四旋翼吊挂运输系统动态反馈线性化轨迹控制

三维空间下的四旋翼吊挂运输系统是一种欠驱动、强耦合、多变量的非线性系统. 根据系统的动力学特点, 将系统分解为双质点系绳连接子系统和四旋翼姿态控制子系统. 选择与系统自由度维数相同的广义坐标并基于虚位移原理计算对应的广义力, 从而建立系统的拉格朗日动力学方程. 利用微分平滑特性证明了运输系统存在平凡零动态, 因此可通过动态反馈转化为线性和能控系统. 经过2次动态扩展和变量代换, 原系统扩展为总相对阶等于系统状态维度的线性能控系统. 基于赫尔维茨稳定性判据, 设计了跟踪误差指数收敛的动态反馈控制律. 该方法可作为一类非线性系统控制器设计的标准方法. 最后以三维空间的螺旋曲线及水平面内频率变化的圆周曲线为参考轨迹进行仿真, 仿真结果验证了控制系统的有效性.     

On Robust Approximate Feedback Linearization: Control with Two Gain-scaling Factors

In this paper, we consider a problem of global stabilization for a class of approximately feedback linearized nonlinear systems. In order to handle more nonlinearity over the existing results, we provide a new feedback controller with two gain-scaling factors and we show that more nonlinearity can be treated by our control scheme. Moreover, we analytically show that the considered nonlinear systems can be stabilized by the proposed controller. Through comparison practical examples, we illustrate the improved features of our proposed control method.

     

基于最大反馈线性化的两轮机器人平衡控制

为了对两轮直立式机器人进行平衡控制研究,首先应用一种拉格朗日方法对两轮直立式机器人系统进行动力学建模,以力矩作为模型控制输入并且考虑到了系统无滑动的非完整约束方程.求出了系统的最大相对阶并对非线性系统进行了部分反馈线性化,经过坐标变换和输出反馈得到了2个由两链积分器构成的子系统,外加3个代表系统内动态的非线性方程.根据...     

动态输出反馈鲁棒模型预测控制离线算法

研究具有多包不确定性和有界噪声系统的动态输出反馈鲁棒模型预测控制(Robust model predictive control, RMPC)的离线方法. 先前的在线方法中, 在估计状态和估计误差集合已知的情况下, 在每一采样时刻通过近似最优算法求解控制器参数. 本文采用先前的方法计算离线控制器参数和吸引域. 首先, 选定一系列估计状态, 其中,每个估计状态对应同样一组嵌套的估计误差集合. 然后,针对每一估计状态和每一估计误差集合的组合,离线计算唯一的控制器参数和对应的吸引域. 这些控制器参数和对应的吸引域存储在表中. 如果离线确定的吸引域包含实时的扩展状态, 则该离线控制器参数是实时可行的. 在线时, 根据实时估计状态和选取实时估计误差集合, 在表中搜索包含实时扩展状态且优化性能指标最小的吸引域所对应的控制器参数. 通过连续搅拌釜式反应器控制系统验证了该方法的有效性.     

基于反馈线性化同步伺服电机鲁棒跟踪控制

为了保证具有不确定非线性的PM同步伺服电机驱动系统的稳定性,确保闭环系统的输出准确跟踪期望输出并减少不确定项对该驱动系统的影响,利用Lyapunov稳定性理论,设计了一种基于反馈线性化的鲁棒跟踪控制器,并作了相应的仿真研究。仿真结果表明,该控制器不仅确保闭环系统的输出按指数规律跟踪期望输出,而且保证闭环系统状态的一致最终有界。该控制器设计简单,易于实现,具有很好的实用性。     

Robust Linear Control of Flexible Joint Robot Systems

This paper presents the development and design of a robust linear controller for a flexible joint robot. First, a realistic model is developed taking into account the effects of stick-slip friction, nonlinear spring force characteristic, the rotors' Coriolis and centrifugal acceleration due to the velocities of the precedent links and rotors, and measurement noise. Second, a robust controller is designed using LQG/LTR techniques. Extensive simulation was performed on an experimental robot system using several trajectories. The results demonstrate that the proposed model/controller provides excellent tracking and regulation performance.     

