全方位移动机械手路径规划仿真平台的设计

机器人的三维仿真在机器人的研究中起着重要作用,论文以实验室中的全方位移动机械手为背景,建立了该移动机械手的运动学模型,然后利用VisualC++调用OpenGL建立了移动机械手的三维模型及路径规划的仿真平台,给出了实现算法,为移动机械手路径规划算法的研究提供了更为生动形象的仿真平台。     

检测与修补移动机械手系统的协调控制技术研究

针对2自由度轮式移动载体与5自由度机械手组成的检测与修补移动机械手进行了运动分析及其控制技术的研究．首先分析了移动机械手的结构特点,描述了移动载体与机械手的动力耦合对机械手系统的性能影响．其次,根据移动机械手动力学的复杂性,提出了移动机械手的运动控制策略,建立了基于神经网络的移动机械手三层智能控制的体系结构,底层是执行层,中间层是处理层,顶层是决策层．处理层包括两个RBF神经网络子控制器,未知的移动载体和机械手的动力学参数分别由各自的RBF神经网络辨识和补偿,形成闭环逼近的控制．应用Matlab编程软件对所建立的RBF神经网络进行训练仿真,最后,在实验环境中对移动机械手的运动进行了相关的实验验证．实验结果验证了移动机械手完成相关任务的有效性和可靠性．     

冗余机器人的双向自运动路径规划

冗余机器人的自运动路径规划是在保持手端任务向量不变的情况下,在关节空间内寻找一条连接机器人初始关节构形和期望关节构型的几何路径.本文给出一种双向自运动路径规划算法,其基本思想是使位于初始关节构形的真实机器人和位于期望关节构形的虚拟机器人在自运动流形上运动并收敛到同一关节构形,从而得到一条连接初始和期望关节构形的自运动几何路径.该算法克服了以往算法容易陷入局部极小构形的缺陷.仿真结果证实了算法的有效性.     

一种末端任务给定的移动机械手动态路径规划方法

移动机械手末端任务给定情况下的路径规划在喷绘、焊接等工作中有广泛的应用,但这方面的研究还比较少,尤其是在动态环境中.针对该情况提出一种动态规划方法,该方法包含预处理和动态规划两个阶段,使移动机械手在完成任务的前提下,能够有效地回避静态和动态障碍物.仿真结果证明了该方法的正确性.     

移动机械手控制研究进展

我国在移动机械手方面所作的工作相对较少，本文针对移动机械手，重点从运动规划、协调控制和多移动机械手三个方面综述了近年来的发展状况，介绍了涉及的各种问题及相应的处理方法，同时探讨了这一研究领域的发展方向和需要解决的问题。     

面向3维物体的三指机械手"包笼抓取"方法

研究了面向3维多面体和类多面体的三指机械手包笼抓取策略.为了减小计算量,将高维包笼抓取构形的搜索问题转换成低维空间中包笼抓取集合的搜索问题,提出了利用机械手手指在构形空间中形成的约束域搜索包笼抓取构形的方法.这种方法搜索到的包笼抓取构形能够收敛到不完全形封闭抓取构形.最后,通过Barrett手的抓取实验验证了算法的有效性.     

构形可变移动机器人的构形评价、优选及变换规划

为提升移动机器人对环境的适应能力,提出了一种适用于车体构形、轮距和轮向可变的轮式移动机器人的构形评价、优选和变换规划方法。该方法以转弯所需半径、通过宽度和稳定角为指标评价不同构形下机器人的移动性和稳定性,然后构建权系数多目标模型从构形集合中优选与环境特征匹配的构形,再将任意两构形之间的变换规划转化为网络路径搜索问题来求解耗能最少的变换路径。最后,通过实验验证了所提评价指标、构形优选以及变换路径规划方法的合理性和有效性。研究结果可为此类构形可变轮式移动机器人的设计分析和运动规划提供指导或参考。     

非完整移动机械手鲁棒自适应模糊控制

考虑系统存在的参数、外界扰动和未建模动态等不确定性,研究非完整移动机械手的鲁棒自适应控制器设计方法.基于用旋量理论建立的非完整移动机械手的动力学模型,设计了移动平台子系统的运动控制器,然后应用非线性反步控制技术和模糊逻辑系统的通用逼近性,用参数化线性模糊逻辑系统逼近非完整移动机械手动力学模型中的不确定项,基于Lyapu...     

