噪声有源控制的递归神经网络方法

使用Filter－X算法研究有源噪声控制问题,存在需要较高阶次的滤波器和当噪声出现非线性时控制效果不佳的缺陷。为此提出一种基于对角递归神经网络的非线性噪声有源自适应控制方法,并给出一种基于误差梯度下降的在线学习算法,同时证明了闭环控制系统在Lyapunov意义下的稳定性。数值仿真表明,基于对解递归神经网络的噪声有源自适应控制是一种非常有效的噪声控制方法。     

Fuzzy and Recurrent Neural Network Motion Control among Dynamic Obstacles for Robot Manipulators

An integration of fuzzy controller and modified Elman neural networks (NN) approximation-based computed-torque controller is proposed for motion control of autonomous manipulators in dynamic and partially known environments containing moving obstacles. The fuzzy controller is based on artificial potential fields using analytic harmonic functions, a navigation technique common used in robot control. The NN controller can deal with unmodeled bounded disturbances and/or unstructured unmodeled dynamics of the robot arm. The NN weights are tuned on-line, with no off-line learning phase required. The stability of the closed-loop system is guaranteed by the Lyapunov theory. The purpose of the controller, which is designed as a neuro-fuzzy controller, is to generate the commands for the servo-systems of the robot so it may choose its way to its goal autonomously, while reacting in real-time to unexpected events. The proposed scheme has been successfully tested. The controller also demonstrates remarkable performance in adaptation to changes in manipulator dynamics. Sensor-based motion control is an essential feature for dealing with model uncertainties and unexpected obstacles in real-time world systems.     

基于卷积神经网络的手术机器人控制系统设计

针对传统系统控制精准度低的问题,提出了基于卷积神经网络的手术机器人控制系统设计。根据基于卷积神经网络的手术机器人控制原理,设计控制系统总体结构,选用PCI插槽上直接内插CAN适配卡作为上位机核心组件,采用C++编写的Lib库和DLL库为驱动程序提供适配卡。通过下位机三个节点,处理相关信号,并进行量程转换和越限判断,确保机器人不会失控。选用80C592微控制器设计关节驱动节点结构,以高速工作方式向控制器提供向总线的差动发送和接受能力,避免外界干扰。设计基于视觉的持镜臂,为手术过程提供上下、左右、前后的运动的手术视野。分别采用FN3002力传感器和MPS-M拉线式位移传感器获取相关传感数据,采用卷积神经网络深度学习方法,设计持镜臂运动控制步骤,采用VC++6.0工具,控制软件程序,避免抖动或者误操作主手现象的出现。由实验结果可知,该系统持镜臂轨迹规划与期望轨迹一致,简化了控制系统的复杂性。     

一种基于PSO的自适应神经网络预测控制

针对非线性系统,提出了一种基于微粒群优化(PSO)的自适应神经网络预测控制方法.采用对角递归网络(DRNN)对非线性系统进行建模,并利用扩展卡尔曼滤波(EKF)递推估计算法在线计算网络模型参数的Jacobian矩阵以实现模型参数的自适应.利用PSO算法在线优化求解非线性系统的预测控制律,以克服传统基于梯度法的非线性规划方法求解预测控制律时对初始条件非常敏感的缺点.生化发酵过程的仿真结果表明,所提出的控制方法具有良好的跟踪能力和抗干扰能力.     

基于动态递归神经网络的自适应PID控制

提出一种基于动态递归神经网络的自适应PID控制方案,该控制系统由神经网络辨识器和神经网络控制器组成。辨识器采用单隐层的动态递归神经网络,网络结构为2-4-1;辨识算法为动态BP算法;控制器采用两层线性结构的神经网络,输入为系统偏差及其一阶、二阶微分,因此具有增量型PID控制结构。应用该控制系统对一非线性时变系统进行仿真研究,仿真结果表明该控制方案不仅具有良好的跟踪特性,而且对系统参数变化具有较强的鲁棒性。     

