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为了解决存在外部不确定随机干扰情况下机械臂的高精度轨迹跟踪问题,提出了一种自适应鲁棒滑模控制方法,并用Lyapunov稳定性定理证明了其闭环系统的稳定性。采用饱和函数取代控制器中的符号函数,有效消除了控制器的抖振现象。仿真结果证明:与传统的PID控制器相比,提出的自适应鲁棒滑模控制器具有更高的鲁棒性、稳定性和精度。 相似文献
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为了提高机械臂轨迹跟踪的精度和速度,提出了干扰观测器与非线性滑模控制相结合的轨迹跟踪控制方法.建立了机械臂动力学模型,设计了机械臂轨迹跟踪控制方案.将机械臂受到的扰动分为可观测部分和不可观测部分,对于可观测部分,设计了干扰观测器用于估计扰动大小,依据扰动观测值对控制力矩进行补偿,主动消除可观测部分扰动的影响;对于不可观测部分,设计了非线性滑模控制器,用于减小不可观测扰动造成的跟踪误差与抖动.经仿真验证,与传统滑模控制和非线性滑模控制相比,干扰观测器与非线性滑模控制相结合的轨迹跟踪误差减小了一个数量级以上,且跟踪速度最快. 相似文献
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为了提高机器人机械臂故障曲线跟踪准确性,本文设计了基于故障在线估计的欠驱动机械臂容错控制方法。分析机器人欠驱动机械臂关节故障原理,建立动力学模型实现对关节故障的检测。采用分散控制的思想将机器人欠驱动机械臂容错控制分为故障检测、信号重构、取代控制以及反馈控制四个部分,依据这四部分设计容错控制律,实现对速度信号与错误信息的实时反馈。在此基础上,通过干扰观测器实现控制律的干扰补偿,使容错控制后的机器人欠驱动机械臂具有抗外界干扰能力,以此完成控制方法设计。分析实验结果可知,所提方法不仅提高了故障曲线跟踪的准确性,减少了欠驱动机械臂容错控制后的稳态时间,满足了机器人欠驱动机械臂容错控制设计需求。 相似文献
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针对同时具有被动关节和柔性杆的欠驱动平面机械臂,提出一种简单易行的分段位置控制策略。以2R欠驱动平面柔性机械臂为研究对象,建立机械臂的假设模态动力学模型,分析系统的动力学耦合特性与可控性。通过被动关节处制动器的开闭切换,研究平面柔性机械臂的分段位置控制策略,采用PID方法分别设计各阶段主动、被动关节的控制算法。最后,基于自行开发的欠驱动平面机械臂的试验平台及实时控制系统,完成了2R欠驱动平面柔性机械臂位置控制的试验研究。仿真和试验结果表明,主动关节和被动关节在各阶段都能很好地跟踪目标值,进而实现机械臂的操作任务,验证了所提控制方法的可行性和有效性,以及欠驱动柔性机械臂动力学模型的正确性。 相似文献
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基于Lagrange方程和假设模态法,推导出单连杆柔性机械臂的动力学模型,应用微分几何输出重定义的方法,将电动机转角和振动模态变量的线性组合作为柔性机械臂系统的控制输出量,使柔性机械臂系统在平衡点附近转变为易于控制的最小相位系统。设计了一种滑模控制器,实现了柔性机械臂的振动抑制,仿真试验结果表明了该方法的有效性。 相似文献
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为建立柔性3R欠驱动机械臂的动力学方程,采用Euler-Bernoulli梁模型并添加经迭代计算的边界条件,对柔性机械臂进行了动力学耦合与仿真分析。在对柔性机械臂进行模态分析的基础上,将柔性机械臂视为包含边界条件的悬臂梁和简支-自由梁模型,采用假设模态法建立柔性3R欠驱动机械臂的动力学模型。仿真结果证明:添加经迭代计算的边界条件的柔性梁模型能更好地反映自由关节的加速度耦合情况。最后对柔性欠驱动机械臂与刚性欠驱动机械臂进行关节耦合指标分析,结果表明柔性欠驱动机械臂的自由关节包含更复杂的耦合情况,对柔性机械臂弹性振动的控制是对柔性欠驱动机械臂控制的关键。 相似文献
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欠驱动机器人的切换姿态优化及全局稳定控制 总被引:1,自引:1,他引:0
讨论了欠驱动两杆机器人控制中存在的控制器切换问题并将其归纳为一类优化问题,提出了一种优化切换姿态并保证全局稳定的控制器设计方案。在系统全局稳定的条件下,将对欠驱动关节的控制能力作为优化目标。采用基于弱控制Lya-punov函数的方法设计摆起控制器;利用线性二次调节器(linear quadratic regulator,LQR)方法设计平衡控制器;使用控制器切换环节实现控制器的最优切换,其中控制器切换环节的设计借助平衡控制器吸引域的概念和遗传算法来实现。仿真实验中,应用该方法得到的控制器不仅能实现控制目标,还能使系统具有更强的抗干扰能力,并缩短18.8%的控制时间。 相似文献
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A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method. 相似文献
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This paper presents a position control strategy based on the differential evolution (DE) algorithm for a planar four-link underactuated manipulator (PFUM) with a passive third joint, which is to move its end-point from any initial position to any target position. Based on the structural characteristic of the PFUM, a model reduction method is conceived to reduce the PFUM to a planar virtual three-link manipulator and a planar Acrobot in turn. Considering the existence of the angle constraint in the planar Acrobot, the DE algorithm is used to optimize and coordinate the control objective of each reduced system, and also to ensure the target angles of the planar Acrobot corresponding to the target position of the PFUM can be found. Simulations demonstrate the validity of the proposed control strategy. 相似文献
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针对复合干扰影响下机械臂的故障检测和控制精度问题,提出了一种基于滑模观测器的故障检测和控制优化方法。首先建立了带有电机故障、模型误差和机械摩擦等复合干扰的机械臂系统故障模型,然后设计了滑模观测器来实现在复合干扰下对电机故障的准确检测,最后引入滑模观测器对电机故障程度进行估计,并设计了反步容错控制方法,从而实现了对机械臂系统的精确控制。仿真结果表明,基于滑模观测器的故障检测和控制优化方法能够快速、准确检测和估计电机故障,确保机械臂系统准确跟踪指令信号,角度跟踪误差范围仅为-0.2°~0.2°,能够准确估计出复合干扰的大小,估计误差范围仅为-0.1~0.1 (°)/s2,大大改善了对机械臂的控制效果。 相似文献
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针对机械臂轨迹跟踪控制中传统滑模控制需估计其建模误差及外界干扰等不确定性,当建模不确定性及外界干扰较大较复杂时,将会导致出现抖振现象。该文在以传统滑模控制为主控制器的基础上,通过对传统干扰观测器进行改进,对外界干扰进行反馈补偿,同时利用神经网络对其建模误差进行逼近。通过机械手仿真实验结果表明,所提方法能够有效抑制系统抖振现象,提高响应速度及其轨迹跟踪精度。 相似文献