动态输出反馈鲁棒模型预测控制

研究了具有多包不确定性和有界噪声的系统的动态输出反馈鲁棒模型预测控制的综合方法.系统为准线性参数时变的,即系统时变参数在当前时刻精确已知,但在将来时刻未知.采用二次有界概念刻画扩展闭环系统的稳定性.本文主要创新在于提出了一种辅助优化方法,从而为下个采样时刻的主优化问题提供可靠的真实状态的界.通过连续搅拌釜式反应器控制系统验证了该方法的有效性.     

柔索牵引式力觉交互机器人控制策略

为了让航天员在没有太空真实环境的地面上模拟太空环境进行虚拟作业训练,设计了一种与虚拟现实（VR）技术相结合的柔索牵引式力觉交互机器人．首先,根据微重力环境中物体的运动特性设计机器人的构型,建立移动平台、驱动单元、人推物体运动过程的动力学模型并进行运动学分析．然后,针对系统冗余驱动及力控制任务,提出一种复合控制策略,即以柔索长度变化为速度控制内环,力的外环控制为力／速混合控制．最后,分别进行单柔索加载和人机系统力觉交互仿真分析,分析结果表明该控制策略可以使柔索驱动单元降低10%的恒力跟随误差并能稳定地跟随余弦力的变化,验证了该控制策略对多余力抑制的有效性．     

Robust Output Feedback Model Predictive Control: A Stochastic Approach

This paper addresses the robust explicit model predictive control scheme for linear systems with input and output constraint in the presence of disturbances and noise. Conditions for disturbance rejection are established by incorporating a full state/disturbance observer. The separation principle is applied to design an optimal observer in the unconstrained problem. Then, an efficient algorithm is developed to explicitly design observer gains by minimizing a quadratic performance criterion. It is shown that the solution includes a set of regions with piecewise affine functions of the state and reference vectors and a set of regions with optimal observers. In the proposed method, two sets of partitions associated with the control law and the observer gains are obtained. Therefore, the online computation includes finding the active regions of both observer and control law partitions in which the current state is located. The proposed technique is particularly attractive for a wide range of practical problems where the exact model of the actual system is not available.     

Robust Stable Fuzzy Control via Fuzzy Modeling and Feedback Linearization with Its Applications to Controlling Uncertain Single-link Flexible Joint Manipulators

In this paper, a robust stable fuzzy control design based on feedback linearization is presented. Takagi–Sugeno fuzzy model is used as representing the nonlinear plant model and uncertainty is assumed to be included in the model structure with known bounds. For this structured uncertainty, the closed system can be analyzed by applying the perturbation system stability analysis to the fuzzy feedback linearization systems and a sufficient condition is derived to guarantee the stability of the closed-loop system with bounded parameter uncertainties. Based on the developed analysis method, we can design a robust fuzzy controller by choosing the control parameters satisfying the robust stability condition.     

Neural Network Identification Based Multivariable Feedback Linearization Robust Control for a Two-Link Manipulator

Regarding to the variations of the load and unmodeled dynamic, robot manipulators are known as a nonlinear dynamic system. Overcoming such problems like uncertainties and nonlinear characteristics in the model of two-link manipulator is the principal goal of this paper. To approach to this aim, a neural network is combined with a linear robust control in which the result has the advantages of, the first, approximated nonlinear elements and the second, the guaranteed robustness. To design the proposed controller, at first, multivariable feedback linearization is employed to convert the nonlinear model to linear one. Second, the unknown parameters of the system are identified by neural network based on a new proposed learning rule. Third, Mixed linear feedback-H_?∞? robust control method is proposed to stabilize the closed loop system. The closed loop system based on the proposed controller is analyzed and some numerical simulations are performed. Results show suitable responses of the closed loop system.     

Dynamic Modeling and Robust Controller Design of a Two-Stage Parallel Cable Robot

Cable robots have been extensively used for the loading and unloading of cargo in shipping industries. In this paper, we look at a two stage cable robot, i.e., a cable robot with two moving platforms connected in series. The sea condition introduces disturbance into the system. This disturbance is considered while modeling the dynamics of the two stage cable robot. A robust controller is designed which can assure robust tracking of the desired end-effector trajectory in the presence of the disturbance. Simulation results presented show the effectiveness of the controller.     

