毕业设计翻译--小型攀爬式窗户清洗机器人

毕业翻译--小型攀爬式窗户清洗机器人 SMALL-SIZE WINDOW CLEANING ROBOT BY WALL CLIMBING MECHANISM 1. INTRODUCTION Recently, there have been many demands for automatic cleaning system on outside surface of buildings such as window glass by increasing of modern architectures. Some customized window cleaning machines have already been installed into the practical use in the field of building maintenance. However, almost of them are mounted on the building from the beginning and they needs very expensive costs. Therefore, requirements for small, lightweight and portable window cleaning robot are also growing in the field of building maintenance. As the results of surveying the requirements for the window cleaning robot, the following points are necessary for providing the window cleaning robot for practical use: 1) It should be small size and lightweight for portability. Clean the corner of window because fouling is left there often. 2) 3) Sweep the windowpane continuously to prevent from making striped pattern on a windowpane 4) Automatic operation during moving on the window. The locomotion mechanism must be chosen to satisfy these demands, especially later two subjects. Here locomotion mechanism means the combination of adhering mechanism, traveling mechanism and a mechanism for changing a traveling direction. First requirement brought the following specifications for designing the window cleaning robot. ?Weight: less than 5kg, including the weight of battery and washing water, ?Size: 300mm x 300mm x 100mm. These were also defined by the results of surveying the demands from the cleaning companies. In previous researches, we have proposed outline of mechanical system for window cleaning robot for filling above mentioned demands. And we confirmed basic properties and its possibility by the experiments. That mechanical system consists of two-wheel centered differential drive specialized in making a right-angled turn at the corner of window and a suction cup with vacuum pomp as adhering method. By this mechanical system, window cleaning robot can move on vertical window with adhering smoothly. Fig. 1 is the rendering at a scene of practical use of proposed window cleaning robot. This robot adheres on a windowpane with cleaning as moving on large windows. This paper deals with traveling control system in order that above mentioned - 1 - mechanical system of window cleaning robot can be operated automatically. We know a lot of studies on wall climbing robot including window cleaning robot by various research groups[1]-[10], but there are few researches and development of motion control of wall climbing robot. However the environment of robot which moves on vertical or inclined plane is quite different from the robot moves on horizontal plane at conditions of motion control. This is due to difference of direction of Fig. 1 Rendering of small-size window cleaning robot gravity works on the robot. In this paper, we explain window cleaning robot installed traveling control system and report results of basic traveling experiments and autonomous wiping motion on vertical window majored quantitatively. This paper includes four chapters. The second chapter illustrates prototyped mechanical systems used for experiments and moving path of window cleaning. The third chapter shows experimental result of basic traveling control and window wiping motion by comparing to with or without of motioned control system and says some discussions in Fig. 1 Rendering of small-size window each experiment. And the third chapter The cleaning robot forth chapter gives a conclusion. 