Swing-up control strategies for a reaction wheel pendulum

Control of a reaction wheel pendulum, a prototype of an under-actuated system, is easily done using switching control strategies, which combines swing-up control and balancing control schemes. In this article, two novel swing-up control strategies for a reaction wheel pendulum have been proposed. The first swing-up control strategy treats the oscillations of the pendulum as perturbations from the bottom equilibrium point. The second swing-up control is based on interconnection and damping assignment-passivity based control (IDA-PBC). IDA-PBC preserves Euler Lagrangian structure of the system and gives more physical insight about any mechanical system. Any balancing controller can be coupled with the proposed swing-up control strategies to stabilise the pendulum at the top unstable equilibrium position. The control task of balancing the pendulum in top upright position is completed by switching from swing-up scheme to the balancing scheme at the point where the pendulum is very near to the top equilibrium point. Proposed swing-up control strategies have been implemented in real time in switching mode. The two proposed swing-up control schemes provide fast responses as compared to existing energy based schemes.     

Systematic design method of stabilization fuzzy controllers for pendulum systems

A systematic method to construct stabilization fuzzy controllers for a single pendulum system and a series-type double pendulum system is presented based on the single input rule modules (SIRMs) dynamically connected fuzzy inference model. The angle and angular velocity of each pendulum and the position and velocity of the cart are selected as the input items. Each input item is given with a SIRM and a dynamic importance degree. All the SIRMs have the same rule setting. The dynamic importance degrees use the absolute value(s) of the angle(s) of the pendulum(s) as the antecedent variable(s). The dynamic importance degrees are designed such that the upper pendulum angular control takes the highest priority and the cart position control takes the lowest priority when the upper pendulum is not balanced upright. The control priority orders are automatically adjusted according to control situations. The simulation results show that the proposed fuzzy controllers have high generalization ability to completely stabilize a wide range of single pendulum systems and series-type double pendulum systems in short time. By extending the architecture, a stabilization fuzzy controller for a series-type triple pendulum system is even possible. © 2001 John Wiley & Sons, Inc.     

Global stabilization of the unstable Reaction-Wheel Pendulum

The paper deals with the problem of the Reaction Wheel Pendulum stabilization about unstable (inverted) position for arbitrary initial conditions. Considered mechanical system consists of a physical pendulum with a symmetric disk attached to the end of the pendulum, which is free to spin about an axis parallel to the axis of rotation of the pendulum. The disk is actuated by a DC-motor. The coupling torque generated by the angular acceleration of the disk is used to control of the pendulum. The switching control law is proposed to swinging up the pendulum and balancing it about the inverted position. The nonlinear swinging up control law is proposed ensuring global stabilization of the pendulum about inverted position. The Energy-based Speed-gradient (EBSG) control scheme is used to designing the swinging-up controller. The modification of the EBSG method is proposed to ensure attainability of the inverted position of the pendulum for all initial states of the system. The balance controller is designed on the basis of the Variable Structure Control with forced sliding mode. Numerical simulation results are presented showing achievement of the posed control goal by means of the control action of small magnitude.     

倒立摆系统的T-S模糊控制研究

针对倒立摆的非线性采用T-S模糊控制的方法对倒立摆进行控制,建立了倒立摆的数学模型,并用Matlab进行了仿真,仿真结果表明该控制方法对倒立摆具有好的控制效果。     

基于能量反馈的圆轨倒立摆摆起控制

基于拉格朗日方程建立圆轨倒立摆单摆模型,根据能量反馈控制理论,设计圆轨倒立摆摆起控制器,从而使摆杆从稳定平衡点摆起到不稳定平衡点并稳定不倒。采用具有流水线指令结构CIP-51控制器内核的C8051单片机实现控制算法。实验结果表明,采用能量反馈控制器可以对具有复杂非线性、强耦合、自然不稳定特性的倒立摆系统实现摆起控制,摆起效果良好。同时也为其他非线性多变量系统的控制提供了有效方法。     

基于变量分组模糊控制算法的倒立摆系统

采用模糊控制理论研究了直线一级倒立摆控制问题。直线一级倒立摆系统是多变量不稳系统,为了解决模糊规则爆炸问题,本文采用了变量分组的方法完成倒立摆模糊控制器的设计方案。要使直线一级倒立摆系统稳定,必须对小车位置和摆杆角度同时进行闭环控制,而单一的控制只能控制一个控制量,本文提出了两回路的模糊控制方案。仿真和实验结果证明了该方案的可行性和良好的控制性能。     

