡尔曼滤波技术构造状态估计器.采用试验模态测试方法得到结构的前4阶固有频率和阻尼比,与有限元方法的结果比较,说明该模型的正确性.使用dSPACE实时仿真系统和MATLAB/Simulink搭建控制系统,进行了振动主动控制试验.试验结果表明,所设计的控制器能有效抑制结构的振动响应.     

基于模型参考的主动空气悬架模糊自适应滑模控制

针对主动空气悬架这种时变、非线性复杂系统,以空气悬架客车1/4模型为控制对象,提出了模糊自适应滑模控制策略(FASMC),其中模糊自适应系统用来处理空气悬架系统的非线性和参数不确定性,并以最优控制的理想空气悬架作为参考模型。仿真试验表明,所提出的控制器能够有效降低车身振动幅度、提高车辆的可操纵性。     

一种新型趋近律的航空发动机滑模控制

针对滑模控制中传统趋近律收敛速度慢、抖振严重的问题,提出了 一种特殊幂次函数和幂指数趋近律组合的新型趋近律,与传统的指数趋近律和等速趋近律相比较,该趋近律通过幂次项系数对趋近过程的不同的阶段进行有效调节,提高了运动过程的运动品质,且有效地削弱了抖振,证明了滑模控制的存在性和可达性.将所设计的趋近律应用在航空发动机控制系...     

基于双幂次趋近律的单舵轮AGV双闭环轨迹跟踪滑模控制策略

为了实现单舵轮自动导引车(Automated Guided Vehicle, AGV)轨迹跟踪的快速稳定响应,设计了一种基于双幂次趋近律的单舵轮AGV双闭环轨迹跟踪滑模控制策略。建立了单舵轮AGV的运动学模型,构建包括外环位置子系统和内环姿态子系统的双闭环轨迹跟踪控制方案;采用基于双幂次趋近律的滑模变结构控制算法,分别设计了前轮速度和前轮转角控制律,并利用李雅普诺夫稳定性理论分别对所设计的外环位置子系统和内环姿态子系统进行稳定性证明;MATLAB软件仿真结果表明,相较于基于指数趋近律的单舵轮AGV双闭环轨迹跟踪滑模控制器,基于双幂次趋近律的单舵轮AGV双闭环轨迹跟踪滑模控制器在保证单舵轮AGV轨迹跟踪稳定性的同时具有更快的响应速度。     

基于Backstepping的改进等速趋近律AGV滑模轨迹跟踪控制方法

针对自动导引小车(AGV)轨迹跟踪过程中如何快速平稳消除行进所产生的距离和角度误差问题,提出了一种改进等速趋近律的滑模轨迹跟踪控制方法。在全局坐标系下建立了AGV运动学模型,基于反演算法(Backstepping)处理非线性系统的控制策略得到AGV的滑模切换函数,从而解决了非线性系统滑模控制切换函数难的问题;为了更好地实现AGV从任意初始的偏差状态达到滑模切换面,针对等速趋近律中ε常数对趋近过程的影响,通过连续的函数取代原趋近律中的符号函数,得到基于改进等速趋近律AGV滑模控制的切换函数式和轨迹跟踪的控制律式。通过仿真数据与实验结果表明,所提出的轨迹跟踪控制方法能够使AGV在不同转弯半径和不同速度下均能实现较快的误差纠偏,并最终使系统趋于稳定。     

基于模糊滑模控制的再生制动系统稳定性分析

针对电动汽车再生制动系统稳定性问题,将模糊滑模控制技术应用于再生制动过程的稳定性研究。分析了再生制动过程中3种制动模式之间的相互关联以及动态演化,并综合考虑车辆制动稳定性及制动能量回收率,提出了电机再生制动力和前后轮液压制动力协调控制的最大化制动力分配策略;以滑移率为控制目标,将模糊控制与变结构控制相结合,建立了基于电机再生制动的稳定性模糊滑模控制策略;依据实车参数,对控制策略模型进行了仿真分析。研究结果表明,模糊滑模控制实现了电动汽车制动模式的合理切换,并验证了控制策略的有效性。     

Fuzzy logic sliding mode control for command guidance law design

Recently, the combination of sliding mode and fuzzy logic techniques has emerged as a promising methodology for dealing with nonlinear, uncertain, dynamical systems. In this paper, a sliding mode control algorithm combined with a fuzzy control scheme is developed for the trajectory control of a command guidance system. The acceleration command input is mathematically derived. The proposed controller is used to compensate for the influence of unmodeled dynamics and to alleviate chattering. Simulation results show that the proposed controller gives good system performance in the face of system parameters variation and external disturbances. In addition, they show the effectiveness of the proposed missile guidance law against different engagement scenarios where the results demonstrate better performance over the conventional sliding mode control.     

