共查询到20条相似文献,搜索用时 15 毫秒
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Shengfeng Zhou Yazhini C. Pradeep Ming Zhu Kendrick Amezquita‐Semprun Peter Chen 《Asian journal of control》2018,20(5):1745-1754
In this paper, the motion control of a mobile manipulator subjected to nonholonomic constraints is investigated. The control objective is to design a computed‐torque controller based on the coupled dynamics of the mobile manipulator. The proposed controller achieves the capability of simultaneous tracking of a reference velocity for the mobile base and a reference trajectory for the end‐effector. The aforementioned reference velocity and trajectory are defined in the task space, such task setting imitates the actual working conditions of a mobile manipulator and thus makes the control problem practical. To solve this tracking problem, a steering velocity is firstly designed based on the first‐order kinematic model of the nonholonomic mobile base via dynamic feedback linearization. The main merit of the proposed steering velocity design is that it directly utilizes the reference velocity set in the task space without requiring the knowledge of a reference orientation. A torque controller is subsequently developed based on a proposed Lyapunov function which explicitly considers the coupled dynamics of the mobile manipulator to ensure the mobile base and end‐effector track the reference velocity and trajectory respectively. This proposed computed‐torque controller is able to realize asymptotic stability of both the base velocity tracking error and the end‐effector motion tracking error. Simulations are conducted to demonstrate the effectiveness of the proposed controller. 相似文献
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Kaichun Jiang Lakmal D. Seneviratne S. W. E. Earles 《Journal of Intelligent and Robotic Systems》1999,24(4):347-366
A path planning algorithm for a mobile robot subject to nonholonomic constraints is presented. The algorithmemploys a global- local strategy, and solves the problem in the 2D workspace of the robot, without generating the complexconfiguration space. Firstly, a visibility graph is constructed for finding a collision-free shortest path for a point. Secondly,the path for a point is evaluated to find whether it can be used as a reference to build up a feasible path for the mobile robot.If not, this path is discarded and the next shortest path is selected and evaluated until a right reference path is found. Thirdly,robot configurations are placed along the selected path in the way that the robot can move from one configuration to the nextavoiding obstacles. Lemmas are introduced to ensure that the robot travels using direct, indirect or reversal manoeuvres. Thealgorithm is computationally efficient and runs in time O(nk + n log n) for k obstacles andn vertices. The path found is near optimal in terms of distance travelled. The algorithm is tested in computersimulations and test results are presented to demonstrate its versatility in complex environments. 相似文献
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We study the control of a prismatic‐prismatic‐revolute (PPR) robot manipulator subject to a nonholonomic jerk constraint, i.e., a third‐order nonintegrable design constraint. The mathematical model is obtained using the method of Lagrange multipliers. The control inputs are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is to control the robot end‐effector movement while keeping the transverse jerk component as zero. The main result of the paper is the construction of a feedback control algorithm that transfers the manipulator from any initial equilibrium configuration to the zero equilibrium configuration in finite time. The effectiveness of the algorithm is illustrated through a simulation example. 相似文献
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研究了具有未知惯性参数非完整动力学系统的镇定问题,对于一类非完整系统,给出了一种新的时变自适应律镇定律,不同于其它文中的控制律,该镇定律不是高增益的,文中也讨论了一般不确定非完整动力学系统的镇定问题,证明了时变周期镇定律的存在性,一个简单的例子说明了如何应用文中结果设计镇定律,仿真结果表明了本文所提设计方法的有效性。 相似文献
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Pang Chen 《Journal of Intelligent and Robotic Systems》1997,19(3):299-320
