A computerised system for analysing working postures in agriculture

This paper aims to show a computerised program for analysing work postures in agriculture. The system contains two types of routines for studies of observation, Working Posture Analysing Sytem (WOPALAS) and a simple Video film technique for Registration and Analysis of working postures and movements (VIRA). Furthermore the system consists of programs for moment calculations and routines for registration of problems in the locomotive organs. The computerised system provides several advantages compared with traditional manual systems. For the operator, it is a less demanding work and the analyses are more accurate. The system rapidly provides the results of an analysis.     

一种三腿并联机器人的运动分析

本文提出了一种３—ＴＲＳ型并联机器人，介绍了它的结构和特点，给出了几种二自由度Ｒ—Ｒ型驱动装置的结构简图；分析了该机器人的运动问题，即从正、反两个方面分析了它的位姿、速度和加速度问题。     

The interaction between skill, postures, forces and back pain in wool handling

Wool handling is an important rural occupation where workers process 200 or more fleeces daily, separating them into various quality components. Loads and postures they experience carry substantial risk of low back pain (LBP). Although a formal skill training structure exists, interaction with loads and LBP is unknown. We examined whether skill and LBP influenced trunk postures and loads of 60 wool handlers representing 3 skill levels. LBP prevalence ranged from 20% for junior (lowest skill) to 45% for open class (highest skill) wool handlers. Open class wool handlers demonstrated increased lateral bend and more axially twisted postures, generating greater medio-lateral shear forces and lateral bend and axial twist moments. LBP was associated with open class wool handlers spending more time in severe axially twisted postures. These findings suggest that skill-based training needs to be reviewed to reduce the quantity of axially twisted posture which may help reduce the prevalence of LBP in this workforce.     

微机械全方位水平姿态传感器的研究

提出了一种能敏感全方位水平姿态的微机械传感器.采用微机械工艺制作的正八边形敏感元件敏感全方位水平姿态;通过前置信号电路和数字电路构成信号处理电路,实现倾角电压信号的提取,全方位信号合成和全方位倾角信号的灵敏度补偿.测试结果表明,分辨率优于0.1°,方位角测量范围可达360°,倾斜角度测量范围可达到20°.该传感器不仅体积小,且结构紧凑,工艺简单,敏感元件输出一致性好,适于批量生产.     

融合表面肌电和姿势信息的轮椅绩效评价方法

目的 为客观评价轮椅的使用效益,使用表面肌电设备测试轮椅使用过程中的肌电信号,并融合姿势信号IMU来构建人机评价模型。方法 分别对轮椅的折叠、刹车方式及行驶坡度进行试验来评估轮椅的使用绩效,通过对比用力肌群间的疲劳状况来判定较为舒适的轮椅折叠及刹车方式。实验要求被试者在执行轮椅任务时,分别使用两种折叠方式和三种刹车方式不同的轮椅进行实验,并在操作动作任务过程中采集sEMG和IMU信号,在实验任务结束后填写NASA-TLX量表。结果 根据模型的评价指标对实验数据进行了比较与分析,横向收折式折叠和凹口式刹车(手刹位于前方)的轮椅疲劳度低,在3~4°坡度范围下轮椅使用者的受力最小,较为舒适,从而验证了模型在轮椅人机评价上的可行性,为优化轮椅设计提供参考。结论 人机评价模型适用于评估产品绩效,同时提出的融合表面肌电和姿势信息的轮椅绩效评价方法具有较高的精度和准确性,能够有效地评估轮椅使用者的绩效水平。     

