机械外文文献翻译-一种新型线性折叠机构:配置和定位机构分析 【中文5370字】【中英文WORD】
机械外文文献翻译-一种新型线性折叠机构:配置和定位机构分析 【中文5370字】【中英文WORD】,中文5370字,中英文WORD,机械外文文献翻译-一种新型线性折叠机构:配置和定位机构分析,【中文5370字】【中英文WORD】,机械,外文,文献,翻译,一种,新型,线性,折叠,机构,配置,定位,分析
译文标题
一种新型线性折叠机构:配置和定位机构分析 【中文5370字】
原文标题
A Novel Linear Folding Mechanism: Configuration and Position Precision Analysis
作 者
LeiyuZhang YangYang
译 名
张磊宇 杨阳
国 籍
中国
原文出处
Advances in Reconfigurable Mechanisms and RobotsⅡ
一种新型线性折叠机构:配置和定位机构分析
摘要:线性折叠机构用于将末端执行器移动到所需位置,可以提高安全性,减少多关节机器人占用的空间。设计了一种矩形块作为折叠机构的通用元件。以刚性方式连接一系列块以形成折叠臂。四个相邻块之间的连接方法。基于连接方法,几个配置的远距观测仪的机制提出了。此外,折叠臂的定位精度进行了分析,由折叠距离和其他因素的影响。分析结果表明,提出的折叠臂配置具有高定位精度和长折叠距离。这种类型的线性折叠机制可以应用到服务机器人与人类合作。
关键词 折叠机制 矩形块 同步带 精密分析配置
1 介绍
折叠机制通常连接基础部分和末端执行器,以确保远程终端执行器的运动。有几种类型的机制用于移动远程处理设备。剪刀高空作业平台是典型的类型的望远镜设备,广泛用于高海拔的运转和维护。Enders等人开发的折叠机制延伸通过引进流体和缩进排气液体. Lee等人公开了一种用于桥梁运输系统的折叠管组,其包括多个圆筒形管和延伸/收缩线。Lee等人。 设计了一种由钢丝和钢丝组成的钢丝驱动双向折叠机构。然而,在这些类型的折叠机制之上,基础部分的体积相当大为了达到足够的刚度。此外,终端执行器需要一个相当大的扩展长度的差异,以确保一个适当的移动空间。此外,终端执行器需要一个相当大的扩展长度的差异,以确保一个适当的移动空间。因此,折叠机制上面提到的体积收缩状态将会十分笨重。
孔等人已经开发了一个可折叠的样品罐捕获机制(TSCCM)为翻滚的样品容器在轨道上检索。另一个直线折叠机构由川渊等人发明的。包括多个块。折叠臂以刚性连接的方式实现。黎平和叶浓描述一个往复推送链可扩展在它自身的重力下以直线水平方向。推动链通常用于将对象从一个位置到另一个地方。一些作者提出使用折叠机制以紧凑的体积为机械臂的发展方向。然而,上述研究缺乏足够的配置和相对精度分析.
线性折叠机制提出了一种新型折叠机制。这种类型的折叠机制可以提高安全通过消除这种风险,不可避免的对于一个典型的机器人手臂肘关节,物体在机器人手臂肘关节时手臂部分之间被关闭。此外,折叠臂组成的块可以存储在一个紧凑的情况下。因此,这种机制可以减少空间来容纳传统的关节。本文几个配置这种机制的支持。相对位置精度分析的数值模拟是通过折叠臂的数学模型。
2 折叠机构的结构
有各种各样新型折叠机构的配置。一般来说,这种折叠机构包括多个块、存储箱、驱动单元和终端执行器。自由连接的块被存储在存储盒中。驱动单元驱动的块可以在任意方向上伸出,并以刚性方式对齐以形成刚性对准。因此,折叠臂可以由刚性的块对齐,如图1所示。端部执行器安装在折叠臂前端。这种折叠机构与传统的多关节机器人相比,收缩状态占用更少的空间。
(a) (b)
图1折叠机构的两种状态 a收缩状态b扩张状态
2.1 折叠机构的配置
为了保持扩展块以刚性的方式,本节提出了几种连接方法。第一次连接方法具有最高的铰链连接的可靠性,为 在图2a所示。在自由连接方式的块可以在相对于下一块铰链销转动。钢丝绳是另一种连接方法,如图2b所示,对钢丝绳的两端分别固定在头块和最后一个,所有的块都使连接在一起。
第三种连接方式是两个相邻的块由同步带连接,如图2所示。同步带,齿形带,与上表面网格波纹每一块结构使块固定以一个刚性的方式。如图3a所示,有一个锁紧机构和凹进部分的上表面。当锁机构与相邻块的相应凹入部分接合时,相邻块连接。因此,可以连续扩展块固定的最后方法。
(a) (b)
图2两个折叠机制的配置
(a) (b)
图3 另两个配置折叠机制
基于结构和连接方法,提出了若干折叠机制的配置。为了确保扩展块相互固定,所有的上表面和正下方相邻块的连接形成一个可折叠的手臂。因此,这个线性折叠手臂可以沿任意方向扩展。有一个终端执行器安装在前端的手臂。折叠臂也能承受在任何方向上施加在末端执行器上的力。因为有四个连接方法,创建16个组合。这意味着有十六个折叠臂理论上的配置。根据加载条件和连接的可靠性,四种典型的配置如图2和3所示。折叠臂的安排并不局限于上述配置的描述。新组合可一满足一些特定的目的,如最小空间需求和方便的存储。此外,此外,自由结合方式可能存储在一个螺旋面情况下或其他情况下合适的形状。
在传动方式的选择上,可采用链轮传动和蜗杆传动,将挡块推离。链轮传动可实现快速延伸和回缩。每一块在底槽。然后链轮与凹槽接合,如图3所示。由于多边形效应和啮合冲击,末端执行器可能产生剧烈振动。链轮驱动的折叠机构适用于高速、低精度场合。 与蜗杆传动折叠臂可以稳步扩展,如图4所示。此外,延伸和回缩的速度是连续的和光滑的。带蜗杆传动的折叠机构可代替穆蒂关节臂在维修机器人中使用。因此,这种折叠臂应该具有很高的定位精度。在2.2章,对折叠机构的位置精度进行了详细的建模和分析。
O
M f ,i
Oi−1
O
G
i
G
图4 直线折叠机构
2.2 直线折叠机构的设计
