斜拉索的磁流变半主动自适应控制器设计

考虑描述磁流变(MR)阻尼器力学行为的LuGre动态摩擦模型,建立了新的斜拉索-MR阻尼器系统模型,该模型能够很好地描述斜拉索-阻尼器系统的动态特性,且能够实时辨识MR阻尼器内部参数.对于新的系统模型,基于Lyapunov直接法设计了抑制斜拉索振动的半主动自适应控制方法;原系统可变换为带有小参数的奇摄动系统,采用奇摄动理论对该系统进行分析,得到了另一类半主动自适应控制方法.仿真结果表明提出的两种控制方法均能够很好地抑制拉索振动.     

Modeling and feedback control of a flexible arm

When a flexible arm is rotated by a motor about an axis through the arm's fixed end, transverse vibration may occur. The motor torque should be controlled in such a way that the motor rotates by a specified angle, while simultaneously stabilizing vibration of the flexible arm so that it is arrested as soon as possible at the end of rotation. In this paper, we first derive a partial differential equation and a set of boundary conditions governing the vibration. Then, a feedback control system which incorporates a dynamic compensator is designed using sensor outputs. A set of experiments has been constructed to demonstrate control strategies for a flexible arm, where a strain gage was used as a vibration sensor and a microcomputer was equipped as a controller. Several satisfactory experimental results are shown.     

汽轮发电机组转子轴系扭振系统部分模态施控特性研究

在汽轮发电机组转子轴系扭振动力响应计算结果的基础上,根据独立模态空间控制的思想,探讨了对轴系扭振部分模态进行施控的可行性,导出了轴系扭振部分施控反馈最优控制规律,并对一台200MW汽轮发电机组转子轴系进行了主动控制部分施控的模拟计算,取得了理想的效果.     

Vibration damping in manipulation of deformable linear objects using sliding mode control

In this paper, we proposed a position-based control strategy for eliminating the vibration at the end of deformable linear objects (DLOs) during its manipulation. Using Schur decomposition of matrices and linear transform of variables, actuated and underactuated parts of the DLO dynamic model are separated. Based on the decoupled dynamic model of a DLO system, a sliding mode control with exponential approach law is designed to force the state variables to converge to an equilibrium and to allow vibration at the end of the DLO to be damped quickly. The DLO system, subjected to control input saturation, is further studied to solve the input saturation problem. An adaptive sliding mode control law is designed to suppress the damping at the end of the DLO. Proposed control strategies are verified by numerical simulations. The simulation results show that proposed methods can effectively damp the vibration at the end of the DLO.     

汽轮发电机组转子轴系扭振系统部分模态施控特性研究

在汽轮发电机组转子轴系扭振动力响应计算结果的基础上, 根据独立模态空间控制的思想, 探讨了对轴系扭振部分模态进行施控的可行性, 导出了轴系扭振部分施控反馈最优控制规律, 并对一台 2 0 0MW汽轮发电机组转子轴系进行了主动控制部分施控的模拟计算, 取得了理想的效果.     

Observer-based continuous finite-time attitude control for rigid–flexible coupling satellites

In this paper, a novel finite-time attitude control law is proposed for rigid–flexible coupling satellites in large angle manoeuver. First, the rigid–flexible coupling dynamic model is set up to reflect the coupling effect between the deformation of flexible appendages and the spatial movement of the rigid hub. Then an extended state observer (ESO) is designed to estimate and compensate the total perturbation including high-order flexible coupling terms, external disturbances and uncertain inertia. Following this, a continuous finite-time attitude controller is designed based on non-singular fast terminal sliding mode (NFTSM) and fast power reaching law, which is introduced to smooth the control input and eliminate the chattering. Numerical simulation is designed to verify the finite-time stability, high accuracy, disturbance rejectionand vibration damping of the proposed control scheme and then a ground experimental system is set to further test the controller's practicability.     

挠性智能梁的振动控制

研究采用共位配置的压电敏感器和致动器的挠性是臂梁的振动控制问题,建立了智能梁的模型,设计了一种线性反馈控制律,并应用无空维空间的ＬａＳａｌｌｅ不变原理和线性半群理论证明了当敏感器和控制器的分布使得系统能镇条件成立时,所设计的控制抑制了梁的振动。     

受扰线性离散系统的前馈2反馈最优控制

研究具有已知动态特性但未知初始条件的持续外界扰动的线性离散系统最优控制问题。给出了前馈一反馈最优控制律的存在唯一性条件，并提出了最优控制律的设计算法．通过降维扰动观测器解决了前馈一反馈最优控制律的物理不可实现问题．对近海结构物振动控制的实例仿真表明，该设计算法易于实现，在抑制外部持续扰动和鲁棒性方面优于经典的状态反馈最优控制。     