移动机械手运动/力鲁棒自适应轨迹跟踪

针对移动机械手控制器设计中用隐函数定理进行模型降阶时存在的一些问题,把完整和非完整约束的统一形式引入到系统的动力学模型降阶中．基于该降阶模型设计了不确定移动机械手稳定的运动／力鲁棒自适应线性参数模糊控制器．理论分析和仿真结果表明,设计的控制器简单有效．     

远程遥控移动机械手的可视化实时控制

采用OTG接口连接摇杆手柄的Android手机和无线视频传输方案,来实现对移动机械手的可视化实时控制。本设计以OMAP4430开发板和Android手机为核心,通过响应摇杆水平、竖直方向的移动事件和手柄按键事件来控制机械手的地表移动及机械手马达操作,同时借助车载USB摄像头拍摄720P视频,经H264编码后用无线网卡发送到Android手机,解码后显示在控制界面上。实验结果表明,可视化远程遥控机械手能够实现全方位移动、捉取地面目标等功能,同时无线视频传输帧率达到28fps,满足实时视频传输要求。     

Mobile Manipulator Motion Planning for Multiple Tasks Using Global Optimization Approach

A mobile manipulator can perform various tasks efficiently by utilizing mobility and manipulation functions. The coupling of these two functions creates a particular kinematic redundancy introduced by mobility, which is different from that introduced by extra joints. This redundancy is quite desirable for dexterous motion in cluttered environments, but it also significantly complicates the motion planning and control problem. In this paper we propose a new motion planning method for mobile manipulators to execute a multiple task which consists of a sequence of tasks. The task considered in this paper is that the end-effector tracks a prespecified trajectory in a fixed world frame. In a multiple task, the final configuration of each task becomes the initial configuration of the next subsequent task. Such a configuration is known as a commutation configuration, which significantly affects the performance of the multiple task.We formulate the motion planning problem as a global optimization problem and simultaneously obtain the motion trajectory set and commutation configurations. In the formulation, we take account of the case that the platform has a non-holonomic constraint as well as the one that the platform has a holonomic constraint. Simulation results are demonstrated to verify the effectiveness of the proposed method.     

Endogenous configuration space approach to mobile manipulators: A derivation and performance assessment of Jacobian inverse kinematics algorithms

By a mobile manipulator we mean a robotic system composed of a non-holonomic mobile platform and a holonomic manipulator fixed to the platform. A taskspace of the mobile manipulator includes positions and orientations of its end effector relative to an inertial coordinate frame. The kinematics of a mobile manipulator are represented by a driftless control system with outputs. Admissible control functions of the platform along with joint positions of the manipulator constitute the endogenous configuration space. Endogenous configurations have a meaning of controls. A map from the endogenous configuration space into the taskspace is referred to as the instantaneous kinematics of the mobile manipulator. Within this framework, the inverse kinematic problem for a mobile manipulator amounts to defining an endogenous configuration that drives the end effector to a desirable position and orientation in the taskspace. Exploiting the analogy between stationary and mobile manipulators we present in the paper a collection of regular and singular Jacobian inverse kinematics algorithms. Their performance is evaluated on the basis of intense computer simulations.     

利用adams仿真分析五自由度机械手

串联机械手的运动动力问题分析是一个研究重点，也始终是一个难点。相关的研究人员一直都在寻找一种简便的方法来分析此类问题。该文首先计算机械手各杆件的质量、重心坐标和惯性矩，然后在adams中建立机械手的最简模型。按照计算修改相关变量，对各关节定义自变量，进行相关的编程，形成可用对话框控制的仿真模型。再利用ADAMS／PostProcessor，可得到机械手上任一点的速度、加速度和受力等方面的分析曲线。最后，利用推导的此机械手的终端的X方向位移x表达式，验证所得曲线正确与否。     

Sliding Mode Adaptive Neural-Network Control for Nonholonomic Mobile Modular Manipulators

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.     