2. MECHANICAL SYSTEMS In this study, we use climbing mechanism which consists of the two-wheel locomotion mechanism and adhering mechanism by a suction cup. This mechanism is reported in previous researches [11]. This mechanism was designed under focusing on the window cleaning robot for just a single windowpane. It is apparently necessary to cross over the window frame or joint line to use it at any window, but the single windowpanes like as a show window also exist as an important application. A. Traveling path In order to sweep all over the window plane, two types of traveling paths shown in Fig. 2 were considered. Here we adopted type (A) in Fig. 2 because of energy efficiency and cleaning affectivity. Type (A) in Fig. 2 principally involves horizontal direction movements. The robot will climb up just once. On the other hand path of type (B) consists of mainly vertical direction movements, i.e. the robot must continue to climb up and go down the - 2 - window recursively. Therefore type (A) is better on energy efficiency. And further, we must remember that the robot has a possibility to be in damage of bringing pollutions to where cleaned already, if the robot moves along the path of type (B). B. Locomotion Mechanism and robot body The robot moves on windowpane by two-wheel locomotion mechanism with holing the body on the surface using a suction cup vacuumed by a pump. The most important point in the mechanism is the friction coefficient of suction cup and tire against the adhering surface, e.g. high friction between the tire and the surface of window can transmits the torque, and low friction between the suction cup and the surface of window can achieves to move the robot with holding the body on the window. We selected PTFE (Polytetrafluoroethylene) for the materials of surface of a suction cup, and silicon rubber for the material of tires. C. Turning Mechanism and robot body Turning mechanism is a key to clean even at the corner of window. Fig. 3 shows the scenes that the robot changes its traveling direction at the corner. Fig. 3-(a) shows a usual turning way like as turning of motorcars. In this case, since the robot changes a direction as tracing an arc, it can not reach the end of corner of window. It needs the robot can not move along desired lines. In consequence, the robot can not cover the window surface without any hole, or the robot come to dead end by going off the course therefore the robot can not continue operation any more shown as Fig.8 It seems that this problem is caused by the gravity whose direction intersects with traveling direction of the robot at grade. It is a particular problem in traveling control of the robot moves on vertical or inclined plane like as windows. To determine this problem, we adopted attitude control using acceleration sensor. This chapter explains its control methods and outline of electronic system. In this control, input value is the desired attitude angle θ0, output value is attitude angle of the robot θ which is measured by acceleration sensor whose characteristics are shown in Table 2 .This sensor was installed into the robot body as shown in Fig. 10. - 3 - In order to control the