含未校准摄像机参数的非完整移动机器人自适应动态反馈跟踪控制

研究基于视觉伺服的不确定非完整移动机器人的跟踪控制问题.基于视觉反馈和状态输入变换,提出一类非完整运动学系统的不确定模型,并运用两个新的变换,对3种不同情况分别设计自适应动态反馈控制器来跟踪不确定系统的期望轨迹.利用李雅普诺夫方法和推广的Barbalat引理,严格证明了误差系统的收敛性.仿真结果验证了所提方法的有效性.     

未校正摄像机的非完整机器人的自适应镇定

针对基于未校准顶置摄像机的非完整移动机器人视觉伺服镇定问题,首先从标准机器人运动学模型以及视觉空间与工作空间的转换得到视觉平面上的机器人运动学模型,而后根据视觉空间的运动学的速度误差以及视觉空间的机器人的动力学模型设计了一个自适应控制器,而且控制器具有鲁棒性,控制器中的鲁棒项函数用以抑制动力学的扰动,摄像机估计值用以估计未知的摄像机参数,动力学的惯性参数估计值用以消除动力学参数的不确定性.控制系统的稳定性以及参数估计值的有界性由李雅普诺夫定理证明.仿真结果用于说明控制律的有效性.     

具有未知视觉参数的非完整移动机器人的自适应动态反馈跟踪控制

基于视觉反馈和标准链式形式,研究了一类不确定非完整移动机器人的轨迹跟踪控制问题.首先,利用针孔摄像机模型,提出了一种新的基于视觉伺服的移动机器人运动学跟踪误差模型.基于这个模型,在具有不确定视觉参数的情形下,利用back-stepping技术,设计出了一种新的自适应动态反馈跟踪控制器,实现了全局渐近的轨迹跟踪,并通过李亚普诺夫方法严格证明了闭环系统的稳定性和估计参数的有界性.仿真结果证明了所提出的控制器的有效性.     

非完整移动机器人轨迹跟踪自适应控制器设计

针对轮式移动机器人的非完整运动学模型,将自适应反演控制技术和李亚普诺夫稳定性理论应用于机器人轨迹跟踪控制,设计了具有全局渐近稳定性的自适应轨迹跟踪控制器,并在Matlab环境下实现了移动机器人对直线和椭圆2种轨迹追踪的仿真实验.实验表明:该控制方法在轨迹跟踪控制中有较好的航向跟踪效果,对机器人非完整系统模型的非线性特性...     

受非完整约束移动机器人的跟踪控制

讨论受非完整约束移动机器人运动学模型和动力学模型的跟踪控制问题.通过把它们化成统一的标准型,提出了新的动态跟踪控制器.这些控制器具有维数低和没有奇异点的优点.仿真结果表明了所提出控制方法的有效性.     

不确定非完整移动机器人的轨迹跟踪控制

具有未校准视觉参数的非完整移动机器人的运动学系统具有参数不确定性,较一般的运动学系统更加复杂.基于视觉反馈、Barbalat's定理和Lyapunov直接方法,研究了具有未标定摄像机参数的非完整移动机器人的轨迹跟踪问题.首先,利用固定在天花板上的针孔摄像机透视投影模型,提出了一种新的基于视觉伺服的移动机器人运动学跟踪误差模型;基于这个模型,提出了一种新的与未知视觉参数无关的动态反馈跟踪控制器.该控制器不仅保证系统的状态渐近跟踪给定参考轨迹,而且控制器是全局的,通过Lyapunov方法严格证明了闭环系统的稳定性.在惯性系和图像坐标系下讨论跟踪问题,使问题变的简单且设计的控制器更加有用.最后,仿真结果证实了所提出的控制器的有效性.     

基于神经动力学的非完整移动机器人跟踪控制

主要研究了非完整移动机器人轨迹跟踪问题。基于后退控制和神经动力学生物激励模型,采用自适应参数调节的方法提出了一种新的跟踪控制器。该控制器能够生成平稳合理的速度,解决了以往大部分跟踪控制器所产生的速度突变问题,并且具有很好的鲁棒性。运用李雅普诺夫稳定性理论证明控制系统的稳定性。对连续、离散轨迹的仿真及与传统后退方法的比较分析验证了该方法的有效性。     

具有未校准视觉参数的移动机器人的跟踪控制

基于未校准视觉反馈的非完整运动学系统具有参数不确定性,较一般的运动学系统更加复杂.根据视觉反馈和非完整移动机器人的链式标准形式,研究了具有未标定摄像机视觉参数的移动机器人的轨迹跟踪控制问题.利用固定在天花板上的摄像机系统提出运动学跟踪误差模型,并对该误差系统模型提出了一种动态反馈跟踪控制器;对具有不确定机械参数的动力学模型,提出一种自适应力矩控制器,该控制器保证了实际机器人状态渐近跟踪给定的参考轨迹,并通过Lyapunov方法严格证明了整个闭环系统的稳定性.仿真结果证实了所提出的控制器的有效性.     

基于视觉伺服反馈的不确定非完整动态移动机器人的自适应镇定

研究了带有固定在天花板上的摄像机系统的非完整动态移动机器人的镇定问题. 首先, 利用针孔摄像机模型引入了基于摄像机目标的视觉伺服运动学模型,并针对该运动学模型给出了一个运动学镇定控制器. 然后,在摄像机参数不确定的情形下设计了一个自适应滑模控制器实现了不确定动态移动机器人的镇定. 提出的控制器不仅对结构不确定性如质量变化, 而且对无结构不确定性如外部扰动都具有鲁棒性. 通过Lyapunov方法严格证明了提出的控制系统的稳定性和估计参数的有界性. 仿真结果证实了控制律的有效性.     