结构振动控制仿真分析软件TSHOW

介绍结构振动控制仿真分析软件TSHOW基于结构振动控制的算法和原理,建立了在无控、主动控制、隔振控制和半主动控制时结构运动的微分方程,并应用MATLAB控制系统工具箱（Control System Toolbox）中的函数,研制了仿真分析程序。对于实验结果,经TSHOW进行后处理,可以与仿真结果进行对比,从而分析控制实验的效果。仿真结果以图形方式显示,内容包括控制力时程、所选楼层的动力响应等,例如位移、速度、加速度时程。频域分析包括位移、速度、加速度的幅频响应曲线。所绘曲线的显示特性可以按照要求进行设置和调整。为了探求隔振层和控制装置的动力特性,利用图形技术,实现了层间恢复力-位移曲线的动态显示。     

Global set stabilization of the spacecraft attitude control problem based on quaternion

In this paper, we develop a global set stabilization method for the attitude control problem of spacecraft system based on quaternion. The control law that uses both optimal control and finite‐time control techniques can globally stabilize the attitude of spacecraft system to a set of equilibria. First, for the kinematic subsystem, we design a virtual optimal angular velocity. To obtain the global minimum of the performance index, this optimal angular velocity is only discontinuous in initial values. It can be regarded as a combination of open loop control and closed loop control. Then for the dynamic subsystem, we design a finite‐time control law that can force the angular velocity to track the virtual optimal angular velocity. It is proved that the closed loop system satisfies global set stability in the absence of disturbances. In the presence of disturbances, the system trajectory will converge to a neighborhood of the equilibrium set. Rigorous analysis shows that by introducing finite‐time control techniques, the closed loop system possesses a better disturbance rejection property. The control method is more natural and energy‐efficient. The effectiveness of the proposed method is demonstrated by simulation results. Copyright © 2009 John Wiley & Sons, Ltd.     

Active vibration control of large space flexible slewing truss using cable actuator with input saturation

This paper proposes a composite approach to implementing attitude tracking and active vibration control of a large space flexible truss system. The system dynamic model is based on Hamilton's principle and discretized using the finite difference method. A nonlinear attitude controller for position tracking is developed based on the input‐output linearization of the discretized system, which can effectively improve system performance compared with a traditional proportional‐differential feedback controller. A taut cable actuator scheme is presented to suppress tip vibration because the mechanical model is a large large‐span spatial structure; furthermore, because the cable has the feature of unilateral input saturation constraint, which can provide only a pulling force, a nonlinear quadratic regulator controller is developed by introducing a piecewise nonquadratic cost function to suppress the vibration of the flexible structure. To investigate the factors that influence the damping effects of the cable, the parametrically excited instability of a cable under 2 supports is analyzed. Simulation results illustrate that the proposed attitude controller can implement the task of position tracking, and the vibration suppression control law is shown to be optimal for functional performance with input saturation.     

Asynchronous switching output feedback control of discrete-time switched linear systems

In this paper, the problem of dynamic output-feedback control synthesis is addressed for discrete-time switched linear systems under asynchronous switching. The proposed hybrid controller consists of a standard dynamic output-feedback switching control law and an impulsive reset law induced by controller state jumps. Using the average dwell time technique incorporating with multiple quadratic Lyapunov functions, the switching control synthesis conditions for asymptotic stability with guaranteed weighted ?₂-gain performance are derived as a set of linear matrix inequalities (LMIs). The proposed hybrid synthesis scheme advances existing design methods for output-feedback asynchronous switching control of switched linear systems in two important aspects: LMI formulation of the synthesis problem; and arbitrary order of the controller state. A numerical example is used to illustrate the effectiveness and advantages of the proposed design technique.     

Robust discontinuous exponential regulation of dynamic nonholonomic wheeled mobile robots with parameter uncertainties

For regulating a dynamic nonholonomic WMR (wheeled mobile robot) with parameter uncertainties, we derive a simple robust discontinuous control law, yielding a global exponential convergence of position and orientation to the desired set point despite parameter uncertainties. The controller design relies on separating the error dynamics into two subsystems, followed by robust feedback control laws to stabilize the subsystems. The effectiveness of the proposed control laws is verified by simulation. Copyright © 2007 John Wiley & Sons, Ltd.     

