A Composite State Convergence Scheme for Bilateral Teleoperation Systems

State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator’s force channel intact. We show that, with these composite and force variables; it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.      

Generalized control method by state convergence for teleoperation systems with time delay

In this paper a generalized design and control method for teleoperation systems with communication time delay is presented. The design method is based on the state space formulation and it allows to obtain the control parameters for any teleoperation system where the master and the slave manipulators would be represented by nth-order linear differential equations. Through state convergence between the master and the slave, the control system allows the slave to follow the master inspite of the time delay. The method is also able to establish the desired dynamics of this convergence and the dynamics of the slave manipulator. Experimental results are presented showing the validity of the proposed design and control method.     

Control of Teleoperators with Communication Time Delay through State Convergence

This paper describes a new control method of teleoperation systems with communication time delay. This method models the teleoperation system in the state space, considering all the possible interactions that could appear in the operator‐master‐slave‐environment set, and it uses the Taylor expansion to model the time delay. The control system allows that the slave manipulator follows the master in spite of the time delay in the communication channel. The tracking is achieved by state convergence between the master and the slave. The method is also able to establish the desired dynamics of this convergence and the dynamics of the slave manipulator. Furthermore, a simple design procedure is provided to obtain the control system gains. These control gains are calculated solving a set of seven equations. The control method is robust to the uncertainty of the design parameters, so it is not necessary to obtain good estimations of these parameters. Simulations and experiments with a one DOF teleoperation system are presented to verify the control method. © 2004 Wiley Periodicals, Inc.     

新型联动报警系统

提出对传统报警系统改进的办法:用PC机作为主机,用AT89S52单片机作为从机,采用RS485总线型网络系统。该系统的特点:(1)不仅主机可以呼叫从机,从机在必要时可以主动呼叫主机,避免了从机只能等待主机轮询访问的弊端,从而提高了系统实时性和可靠性;(2)由于报警的时间毕竟很少,因此没有必要让主机无休止地轮询访问各个从机。而且轮询的方式效率很低,主机未必能从多台从机中立刻定位到报警的那台从机。     

Synchronization of A Class of Uncertain Chaotic Systems with Lipschitz Nonlinearities Using State‐Feedback Control Design: A Matrix Inequality Approach

This paper proposes a new state‐feedback stabilization control technique for a class of uncertain chaotic systems with Lipschitz nonlinearity conditions. Based on Lyapunov stabilization theory and the linear matrix inequality (LMI) scheme, a new sufficient condition formulated in the form of LMIs is created for the chaos synchronization of chaotic systems with parametric uncertainties and external disturbances on the slave system. Using Barbalat's lemma, the suggested approach guarantees that the slave system synchronizes to the master system at an asymptotical convergence rate. Meanwhile, a criterion to find the proper feedback gain vector F is also provided. A new continuous‐bounded nonlinear function is introduced to cope with the disturbances and uncertainties and obtain a desired control performance, i.e. small steady‐state error and fast settling time. Several criteria are derived to guarantee the asymptotic and robust stability of the uncertain master–slave systems. Furthermore, the proposed controller is independent of the order of the system's model. Numerical simulation results are displayed with an expected satisfactory performance compared to the available methods.     

基于多处理器系统的超级指令任务调用实现

介绍了一种新型的超级指令任务调用方法,该任务调用方法基于单芯片多处理器架构,它由一个主处理器和三个从处理器构成;在该系统中,终端用户无需掌握应用领域中复杂的、底层的专业算法,这些算法可以由底层的算法工程师事先集成在各个从处理器中,而终端用户只需要对主处理器进行编程;当主处理器的应用程序需要调用某个算法程序的时候,只需要发送一条超级指令给相应的从处理器,该算法程序就可以由从处理器独立完成,这种任务调用方法大大简化了多处理器任务调用,提高了整个系统的并行工作能力.     