attitude, the robot measures a direction of gravity since the related angle between gravity direction and robot body gives attitude angle. When the robot moves on the window, there is a possibility that the sensor detect convoluted value both the acceleration gravity and acceleration by the motion of the robot. But the robot will be operated with static and low velocity. Therefore the acceleration by motion of the robot is ever-smaller than acceleration gravity. So, in this control, we do not consider complicated process as follows to clean the corner by such robot: first, the robot goes into a corner, next it moves back the distance to turn, then it changes its direction as tracing an arc. The robot can clean a corner easily and rapidly. Round-shape robot is easily able to turn at the corner, but it unable to reach the end of corner. On the other hand, a quadrangular robot can clean to the end of corner, but never turn itself there. To get a function to change direction as shown in Figure 3-(b), we designed the mechanism that a mobile unit and a cleaning part are rotatably connected at the center shaft as shown in Fig. 4. 3. EXPERIMENTS AND DISCUSSIONS This chapter reports experimental result of motion control of prototyped window cleaning robot installed attitude controller illustrated in Chapter III. This experiment consists of two kinds of experiments. One is measurement of performance of attitude control when the robot moves to horizontal direction and elevation angle of 45 degrees. The other is an experience of window wiping operation with attitude controller on actual window glass. The robot was examined on the window stood vertically. The glass of the window is flat, clear and the thickness of 8mm. The glass is held by window frame made of aluminium. In all the experiment, the motions of robot measured by digital stereo vision camera, - 4 - Bumblebee. This camera system can recode absolute position coordinate of the robot by measuring the position of colored light mounted on the two corners of the robot in darkroom. The experimental setups are illustrated in Fig. 9. In this experiment, electric power is supplied form batteries placed in the robot, i.e. the robot is operated without any cables Test 1: Horizontal direction Moving of horizontal direction was measured as two conditions; one is without attitude control and the other is with attitude control using an acceleration sensor. Each experiment is measured in same position on the window, and same moving distance of 1.8 meters. At the starting point, the robot is attached on the window direct to horizontal direction shown as Fig. 14-(A). Fig. 15 shows motion trajectory both controlled and uncontrolled by attitude control system. A square in the figure represents the position and attitude of robot body recorded every 1 second. Fig. 15 says that as the robot goes, its trajectory is decurved. The average moving velocities of controlled case is 0.199 m/s; uncontrolled case is 0.374 m/s. The trajectory of controlled case shift 0.226m of the –Y direction at goal point (X=1.80m). The trajectory of uncontrolled case shift 0.862m of the –Y direction at goal point (X=1.80m).Then the attitude of uncontrolled robot inclines to clockwise as the robot runs, shown in Fig. 16. On the other hand, attitude angle of controlled robot is stabilized around 0 degree with a margin of error of plus or minus 