模块化多功能护理床抬背机构设计与分析

针对康养行业的需求,基于模块化设计方法,对多功能护理床进行了模块划分和功能分析,完成了多功能护理床的整体方案设计。基于人机工程学原理,对抬背机构进行研究,通过分析对比现有抬背机构的优劣,设计了一种两折抬背机构;建立了相应的运动数学模型,借助Matlab对其进行理论运动分析,并与Adams运动学仿真结果进行对比,验证了机构设计的合理性。借助Ansys对抬背机构的关键部件进行有限元分析,确保了机构的安全性,并制作实验样机进行了验证。     

Kinematics and Wear of Tool Blades for Scrap Tire Shredding

Abstract

The wear of tool blades for cost-effective scrap tire shredding is investigated. Rotary disk cutters are widely used for cutting scrap tires into small pieces. The hard, wear-resistant tool blades mounted on the periphery of disk cutters maintain a narrow gap between blades and generate the cutting action. The kinematics of the relative motion of two adjacent disk cutters is derived to model the overlap region on blades during cutting. The model predictions match well with the actual shapes of the worn regions on used tool blades. The wear of tool blades made of AISI D2 and CRU-WEAR (CW) tool steels for scrap tire shredding is evaluated. A coordinate measurement machine was used to measure the tool wear. The wear on the blade surface is not uniform. Regions with high wear rate are explained using the kinematics analysis. The CW blades show a lower wear rate, about half of that of D2 blades, and a potential choice for cost savings.     

座面可调电动轮椅的机构运动仿真

通过运动仿真,对座面可调的多功能轮椅进行机构设计。基于人机工程学及位姿分析,设计各构件尺寸。在MATLAB中建立轮椅运动学模型,通过仿真分析得到了各刚体关键铰接点的位移、速度、加速度等参数。将得到的运动学参数与轮椅的功能要求进行比较,对轮椅整车机构进行修正。所设计的轮椅能辅助残障者实现坐立、站立、平躺等多种姿态间的转变,也便于轮椅与其它康复设备的安全对接。多刚体运动学仿真方法能更直观进行机构功能分析,从而缩短设计周期。     

The self-adaptation of weights for joint-limits and singularity avoidances of functionally redundant robotic-task

Kinematic redundancy of a pair of manipulator-task can be classified into intrinsic and functional redundancies. With the help of redundancy, the manipulator is able to approximate a secondary task while completing the main task. However, the success of the redundancy resolution relies on a proper choice of weights, that plays an important role in balancing the different components of the secondary task. In order to ensure the fulfillment of both the main and secondary tasks, the weights have to be tuned for each given manipulator-task. In this paper, a self-adaptation system is presented in replacement of the low-effective manual tuning of weights. The self-adaptation system is integrated into the twist decomposition algorithms, and is successfully applied to the examples of joint-limits and singularity avoidances as secondary task.     

挖掘机自动测深模型

根据挖掘机工作装置的结构特点，建立了挖掘机工作装置运动学模型，进而得到自动测深模型，为实现挖掘机自动测深奠定了基础。     

七自由度仿人臂形操作机器人的运动学问题

本文根据七自由度仿人臂形操作机器人的结构特点,借助齐次变换矩阵,建立了运动学正问题的数学模型.并利用几何等同性条件,建立了运动学逆问题的数学模型,同时还建立了基于点位控制的轨迹规划数学模型,最后给出求解操作机器人各质点的速度和加速度的算法.     

New method for simultaneous anatomical and functional studies of articular joints and its application to the human knee

In this paper a new methodology is described for the acquisition and computer elaboration of joint anatomy and motion data and the study of their correlation. The method uses a particular commercial electrogoniometer never used before for biomechanic investigations and software developed by the author for numerical interpolations and interactive display of the anatomical structures during joint motion. The original data acquisition protocol and computer elaboration software are described in detail, the theoretical and experimental accuracy of the method is reported and the original features and potential benefits of this approach in the field of joint biomechanics are discussed. Finally an experimental application for geometrical and functional analysis of the knee is presented as a practical example.     

Effect of Nonlinear Wave Kinematics on Dynamic Response of Spars

The difference between various approximate methods to compute the wave kinematics and forces acting on a Spar platform up to the instantaneous free water surface is investigated. Three types of procedures are considered; i.e., extrapolation, stretching (both simple extensions of linear wave theory) and the hybrid wave model (which involves decomposition of the incident wave into first- and second-order components). Of particular interest for the dynamic response of a Spar are the nonlinear (second- and higher-order) low-frequency forces. The effects of the different procedures are compared analytically and numerically for the inertia forces using Morison et al.’s equation as reported in 1950, but the conclusions can be extended to diffraction theory formulations.     

Delta并联机器人的研究进展

Delta并联机器人是一种最经典的空间三自由度并联机构,弥补了串联机器人存在的许多不足,是目前应用最为成功的高速并联机器人之一,吸引了国内外许多学者的关注。根据查阅的大量相关文献,对Delta并联机器人在运动学、动力学、机构性能、控制策略等方面的研究成果进行总结,进而探索Delta并联机器人的研究趋势和尚未解决的难题。