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A robust sliding mode control that follows a self-tuning law for nonlinear systems possessing uncertain parameters is proposed. The adjustable control gain and a bipolar sigmoid function are on-line tuned to force the tracking error to approach zero. Control system stability is ensured using the Lyapunov method. Both simulation and experimental application of a planetary gear type inverted pendulum control system verify the effectiveness of the developed approach. 相似文献
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In this paper, a chattering free optimal second order sliding mode control (OSOSMC) method is proposed to stabilize nonlinear systems affected by uncertainties. The nonlinear optimal control strategy is based on the control Lyapunov function (CLF). For ensuring robustness of the optimal controller in the presence of parametric uncertainty and external disturbances, a sliding mode control scheme is realized by combining an integral and a terminal sliding surface. The resulting second order sliding mode can effectively reduce chattering in the control input. Simulation results confirm the supremacy of the proposed optimal second order sliding mode control over some existing sliding mode controllers in controlling nonlinear systems affected by uncertainty. 相似文献
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A novel adaptive sliding mode control algorithm is derived to deal with seam tracking control problem of welding robotic manipulator, during the process of large-scale structure component welding. The proposed algorithm does not require the precise dynamic model, and is more practical. Its robustness is verified by the Lyapunov stability theory. The analytical results show that the proposed algorithm enables better high-precision tracking performance with chattering-free than traditional sliding mode control algorithm under various disturbances. 相似文献
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This paper presents an adaptive chattering-free sliding mode controller for trajectory tracking of robotic manipulators in the presence of external disturbances and inertia uncertainties. To achieve fast convergence and desirable tracking precision, a second-order fast nonsingular terminal sliding mode (SOFNTSM) controller is designed to guarantee system performance and robust stability. Chattering is eliminated using continuous control law due to high-frequency switching terms contained in the first derivative of actual control signals. Meanwhile, uncertainties are compensated by introducing the adaptive technique, whose prior knowledge about upper bound is not required. Finally, simulation results validate the effectiveness of the proposed control scheme. 相似文献
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In this paper, a robust adaptive motion/force control (RAMFC) scheme is presented for a crawler-type mobile manipulator (CTMM) with nonholonomic constraint. For the position tracking control design, an adaptive sliding mode tracking controller is proposed to deal with the unknown upper bounds of system parameter uncertainties and external disturbances. Based on the position tracking results, a robust control strategy is also developed for the nonholonomic constraint force of CTMM. According to the Lyapunov stability theory, the stability of the closed-loop control system, the uniformly ultimately boundedness of position tracking errors, and the boundedness of the force error and adaptive coefficient errors are all guaranteed by using the derived RAMFC scheme. Simulation and experimental tests on a CTMM with two-link manipulator demonstrate the effectiveness and robustness of the proposed control scheme. 相似文献