基于DRNN的传感器的建模研究

针对传感器受温度影响的复杂非线性输入输出特性,利用对角递归神经网络（DRNN）建模,并实现了温度补偿和非线性校正。对于权值的训练采用LM算法,克服了BP算法收敛慢的缺陷,使其在保证收敛的前提下,提高了收敛速度。实验表明：应用DRNN对传感器建模是一种行之有效的方法。     

Using a New Model of Recurrent Neural Network for Control

This paper shows the results obtained in controlling a mobile robot by means of local recurrent neural networks based on a radial basis function (RBF) type architecture. The model used has a Finite Impulse Response (FIR) filter feeding back each neuron's output to its own input, while using another FIR filter as a synaptic connection. The network parameters (coefficients of both filters) are adjusted by means of the gradient descent technique, thus obtaining the stability conditions of the process. As a practical application the system has been successfully used for controlling a wheelchair, using an architecture made up by a neurocontroller and a neuroidentifier. The role of the latter, connected up in parallel with the wheelchair, is to propagate the control error to the neurocontroller, thus cutting down the control error in each working cycle.     

基于神经网络的不确定机器人自适应滑模控制

提出一种机器人轨迹跟踪的自适应神经滑模控制。该控制方案将神经网络的非线性映射能力与变结构控制理论相结合,利用RBF网络自适应学习系统不确定性的未知上界,神经网络的输出用于自适应修正控制律的切换增益。这种新型控制器能保证机械手位置和速度跟踪误差渐近收敛于零。仿真结果表明了该方案的有效性。     

应用于力矩受限自由漂浮空间机器人的神经网络自适应控制

在控制力矩受限情况下,为实现具有模型不确定性自由漂浮空间机器人的轨迹跟踪控制,文章设计了一种新的神经网络自适应控制策略;首先,用双曲函数对控制力矩输入进行限制;其次,设计一种神经网络自适应控制律,对输入力矩受限条件下的非线性系统模型进行在线逼近,同时,利用鲁棒项对神经网络逼近误差和外界干扰进行消除;最后,根据李雅普诺夫理论,证明了所设计控制策略能够使自由漂浮空间机器人系统渐进稳定;仿真实验表明,该控制策略在无需建立复杂系统模型的情况下,便能够对控制力矩进行有效限制,从而使自由漂浮空间机器人在控制力矩受限情况下得到较好的控制.     

Neural and Neurofuzzy FELA Adaptive Robot Control Using Feedforward and Counterpropagation Networks

In this paper, the application of neural networks and neurofuzzy systems to the control of robotic manipulators is examined. Two main control structures are presented in a comparative manner. The first is a Counter Propagation Network-based Fuzzy Controller (CPN-FC) which is able to self-organize and correct on-line its rule base. The self-tuning capability of the fuzzy logic controller is attained by taking advantage of the structural equivalence between the fuzzy logic controller and a counterpropagation network. The second control structure is a more familiar neural adaptive controller based on a feedforward (MLP) network. The neural controller learns the inverse dynamics of the robot joints, and gradually eliminates the model uncertainties and disturbances. Both schemes cooperate with the computed torque control algorithm, and in that way the reduction of their complexity is achieved. The ability of adaptive fuzzy systems to compete with neural networks in difficult control problems is demonstrated. A sufficient set of numerical results is included.     

非最小相位非线性系统的简单递归神经网络控制

从简单递归神经网络的统一结构出发设计了简单递归神经网络控制器,在引入了控制加权的目标函数下优化神经网络权值学习,因此是通常意义的神经网络控制的推广。证明了整个系统的稳定性,并通过仿真验证了控制器的有效性。     

EMG-Based Motion Discrimination Using a Novel Recurrent Neural Network

This paper presents a pattern discrimination method for electromyogram (EMG) signals for application in the field of prosthetic control. The method uses a novel recurrent neural network based on the hidden Markov model. This network includes recurrent connections, which enable modeling time series, such as EMG signals. Weight coefficients in the network can be learned using a well-known back-propagation through time algorithm. Pattern discrimination experiments were conducted to demonstrate the feasibility and performance of the proposed method. We were able to successfully discriminate forearm motions using the EMG signals, and achieved considerably high discrimination performance compared with other discrimination methods.     