5 degrees as shown in Fig. 16 Test 2: Direction of elevation angle of 45 degrees In this experiment, control results of moving direction of elevation angle of 45 degrees were measured as test 1, shown in Fig 14-(B). Fig. 17 shows motion trajectory of climbing to direction of elevation angle of 45 degrees. A square in the figure represents the position and attitude of robot body recorded every 1 second. The average moving velocity of controlled case is 0.138 m/s; uncontrolled case is 0.153 m/s. Fig. 18 shows that attitude angle of the robot controlled is constant and stabilized at 43 degrees. On - 5 - the other hand, the robot which was uncontrolled is increase up to approximately 100 degrees. Test 3: Window Wiping Motion Fig. 19 indicates moving trajectory of window wiping motion when the robot moved on the window toward a path shown in Fig. 8. The robot was started from the corner of lower left and climbed up toward window frame of left side, and it ran to horizontal direction toward window frame of top, next, the robot went down as the distance less than length of robot body. At the each corner, the robot changed the traversing direction at right angle using specialized turning mechanism. A square in the figure represents the position and attitude of robot body recorded every 1 second. 4. CONCLUSION This paper described an application of small-size and light weight wall climbing robots for window cleaning. The window cleaning robot consists of two-wheel locomotion mechanism and a suction cup. This robot moved on the window smoothly with adhering by a suction cup. And this robot has a function to change a traveling direction at right angle at the corner of the window. Above mentioned window cleaning robot was prototyped and its mechanism and some of characteristics were illustrated. Next, we developed attitude control system which is important technology to operate automatically. This control system was installed into prototyped robot mentioned above. Then, in order to measure the specifications of widow cleaning robot with attitude control systems on the vertical window, some of the experiments have been done. And the trajectory of window wiping movement was recorded quantitatively. As the results of these examinations, we got result that the attitude - 6 - angle of robot is under control, but robot trajectory is not fit with desired trajectory perfectly. Because, a robot has errors not only attitude angle, but also error of translation motion. To solve this problem, we will have to obtain the way to measure those errors and it control. 译文: 小型攀爬式窗户清洗机器人 1. 简介 目前，随着玻璃外墙建筑物的增长，人们对建筑物外墙表面(特别是玻 璃外墙表面)进行自动化清洗要求的需求量也越来越大，一些专用的窗户清 洗机也已经实际运用在了建筑维护领域。但是，他们之中大多数都是从一开 始就要一直安装在建筑物上面，这需要很高的费用。因此，在建筑物的维护 方面，我们迫切需要一种小巧、重量轻、可携带的窗户清洁机器人。根据我 们对窗户清洗机器人的要求进行的调查的结果，为了满足实际运用，其应该 必须具备以下几点要求: 1) 小巧、重量轻、便于携带。 2) 能够清洁到的窗户的各个角落，因为那里往往是污垢聚集地。 3) 能够连续式的清洗窗户表面以防留 下污垢走过的条痕。 4) 在窗户上能自动运行并调整前进方 向。 选择的运动机制必须满足这些条件，特 别是后面两项要求。这里的运动机制是指: 与窗户表面的附着粘合机制、路线行走机 制，以及改变行进方向的机制与原理。 运用于这种领域的机器人应该首先满 足以下设计要求: 图1小型窗户清洗机器人示例 ? 重量:不超过5kg，包括电池和清洗用水的重量。 ? 外形尺寸: 300mm x 300mm x 100mm. 这些要求也是通过对众多清洁公司的需要进行调查而得出的。在以前的 研究中，根据以上给出的要求，我们已经确定了窗户清洗机器人机械系统的 - 7 - 大致轮廓;通过实验，我们也确定了这个机器的一些基本属性和性能。这个机械系统包括一个用以保证在窗户角落处正确转向的两轮差动驱动中心和一个能将机器吸附在窗户表面的真空泵吸盘。有了这个机械系统，机器人就能吸附在窗户面上平稳垂直的行走。如图1所示，就是窗户机器人在实际运用过程中的动作情况，它附着在窗玻璃上边走边清洗窗户表面。 为了上述的清洁机器人机械系统能够实现自动操作，所以其行走控制系统是这篇文章主要的讨论对象。我们知道有许多研究机构对墙面爬行机器人，包括窗户清洗机器人都做过许多研究。