不确定Van der Pol混沌系统的模糊同步控制

本文研究了不确定Van der Pol混沌系统的同步问题,并进行了基于规则的模糊逻辑控制器(FLC)的控制。首先寻找主从Van der Pol混沌系统满足Lyapunov稳定性理论的条件,在此基础上建立模糊规则,设计模糊控制器,实现不确定混沌系统的同步。通过不确定VanderPol混沌系统的两组仿真结果,验证了模糊同步控制方法具有很好的鲁棒性。最后为了进一步验证该方法的有效性,本文在相同条件下,利用反馈控制的方法实现不确定主从VanderPol混沌系统的同步,然后再将此方法的仿真结果与本文的模糊同步控制方法的仿真结果在稳态误差及同步所需时间这两个方面进行对比分析。分析结果验证了本文同步方法的可行性及有效性。     

Lorenz系统的混沌同步控制及计算机仿真

针对Lorenz系统提出了以一定的耦合比例系数,实现主动系统和被动系统的同步控制以及计算机仿真.计算机仿真结果表明:在控制的过程中,控制周期随着松弛系数值的增大而减小,较大的松弛系数导致较快的控制.这个控制法则来源于李雅普诺夫稳定性原理,可以用来控制非同步系统达到同步,最终实现所要求的P-同步,即通过加入微小的控制可以在短时间内按任意比例系数实现对主动系统的响应的放大或缩小.数值仿真结果证实了所提新方法的有效性,并且可以按照实际需要的耦合比例实现同步控制.     

A generalized function projective synchronization scheme for uncertain chaotic systems subject to input nonlinearities

In this paper, a modified generalized function projective synchronization scheme for a class of master–slave chaotic systems subject to dynamic disturbances and input nonlinearities (dead-zone and sector nonlinearities) is investigated. This synchronization system can be seen as a generalization of many existing projective synchronization schemes (namely the function projective synchronization, the modified projective synchronization and so on), in the sense that the master system has a scaling function matrix and the slave system has a scaling factor matrix. To practically achieve this generalized function synchronization, an adaptive fuzzy variable-structure control system is designed. The fuzzy systems are used to appropriately approximate the uncertain nonlinear functions. A Lyapunov approach is employed to prove the boundedness of all signals of the closed-loop control system as well as the exponential convergence of the synchronization errors to an adjustable region. Simulations results are presented to illustrate the effectiveness of the proposed generalized function PS scheme.     

Asymptotic synchronization of the Colpitts oscillator

In this paper we deal with the observer-based asymptotic synchronization problem for a class of chaotic oscillators. Some results based on a differential algebraic approach are used in order to determine the algebraic observability of unknown variables. The strategy consists of proposing a slave system (observer) which tends to follow asymptotically the master system. The methodology is tested in the real-time asymptotic synchronization of the Colpitts oscillator by means of a proportional reduced order observer (PROO) of free-model type.     

弹性堆叠系统中的数据批量同步方法

在弹性堆叠系统中,主备设备都处于工作状态,对于实时操作系统,数据批量同步所在的进程优先级一般不是最高,主备设备间数据批量同步很难保证既快速又可靠。该文提出一种数据批量同步方法,通过定时检测批量同步消息通道,结合异常序列号确认,保证数据快速同步和同步可靠性,能在实时操作系统中很好地运行。     

基于RS-485总线的温室环境控制系统研制

作物生长需要一个适宜的环境,在可控环境下,可以不分季节、不分地区地种植所需的作物。控制系统为实现这一目标提供了基础。控制系统设计采用主从模式,基于RS—485总线协议,设计全数字化传感器和测控输入输出模块;采用COM组件技术设计应用软件的数据采集、控制算法和控制输出组件。整个系统经过测试和运行,证明满足可控环境调控要求。     

遥控系统理想性能的实现和实验研究

本文对主从遥控系统理想性能的实现进行了理论分析和实验研究。对于位置／力控制的遥控机器人，理想性能就是要实现主从操作器的位置跟踪和力跟踪。文中首先通过分析得到了一组控制规律，利用这组控制规律就可以实现理想性能，而且这组控制规律由于引入了力微分信号而比较简单。接着以无源性为基础，对系统的稳定性进行了研究。最后通过实验可知在从操作器同环境有或无作用的情况下，主从遥控系统都可以实现理想性能。     

入侵检测系统中应用层协议的并行重组

针对传统入侵检测系统的不足之处,将并行算法引入到应用层报文重组过程,提出了应用层协议自适应外行重组的设计思想。提出了报文并行重组的算法思想、体系结构和实现环境。系统山探测器、任务分配器、重组结点和控制台组成。并行重组过程主要包括Master和Slave两部分,Master程序运行在任务分配器上,负责任务的分配和调度,Slave程序运行在各个重组结点上,完成对链表中报文的重组。试验结果证明了该重组并行方法具有较高的效率和较低的丢包率。     