Automatic motion planning is one of the basic modules that are needed to increase robot intelligence and usability. Unfortunately, the inherent complexity of motion planning has rendered traditional search algorithms incapable of solving every problem in real time. To circumvent this difficulty, we explore the alternative of allowing human operators to participate in the problem solving process. By having the human operator teach during difficult motion planning episodes, the robot should be able to learn and improve its own motion planning capability and gradually reduce its reliance on the human operator. In this paper, we present such a learning framework in which both human and robot can cooperate to achieve real-time automatic motion planning. To enable a deeper understanding of the framework in terms of performance, we present it as a simple learning algorithm and provide theoretical analysis of its behavior. In particular, we characterize the situations in which learning is useful, and provide quantitative bounds to predict the necessary training time and the maximum achievable speedup in planning time. 相似文献
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考虑动力学模型的非完整移动机器人运动规划 总被引:2,自引:1,他引:2
针对非完整移动机器人,在运动学和动力学约束条件下提出了一种运动规划方法.在工作环境已知情况下,根据移动机器人的动力学模型和无打滑非完整运动约束条件,采用立方螺线对规划的路径光滑化,从而使得移动机器人易于跟踪所规划的路径,同时考虑了移动机器人速度的限制.最后采用Matlab对该算法进行了数值仿真,结果表明该方法是有效的. 相似文献
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In this article a robust and simple procedure for the on-line concurrent motion planning of multi-manipulators is presented. The approach is based on solving for each manipulator a linear system of equations taking into account a vector for motion planning, and an original scheme for the appropriate perturbation of the pseudoinverse matrix. This method can pursue simultaneously both motion coordination and singularities prevention in real time in a sensor based environment. These properties make it suitable for fully autonomous or telerobotic systems operations. 相似文献
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移动机械手的跟踪控制 总被引:1,自引:0,他引:1
讨论一类不确定非完整移动机械手的跟踪控制问题。在系统惯性参数不精确知道的情况下,提出一种鲁棒控制器。为提高跟踪性能,进一步设计出使跟踪误差指数收敛的控制器。计算机仿真验证了所提出控制律的有效性。 相似文献
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Adaptive Stabilization for a Class of Stochastic Nonlinearly Parameterized Nonholonomic Systems with Unknown Control Coefficients 下载免费PDF全文
Yuqiang Wu 《Asian journal of control》2014,16(6):1829-1838
This paper investigates the problem of adaptive state feedback stabilization for a class of stochastic nonlinearly parameterized nonholonomic systems in chained form with unknown control coefficients. By defining two new unknown parameters whose dynamic updating laws are properly chosen and also by skilfully using the parameter separation, input‐state‐scaling, and integrator backstepping techniques, an adaptive state feedback controller is successfully designed, which guarantees that the closed‐loop system is asymptotically stabilized in probability. A simulation example is provided to illustrate the effectiveness of the proposed approach. 相似文献
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研究了一类不确定非完整动力系统的鲁棒镇定问题,设计了时变镇定律,仿真表明了该镇定律有效性。 相似文献
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A general mobile modular manipulator can be defined as a m-wheeled holonomic/nonholonomic mobile platform combining with a n-degree of freedom modular manipulator. This paper presents a sliding mode adaptive neural-network controller for trajectory
following of nonholonomic mobile modular manipulators in task space. Dynamic model for the entire mobile modular manipulator
is established in consideration of nonholonomic constraints and the interactive motions between the mobile platform and the
onboard modular manipulator. Multilayered perceptrons (MLP) are used as estimators to approximate the dynamic model of the
mobile modular manipulator. Sliding mode control and direct adaptive technique are combined together to suppress bounded disturbances
and modeling errors caused by parameter uncertainties. Simulations are performed to demonstrate that the dynamic modeling
method is valid and the controller design algorithm is effective. 相似文献
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不确定非完整动力学系统的指数镇定 总被引:2,自引:0,他引:2
研究具有未知惯性参数非完整动力学系统的镇定问题,基于非连续变换和动力学方程的性质,设计出两类非线地指数镇定律-鲁棒控制和自适应控制律。将其用于一类移动机器人的位姿镇定,仿真结果验证了所提出控制方法的有效性。 相似文献
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针对大部分两轮非完整移动机器人轮轴中心与几何中心不重合的特点, 提出一种多机器人协调编队控制算法. 构造队形参数矩阵确定编队形状, 根据领航机器人和相关队形参数生成虚拟机器人, 把编队控制分解为跟随机器人对虚拟机器人的轨迹跟踪. 建立虚拟机器人与跟随机器人之间误差系统模型, 利用Lyapunov 理论设计相应控制器, 从而实现队形保持和变换. 应用microsoft robotics developer studio 4(MRDS4) 搭建3D 仿真平台, 设计3 组实验, 结果进一步验证了所提出方法的有效性.
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