基于回归神经网络自适应快速BP算法

动态递归网络Elman网络结构简单,运算量少,适合于实时系统辨识。以Elman网络结构推导了在线学习算法。针对于传统BP算法会产生局部收敛和收敛速度慢等缺点,提出了一种改进的自适应BP算法,运用到回归神经网络,提高了在线学习的速度与收敛速度,仿真实验表明了此算法的有效性和快速性。     

柔性关节机操手的神经网络控制

本文在关节柔性较弱的情况下,对柔性关节机器人操作手的轨迹跟踪问题,提出了一种基于奇异摄动理论的机器人神经网络控制设计方法,在一般框架下证明了系统跟踪误差最终一致有界,并且可以通过选取增益矩阵使该误差界任意地小. 该方法克服了对模型参数线性化条件的要求,无需求解回归矩阵,因而具有很强的鲁棒性和模型推广能力. 数值试验表明,所提出的控制方法是可行且有效的.     

直接自适应动态递归模糊神经网络控制及其应用

针对某些仿射非线性系统中各状态变量间呈微分关系的特点,本文提出仅取某些可测状态变量 作为动态递归模糊神经网络(dynamic recurrent fuzzy neural network, DRFNN) 的输入,而由DRFNN 的反馈矩阵 描述系统内部动态关系的直接自适应DRFNN 控制算法,克服了将系统所有变量作为输入的传统模糊神经网 络(traditioanl fuzzy neural network, TFNN) 因某些不可测状态变量所导致的不可实现问题．在电液伺服系统中的 应用结果表明：直接自适应DRFNN 控制算法相对于TFNN 控制算法对系统稳态特性的改善具有较大的优越 性．     

基于动态递归网的无刷直流电动机自适应逆控制

该文给出了基于动态递归神经网络的无刷直流电动机自适应逆控制方案 ,它可以处理电机非线性、变参数的影响。通过使用动态递归网实现了对象逆动态模型的在线控制 ,分析和仿真表明这种方法具有较好的自适应性及良好的收敛性能 ,且具有灵活、简单、方便等特点 ,有实际应用价值     

漂浮基双臂空间机器人系统的模糊神经网络自学习控制

讨论了载体位置、姿态均不受控制的情况下自由漂浮双臂空间机器人系统的高斯基模糊神经网络自 学习控制问题．此类空间机器人系统严格遵守动量守恒和角动量守恒,所以其动力学方程表现出强烈的非线性性 质．将神经网络与模糊控制相结合,即利用神经网络进行模糊推理, 可使模糊控制具有自学习能力．在此基础上, 设计了双臂空间机器人系统关节空间的高斯基模糊神经网络自学习控制方案．系统的数值仿真证实了该方法的有 效性．     

A Recurrent Neural Network for N-Stage Optimal Control Problems

A recurrent neural network is introduced for the N-stage optimal control problem. The new neural network is based on a reformulation of the original optimal control problem and the gradient method. The simulation results on two examples indicate that the new neural network is quite effective.     

Robust Recurrent Neural Network Control of Biped Robot

In this paper, a recurrent neural network (RNN) control scheme is proposed for a biped robot trajectory tracking system. An adaptive online training algorithm is optimized to improve the transient response of the network via so-called conic sector theorem. Furthermore, L ₂-stability of weight estimation error of RNN is guaranteed such that the robustness of the controller is ensured in the presence of uncertainties. In consideration of practical applications, the algorithm is developed in the discrete-time domain. Simulations for a seven-link robot model are presented to justify the advantage of the proposed approach. We give comparisons between the standard PD control and the proposed RNN compensation method.     

一种基于模糊神经网络的机器人控制

采用高斯函数作为模糊隶属函数,将模糊控制与神经网络相结合。利用神经网络实现模糊推理,运用了一种模糊高斯基函数神经网络,并用于两关节机器人的轨迹跟踪控制。仿真结果表明,该网络对机器人轨迹跟踪控制具有很好的效果,是一种行之有效的控制方法。