Intelligent mobile manipulator navigation using adaptive neuro-fuzzy systems

The work presented in this paper deals with the problem of autonomous and intelligent navigation of mobile manipulator, where the unavailability of a complete mathematical model of robot systems and uncertainties of sensor data make the used of approximate reasoning to the design of autonomous motion control very attractive.A modular fuzzy navigation method in changing and dynamic unstructured environments has been developed. For a manipulator arm, we apply the robust adaptive fuzzy reactive motion planning developed in [J.B. Mbede, X. Huang, M. Wang, Robust neuro-fuzzy sensor-based motion control among dynamic obstacles for robot manipulators, IEEE Transactions on Fuzzy Systems 11 (2) (2003) 249-261]. But for the vehicle platform, we combine the advantages of probabilistic roadmap as global planner and fuzzy reactive based on idea of elastic band. This fuzzy local planner based on a computational efficient processing scheme maintains a permanent flexible path between two nodes in network generated by a probabilistic roadmap approach. In order to consider the compatibility of stabilization, mobilization and manipulation, we add the input of system stability in vehicle fuzzy navigation so that the mobile manipulator can avoid stably unknown and/or dynamic obstacles. The purpose of an integration of robust controller and modified Elman neural network (MENN) is to deal with uncertainties, which can be translated in the output membership functions of fuzzy systems.     

A new spatial hyper-redundant manipulator

This work presents a novel hyper-redundant manipulator. Such a manipulator is built with a variable number of tandem-assembled modules. Each module consists of a 3-dof parallel manipulator with asymmetric extremities in which moving platform possesses mixed motions with respect to the base platform. The manipulator's architecture is so simple that the forward position analysis is presented in closed-form solution, more specifically, in echelon-form solution. On the other hand, the velocity and acceleration analyses are carried out using the theory of screws. Finally, a case study consisting of solving the kinematic analysis of a 30-dof hyper-redundant manipulator is presented.     

Optimal positioning of combined mobile platform-manipulator systems for material handling tasks

Mobile manipulators are attracting significant interest in the industrial, military, and public service communities because of the potential they provide for increased efficiency in material handling and manipulation tasks. Corresponding interest has arisen in the robotics research community since the combination and coordination of the mobility of an autonomous platform with the robotic motion of a manipulator introduce complex analytical problems. One such problem arises from the particular kinematic redundancy which characterizes practical mobile manipulators. This paper is concerned with a particular aspect of the resolution of this redundancy, which is its utilization to optimize the system's position and configuration during task commutations when changes occur in both task requirements and task constraints. Basic optimization schemes are developed for cases when load and position constraints are applied at the end-effector. Various optimization criteria are investigated for task requirements including obstacle avoidance, maneuverability and several torque functions. The problem of optimally positioning the platform for execution of a manipulation task requiring a given reach is also treated. Emphasis is then placed on the multi-criteria optimization methods which are necessary to calculate the commutation configurations in sequences of tasks with varying requirements. Sample results are presented for a system involving a three-link planar manipulator on a mobile platform. The various optimization schemes are discussed and compared, and several directions (in particular the novel use of minimax optimization pioneered here for redundancy resolution) are outlined for further extensions of the methods to the general problem of motion planning and control of redundant robotic systems with combined mobility and manipulation capabilities.Research sponsored by the Engineering Research Program of the Office of Basic Energy Sciences, of the U.S. Department of Energy, under contract No. DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc. and by the Advanced Concept and Technology Program of the U.S. Army Material Command under Interagency Agreement No. 1495-CO92-A1 between the Human Engineering Laboratory and the U.S. Department of Energy.     

一种全方位移动机械手的体系结构设计与分析

首先介绍了我们设计和开发的一种全方位移动机械手系统的硬件体系结构,然后根据硬件平台、应用 环境和任务,设计了全方位移动机械手系统的基于行为的混合式软件体系结构,并通过两个实例进一步分析说明所 设计的体系结构的合理性和可行性,同时指出了下一步研究的方向.􀁱