Fuzzy surface-based sliding mode control

A new controller based on a combination of Sliding Mode Control and Fuzzy Logic is proposed. The conventional sliding surface is modified using a set of fuzzy rules. This combination confers controller robustness and flexibility. A neutralization process and a mixing process are used to compare the performance of the new controller to that of a conventional sliding mode controller and a PID controller.     

基于双曲正割函数趋近律的多轴调平滑模控制研究

为解决复合材料压机多轴调平系统的控制精度不高的问题,将滑模变结构控制算法应用到多轴调平系统中。开展了多轴调平系统的不平衡机理、调平控制策略及算法的研究,建立了多轴调平系统的数学模型。结合基于双曲正割函数改进的指数趋近律,提出了一种多输入多输出滑模变结构控制算法,给出了控制器的设计方法,并将其应用到滑块的水平控制中。通过仿真分析和试验验证相结合的方式验证了算法的有效性。研究结果表明:该控制器能削弱抖振,使多轴调平的滑块系统快速准确地进行调平,能较好地抑制干扰和未建模动态,提高了系统的鲁棒性,且控制器简单,易于实现。     

悬架不确定性的滑模半主动控制分析

在电流变液特性试验的基础上,提出基于电流变阻尼悬架的滑模半主动控制。依据滑模控制理论,采用极点配置法确定滑模切换面参数,应用比例切换的控制方法和等速趋近率确定控制律并改善滑模运动的动态品质,同时采用RBF神经网络算法优化滑模控制效果。针对悬架质量参数和车速不确定性,运用MATLAB/SIMULINK进行了悬架半主动控制的建模和仿真分析。仿真结果显示,与被动悬架相比基于RBF神经网络的滑模半主动控制能有效改善悬架性能,对于悬架的不确定性有较好的自适应性。     

Fuzzy sliding mode controller of a pneumatic active isolating system using negative stiffness structure

A novel active vibration isolation system using negative stiffness structure (active system with NSS) for low excitation frequency ranges (< 5 Hz) is developed successfully. Here, the negative stiffness structure (NSS) is used to minimize the attraction of vibration. Then, the fuzzy sliding mode controller (FSMC) is designed to improve the vibration isolation performance of the active system with NSS. Based on Lyapunov stability theorem, the fuzzy control rules are constructed. Next, the experimental apparatus is built for evaluating the isolation efficiency of the proposed system controlled by the FSMC corresponding to various excitation conditions. In addition, the isolation performance of the active system with NSS, the active system without NSS and the passive the system with NSS is compared. The experimental results confirmed that the active system with NSS gives better isolation efficiency than the active system without NSS and the passive system with NSS in low excitation frequency areas.     

Application of full order sliding mode control based on different areas power system with load frequency control

In the traditional sliding mode control method, there always exist the singularity due to the reduced order of the control method. In order to eliminate the singularity, I propose a new full order sliding mode control method in this article, which has been firstly applied to load frequency control. The full order sliding mode control method includes the terminal sliding mode control (TSM) and the linear sliding mode control (LSM). TSM has the good characteristic of eliminating the singularity due to the avoidance of derivative of terms with fractional power factors. While the LSM is easy to design and has fast time convergence comparing to TSM. The model is based on the system with different kinds of turbine or the same kind of turbine, which contains the nonlinearities. The control purpose is to adjust the frequency deviation to zero. Through the simulation results, it is shown that the frequency deviation can be kept to zero in the condition of different load disturbances by the two approaches, which approves the robustness of the proposed methods. In addition, we compare the two methods with the traditional sliding mode control (SMC), which proves the superiority of the two methods in terms of chattering and response time.     

Adaptive fuzzy sliding mode control for electric power steering system

The Electric power steering (EPS) system, a typical non-linear system, is easy to be influenced by parameters perturbation and disturbance of the road. Traditional linear control method based on a simplified linear model such as PID control cannot reach good dynamic performance. To reduce the influence of parameters perturbation and disturbance of the road and enhance the robustness of the system, an Adaptive fuzzy sliding mode control (AFSMC) method is proposed in this paper. First, fuzzy sliding mode control is employed to enhance the dynamic performance of the system. Then, to improve the precision of the controller, genetic algorithm is used to optimize the control rules which are essential to fuzzy control. The experimental results on non-linear EPS model demonstrate that AFSMC is more stable than Sliding mode control (SMC) method and more efficient to the non-linear system than SFPID control method. They can also prove that AFSMC can provide a stable driving in the presence of parameters perturbation and disturbance of the road.     

基于动态滑模的起重机位置控制系统设计

给出了起重机电机负载系统的数学模型,以此模型为基础,采用动态滑模控制理论,分别设计了系统的磁链动态滑模控制器和位置动态滑模控制器,考虑到系统转子磁链无法直接测量,设计了转子磁链观测器;为保证动态滑模面的物理可实现性,对系统的不确定干扰设计了自适应律,进行自适应估计。仿真结果表明系统具有较好的动态性能,较高的位置控制精度及对干扰具有良好的鲁棒性。