一级直线倒立摆匀速行走的模糊控制研究与实现

当前针对倒立摆的研究一般是把角度控制或者位置控制作为控制目标,很少着眼于速度控制,有鉴于此,设计了一种简单的模糊控制器,应用于一级直线倒立摆的匀速行走控制中;仿真实验和实物实时控制实验均验证了该控制器的有效性,对于设定的速度整定值,通过调整几个比例环节的系数,系统具有很好的动态性能指标,而且控制器在有外界扰动时体现了很好的抗扰性;考虑到实际物理系统中倒立摆行程的限制,设计的自动换向开关实现了倒立摆在一段给定的行程上匀速来回行走的控制目标,通过手动切换开关也能实现倒立摆的位置控制。     

倒立摆系统中强化学习的极限环问题

倒立摆系统是强化学习的一种重要的应用领域。首先分析指出在倒立摆系统中,常用的强化学习算法存在着极限环问题,算法无法正确收敛、控制策略不稳定。但是由于在简单的一级倒立摆系统中算法的控制策略不稳定的现象还不明显,因此极限环问题常常被忽视。针对强化学习算法中极限环问题,提出基于动作连续性准则的强化学习算法。算法采用修正强化信号和改进探索策略的方法克服极限环对倒立摆系统的影响。将提出的算法用于二级倒立摆的实际系统控制中,实验结果证明算法不仅能成功控制倒立摆,而且可以保持控制策略的稳定。     

Big Bang-Big Crunch optimized hierarchical sliding-mode control of X-Z inverted pendulum

The control of the X-Z inverted pendulum is a challenging work since the X-Z inverted pendulum is an underactuated, open-loop unstable and multi-input-multi-output (MIMO) nonlinear system. In this paper, we will present a novel state transformation method for the X-Z inverted pendulum and Big Bang–Big Crunch (BBBC) optimized hierarchical sliding-mode control (HSMC) structure. We will firstly show that through the proposed transformation, the model of the X-Z inverted pendulum can be transformed to a typical underactuated form. Thus, based on the obtained system model, the hierarchical sliding-mode control (HSMC) can be directly applied in the trajectory tracking control of the X-Z inverted pendulum. Then, to ensure a convergent performance of the auxiliary sliding surfaces, the BBBC method is applied to obtain the optimal coupling factors for the HSMC. The control performance of the proposed BBBC based HSMC structure is compared with that of the present SMC and the HSMC with particle swarm optimization (PSO). Simulation results show the effectiveness of the proposed controllers for the X-Z inverted pendulum.     

二级倒立摆系统设计

自行设计了二级倒立摆硬件系统，完成了机械部分与电路部分的总体设计、加工、组装和调试。自行设计并制作了倒立摆系统控制盒，利用控制盒实现了对角度、位移等状态变量信息的滤波、处理与控制指令的输出。利用Lagrange方法建立了二级倒立摆系统的完整数学模型，同时利用滑动模态变结构控制算法设计了相应的控制率，基于VisualStudi06．0环境编写了控制算法，成功的实现了对于二级倒立摆系统的稳定控制。     

Neural network control for position tracking of a two-axis inverted pendulum system: experimental studies.

In this paper, experimental studies of a decentralized neural network control scheme of the reference compensation technique applied to control a 2-degrees-of-freedom (2-DOF) inverted pendulum on an x - y plane are presented. Each axis is controlled by two separate neural network controllers to have a decoupled control structure. Neural network controllers are applied not only to balance the angle of pendulum, but also to control the position tracking of the cart. The decoupled control structure can compensate for uncertainties and cancel coupling effects. Especially, a circular trajectory tracking task is tested for position tracking control of the cart while maintaining the angle of the pendulum. Experimental result shows that position control of the inverted pendulum and cart is successful.     

Stabilization of the inverted pendulum around its homoclinic orbit

The inverted pendulum has been used as a benchmark for motivating the study of nonlinear control techniques. We propose a simple controller for balancing the inverted pendulum and raise it to its upper equilibrium position while the cart displacement is brought to zero. The control strategy is based on an energy approach of the cart and pendulum system.     

Stabilization control of series-type double inverted pendulum systems using the SIRMs dynamically connected fuzzy inference model

A new fuzzy controller for stabilizing series-type double inverted pendulum systems is proposed based on the SIRMs (Single Input Rule Modules) dynamically connected fuzzy inference model. The controller deals with six input items. Each input item is provided with a SIRM and a dynamic importance degree (DID). The SIRM and the DID are set up such that the angular control of the upper pendulum takes the highest priority order over the angular control of the lower pendulum and the position control of the cart when the relative angle of the upper pendulum is big. By using the SIRMs and the DIDs, the control priority orders are automatically adjusted according to control situations. Simulation results show that the controller stabilizes series-type double inverted pendulum systems of different parameter values in about 10.0 s for a wide range of the initial angles.     