基于模糊动态模型的多变量系统模糊控制

采用模糊动态模型对多变量复杂非线性系统进行模糊控制.首先针对局部线性动态模 型设计状态反馈控制器,然后利用模糊推理确定整个系统的控制;在一系列局部模型通过模糊 隶属函数连接得到的连续的全局模型中,全面考虑其它关联子系统对标称线性系统的摄动,并 利用大系统分散控制关联稳定性的概念和方法,得到了闭环模糊系统稳定的充分条件.仿真例 子验证了该设计方法的正确性.     

飞艇隔振云台电机控制器设计与实现

飞艇隔振云台的主要执行机构是三相无刷直流电机,电机控制的精度决定了隔振云台系统的隔振效果。传统的云台电机控制器设计方法是根据控制规律通过反复试凑,得到PID控制器参数,这种方法费时费力,需要一定的调参经验。针对云台调参问题,对无刷直流电机进行了理论分析与模型建立,并提供一种与传统方法不同的利用特定工具和技术手段获取模型参数的方法,通过Matlab中rltool根轨迹零极点配置工具设计出合理的控制器,使得电机具有良好的动态响应和稳态响应。并且在此基础之上将控制器实际运用到云台平台上,实验取得良好的控制效果,为隔振云台中三相无刷直流电机控制器设计与调参方案提供参考。     

Inverse response problem (control) of dynamic systems via Hamilton's law

By using Hamilton's law (of varying action) directly, the solution of a control problem becomes one of solving a set of algebraic equations only; no differential equations are needed. The approach specifies the response as a polynomial in power series of time, the coefficients of which are chosen to yield the desired behavior of the dynamic system. The unknown control inputs are assumed to be also polynomials in power series of time with unknown coefficients. The inverse response (control) problem is solved by finding these unknown input coefficients by an application of Hamilton's law which must always be satisfied by the dynamic system. The feasibility of the method is demonstrated for the control of a spatially discrete nonlinear dynamic system.     

基于Haar小波分解的轮式移动机器人轨迹跟踪控制

利用Haar小波在满足机器人动力学约束的前提下 ,对期望轨迹进行曲线分解 ,得到所需的一系列参考点 ,并由这些参考点构造出虚拟小车的运动轨迹 .基于控制Lyapunov函数设计了速度跟踪控制律 ,驱动机器人跟随虚拟小车实现对期望轨迹的跟踪 .该方法的突出特点是可实现对任意复杂轨迹的跟踪控制 ,且不存在速度跳跃点 .仿真实验结果表明它的有效性 .     

Nonlinear torque control of a single‐link flexible robot

In this research, a nonlinear torque control law with a free function is applied to the simultaneous motion and vibration control of a single‐link flexible robot. A rigorous proof of the asymptotic stability of the closed‐loop system is provided and experiments are conducted by taking the free function in the feedback law as the output of one of the following vibration sensors: strain, shear force, reaction force, tip acceleration, and acceleration at some intermediate point. The experimental results demonstrate that the use of strain, shear force, and reaction force information in the control law can substantially suppress vibrations in the arm, while the effect of incorporating the acceleration information can be better or worse, depending on where the accelerometer is placed. ©1999 John Wiley & Sons, Inc.     

Robust time-optimal control of constrained linear Systems

A version of dynamic programming, which computes level sets of the value function rather than the value function set itself, is used to design robust non-linear controllers for linear, discrete-time, dynamical systems subject to hard constraints on controls and states. The controller stabilizes the system and steers all trajectories emanating in a prescribed set to a control invariant set in minimum time. For the robust regulator problem, the control invariant terminal set is a neighborhood, preferably small, of the origin; for the robust tracking problem, the control invariant terminal set is a neighborhood of the invariant set in which the tracking error is zero. Two non-linear controllers which utilize the level sets of the value function, are described. The first requires the controller to solve, on-line, a modest linear program whose dimension is approximately the same as that of the control variable. The second decomposes each level set into a set of simplices; a piecewise linear control law, affine in each simplex, is then constructed.     

中心刚体-柔性梁应变反馈多目标优化控制

本文针对柔性结构在轨组装任务背景,将自动飞船和待运送部件分别简化为中心刚体和柔性梁附件,研究自由漂浮中心刚体-柔性梁系统的动力学与控制问题.首先基于小变形和低转速假设,将梁用假设模态法离散,采用Lagrange方程导出系统动力学方程.继而设计一种带有应变反馈的PD控制律用于完成中心刚体的状态镇定以及柔性梁振动抑制.此外,本文还使用遗传算法对控制器中的参数进行多目标优化.最后,通过数值算例验证了所设计控制器的有效性.