但是，墙面攀爬机器人的运动控制依然很少有大的进展。机器人在垂直平面上运动和在水平面上运动所处的环境是不同的，从而其运动控制也有着很大的不同，这主要是由于其运动的方向不同，如图1所示，小型窗户清洗机器人工作时将受到重力的作用。 这篇文章将介绍擦窗机器人的行走控制系统，并得出在行走实验中其自动擦窗时垂直运动的主修定量结果。本文共有四个部分，第二部分主要介绍了实验中清洗机原型机械系统和擦窗行走的路径;第三章对清洗机器人进行了实验，分析了其运动控制，并通过对在有运动控制系统和没有运动控制系统时机器的运动情况作比较给出了相关结论;而第四部分则主要是作了一个总结。 2. 机械系统 在这项研究中，我们采用的攀爬机械装置包含了一个两轮的运动导向装置和吸盘吸附装置。这种机械装置在之前我们已经提到过，主要是设计用于单一窗玻璃表面的清洗工作。当然，为了有较为广泛的应用，机器人理应能够跨越窗户边框或连接处以适应各种窗户表面的清洗，但诸如像玻璃展示窗一类的单玻璃窗户表面的清洗依然是一个很重要的应用领域。 A( 运动路径 为了能够清洗到整个玻璃窗户表 面，我们考虑了两种清洗路径，如图2 所示。考虑到能源效率和清洁效率的因 素，这里我们采用图2中(A)所示的 路径。图2中的(A)主要是以水平 运动为主，机器人将一次性爬至最高 点;而(B)中的运动路径则主要是垂 直运动，机器人必须持续不断的来回上图2 小型窗户清洗机清洗路径 下运动。所以，(A)所示的运动方案能 更好的节约能源。除此之外，我们还必须考虑到若选择行走路径(B)，机器人有可能在刚刚清洗干净的地方带来二次污染。 B( 机械运动与机器人主体 机器人通过两个轮子在窗户面上进行运动，而真空泵驱动真空吸盘使则 - 8 - 得整个机器人能够紧紧吸附在玻璃表面上不掉下来。整个机器最重要的就是吸盘以及轮胎和吸附面的摩擦系数，例如:轮胎与窗玻璃表面的高摩擦系数就会产生扭矩，而吸盘与玻璃表面较低的摩擦就能使得机器能紧贴在窗户表面上。吸盘我们选择的是PTFE (聚四氟乙烯)，而轮胎的材料则是硅橡胶。 C( 转向机构与机器人主体 转向机械装置是机器能在窗户转 角处能干净清洗的关键部分。如图3 所示，显示了机器在窗角处的运动转向 情况。如图3-(a)所示，采用的是一 (a)传统转向 种常见的方法，机器人如同汽车一样在 窗角处转向。在这种情况下，因为机器 人是弧线形转向，使得其并不能清洗到 转角的边角处，机器人是不能按照这种 运动轨迹运动的。因此，机器人并不能 清洗整个玻璃表面而不留下一点漏洞，(b)新型转向方法 或许在转向之前有可能会卡死在转角图3 小型清洗机器人俯视图 处而不能继续运动，如图8所示。 似乎导致这样的问出现好像 是因为重力的方向与行驶在窗户表 面的机器人的方的运动向相交所导 致的。这个问题是机器人要能在垂 直光滑的表面上(如玻璃窗)运动 的一个典型的问题。为了解决这个 问题，我们采用的一种加速度传感 器来调整机器人的行走姿势。本章 主要是解释它的控制方法和大致的 电子控制系统组成。在此控制，输 入值是理想姿态角θ0，而输出角的图8 没有姿态控制系统下的清洗动作情况 值是其与运动方向之间的夹角θ，它由加速度传感器所测得，其值如表2所示。传感器安装在机器人的位置可见图10。 为了能够控制这个角度，机器人通过测量相关角度与重力方向的夹角来测得并给出正确的方向和角度。当机器人在窗户玻璃上移动的时候，安装在机器人身上的传感器就会随时监测机器人运动方向和其重力加速度方向错综复杂的值，但是，机器人的操作是很平稳的，其运动的速度也是较低的。因此，机器人的运动加速度要比重力加速度小得多。所以，在这个控制，我们认为这种机器人要清洗拐角处并不需要考虑以下复杂的过程:首先，当机器人到达一个角落的时候，在它移动一段距离的时候再转过来，然后转过一个弧线改变其前进的方向。这样，机器人就能简单快速的把拐角处清洗干净。轮型机器人可以很容易地把角落处的污垢清洗干净，但它并不能清洗拐角深处的污物。另一方面，一种四角机器人可以清洁到各个死角，但在那里并不 - 9 - 需要转向。为了以一种函数的方式来改变方向，如图3-(b)所示，我们设计了一个移动单元和清洁一个于中心轴相连接的旋转清洗头，如图4所示。 4.实验与讨论 本章主要是给出了窗户 清洗机器人原型运动控制的 实验结果。这个实验包含了 两项试验:一项是当机器人 的运动方向与水平方向成 图4 小型窗户清洗机器人机械系统 图10 两轮姿态控制模型 45度时测量其姿态控制性能;而 另一项实验则是测试机器人在实际擦窗过程中姿态控制系统对擦窗动作的控 制。 该机器是垂直紧贴在窗图9 行走路线图。粗线表示控制追踪部分，双户表面上的;玻璃窗很平很光线表示姿态控制部分 滑也很薄，大约只有8mm; 窗户边框是由铝制成的。在所有的试验中，机器人的运动情况由一个叫“大黄蜂”的数码立体视觉相机所捕捉，这台相机通过在暗室中测量安装在机器人两端的彩色光源位置来记录机器人运动的坐标位置，如图9所示。 在试验中，机器人的能量主要有安装在机器里的电池供给，而不是通过线缆来供电的。 测试1:水平方向 我们在两中不同的条件 下对机器人水平方向的移动 情况进行了对比测试，条件 一:没有姿态控制系统;条 件二:有加速度传感器的姿 态控制系统。每一个实验都(A)测试1:水平方向 (B)45度角方向 是机器在玻璃窗上相同的位 图14 姿态控制测试图 置、运动相等的位移(1.8m) 进行的，在开始的时候机器 - 10 - 人的位置如图14—(A)所示。 如图15，是机器人在有运动控制系统和没有运动控制系统下运行的情况，每一秒钟记录一次其所处的位置和运行姿态。从图中可以看出，随着机器人的运动其运动轨迹不断向下弯曲;有控制系统的时候其平均速度为0.199 m/s，–Y方向偏移了0.226m(X方向为1.80m)，没有控制系统的时候其平均速度为0.374 m/s，–Y方向偏移了 0.862m (X方向为1.80m)。图16 两种情况下机器人的水平运动情况 其次，没有控制系统的情况 下，机器人将会顺时针旋转，如图16所示;而有控制系统的情况下，机器人的旋转角基本上稳定在0度至1度的范围之内。 图16 两种情况下水平运动时机器人的姿态角 测试2:运动方向与水平方向成45度 在这项实验中，按照测试1的方法分别测试了其在与水平方向成45度角的时候的运动情况，如图14-(B)所示。 图17表示了机器人在45度角时两种条件下其爬行运动的情况，其运动位置和运动姿态每1秒钟记录一次 ，有控制系统情况下的平均速度为0.138 m/s，没有控制系统时为0.153 m/s。 图17 两种情况下45度角时机器人的运动情况 图18 两种情况下45度角时机器人的姿态角 如图18所示，有控制系统的机 器人其姿态角稳定的保持在43度，而没有控制系统的时候其姿态角增加到了100度。 - 11 - 测试3:擦窗动作 如图19所示，机器人 按照图8所示的运动路径进 行窗户清洗。机器人从窗户 的左下角处出发向上爬行到 左上角处，再沿着窗户边框 水平运动至右上角处，然后 向下移动不大于一个机身的 距离再向左水平移动。在每 一个拐角处，机器人都通过 其特别的转向机制转过正确 的角度保证向着正确的方向 运动。 机器人的运动位置及其 姿态每一秒钟记录一次。 图19 姿态控制器下机器人的擦窗路径与姿态 4.结论 本文主要描述了一种小尺寸，重量轻攀爬式玻璃窗自动清洁机器人。它由一个两轮驱动装置和一个吸盘吸附装置组成。通过吸盘的吸附，使其能在窗户表面上平稳的运动;在窗户转角处，他也能自动的改变行进方向精确的实现转向与清洗。首先，我们对上述清洗机器人原型及其机制和一些特点进行了研究;然后，跟着开发姿态控制系统、自动操作等重要技术并应用到该机器中;最后，做了一些实验记录机器人的运动轨迹以衡量垂直清洗机器人姿态控制系统的性能。根据这些实验结果，我们可以知道机器人的运动时可以控制的，但是机器人的运动轨迹与期望轨迹并不是完全一样的。因为，不仅仅是姿态角，其传动的过程都会使机器人产生误差。为了解决这个问题，我们将必须获得控制这些误差的方法。 - 12 -