三级倒立摆的自动摆起与稳定控制

采用非线性逆系统轨迹控制实现三级倒立摆的自动摆起,并设计了变增益LQR控制器将其稳定在竖直倒立位置.首先,三级倒立摆从静止下垂状态摆起到竖直倒立位置的过程,从数学角度看是一个两点边值问题,通过求解该两点边值问题获得摆起的标称轨迹,利用逆系统方法设计前馈控制,同时结合增益调度反馈控制使摆起过程稳定;其次,在稳定控制阶段,...     

基于飞轮的单级倒立摆系统的建模与仿真

针对目前融轮机器人的侧向平衡控制问题,设计了一种基于飞轮的单级倒立摆系统.简单地介绍了目前有关倒立摆系统的研究现状,然后利用拉格朗日方法建立了基于飞轮的单级倒立摆系统的数学模型,同时,对所建立的数学模型(精确模型和线性化模型)在Matlab/Simulink中进行了仿真验证,仿真结果证实了所建立的模型是可信的,并用现代...     

二级倒立摆变结构控制改进方案的对比研究

关于二级倒立摆稳定性优化控制问题,二级倒立摆是一个高度非线性系统,具有强耦合和快速运动的特点。但目前采用常规滑动模态变结构控制方法使系统出现高频抖动,导致系统存在稳定性差的问题。采用直线二级倒立摆为被控对象,通过用指数趋近律、边界层法和连续函数的趋近律三种改进方案对二级倒立摆系统进行了仿真,实验效果的对比结果表明,三种方案均能实现对二级倒立摆的稳定性有效控制,并可以使系统抖振得到抑制,为二级倒立摆稳定性设计提供了依据。     

单级倒立摆LQR最优控制及其嵌入式系统实现

倒立摆以其非线性特点成为控制理论分析和设计的典型实验设备.针对单级倒立摆系统,建立其数学模型,设计了线性二次型最优控制器,利用Matlab进行了仿真验证.同时,搭建了控制系统的实物实验平台,利用Z-World公司的嵌入式系统实现了该控制算法,并进行了调试,完成了倒立摆的平衡控制.并作了一些干扰实验来验证系统性能.仿真研究和实物实验的结果,表明在嵌入式控制系统中实现的LQR最优控制算法具有很好的控制效果,使倒立摆具有良好的动态性能和稳态性能.     

基于滑模变结构的柔性倒立摆控制研究

针对柔性倒立摆稳摆控制比较困难且传统指数趋近率的滑模变结构控制易对系统造成抖振,基于机理建模方法建立柔性倒立摆数学模型,提出变指数趋近率的滑模变结构控制方法,设计了滑模变结构控制器,使系统具有较好的稳摆控制和鲁棒性。仿真结果表明,基于变指数趋近率的滑模变结构控制方法能够更好的实现倒立摆稳定控制,相比于传统指数趋近率的滑模控制器输出更加平滑,进而减小了控制器的负担。     

带有时变计算时延的倒立摆视觉实时控制研究

针对倒立摆视觉实时控制系统中,通过每帧图像处理检测小车位移和摆杆偏角带来的时变图像处理计算时间,直接影响控制系统采样周期和系统性能的问题,不同于目前不考虑图像处理计算时间或将其视为定时滞进行倒立摆视觉实时控制的研究方法,本文首先构建了倒立摆视觉伺服控制实验平台,考虑倒立摆的小车与摆杆特征,提出了小车位移和摆杆偏角的实时计算方法;然后统计分析了图像处理计算时间的特性并设计了视觉传感事件触发采样策略,进一步刻画了时变时延与计算时间的直接关系,进而建立了带有时变计算时延的倒立摆视觉控制系统闭环模型,证明了系统稳定性并建立了反映图像处理计算时间与系统稳定性之间的关系.最后,仿真和实时控制实验验证了所提方法的可行性和有效性.     

圆轨单级倒立摆摆起过程控制

研究圆轨单级倒立摆摆起控制问题，以离散控制律为设计交量，以终点约束条件为目标函数，提出了倒立摆摆起控制律的优化算法。对控制律进行编程计算，成功地实现了圆轨单级倒立摆的快速摆起。仿真计算结果表明了所提出方法的有效性和可行性。