本节重点研究了带蜗轮传动的折叠机构。同步带的结合和铰链采用折叠臂的配置,如图4所示。它的齿形带前端与第一块粘合。它的齿啮合的上表面波纹结构确保相邻两块面之间的紧密联系。与钢丝绳相比,同步带通常拥有足够的强度和刚度。在该机制中,一个中国标准的带,指标选择10吨。压力辊用于压缩带紧。然后折叠臂由刚性块的方式支持两个支撑轮。折叠距离,延长长度,是扩展块的长度的总和。折叠臂缩回时,同步带通过刮刀与波纹结构分离。块是分开的 从刚性排列到离散排列。然而,离散块仍以铰链连接,可在任何方向弯曲。因此,离散的可安置在一个合适的形状。
这种线性折叠机制(图4)是由蜗轮传动驱动的。手臂的移动方向相同的方向转动蜗杆的轴。此外,这种机制包括基架可以旋转中心O改变仰角α的折叠臂相对于水平方向。
3 折叠臂位置精度分析
终端执行器的位置精度对实现抓取任务非常重要。在块的重力与物体,同步带张紧。然后,将弯曲折叠臂。然后终端执行器将偏离目标的位置。为了确定偏差,定位精度的数学模型。为简化复杂性,符合降低假设在力学模型的推导过程。
(1)铰链中的间隙被忽略。
(2)每个块的变形被忽略。
4 模拟结果和讨论
对上述数学模型的计算方法与MATLAB编程。对于这种线性折叠机构,最大折叠距离为1500 mm,折叠臂由O形折叠臂组成30块。计算程序中使用的主要参数见表1。
通过数值模拟,得到了折叠臂末端α= 30°的偏差,如图5所示。横向偏差dh上涨增加的扩展长度。与此同时,整个偏差在一定长度的增加上升。dh和dv的分布是相似的。折叠臂无负荷的最大偏差是0.104毫米和0.06毫米在水平和垂直方向i= 30,分别。
那么这两个偏差达到最大值 i = 30,mt= 2.5公斤。
表1直线折叠机构主要参数
图5 在α= 30°的偏差 水平偏差dh 垂直偏差dv
图6显示了仰角α对偏差的影响某些质量(mt = 2.5 kg)。但是,仰角α由于折叠臂的限制和基础框架只能改变−70°到70°。在一定长度的偏差度达到最大时,仰角α等于零,如图6a所示的。 两侧,整个偏差dh为折叠臂绕中心旋转向上或向下逐渐降低从水平位置的。dh几乎为零的偏差时 角α等于 70° 或 −70°。然而,垂直偏差dv几乎是零角度时α等于 70° ,0,−70°如图6B所示。dv 出现偏差的最大值 在上部和下部的旋转范围内。可以发现偏差dh和dv 有相对的角α双边对称。这是因为两个偏差是 主要受Mi 这是对称的角度α。
由于调频的限制力F,我总是要满足式(4)。然后最大值FN,最大的力FN,我可以计算其中Fn,max = 432.38,根据T的影响 他α和mt参数以上,力FN,我通过在α= 0和MT = 2.5公斤的数值模拟获得的,如图7所示。可以看出,折叠机构的安全负荷 从2.5公斤的有效折叠长度为1500 mm。
图6 在mt = 2.5 kg.的偏差 水平偏差dh 垂直偏差dv
图7 力FN,i
5 结论
(1)该块采用的折叠机构的主要组成部分。四相邻两块之间的连接方法。根据各连接方式的优点提出了机构,提供了四个切实可行的折叠配置。
(2)建立了位置精度的数学模型,得到了扩展长度、质量mt和仰角α。
(3)一个精确的模型进行数值模拟,利用MATLAB。随着延伸长度或质量太增加DH和DV兴起的偏差。
因此,这种体积小巧的折叠机构具有优良的定位精度和较长的折叠长度。
A Novel Linear Folding Mechanism: Configuration and Position Precision Analysis
Abstract: The linear folding mechanism, which is used to move the end effector to a desired position, can enhance the safety and reduce the space to be occupied by the multi-joint robot. A rectangle shaped block is designed as the general element of the folding mechanism. A series of blocks are connected in a rigid manner to form a folding arm. Four connection methods between the adjacent blocks are presented. Based on the connection methods, several configurations of the tele- scopic mechanism are proposed. Besides, the position precision of the folding arm is analyzed which is influenced by the folding distance and other factors. The analysis results show that the folding arm with the proposed configuration possesses high position precision and a long folding distance. This type of linear folding mechanism can be applied to service robots which cooperate with humans.
Keywords folding mechanism Rectangle shaped block Configuration
Precision analysis Synchronous belt
1 Introduction
