四足步行机器人中缩放式腿机构设计参数的选择

为了研制实用的缩放式四足步行机器,本文对在三维直角坐标系中用三个直线运动来实现足端空间运动的缩放式腿机构的运动空间进行了分析。用优化的方法得出了K_2=1和K_1越大越好的结论;并给出了较优的运动行程和驱动器的安放位置。     

战地机器人步行腿机构研究

本文研究一种用作机器人步行腿的闭式运动链八杆机构,讨论了该机构的特点,对各构件尺寸进行了初步优化。在此基础上,用拆杆拆副法进行了该机构末端件的相对轨迹仿真、机器人行走时末端件的绝对轨迹及机器人本体运动轨迹的仿真;并进行了速度、加速度分析。文末附有机构运动简图、相对轨迹。绝对轨迹及速度、加速度线图。研究结果表明;该机构用作机器人步行腿机构是较合适的。根据初步优化尺寸研制的模型经试验证明基本成功。     

六足步行机运动学及步行机构

六足步行机尚有许多问题需要解决.本学位论文对六足步行机的步态、步行机构以及足端轨迹规划等步行机基本间题展开了深入的研究,分析了步行的横向行走特性,得到了最佳稳定的横向步态,和纵向步态结合在一起,形成正交步态.将现有关单方向行走步态扩展到两个正交方向的行走步态,用分析的方法得出全方位步行机构应采用圆柱型空间缩放机构,并对步行机构作了运动学探讨.用级数方法对     

半步行移动机器人机构的实验研究

本文给出了半步行移动机器人机构,分析了其运动特点和性能。最后,在不同的地面条件下进行了行驶实验,实验证明半步行机构的行驶通过性,为进一步开发完整的半步行移动机器人奠定了基础。     

踏步式两足步行机构运动稳定性的研究

本文通过分析下支撑物体的平衡状态将人体运动区分为稳定平衡状态和不稳定平衡状态,为踏步式两足步行机构的稳定步态分析奠定了理论基础.运用多刚体动力学方法对未加平衡措施的模型机构的 ZMP 点进行计算,分析了其运动稳定性,提出了斜面脚板和摆头机构相结合的双重平衡方法,得到了机构能够稳定动作的步态,并通过实验得以验证.     

仿生并联眼动机构多目标优化设计

针对低空空域视觉监控系统需同时保证大范围搜索和对目标持续平滑跟踪的要求,依据仿生原理,设计了一种模拟人类眼外肌功能的仿生并联眼动机构构型.为克服当前并联眼动机构多采用单目标优化方法而无法保障动平台倾角及运动精度、机构灵巧度、运动传递性能等运动性能同时取优的问题,在安装空间、驱动件尺寸、铰链偏角等约束条件下,采用改进非支配排序遗传算法(NSGA-Ⅱ)优化机构的结构参数.根据优化得到的结构参数搭建了实验样机.实际测量结果表明,所设计的机构能够在动平台最大倾角、综合运动性能方面取得较为理想的效果,动平台倾角可达55.94?,精度可达0.01?,优于人类视觉系统及相关研究,满足低空空域监控需求.     

两足步行机器人步态轨迹优化设计的可行方法

步态规划是预先设计出整个步行过程中各关节运动的时间函数,这样一组时间函数的优化设计,求解十分困难。在此我们将其转化为参数优化问题。即给出机器人机构某一特殊点在步行过程中的移动轨迹,以此来描述整个步行运动。然后将该点运动过程离散化,找出每一时刻各关节对应的角度,使其满足一定的限制条件,并达到某一指标条件下的最优。     

腹腔微创机器人远心定位机构优化设计

提出一种新型的三角形远心定位机构用于腹腔微创手术,该机构简单,刚度高.为得到综合性能较优的三角形远心定位机构,提出了一种新型的多目标优化模型,该模型中包含4个优化目标函数:全局运动学性能指标、机构紧凑性指标、全局刚度综合性能指标和全局动力学性能指标;3个约束条件:工作空间约束、机构参数约束和质量约束;2个设计变量:2个关节之间夹角.应用非支配遗传算法求解多目标优化问题.根据优化结果建立了三角形远心定位机构实物模型.实验验证了该三角形远心定位机构的有效性.     

4U平行四边形机构的一类新用途——整设计为两足步行机构

提出了将4U平行四边形机构整体设计为两足步行机构的一类新用途,此类两足步行4U平行四边形机构均由4个构件和4个万向铰组成,能够实现平面运动.根据万向铰布置方式的不同,分为3种构型.在针对构型I的前期研究基础之上,应用螺旋理论分析了构型Ⅱ和Ⅲ的自由度,并分别对其进行了运动学分析、步态分析和稳定性分析.此外,还将3种构型的...     

