基于激光雷达的移动机器人避障控制研究

以VFH算法思想为基础,提出适用于激光雷达的数据处理算法,将其作为避障算法用于移动机器人的室内自主行进过程中。根据室内避障问题的特点,通过仿真研究设计了适用于室内避障的障碍物阈值规则。在移动机器人实验中发现,受室内地面环境影响,直接将仿真程序应用到移动机器人实际操作中,会出现打滑偏航乃至不能顺利到达目标点的严重后果。为此,根据航向角变化率提出了分段降速方法,应用该方法移动机器人在起始点与目标点可以自主移动,验证了算法的有效性与实用性。     

Vibration control for a flexible-link robot arm with deflection feedback

The use of flexible links in a robot inevitably causes the elastic deflection and vibration of the endpoint of the robot during high-speed operations. The deflection and vibration will tend to degrade the positioning performance of the robot. In this paper, an optical sensing system consisting of a laser diode and a position sensitive detector is introduced for the real-time measurement of the dynamic deflection. Utilising a non-linear, coupled and measurement-based dynamic system model, a Lyapunov-type controller based on the deflection feedback is then proposed to damp out the tip oscillations and regulate the endpoint of the flexible robot. Experimental tests are conducted for a flexible one-link robot arm with a payload mass at the tip. The results demonstrate the effectiveness of the proposed measuring and control schemes.     

机器人与其连带的安全装置构成的系统稳定性分析

本文用强连续算子半群理论证明了机器人与其连带的安全装置构成的系统存在唯一的非负动态依赖解 ,并表明在一定条件下 ,系统存在稳态正解 ,且系统的动态解在通常意义下 (空间范数意义下 )渐近收敛于稳态解     

Randomized tree construction algorithm to explore energy landscapes

In this work, a new method for exploring conformational energy landscapes is described. The method, called transition-rapidly exploring random tree (T-RRT), combines ideas from statistical physics and robot path planning algorithms. A search tree is constructed on the conformational space starting from a given state. The tree expansion is driven by a double strategy: on the one hand, it is naturally biased toward yet unexplored regions of the space; on the other, a Monte Carlo-like transition test guides the expansion toward energetically favorable regions. The balance between these two strategies is automatically achieved due to a self-tuning mechanism. The method is able to efficiently find both energy minima and transition paths between them. As a proof of concept, the method is applied to two academic benchmarks and the alanine dipeptide.     

Psychomotor Predictive Processing

Psychomotor experience can be based on what people predict they will experience, rather than on sensory inputs. It has been argued that disconnects between human experience and sensory inputs can be addressed better through further development of predictive processing theory. In this paper, the scope of predictive processing theory is extended through three developments. First, by going beyond previous studies that have encompassed embodied cognition but have not addressed some fundamental aspects of psychomotor functioning. Second, by proposing a scientific basis for explaining predictive processing that spans objective neuroscience and subjective experience. Third, by providing an explanation of predictive processing that can be incorporated into the planning and operation of systems involving robots and other new technologies. This is necessary because such systems are becoming increasingly common and move us farther away from the hunter-gatherer lifestyles within which our psychomotor functioning evolved. For example, beliefs that workplace robots are threatening can generate anxiety, while wearing hardware, such as augmented reality headsets and exoskeletons, can impede the natural functioning of psychomotor systems. The primary contribution of the paper is the introduction of a new formulation of hierarchical predictive processing that is focused on psychomotor functioning.     

