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针对机械臂滑模控制中存在抖振的问题以及对外界干扰较为敏感的特性,设计了一种基于干扰观测器的机械臂改进趋近律的滑模控制策略。该策略在指数趋近律中引入饱和函数,提出了一种改进趋近律;根据系统动力学模型,对系统的不确定性和外部干扰采用干扰观测器进行观测;在此基础上设计系统滑模控制律,控制律对未观测的干扰进行补偿。仿真结果表明,控制策略能有效地抑制轨迹跟踪中的抖振问题,较好地克服外界干扰,保证系统的控制性能。 相似文献
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针对带有摩擦力矩、负载力矩以及扰动力矩等不确定性的机电伺服系统,提出一种基于变速趋近律的自适应滑模控制方法.首先,构造双曲正切型辅助函数并设计新的变速趋近律,用以调节滑模变量的收敛速度,使其在到达减速点之前具有较快的收敛速度,而在到达减速点以后则能有效削弱抖振.在此基础上,构造自适应滑模控制器,保证系统位置输出能够快速稳定地跟踪期望轨迹.同时,设计参数更新律估计不确定项平方的上界,确保控制信号的连续性和减小控制信号抖振.基于李雅普诺夫稳定性定理给出误差收敛性分析,并给出仿真对比验证所提出方法的有效性. 相似文献
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针对存在复合干扰的飞翼布局无人机(UAV)姿态控制问题,提出了一种基于分数阶积分滑模与双幂次趋近律的姿态跟踪控制方案.结合分数阶微积分及滑模变结构控制理论,设计了分数阶积分滑模面.为解决传统趋近律收敛时间长和抖振严重等不足,提出一种具有二阶滑模特性且有限时间收敛的双幂次趋近律.在名义控制律的基础上,设计super twisting滑模干扰观测器,实现对复合干扰的估计和补偿,增强内外环控制器应对复合干扰的鲁棒性.为充分利用冗余操纵面与解决非线性舵效问题,在飞行控制系统中引入了非线性控制分配环节.仿真结果验证了所提方案的有效性. 相似文献
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根据一类典型的三轴动中通系统的耦合特性及载体扰动特点,提出一种新型滑模趋近律方法,并在此基础上设计了滑模稳定跟踪控制器.理论证明和仿真实验均表明了所设计的基于新型趋近律的滑模稳定跟踪控制器的合理性和有效性. 相似文献
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为针对双起升桥式吊车双吊具同步运行过程中普遍存在的无法精确建模、系统参数变化、外部扰动未知等问题,采用交叉耦合策略,提出了一种基于非线性扰动观测器的时变滑模同步控制方法。首先,采用时变滑模控制保证了控制器的全局鲁棒性;其次,利用非线性扰动观测器观测聚合扰动,对控制器进行扰动补偿;此外,提出一种可动态适应控制系统变化的变增益趋近律,有效抑制了控制输入抖振、缩短了趋近时间。最后,利用Lyapunov理论证明控制器的渐进稳定性,并通过仿真结果表明了所提出方法的有效性,控制器在未知扰动存在的情况下仍具有良好性能。 相似文献
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针对多输入多输出二阶不确定非线性机械系统中轨迹跟踪控制的问题,提出一种新的基于指数趋近律的滑模变结构控制方法,用于提高系统的平稳性和快速性。在滑模变结构控制器设计过程中采用一种新的指数趋近律以改进闭环系统的暂态和稳态响应性能,使系统跟踪误差收敛速度加快,特别是减少轨迹跟踪误差到达滑模面的时间,同时提高了系统轨迹跟踪过程的平稳性。通过采用边界层方法消除滑模控制输入抖振问题,避免控制过程中执行器的频繁切换,进一步提高所提出滑模控制器在实际系统中的实用性。基于李雅普诺夫稳定性理论证明了闭环系统的稳定性和跟踪误差的收敛性。数值仿真验证了所提出的控制方法的有效性。 相似文献
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This paper presents the first attempt to design a reaching law-based discrete-time sliding mode controller with a relative degree 2 switching variable. The current value of this variable is only affected by the control signal and disturbance generated two time instants ago. It is demonstrated that the new reaching law-based strategy offers a smaller quasi-sliding mode band width when compared to a similar control scheme with relative degree 1 switching variable. This in turn leads to reduced system output error in the control system proposed in the paper. 相似文献
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一种新型滑模控制双幂次趋近律 总被引:8,自引:1,他引:7
针对滑模控制中传统趋近律存在收敛速度慢、时间长和抖振严重等不足,提出一种利用双幂次趋近律提高系统状态收敛速度的设计方案.该双幂次趋近律无论在远离滑动模态还是在接近滑动模态的空间内均具有快速收敛能力.理论分析表明,该双幂次趋近律具有二阶滑模特性,当系统存在不确定性时,系统状态及其导数可以快速收敛到平衡零点的邻域内.仿真结果表明,双幂次趋近律与传统幂次趋近律、指数趋近律、快速幂次趋近律相比,具有更快的收敛速度和更好的运动品质. 相似文献
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Adaptive nonsingular fast terminal sliding mode guidance law with impact angle constraints 总被引:2,自引:0,他引:2
Junhong Song Shenmin Song Huibo Zhou 《International Journal of Control, Automation and Systems》2016,14(1):99-114
This paper considers the terminal guidance problem of missiles intercepting maneuvering targets with impact angle constraints. Based on an advanced nonsingular fast terminal sliding mode control scheme and adaptive control, an adaptive nonsingular fast terminal sliding mode guidance law is proposed in the presence of the target acceleration as an unknown bounded external disturbance. In the design procedure, an adaptive law is presented to estimate the unknown upper bound of the external disturbance. Theoretical analysis shows that the proposed guidance law can guarantee the finite-time convergence in both the reaching phase and the sliding phase by applying a Lyapunov-based approach. Numerical simulations are presented to demonstrate the effectiveness of the proposed guidance law. Although the proposed guidance law is developed for the constant speed missiles, by the extensive numerical simulations with a realistic missile model, the performance is shown to be equally good for the varying speed missiles. 相似文献
