基于领航-跟随法的多机器人编队控制

编队控制是多机器人系统研究的核心问题之一,具有广泛的研究价值。针对编队问题,通过对轮式差分驱动机器人运动模型进行分析,并设计相应的控制器。在传统的领航-跟随模型上,引入“虚拟机器人”,将跟随者机器人对领航者机器人的轨迹跟踪转换为跟随者对“虚拟领航者”的轨迹跟踪。首先,预设定实际领航者机器人的行进路径,由实际领航者引导运动方向的运动轨迹被视为主轨迹,虚拟机器人通过数据产生参考点从而生成参考轨迹,跟随者机器人通过对参考轨迹的跟踪与“虚拟领航者”构成轨迹误差跟踪系统。然后通过Lyapunov的控制理论验证控制器的理论可行性,最后在MATLAB/Simulink仿真平台进行实验,通过改变控制参数来使机器人形成相应的期望队形,在较短的时间内,跟随机器人对参考轨迹的跟踪误差趋向于0且速度收敛,验证了编队系统的可行性。     

非完整移动机器人的双自适应神经滑模控制

针对非完整移动机器人轨迹跟踪控制问题,提出一种基于Backstepping运动学控制器与双自适应神经滑模鲁棒动力学控制的混合鲁棒控制算法.利用两个带自适应调节算法的径向基神经网络(Radial basis function neural network,RBFNN)分别计算滑模的等效控制部分和调节滑模控制的增益,不但解决了移动机器人的参数与非参数不确定性问题,同时也消除了在滑模控制中的输入抖振现象.设计过程采用Lyapunov方法,保证了控制系统的稳定与收敛.仿真结果表明了该方法的有效性,且在多种不确定性存在的情况下,该方法能较好地消除非完整机器人的跟踪误差.     

全方位移动机器人编队控制研究

针对多机器人系统编队的控制问题,将编队行为分为了任务执行行为、队形保持行为、安全运行行为,并分别对各行为进行了研究,对各种传统编队方法进行了总结和比较,通过建立移动机器人的运动学模型,得到了车体运动的控制参数,提出了针对基于麦克纳姆轮的全方位移动机器人编队的基于行为的融合编队控制算法,利用Matlab软件对编队的各种行为进行了仿真。研究结果表明,该基于行为的融合编队控制算法能使全方位机器人完成编队行为,能够实现队形形成、队形保持、躲避静态障碍物、躲避机器人及驶向目标点等行为,编队基于该方法,实现迅速、可靠性高。     

非完整移动机器人的自适应全局轨迹跟踪控制

针对含有未知参数的移动机器人运动学模型,利用自适应反演控制技术,讨论了两后轮角速度为控制输入的非完整移动机器人轨迹跟踪问题,构造了具有全局渐近稳定性的自适应轨迹跟踪控制器,该方法将系统分解为低阶子系统来处理,利用中间虚拟控制量和部分Lyapunov函数简化了控制器的设计并具有直观的稳定性分析。仿真结果验证了所设计控制器的有效性和正确性。     

多AUV编队控制

使用一致性算法l-φ和虚拟领航跟随结构法研究自主水下机器人的集群编队控制.基于一致性算法l-φ对各AUV所持有的参考信息进行一致性协商而达到状态一致.基于虚拟结构思想,将编队控制问题转化为跟随AUV对虚拟领航AUV的轨迹跟踪控制,使得各AUV相对于虚拟领航者的位置且在有限的时间内确保到达各自的期望位置.通过Java的G...     

输入受限的非完整移动机器人的自适应模糊控制

提出了一种非完整移动机器人饱和自适应模糊轨迹跟踪控制方法,该方法基于反演技术分别设计了系统的运动学控制器和动力学控制器。运动学控制器通过引入分流控制技术解决了初始速度跳变引起的控制量突变问题,动力学控制器利用饱和函数和受限控制参数实现了其有界力矩控制。自适应模糊控制器将模糊逻辑系统与自适应方法相结合,有效消除了常规方法难以解决的系统未知不确定性对系统的影响。通过Lyapunov直接法证明了该系统是收敛且渐进稳定的。仿真结果验证了所设计控制器的良好控制性能和强鲁棒性。     

基于改进领航-虚拟跟随法的车辆队列控制

文中分析了车辆队列控制方法中传统的领航-虚拟跟随法存在模型误差的问题,提出一种考虑跟随车参考路径点连线与横轴的夹角作为参考航向角的改进领航-虚拟跟随方法,将队列控制问题转化为对特定位置的轨迹跟踪问题。然后基于车辆运动学模型实时规划跟随车的速度,运用误差修正的Stanley方法和PD控制分别进行车辆横向控制和车辆纵向油门/刹车控制。最后,通过CarSim/Simulink联合仿真,验证了改进领航-虚拟跟随方法在3车三角形队列圆周和正弦曲线工况下的效果。结果表明：改进领航-虚拟跟随方法较传统领航-虚拟跟随法,使1号和2号跟随车横向误差均值和最大值得到了降低。     