Adaptive observer-based trajectory tracking control of nonholonomic mobile robots

In this paper, an adaptive observer-based trajectory tracking problem is solved for nonholonomic mobile robots with uncertainties. An adaptive observer is first developed to estimate the unmeasured velocities of a mobile robot with model uncertainties. Using the designed observer and the backstepping technique, a trajectory tracking controller is designed to generate the torque as an input. Using Lyapunov stability analysis, we prove that the closed-loop system is asymptotically stable with respect to the estimation errors and tracking errors. Finally, the simulation results are presented to validate the performance and robustness of the proposed control system against uncertainties.     

带有未知参数和有界干扰的移动机器人轨迹跟踪控

针对模型参数未知和存在有界干扰的非完整移动机器人的轨迹跟踪控制问题,本文提出了一种鲁棒自适应轨迹跟踪控制器方法.非完整移动机器人的控制难点在于它的运动学系统是欠驱动的.针对这一难点,本文利用横截函数的思想,引入新的辅助控制器,使得非完整移动机器人系统不再是一个欠驱动系统,缩减了控制器设计的难度,进而利用非线性自适应算法和参数映射方法构造李雅谱诺夫函数.通过李雅普诺夫方法设计控制器和参数自适应器,从而使得非完整移动机器人的跟随误差任意小,即可以任意小的误差来跟随任意给定的参考轨迹.仿真结果证明了方法的有效性.     

非完整移动机器人的轨迹跟踪控制

讨论基于运动学模型的非完整移动机器人的轨迹跟踪控制问题。在一定的假设条件下实现了全局指数跟踪，该假设允许参考模型角速度和平移速度均趋于零，并将该方法推广到 动力学模型。仿真例子证明了该方法的有效性。     

Adaptive tracking control for uncertain dynamic nonholonomic mobile robots based on visual servoing

The trajectory tracking control problem of dynamic nonholonomic wheeled mobile robots is considered via visual servoing feedback.A kinematic controller is firstly presented for the kinematic model,and ...     

Adaptive tracking control for uncertain dynamic nonholonomic mobile robots based on visual servoing

The trajectory tracking control problem of dynamic nonholonomic wheeled mobile robots is considered via visual servoing feedback. A kinematic controller is firstly presented for the kinematic model, and then, an adaptive sliding mode controller is designed for the uncertain dynamic model in the presence of parametric uncertainties associated with the camera system. The proposed controller is robust not only to structured uncertainties such as mass variation but also to unstructured one such as disturbances. The asymptotic convergence of tracking errors to equilibrium point is rigorously proved by the Lyapunov method. Simulation results are provided to illustrate the performance of the control law.     

非完整移动机器人路径跟踪的模糊控制

以步进电机驱动的差动式移动机器人为对象,建立非完整约束的离散运动学模型.基于参数整定的思想,并结合路径跟踪的特点来设计用于非完整移动机器人路径跟踪的分阶段模糊控制器,在跟踪的趋近和稳定阶段,分别采用了不同的模糊化比例因子和解模糊比例因子.仿真和实验表明,移动机器人采用分阶段模糊控制器对路径进行跟踪,响应速度快,稳态误差小,鲁棒性强.     

Visual tracking control for an uncalibrated robot system with unknown camera parameters

The robust trajectory tracking problem for an eye-in-hand system is addressed in this paper. A novel visual feedback control model is proposed. It considers not only the uncertainties and disturbances in the robot model, but also the unknown camera parameters. By using sliding mode control, filter method and adaptive technique, the controller is designed such that the robot can track the desired trajectory well by using information provided by camera. Finally, stability and robustness are rigorously proved by using Lyapunov method. Computer simulations are presented to show the effectiveness of the proposed visual feedback controller.     

Simultaneous tracking and regulation visual servoing of wheeled mobile robots with uncalibrated extrinsic parameters

This paper presentsa global adaptive controller that simultaneously solves tracking and regulation for wheeled mobile robots with unknown depth and uncalibrated camera-to-robot extrinsic parameters. The rotational angle and the scaled translation between the current camera frame and the reference camera frame, as well as the ones between the desired camera frame and the reference camera frame can be calculated in real time by using the pose estimation techniques. A transformed system is first obtained, for which an adaptive controller is then designed to accomplish both tracking and regulation tasks, and the controller synthesis is based on Lyapunov's direct method. Finally, the effectiveness of the proposed method is illustrated by a simulation study.     

Distributed adaptive control for consensus tracking with application to formation control of nonholonomic mobile robots

In this paper, we investigate the output consensus problem of tracking a desired trajectory for a class of systems consisting of multiple nonlinear subsystems with intrinsic mismatched unknown parameters. The subsystems are allowed to have non-identical dynamics, whereas with similar structures and the same yet arbitrary system order. And the communication status among the subsystems can be represented by a directed graph. Different from the traditional centralized tracking control problem, only a subset of the subsystems can obtain the desired trajectory information directly. A distributed adaptive control approach based on backstepping technique is proposed. By introducing the estimates to account for the parametric uncertainties of the desired trajectory and its neighbors’ dynamics into the local controller of each subsystem, information exchanges of online parameter estimates and local synchronization errors among linked subsystems can be avoided. It is proved that the boundedness of all closed-loop signals and the asymptotically consensus tracking for all the subsystems’ outputs are ensured. A numerical example is illustrated to show the effectiveness of the proposed control scheme. Moreover, the design strategy is successfully applied to solve a formation control problem for multiple nonholonomic mobile robots.