The folding mechanism usually connects the base portion and the end effector to ensure the long-distance movement of the end effector. There are several types of this mechanisms used to move a remote handling equipment. The scissors aerial work platform is a typical type of folding equipment that is widely used for high altitude operation and maintenance . A folding mechanism developed by Enders et al. extends by rapidly introducing a fluid and retracts by venting the fluid . Lee et al. disclosed a folding tube set for a bridge transport system, which includes several cylindrical tubes and extension/retraction lines. Lee et al. designed a wire-driven bidirectional folding mechanism consisting of stages and steel wires. However, in these types of folding mechanisms above, the volume of the base portion is quite large in order to achieve sufficient stiffness. In addition, the end effector needs a considerable difference in extension lengths so as to ensure an adequate moving space. As a result, the volume of folding mechanisms men- tioned above in the contraction state will be quite bulky.
Kong et al. have developed a telescoping sample canister capture mechanism (TSCCM) for retrieval of tumbling sample containers on orbit. Another linear-motion folding mechanism invented by Kawabuchi et al. includes a plurality of blocks. A folding arm is achieved in a manner that blocks are rigidly connected with each other. Liping and Yenong escribe a reciprocating pushing chain which can be extended horizontally in a straight line under its own gravity. The pushing chain is usually used to push objects from one position to another. Several authors have proposed the use of folding mechanisms with the compact volume as the development direction of the robot arm. However, the researches above lack of enough configurations and the relative precision analysis.
The linear folding mechanism presented in this paper is a novel folding mechanism. This type of folding mechanism can enhance safety by eliminating such a risk, inevitable for a typical robot arm having an elbow joint, that an object around the robot arm gets caught between arm sections when the elbow joint is closed. Besides, the folding arm consisting of blocks can be stored in a compact case. Hence this mechanism can reduce the space to be occupied by the traditional multi-joint robot. In this paper several configurations of this mechanism are pro- posed. The relative position precision analysis is achieved through the numerical simulation of the mathematical model of the folding arm.