4U平行四边形机构的一类新用途——整体设计为两足步行机构

提出了将4U平行四边形机构整体设计为两足步行机构的一类新用途.此类两足步行4U平行四边形机构均由4个构件和4个万向铰组成,能够实现平面运动.根据万向铰布置方式的不同,分为3种构型.在针对构型Ⅰ的前期研究基础之上,应用螺旋理论分析了构型Ⅱ和Ⅲ的自由度,并分别对其进行了运动学分析、步态分析和稳定性分析.此外,还将3种构型的性能与应用作了进一步的分析与比较.运用ADAMS软件建立3种构型的动力学模型,仿真其运动的全过程,验证该类构型及其运动的可行性.制作出2台样机,实现了预期的运动.     

步行机足底静动态反力的测定装置

本文研究了一种新型的应用于步行机研究中的步行足底静动态反力的测定装置,并就该装置的测试原理、装置结构进行了介绍。针对正常步行的二足步行机器人的地面反力的变化规律进行了实测,对步态规划、运动规划及零矩点(ZMP)规划进行了有较大参考价值的分析,并得出结论。最后成功地测定了在步行过程中 ZMP 的移动轨迹.     

基于最优控制的仿人机器人行走振动抑制

针对仿人机器人行走过程中由腿部非刚性特性引起的振动,提出了一种基于最优控制的行走振动抑制方法．首先对振动进行建模,并将这一模型加入到原有机器人动力学模型中去．然后基于拓展的动力学模型,使用预观控制方法求取一条符合质心加速度约束的控制轨迹,作为求解最优控制问题的初始解．进而由此初始解出发,迭代求解此带约束的最优控制问题,利用得到的最优控制轨迹即能以前馈方式抑制行走过程中的振动．最后,使用预观控制方法和本文方法在仿人机器人“空”上进行行走对比实验．实验结果表明提出的方法显著减小了机器人行走过程中零力矩点（ZMP）的振荡和躯干的晃动．该方法对行走振动抑制的有效性得到了验证．     

Application of parallel mechanism in varistructured quadruped/biped human-carrying walking chair robot

For the existing problems of walking chair robot such as simple function,lower bearing capacity and not walking in complex environment,a novel varistructured quadruped / biped human-carrying walking chair robot is proposed.The proposed robot could be used as biped and quadruped walking chair robots.Considering the conversion of the walking chair robot from the quadruped to the biped or vice versa,6-UPS and 2-UPS+UP(U,P and S are universal joint,the prismatic pair,and sphere joint,respectively) parallel mechanisms are selected as the leg mechanism of the biped walking robot and quadruped walking robot,respectively.Combining the screw theory and theory of mechanism,the degrees of freedom of the leg mechanism and the body mechanism in diferent motion states are computed so as to meet the requirements of mechanism design.The motion characteristics of the 2-UPS+UP parallel mechanism which is the key part of the walking chair robot are analyzed.Then,the workspace of the moving platform is drawn and the efect of the structural parameters on the workspace volume is studied.Finally,it is found that the volume of the workspace of the moving platform is bigger when the side length ratio and the vertex angle ratio of the fxed platform and the moving platform which are isosceles triangles are close to 1.This study provides a theoretical foundation for the prototype development.     

Numerical construction of balanced state manifold for single-support legged mechanism in sagittal plane

Legged mechanisms can walk and run but sometimes encounter a risk of falling. In this article, a general numerical framework of balance criteria for a single-support legged mechanism is proposed and demonstrated. Explicit forms of necessary and sufficient conditions for balancing are identified and the balanced state manifold is constructed accordingly in the extended phase space of joint angle, joint velocity, and actuation limit. Within the iteration loops for partitioned joint angle and actuation limit, a nonlinear constrained optimization problem is formulated where the dynamic models of the legged mechanism are incorporated. The necessary conditions for balancing, such as the Zero-Moment Point, positive normal reaction, friction, and the ability to end up at a final static equilibrium, are implemented along with the system parameters for generality. The sequential quadratic programming method numerically solves for the velocity extrema within the complete feasible domain to construct the balanced state manifold as a viability kernel, which is a reachable superset of all possible controller-based domains. The balanced state manifold, along with its demonstration using the proposed optimal balancing motion for minimum energy and biped walking motions in sagittal plane, shows valid features that are physically consistent. The framework can be extended to systems in three-dimension with higher complexity, both in single and double support phases, for the development and stability analysis of walking robots and humans.     