球形移动机器人基于神经网络的反馈线性化运动控制研究与实验

实现了一种对球形移动机器人的滚动速度进行控制的方法.球形移动机器人的控制输入和状态输出间存在难以精确数学描述的非线性关系,本文采用径向基函数神经网络,以在线训练的方式建立了球形机器人输入与输出的非线性映射;然后采用反馈线性化方法,设计了球形机器人的速度控制器,该控制器由反馈线性化控制器和减小神经网络逼近误差的补偿控制器构成;给出了该控制器的实现步骤.多次实验结果表明,该方法可以实现球形移动机器人稳定的速度控制.     

Tip Tracking Control of a Single-Link Flexible Robot: A Backstepping Approach

In this paper, tip tracking control is investigated for a single-link flexible robot. The flexible beam is first lumped to a spring-mass system, to which the so called backstepping approach is applicable, then two robust controllers and an adaptive controller are developed in the presence of system disturbances/uncertainties. The controllers are rigorously proven to be able to achieve stable tip position and velocity tracking control in the sense of Global Uniform Ultimate Boundedness (GUUB). Numerical simulation results are provided which show that the proposed controllers are effective.     

单级倒立摆反馈线性化控制仿真

本文以单级倒立摆为控制对象,介绍了反馈线性化的基本原理,设计神经网络控制器对消系统的非线性,实现对单级倒立摆的反馈线性化控制。并通过MATLAB软件进行仿真实验,结果表明了该方法的有效性。     

Introduction of Feedback Linearization to Robust LQR and LQI Control – Analysis of Results from an Unmanned Bicycle Robot with Reaction Wheel

In this paper, the Jacobian‐linearization‐ and feedback‐linearization‐based techniques of obtaining linearized model approaches are combined with a family of robust LQR control laws to identify the pairing which results in superior control performance of the bicycle robot, despite uncertainty and constraints, what is the main contribution of the paper. The control performance is analyzed using various indices, related, e.g. to energy consumption of the considered laws, with the experiments conducted on a real bicycle robot. As a result, the easily‐implementable controller is obtained, which requires only to perform a set of off‐line computations with a single additional parameter δ in comparison with a standard linear‐quadratic controller, to obtain a state‐feedback vector, which, when implemented to the control system, ensures proper regulation of the output signal of the plant, despite uncertainty or possible actuator failures, obtaining energy‐efficient control law.     

基于输出反馈网络化控制系统鲁棒容错控制

研究了一类具有时延不确定性的网络化控制系统的鲁棒容错控制问题.针对以往控制器大多采用状态反馈的形式,而对功能和结构复杂的网络化控制系统全部状态往往难于测取,因而状态反馈形式的控制器在应用中会受到限制,完整性问题的结果也主要基于0-1故障模型.采用动态输出反馈控制策略,针对网络化控制系统的时延和不同步对系统产生的影响,基...     

双足机器人的鲁棒控制

利用拉格朗日法建立了双足机器人的动力学模型．在双脚支撑地时,运动学方程的约束造成双足机器人自由度的冗余,本文引入拉格朗日因子消除了双足机器人的冗余自由度．采用鲁棒控制法对双足机器人的轨迹跟踪进行控制,仿真实验结果证明, 鲁棒控制法对模型不精确或外部干扰对双足机器人产生的影响有很好的抑制作用,对双足机器人轨迹跟踪控制是有效的．     

Robust Discrete-Time Markovian Control for Wheeled Mobile Robot Formation: A Fault Tolerant Approach

In this paper we use a recursive robust regulator for discrete time Markovian jump linear systems to control a group of wheeled mobile robots in formation. A leader-following formation is used with directed communication topology. The robustness is checked with a communication fault in blind areas and, if the fault affects the leader, the leadership is changed and the formation continues to follow the defined trajectory. When the communication is reestablished all robots that lost communication return to their position in the formation. Results based on simulation and real implementation are presented to show the effectiveness of the formation control approach used.     

基于反馈线性化的STATCOM控制研究

利用基尔霍夫定律建立STATCOM开关函数模型,采用反馈线性化解耦控制方法,实现STATCOM非线性系统有功电流和无功电流的解耦,并基于线性控制理论中的极点配置方法为解耦线性化模型设计了控制器;并根据瞬时无功功率理论对负载线路中的无功电流进行动态实时检测,作为STATCOM补偿无功功率的给定,实现对无功变化负载的快速响...