基于神经网络的非完整移动机器人鲁棒跟踪控制

针对受非完整条件约束的移动机器人存在的高度非线性、不确定性和外部干扰,提出了一种基于神经网络的鲁棒跟踪控制策略。该控制策略能够对系统中的未知的不确定性和干扰进行补偿。基于Lyapunov方法对控制系统进行设计,保证了系统的稳定性,改善了系统的动态性能。速度跟踪误差、神经网络权值误差和边界估计误差全局有界。仿真实验表明,该控制方法具有很强的鲁棒性和自适应能力。     

非完整移动机器人追踪运动物体的状态反馈控制方法

介绍非完整移动机器人追踪运动物体的状态反馈控制算法.并引入一些非时变函数以计算状态反馈变量,从而获得连续的速度分布.对控制算法的模拟由MATLAB实现.结果表明,通过状态反馈控制算法,轮式机器人可以循合理的轨迹对运动物体进行追踪以及运动避障.     

基于领航跟随法的多AUV编队控制算法研究

针对已知路径下基于领航者的多自主水下机器人(AUV)编队队形控制问题,提出了一种AUV路径控制和编队协调控制相结合的新型编队控制器。其中,AUV的路径跟踪控制采用反步滑模控制器,将AUV位置、姿态和时变速度跟踪转化虚拟速度控制,使AUV能达到期望的位置、速度等,避免了反步控制中的奇异值问题,并能够很好实现不确定的模型的控制,同时又提高了跟随者协同定位精度;在路径跟踪控制基础上,编队协调控制器将领航者与跟随者的位置误差控制转化为跟随者的速度误差控制,使跟随者能快速达到期望位置,从而使所有AUV实现期望的队形并保持。仿真实验对该控制策略进行了可行性验证,结果表明,该算法提高了编队的响应速度、控制精度和稳定性;再应用3台AUV进行了湖上试验验证,证明了该控制策略的有效性,能有效应用到实际中。     

Distributed coordinated attitude tracking control for spacecraft formation with communication delays

This paper investigates the distributed coordinated attitude tracking control problem for spacecraft formation with time-varying communication delays under the condition that the dynamic leader spacecraft is a neighbor of only a subset of follower spacecrafts. We consider two cases for the leader spacecraft: i) the attitude derivative is constant, and ii) the attitude derivative is time-varying. In the first case, a distributed estimator is proposed for each follower spacecraft by using its neighbors’ information with communication delays. In the second case, to express the dynamic leader’s attitude, an improved distributed observer is developed to estimate the leader’s information. Based on the estimated values, adaptive coordinated attitude tracking control laws are designed to compensate for parametric uncertainties and unknown disturbances. By employing the Lyapunov–Krasovskii functional approach, the attitude tracking errors and estimation errors are proven to converge to zero asymptotically. Numerical simulations are presented to illustrate the effectiveness of theoretical results.     

Adaptive PID formation control of nonholonomic robots without leader's velocity information

This paper proposes an adaptive proportional integral derivative (PID) algorithm to solve a formation control problem in the leader–follower framework where the leader robot's velocities are unknown for the follower robots. The main idea is first to design some proper ideal control law for the formation system to obtain a required performance, and then to propose the adaptive PID methodology to approach the ideal controller. As a result, the formation is achieved with much more enhanced robust formation performance. The stability of the closed-loop system is theoretically proved by Lyapunov method. Both numerical simulations and physical vehicle experiments are presented to verify the effectiveness of the proposed adaptive PID algorithm.     

A path tracking control algorithm for underwater mining vehicles

In this paper, a path tracking control algorithm is formulated for the use of tracked underwater mining vehicles. The algorithm consists of two parts, the forward velocity control and the heading angle control. The control algorithm is designed based on kinematics, and it considers the track slips and the longitudinal and yaw dynamic models of the tracked vehicle including the soil-track interaction force model. The desired heading angle is obtained by the so-called “Line of Sight” method. The suggested algorithm is tested by numerical simulations using the TRACSIM software developed by MOERO/KORDI, Korea. After the control gains are tuned by a series of numerical simulations, the algorithm is verified on a scale vehicle on air on a soil bin test bed containing the cohesive soil of the Bentonite-water mixture. This paper was recommended for publication in revised form by Associate Editor Kyongsu Yi Sup Hong received the B.Sc. and the M.sc. degree in the department of naval architecture and ocean engineering from Seoul National University, Korea, and the Doctor of Engineering degree in mechanical engineering from the Technical university of Aachen, Germany. Currently, he is the principal researcher at MOERI (Maritime and Ocean Engineering Research Institute), Korea. His main research areas include dynamics of marine structure, and development of marine mineral resources. Especially, he is focusing on the development of deep seabed mining technologies since 1994. Mooncheol Won received the B.Sc. and the M.sc. degree in the department of naval architecture and ocean engineering from Seoul National University, Korea, and the Ph.D. degree in mechanical engineering from the University of California at Berkeley, USA. Currently, he is a professor in the department of mechatronics engineering of Chungnam national university, Korea. His research interests include control of maritime and mechatronics systems, and machine learning applications of robotic systems.     