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Trajectory Tracking Control of XY Table Using Sliding Mode Adaptive Control Based on Fast Double Power Reaching Law 下载免费PDF全文
Currently, high velocity and precision are the main developing directions of the XY table. However, the nonlinear effects of friction at low speed deteriorate the precision of the XY table servo system. As a result, it is very important to design a control method to carry out friction compensation and trajectory tracking. In this paper, dual sliding mode state observers are used to estimate these immeasurable parameters in the dynamic LuGre model, and the Lyapunov function is used to design the adaptive update law. In addition, fast double power reaching law has the advantage of improving the global asymptotic convergence rate and overcoming these disadvantages where traditional sliding mode control reaching law causes severe chattering. Simulation results that compare the proposed method with exponent sliding mode control and PID control, demonstrate that the fast double power sliding mode control guarantees position and speed signals, tracking the desired references asymptotically. 相似文献
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针对传统带有滑模观测器的永磁同步电机控制系统中的转矩脉动大、抖振明显、反电动势估计精度差等
问题, 在速度环提出了基于双曲正弦函数的新型趋近率, 结合模糊控制思想对趋近率参数实现自整定, 设计了一种
基于新型趋近率的模糊积分滑模速度环控制器; 同时, 在滑模观测器中提出基于变截止频率低通滤波器和修正反
电动势观测器的两级滤波结构来抑制反电动势中的高频分量和纹波分量, 并对转子位置进行合理补偿, 设计了两级
滤波滑模观测器; 通过Lyapunov判据对本文提出的控制策略的稳定性进行了推导证明. 仿真结果表明, 与传统滑模
观测器相比, 本文控制器可使电机在启动和受到外部扰动时系统响应良好. 相似文献
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为解决现有终端滑模控制算法在收敛速度和抖振方面的问题, 提出一种连续非奇异快速终端滑模控制方法. 采用变系数双幂次趋近率和非奇异快速终端滑模面相结合的设计方式, 提高系统状态在趋近和滑动阶段的收敛速度. 通过Lyapunov 稳定性方法证明所提出的控制率可使得状态轨迹在扰动存在的情况下, 在有限时间内快速收敛到一个区域. 与传统方法相比, 所提出的控制率是连续的, 因此抑制了抖振, 拥有更高的控制精度. 将所提出的方法应用于光电稳定平台, 仿真结果验证了算法的有效性.
相似文献18.
Considering that in the trajectory tracking control of a nonlinear robotic manipulator system, the control effect is easily limited by the initial state of the system, and the system has modeling error, unknown disturbance, and friction in the actual control, to overcome the above problems, a fixed-time sliding mode control (SMC) strategy based on adaptive disturbance observer (ADO) is developed in this paper. Firstly, feedforward compensation of the system is achieved by developing an ADO to accurately estimate the compound disturbances in the system. Second, a new fixed-time sliding mode (SM) surface is presented to overcome the singularity issue and accelerate the error convergence. In addition, to enhance the performance of the reaching phase, a variable exponential power reaching law (VEPRL) is developed, which can effectively adjust the convergence rate. Through rigorous theoretical analysis, it is shown that the system state can be stabilized at a fixed time, and an upper bound on the convergence time is also given. Finally, the effectiveness of the control method is verified by comparing it with different control schemes in simulation. 相似文献
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首先, 利用特殊幂次函数和反双曲正弦函数构造一种新型滑模变结构控制趋近律; 然后, 采用该趋近律设计一种自适应滑模控制律, 并证明滑模控制系统误差渐近收敛. 仿真实验表明: 在存在时变转动惯量和摩擦力矩扰动的情况下, 该自适应滑模控制系统具有较高的位置和速度跟踪精度, 并有效减弱了控制输入信号的高频震颤现象; 同时, 采用反双曲正弦函数的自适应律能较好地平滑系统转动惯量估计值, 减小控制输入信号的幅值.
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