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.     

明式椅的装饰艺术研究

目的探究明式椅的造型审美。方法借鉴中外学者的相关研究,以美学、设计心理学、人体工学为理论基础,从形式构成、形态内涵、工艺技巧3方面来论述明式椅的造型艺术。结论从明式椅造型设计的研究中发现了明式家具的形式美规律,发掘了明式家具设计文化的深厚底蕴,为现代家具设计带来了灵感,有利于提升中国家具产品的国际竞争力。     

主人椅的设计进阶路径研究

目的发扬工匠精神,运用传统文化,完成具有中国风格的创新设计。方法站在批评的视角,以汉斯·瓦格纳的中国椅为例,通过中国椅和明式圈椅的设计对比,指出明式圈椅的器物造型所蕴涵的中国文化基因对西方设计的优势,同时受到国外发达国家设计进阶过程所秉承的以人为本的设计理念以及所显现出的工匠精神启发,再结合体验设计方法完成主人椅的设计实践。结论工匠精神和传统文化基因是当代设计创新的保障和资源,蕴涵工匠精神的创新设计值得正在成长的中国企业和设计师借鉴与学习。     

几何形态在现代家具设计中的应用

几何形态家具是现代居室的一部分,它是无风格的,因为它除了用途和必要的结构外,并不期望表达任何特定的风格,所有的组成部分都是用同样的标准化的基本部分构成,这些部分随时都可以分开或转换。正是这种特性使几何化的造型设计手法应用水到渠成,以几何形为基本单位,通过加、减、换、改等设计方法,创造出多种的造型,并成就着若干的设计可能性。     

Effects of differences in office chair controls, seat and backrest angle design in relation to tasks

In this study the influence of chair characteristics on comfort, discomfort, adjustment time and seat interface pressure is investigated during VDU and non-VDU tasks: The two investigated office chairs, both designed according to European and Dutch standards are different regarding: 1) seat cushioning and shape, 2) backrest angle and 3) controls. Thirty subjects in total, both male and female, participated in two experiments: twenty in the first and ten in the second.Significant differences are found for ease of adjustment and adjustment time of controls, independent of the tasks. Related to tasks, a significant difference was found for the backrest range of motion. For non-VDU tasks a larger range of backrest motion was preferred by 70% of the subjects. The chair design differences were most clear for comfort and adjustment time of controls, followed by comfort of backrest angle. No differences are found between seat pan comfort and discomfort, first impressions and peak interface pressure.     

木制椅的情感分析

结合时代的变迁,关注各款新式椅子的诞生,分析木制椅给人们带来的情感因素,提出合理地利用材料性能,选择合适的加工工艺,创造出更美好的椅子造型,给人更惬意的精神享受。     

The impact of office chair features on lumbar lordosis,intervertebral joint and sacral tilt angles: a radiographic assessment

Abstract

Background: The purpose of this study was to determine which office chair feature is better at improving spine posture in sitting. Method: Participants (n = 28) were radiographed in standing, maximum flexion and seated in four chair conditions: control, lumbar support, seat pan tilt and backrest with scapular relief. Measures of lumbar lordosis, intervertebral joint angles and sacral tilt were compared between conditions and sex. Results: Sitting consisted of approximately 70% of maximum range of spine flexion. No differences in lumbar flexion were found between the chair features or control. Significantly more anterior pelvic rotation was found with the lumbar support (p = 0.0028) and seat pan tilt (p < 0.0001). Males had significantly more anterior pelvic rotation and extended intervertebral joint angles through L1–L3 in all conditions (p < 0.0001). Conclusion: No one feature was statistically superior with respect to minimising spine flexion, however, seat pan tilt resulted in significantly improved pelvic posture.

Practitioner Summary: Seat pan tilt, and to some extent lumbar supports, appear to improve seated postures. However, sitting, regardless of chair features used, still involves near end range flexion of the spine. This will increase stresses to the spine and could be a potential injury generator during prolonged seated exposures.     

Active sitting with backrest support: Is it feasible?

Abstract

Ergonomics science recommends office chairs that promote active sitting to reduce sitting related complaints. Since current office chairs do not fulfill this recommendation, a new chair was developed by inverting an existing dynamic chair principle. This study compares active sitting on the inverted chair during a simulated computer-based office task to two existing dynamic office chairs (n?=?8). Upper body stability was analysed using Friedman ANOVA (p?=?.01). In addition, participants completed a questionnaire to rate their comfort and activity after half a working day.

The inverted chair allowed the participants to perform a substantial range of lateral spine flexion (11.5°) with the most stable upper body posture (≤11?mm, ≤2°, p?≤?.01). The results of this study suggest that the inverted chair supports active sitting with backrest support during computer-based office work. However, according to comfort and activity ratings, results should be verified in a future field study with 24 participants.

Practitioner Summary: This experimental laboratory study analyses the feasibility of active sitting with a backrest support during common office work on a new type of dynamic office chair. The results demonstrate that active sitting with a backrest support is feasible on the new but limited on existing chairs.     

按摩模式对揉捏式按摩椅按摩舒适性的影响

以揉捏式按摩椅作为研究对象,采用自由模量幅度估计法.通过对标准化后的按摩舒适度评价值分别进行统计,得到颈肩、背部和腰部区域3个区域共计8个测点最舒适的按摩模式,并通过脑电测试实验从客观角度验证了对由自由模量幅度估计法所得的各按摩区域最佳按摩模式的科学性,探讨了按摩模式对按摩椅按摩舒适性的影响.