Neural network disturbance observer-based distributed finite-time formation tracking control for multiple unmanned helicopters

The distributed finite-time formation tracking control problem for multiple unmanned helicopters is investigated in this paper. The control object is to maintain the positions of follower helicopters in formation with external interferences. The helicopter model is divided into a second order outer-loop subsystem and a second order inner-loop subsystem based on multiple-time scale features. Using radial basis function neural network (RBFNN) technique, we first propose a novel finite-time multivariable neural network disturbance observer (FMNNDO) to estimate the external disturbance and model uncertainty, where the neural network (NN) approximation errors can be dynamically compensated by adaptive law. Next, based on FMNNDO, a distributed finite-time formation tracking controller and a finite-time attitude tracking controller are designed using the nonsingular fast terminal sliding mode (NFTSM) method. In order to estimate the second derivative of the virtual desired attitude signal, a novel finite-time sliding mode integral filter is designed. Finally, Lyapunov analysis and multiple-time scale principle ensure the realization of control goal in finite-time. The effectiveness of the proposed FMNNDO and controllers are then verified by numerical simulations.     

Robust adaptive tracking control for nonholonomic mobile manipulator with uncertainties

In this paper, mobile manipulator is divided into two subsystems, that is, nonholonomic mobile platform subsystem and holonomic manipulator subsystem. First, the kinematic controller of the mobile platform is derived to obtain a desired velocity. Second, regarding the coupling between the two subsystems as disturbances, Lyapunov functions of the two subsystems are designed respectively. Third, a robust adaptive tracking controller is proposed to deal with the unknown upper bounds of parameter uncertainties and disturbances. According to the Lyapunov stability theory, the derived robust adaptive controller guarantees global stability of the closed-loop system, and the tracking errors and adaptive coefficient errors are all bounded. Finally, simulation results show that the proposed robust adaptive tracking controller for nonholonomic mobile manipulator is effective and has good tracking capacity.     

Velocity-free attitude coordinated tracking control for spacecraft formation flying

This article investigates the velocity-free attitude coordinated tracking control scheme for a group of spacecraft with the assumption that the angular velocities of the formation members are not available in control feedback. Initially, an angular velocity observer is constructed based on each individual's attitude quarternion. Then, the distributed attitude coordinated control law is designed by using the observed states, in which adaptive control method is adopted to handle the external disturbances. Stability of the overall closed-loop system is analyzed theoretically, which shows the system trajectory converges to a small set around origin with fast convergence rate. Numerical simulations are performed to demonstrate fast convergence and improved tracking performance of the proposed control strategy.     

铸造起重机的主从控制变频调速系统

结合实例，根据钢厂铸造起重机的特殊性，在PROFIBUS总线和主从控制用宏变频调速系统的基础上，研制出适合恶劣工作环境的主从控制变频调速系统，其性能好，工作级别高，成本低，市场竞争力强。     

Vision-based stabilization of nonholonomic mobile robots by integrating sliding-mode control and adaptive approach

Vision-based pose stabilization of nonholonomic mobile robots has received extensive attention.At present,most of the solutions of the problem do not take the robot dynamics into account in the controller design,so that these controllers are difficult to realize satisfactory control in practical application.Besides,many of the approaches suffer from the initial speed and torque jump which are not practical in the real world.Considering the kinematics and dynamics,a two-stage visual controller for solving the stabilization problem of a mobile robot is presented,applying the integration of adaptive control,sliding-mode control,and neural dynamics.In the first stage,an adaptive kinematic stabilization controller utilized to generate the command of velocity is developed based on Lyapunov theory.In the second stage,adopting the sliding-mode control approach,a dynamic controller with a variable speed function used to reduce the chattering is designed,which is utilized to generate the command of torque to make the actual velocity of the mobile robot asymptotically reach the desired velocity.Furthermore,to handle the speed and torque jump problems,the neural dynamics model is integrated into the above mentioned controllers.The stability of the proposed control system is analyzed by using Lyapunov theory.Finally,the simulation of the control law is implemented in perturbed case,and the results show that the control scheme can solve the stabilization problem effectively.The proposed control law can solve the speed and torque jump problems,overcome external disturbances,and provide a new solution for the vision-based stabilization of the mobile robot.     

Power control of dual-motor electric drive for tracked vehicles

The fundamental problem of the power control for the driving of a dual-motor drive electric tracked vehicle is analyzed. The tracked vehicle and its electric drive system are mathematically modeled. Power control schemes of the dual-motor drive system is put forward, designed, and analyzed, including the distributed control system and the two control schemes speed-regulation and torque-regulation. The field experiment shows that the two types of drive control schemes realize the driving function of the vehicle feasibly and effectively. Obviously the comprehensive controller and two motors’ controllers are closely coupled in the “speed-regulation” control scheme, in which they must coordinate very well to guarantee the control. Contrastingly, in the “torque-regulation” control scheme, the comprehensive controller and two motors’ controller are not dependent closely when the accuracy and response of the torque controlling is guaranteed. The latter is simpler and more practical than the former.