Robust synchronization of chaotic systems using slidingmode and feedback control

We propose a robust scheme to achieve the synchronization of chaotic systems with modeling mismatches and parametric variations. The proposed algorithm combines high-order sliding mode and feedback control. The sliding mode is used to estimate the synchronization error between the master and the slave as well as its time derivatives, while feedback control is used to drive the slave track the master. The stability of the proposed design is proved theoretically, and its performance is verified by some numerical simulations. Compared with some existing synchronization algorithms, the proposed algorithm shows faster convergence and stronger robustness to system uncertainties.     

Neural network-based Smith predictor design for the time-delay in a tele-operated control system

This article presents a methodology for compensating for the time-delay effects in tele-operated control systems. Compensation can be carried out by a neural network. A tele-operated system consists of a master robot to give commands, and a slave robot to work with the environment. The positional command by the master robot is transferred to the slave robot, and the contact force from the environment is transferred back to the master robot. The structure of the Smith predictor is modified by replacing the linear estimator with a neural network whose structure is based on the radial basis function (RBF). The RBF network identifies the slave model to deal with the nonlinearities in the system. Simulation studies have been conducted, and experimental studies of one-directional force control were performed to confirm the simulation results.     

遥操作系统基于观测器的预测控制

在遥操作系统中需要主、从机械手间进行通信,但通信通道中存在较大的通讯时延,这会降低系统操作性能,甚至会使系统不稳定.为了解决这个问题,首先建立系统的状态空间模型,接着提出用时间前向观测器预测从机械手状态,并结合力、位置和速度反馈消除或减小时延对系统影响.系统反馈参数可方便地通过线性矩阵不等式求解.该方法能使系统渐近稳定而且具有良好的透明性.仿真结果表明该方法是有效的.     

Coordination control for bilateral teleoperation with kinematics and dynamics uncertainties

The coordination control design problem for the master–slave system is addressed in this paper. In order to meet the actual work condition, we assume that the master works in a laboratory, the slave works in remote side where the environment is very complex, and the master and slave are in different sizes. Three problems are needed to be solved: system dynamics uncertainties, system kinematics uncertainties, and the asymmetric time-varying delays. The new task-space based Proporation plus damping (P+d) controller and adaptive fuzzy P+d controller are proposed for the master and the slave, respectively. By choosing proper Lyapunov functions, we have proved that the synchronization errors converge to zero asymptotically with the new controllers. The delay-dependent stability criterion is derived. With the given parameters, the proposed allowable maximal transmission delay can be computed. Finally, the simulations are performed to show the effectiveness of the proposed method.     

Synchronization of bilateral teleoperators with time delay

Bilateral teleoperators, designed within the passivity framework using concepts of scattering and two-port network theory, provide robust stability against constant delay in the network and velocity tracking, but cannot guarantee position tracking in general. In this paper we fundamentally extend the passivity-based architecture to guarantee state synchronization of master/slave robots in free motion independent of the constant delay and without using the scattering transformation. We propose a novel adaptive coordination architecture which uses state feedback to define a new passive output for the master and slave robots containing both position and velocity information. A passive coordination control is then developed which uses the new outputs to state synchronize the master and slave robots in free motion. The proposed algorithm also guarantees ultimate boundedness of the master/slave trajectories on contact with a passive environment. Experimental results are also presented to verify the efficacy of the proposed algorithms.     

An Adaptive Control Technique for Motion Synchronization by On-line Estimation of a Recursive Least Square Method

This article presents an adaptive technique to tune controller gains for the motion synchronization of two gimbal systems by using a recursive least square method in the real-time fashion. In the master-slave configuration, the slave gimbal system follows the master’s motion while the master tracks the reference. In order for the slave gimbal system to synchronize with the motion of the master gimbal system, the dynamic difference between two systems is compensated by the controller gains. The controller gains of the slave are adaptively adjusted by the recursive least square method to cope with the deviation. The performances of three control schemes such as an independent PD control, a dependent torque control, and an RLS torque control scheme are evaluated by the experimental studies for the low cost gimbal systems. Experimental studies confirm that the RLS-based adaptive scheme actually outperforms by adjusting controller gains for the motion synchronization of the master and slave configuration.