2 Structure of the Folding Mechanism
There are a variety of configurations of this novel folding mechanism. Generally, this folding mechanism includes a plurality of blocks, a storage case, drive units and an end effector. The freely-jointed blocks are stored in the storage case. The blocks driven by drive units are possible to be extended out in an arbitrary direction and aligned in a rigid manner to form a rigid alignment. Hence, a folding arm can be composed of the blocks in the rigid alignment, as shown in Fig. 1. The end effector is installed at the front end of the folding arm. This type of folding mechanism in a retraction state occupies less space compared with the traditional multi-joint robot.
(a) (b)
Fig. 1 Two states of the folding mechanism. a Retraction state, b Extension state
2.1 Configurations of the Folding Mechanism
In order to keep the extended block in a rigid manner, several connection methods are proposed in this section. The first connection method is the hinge which has the highest connection reliability, as shown in Fig. 2a. The block in the freely jointed manner can rotate around a hinge pin relative to the next block. The wirerope is another connection method, as shown in Fig. 2b. Both ends of the wirerope are fixed on the head block and the end one, respectively. All the blocks are stringed together.
The third connection method is that two adjacent blocks are connected by the synchronous belt, as shown in Fig. 2. The synchronous belt, toothed belt, meshes with the upper-surface corrugated structures of each block to make the blocks fixed to each other in a rigid manner. As shown in Fig. 3a, there is a latch mechanism and a recessed portion in the upper-surface. When the latch mechanism engages with the corresponding recessed portion of the adjacent block, the adjacent block is connected. Hence, the extended blocks can be serially fixed by the last method.
(a) (b)
Fig. 2 Two configuration of the folding mechanism
(a) (b)
Fig. 3 The other two configuration of the folding mechanism
Based on the structures and the connection methods, several configurations of the folding mechanism are presented. In order to ensure the extended blocks fixed to each other firmly, all the upper-surface and the underface are connected to these of the adjacent block forming a folding arm. Hence, this linear folding arm can be extended along an arbitrary direction. There is a end effector installed at the front end of the arm. The folding arm also can bear the forces imposed on the end-effector in any direction. Since there are four connection methods, sixteen combinations are created.
That means that there are sixteen configurations of the folding arm theoretically. According to loading conditions and the reliability of connections, four typical configurations are illustrated in Figs. 2 and 3. The arrangement of the folding arm is not limited to the description of configurations above yet. A new combination can be proposed for some certain purposes, such as minimum space requirements and the convenience of storage. Furthermore, the blocks in free-jointed manner may be stores in a helicoids case or other cases with suitable shape.
On the selection of the drive modes, both the sprocket drive and the worm drive can be adopted to push the blocks out of the storage case. The sprocket drive can accomplish the rapid extension and retraction. Each block has a groove in the undersurface. Then the sprocket engages with the groove, as shown in Fig. 3. A drastic vibration of end effector may generate owing to the polygon effect and meshing impact. The folding mechanism driven by the sprocket is suitable for high speed and low precision occasions. The folding arm with the worm drive can be extended steadily, as shown in Fig. 4. Besides, the velocity of the extension and retraction is continuous and smooth. The folding mechanism with the worm drive can be used in the service robots instead of muti-jointed arms. Hence, this type of folding arm should have high position precision. In the Sect. 2.2, the position precision of the folding mechanism is modelled and analyzed in detail.
O
M f ,i
Oi−1
O
G
i
G
Fig. 4 The linear folding mechanism
2.2Design of the Linear Folding Mechanism
The research focused on the folding mechanism with the worm gear drive is presented in this section. The combination of the synchronous belt and the hinge is adopted as the configuration of the folding arm, as shown in Fig. 4. The front end of the toothed belt and the first block are bonded. The teeth mesh with the upper-surface corrugated structures to ensure the close contact between the upsides of two adjacent blocks. Compared with wireropes, the synchronous belt generally owns sufficient strength and rigidity. In this mechanism, a Chinese standard belt, Metric T Pd: T10, is chosen.