General Torsional Stiffness Matching of Off-road Vehicle

Increasing frame torsional stiffness of off-road vehicle will lead to the decrease of body torsional deformation, but the increase of torsional loads of flame and suspension system and the decrease of wheel adhesive weight. In severe case, a certain wheel will be out of contact with road surface. Appropriate matching of body, flame and suspension torsional stiffnesses is a difficult problem for off-road vehicle design. In this paper, these theoretically analytic models of the entire vehicle, body, frame and suspension torsional stiffness are constructed based on the geometry and mechanism of a light off-road vehicle's body, frame and suspension. The body and frame torsional stiffnesses can be calculated by applying body CAE method, meanwhile the suspension's rolling angle stiffness can be obtained by the bench test of the suspension's elastic elements. Through fixing the entire vehicle, using sole timber to raise wheels to simulate the road impact on a certain wheel, the entire vehicle torsional stiffness can be calculated on the geometric relation and loads of testing. Finally some appropriate matching principles of the body, frame and suspension torsional stiffness are summarized according to the test and analysis results. The conclusion can reveal the significance of the suspension torsional stiffness on off-road vehicle's torsion-absorbing capability. The results could serve as a reference for the design of other off-road vehicles.     

助行训练机器人骨盆位姿控制机构研究

通过对正常人骨盆运动规律分析,提出了一种人行走时骨盆运动的控制机构.用闭环矢量法进行了正逆运动学分析,并在Matlab/Simulink,SimMechanics环境下进行了仿真分析.运用Pto/E设计了助行机器人移动平台虚拟样机,进行了助行训练动态仿真,验证了助行训练机构对骨盆运动控制的可行性.为助行康复训练机器人的人体重心运动控制提供了一种有效方法,对康复机器人进一步研究具有一定的参考价值.     

人体骨盆位姿模拟机构的运动学分析及仿真

根据人体骨盆的运动规律,设计了一种4自由度人体骨盆位姿模拟机构.建立了人体骨盆位姿模拟机构的正运动学模型和逆运动学模型,并推导出了机构的雅可比矩阵.基于机构的运动学模型建立了仿真模型,并采用MATLAB/Simulink对人体骨盆位姿模拟机构进行了仿真分析.仿真结果表明:该机构方案是可行的,能够模拟人体骨盆的运动规律.同时仿真结果也验证了运动学模型的正确性.     

基于车体动态特性的发动机安装位置优化

建立某款全地形车车架挂发动机有限元模型,计算并进行模态分析。通过与实验模态分析结果对比,验证有限元模型的可靠性。在此基础上,分析路面激励及发动机激励与车体动态特性的匹配关系。为改善该款全地形车车体的动态特性,应用形状优化方法,以发动机在车架的前后、左右、上下安装位置及俯仰角度为变量,以提高车体一阶模态频率为目标,进行优化。根据优化结果,调整发动机的安装位置与俯仰角度,使车体的一阶模态频率提高5 Hz。     

爆破拆除楼房时塌落振动的预测

从十余栋楼房塌落振动综合实测中可见,峰值振速总是由楼房倒塌触地的姿态所决定,即可能发生在后支撑爆破楼房下坐、切口闭合或翻倒触地时,且峰值也不尽相同。由此,在量纲分析中引入重心下落高度,分别建立了楼房下坐、楼房切口闭合冲击和建(构)筑物整体翻倒触地振动的峰值振速经验公式,阐述了相应的楼房、建(构)筑物不同塌落振动原理,并从案例实测振速对数图峰值最大包络线中,摄取公式待定参数Kt、β,由此分别提出对应的峰值振速算法的计算公式,并阐明参数的物理意义和取值。预测地点振速可先按结构选取,高大烟囱、现浇剪力墙(包括前跨现浇剪力墙的框剪结构及13层以上的单向倾倒现浇框剪结构的前方预测点)的塌落峰值振速,选取算法(3)计算峰值振速。框架和其他框剪楼房塌落振动的峰值,可按触地姿态选取算法(1)和算法(2)计算,并选取算法中的较大计算值为预测的峰值振速。由于补充了算法(1)和算法(2),综合算法正确地反映了形成峰值振速的楼房触地位置和撞地冲击时重心改变的高度,因此振动原理较明确,由此提高了预测塌落振动的针对性和准确性。并结合观测实例进行了公式验证,证明了公式的合理性。