Efficient reconfiguration of lattice-based modular robots

Modular robots consist of many identical units (or atoms) that can attach together and perform local motions. By combining such motions, one can achieve a reconfiguration of the global shape of a robot. The term modular comes from the idea of grouping together a fixed number of atoms into a metamodule, which behaves as a larger individual component. Recently, a fair amount of research has focused on algorithms for universal reconfiguration using Crystalline and Telecube metamodules, which use expanding/contracting cubical atoms.From an algorithmic perspective, this work has achieved some of the best asymptotic reconfiguration times under a variety of different physical models. In this paper we show that these results extend to other types of modular robots, thus establishing improved upper bounds on their reconfiguration times. We describe a generic class of modular robots, and we prove that any robot meeting the generic class requirements can simulate the operation of a Crystalline atom by forming a six-arm structure. Previous reconfiguration bounds thus transfer automatically by substituting the six-arm structures for the Crystalline atoms. We also discuss four prototyped robots that satisfy the generic class requirements: M-TRAN, SuperBot, Molecube, and RoomBot.     

MATHEMATICAL MODELING AND EXPERIMENTAL STUDY ON SIT-TO-STAND PROCESS BASED ON ASSISTIVE STANDING-UP ROBOT

设计了一种符合人体起立运动的辅助起立机器人,通过牛顿欧拉方程对人体起立过程动力学进行分析与建模,推导机器人辅助起立、上肢辅助起立和肌力不足下肢辅助起立3种情况下,人体力与力矩平衡方程,依据方程在Simulink中建立仿真模型,并使用传感器系统对起立机器人辅助人体起立过程中力与力矩进行测量分析.结果表明：不论采取何种辅助起立方法,辅助起立机器人都可有效辅助起立,特别是对起立初始阶段辅助效果尤为明显.上肢辅助起立时,既可保持身体平衡与稳定,又可补偿起立时所需力与力矩,在接近完全站立时这种效果尤为明显,仿真模型可预测站立过程的关节力与力矩.肌力不足下肢参与辅助起立时,所提供辅助力有限但也起到一定作用.     

基于计算机视觉的非朗伯表面三维重构

基于计算机视觉的三维重构方法已经广泛应用在各行各业中。目前的三维重构研究主要针对不透明的朗伯表面,且已经比较成熟,但对非朗伯表面仍然面临诸多问题。而实际场景中的物体表面大多是非朗伯表面,因而,随着实际应用的推广,非朗伯表面的三维重构问题在计算机视觉领域越来越受到关注。虽然本现状研究不能完全涵盖针对非朗伯表面三维重构的所有方法,但它包涵了三维重构每个步骤中的各种典型方法。文中按照图像获取过程中的照明方式和重构原理对现有方法进行了分类,并逐类进行了介绍。由于不存在公共测试网络平台和带有标准视差的非朗伯表面立体图像集,因而,很难对各种算法的计算效率和匹配质量进行比较,文中主要对非朗伯表面的现有三维重构方法的原理、特点、适用范围和最新研究方向进行了介绍,对非朗伯表面三维重构的现有问题和发展前景进行了讨论。     

考虑摩擦特性的柔性关节空间机器人自适应CMAC神经网络鲁棒控制

讨论了关节摩擦力矩影响下,具有柔性铰关节的漂浮基空间机器人系统的动力学控制问题.设计了基于高斯基函数的小脑神经网络(CMAC)鲁棒控制器和摩擦力矩补偿器.用奇异摄动理论对系统的动力学模型进行快慢变子系统分解,针对快变子系统,设计力矩微分反馈控制器来抑制机械臂关节柔性引起的振动;对于慢变子系统,设计了基于自适应CMAC神...     

Modeling and Simulation of a Three-Wheeled Mobile Robot on Uneven Terrains with Two-Degree-of-Freedom Suspension Mechanisms

A wheeled mobile robot (WMR) will move on an uneven terrain without slip if its torus-shaped wheels tilt in a lateral direction. An independent two degree-of-freedom (DOF) suspension is required to maintain contact with uneven terrain and for lateral tilting. This article deals with the modeling and simulation of a three-wheeled mobile robot with torus-shaped wheels and four novel two-DOF suspension mechanism concepts. Simulations are performed on an uneven terrain for three representative paths—a straight line, a circular, and an ‘S’-shaped path. Simulations show that a novel concept using double four-bar mechanism performs better than the other three concepts.