基于分段保护的内核模块隔离机制

传统单块结构操作系统的所有内核代码在一个公共的、共享的地址空间运行。因此内核中任何一个漏洞或在内核中加载任何不可靠模块都会威胁到整个系统的安全。内核模块隔离机制从安全的角度出发，将原内核中最易引入不安全因素的部分采用保护模块的形式装载到内核中，并利用硬件保护机制与其它内核模块隔离，从而增强现有单块操作系统内核的可靠性与安全性。     

An improved electromagnetism-like mechanism algorithm for constrained optimization

Many problems in scientific research and engineering applications can be decomposed into the constrained optimization problems. Most of them are the nonlinear programming problems which are very hard to be solved by the traditional methods. In this paper, an electromagnetism-like mechanism (EM) algorithm, which is a meta-heuristic algorithm, has been improved for these problems. Firstly, some modifications are made for improving the performance of EM algorithm. The process of calculating the total force is simplified and an improved total force formula is adopted to accelerate the searching for optimal solution. In order to improve the accuracy of EM algorithm, a parameter called as move probability is introduced into the move formula where an elitist strategy is also adopted. And then, to handle the constraints, the feasibility and dominance rules are introduced and the corresponding charge formula is used for biasing feasible solutions over infeasible ones. Finally, 13 classical functions, three engineering design problems and 22 benchmark functions in CEC’06 are tested to illustrate the performance of proposed algorithm. Numerical results show that, compared with other versions of EM algorithm and other state-of-art algorithms, the improved EM algorithm has the advantage of higher accuracy and efficiency for constrained optimization problems.     

Cane-supported walking by humanoid robot and falling-factor-based optimal cane usage selection

In this study, we propose a scheme that enables a humanoid robot to perform cane-supported walking and to select the optimal cane usage depending on its condition. A reaction force is generated through the cane–ground interaction. Although the optimal cane–ground contact position leads to the most effective reaction force from the viewpoint of the walking capability, the cane position is constrained during such contact. Thus, different cane utilities can be achieved based on the priority assigned to the reaction force and cane position. In this light, we propose cyclic, leg-like, and preventive usages, each of which has different priorities. These different priorities lead to different utilities such as the expansion of the support polygon, load distribution, and posture recovery. The robot selects the most suitable of these three cane usages using a selection algorithm for locomotion that is combined with Q-learning (Us-SAL). Through simulations, the robot is made to learn the affinities between these cane usages and falling factors as Q-values and to accordingly select the optimal cane usage. As a result, the robot can perform the desired walking by selecting the optimal cane usage depending on its condition. We conducted walking experiments for each cane usage and found that each improved the walking stability for a suitable falling factor. Furthermore, we experimentally validated Us-SAL; the robot selected the optimal cane usage depending on its condition and walked in a complex environment without falling.     

基于运动函数的行走识别方法研究

结合人体生理特征与物体运动特点,提出了一种用运动函数表示人体运动的方法,来用于视频图像的运动检测。针对智能监控系统的特点,以人行走视频为例,通过提取实验数据并对其进行分析处理,得到人行走函数方程。在此基础上,进行实验验证人行走函数中各参数的有效性,得到人行走函数关系表达式。     

用连续法求一类混合链机器人机构的全部位置正解

本文对一类混合链机器人机构的位置正解问题进行了研究。首先用Ｄ－Ｈ矩阵法建立机构上下平台之间的坐标转换关系；然后利用杆长约束条件得到机构的位置正解方程组；最后应用连续法直接求出其全部位置正解。本文方法形式简洁、求解方便，且具有一般性，可推广应用于其他类型混合链机器人机构及并联机器人机构的位置正解研究。     

考虑综合步行约束的仿人机器人参数化3D 步态规划方法

给出了一种三维环境下双足行走的参数化步态规划方法,建立了仿人机器人13 质量块约束动力学模 型．考虑单腿支撑和双腿支撑无冲击连续切换的六点边界约束条件、可行步态物理约束条件以及ZMP 稳定性约束 条件,以关节输出力矩函数的二次型积分值最小作为优化指标,采用参数化步态优化方法,将复杂关节轨迹的规划 问题转化为分段多项式系数组成的有限参数向量的优化问题,得到了快速和慢速两组光滑无振动的优化步态．仿真 和样机实验验证了该方法的有效性．