The pinch rollers are used to compress the belt tightly on the block. Then the folding arm composed of the blocks in rigid manner is supported by two return roller. The folding distance, extended length, is the sum of the lengths of the extended blocks. When the folding arm is retracted, the synchronous belt is separated from the corrugated structures by a scraper. The blocks are separated from the rigid arrangement to the discrete arrangement. However, the discrete blocks are still connected by hinges and can be flexed in any direction. Therefore, the discrete ones can be housed inside a case with suitable shape.
This linear folding mechanism (Fig. 4) is driven by the worm gear drive. The moving direction of the arm is the same as the direction of a rotational axis of the worm. Besides, this mechanism including the base frame can rotate around the center O to change the elevation angle α of the folding arm relative to the horizontal direction.
3 Position Precision Analysis of the Folding Arm
The position precision of the end effector is very important to achieve the task of grasping. Under the gravity of the blocks and the objects, the synchronous belt is tensioned. Then, the folding arm will be bent. The end effector will deviate from the target location. In order to determine the deviations, the mathematical model of the position precision should be established. For simplifying complexity, the fol- lowing assumptions are made in the derivation of the mechanical model . .
(1)The clearances in the hinges are neglected.
(2)The deformation of each block is neglected.
4 Simulations and Discussions
The calculation algorithm for the mathematical model above is programmed with MATLAB. For this linear folding mechanism, the maximum folding distance is 1500 mm and the folding arm consists of 30 blocks. The main parameters used in the calculation program are listed in Table 1.
Through the numerical simulation, the deviations of the end of the folding arm at α = 30° are obtained, as shown in Fig.5. The horizontal deviation dh rises with the increasing of the extended length. Meanwhile, the whole deviations at the certain length rise along with the increasing of mt. The distribution of dh and dv are similar. The maximal deviations of the folding arm with no loads are 0.104 mm.
Main parameters
Value
Main parameters
Value
Ks/(N/mm)
1 × 106
μ
0.3
h/mm
40
G/N
1.08
l/mm
50
mt/kg
2
N
30
Fm/N
26
rp/mm
5
β/(°)
40
Table 1 Main parameters of the linear folding mechanism
Fig. 5 The deviations at α = 30°. a The horizontal deviation dh, b The vertical deviation dv
and 0.06 mm in the horizontal and vertical directions at i = 30, respectively. Then the two deviations reach a maximum at i = 30 and mt = 2.5 kg.
Figure 6 shows the influences of the elevation angle α on the deviations at the certain mass (mt = 2.5 kg). However, the elevation angle α can only change form −70° to 70° due to the restrictions of the folding arm and the base frame. The deviations dh at a certain length reach a maximum when the elevation angle α is equal to zero, as shown in Fig. 6a. Besides, the whole deviations dh are reduced gradually as the folding arm is rotated around the center O upwards or down- wards from the horizontal position. The deviations dh are nearly zero when the angle α is equal to 70° or −70°. However, the vertical deviations dv are nearly to zero when the angle α is equal to —70○, 0 or 70○, as shown in Fig. 6b. The maximum values of the deviations dv appear in the upper area and the lower area of the rotation range. It can be found that the deviations dh and dv have the bilateral symmetry relative to the angle α. That is because the two deviations are mainly affected by the moment Mi which is symmetrical to the angle α.
Fig. 6 The deviations at mt = 2.5 kg. a The horizontal deviation dh, b The vertical deviation dv
Fig. 7 The forces FN,i
5 Conclusions
(1)The blocks are adopted as the major components of the folding mechanism. Four connecting methods between two adjacent blocks are presented. Meanwhile, four feasible configurations of the folding mechanism are proposed according to the advantages of each connecting method.
(2)The mathematical model of the position precision is established to acquire the influences of the extended length, the mass mt and the elevation angle α.
(3)A numerical simulation of the precision model is conducted using MATLAB. The deviations dh and dv rise with the increasing of the extended length or the mass mt.
Hence, this type of folding mechanism with the compact volume possesses thethe
excellent position precision and the long folding length.
第 13 页
指 导 教 师 评 语
外文翻译成绩:
指导教师签字:
年 月 日
注:1. 指导教师对译文进行评阅时应注意以下几个方面:①翻译的外文文献与毕业设计(论文)的主题是否高度相关,并作为外文参考文献列入毕业设计(论文)的参考文献;②翻译的外文文献字数是否达到规定数量(3 000字以上);③译文语言是否准确、通顺、具有参考价值。
2. 外文原文应以附件的方式置于译文之后。
第15页
收藏