With recent growth of the economy and development of construction technology, the increase of high-rise buildings is appearing rapidly in urban areas. For this reason, the interest in building maintenance has also been increasing. However, it has many safety problems because it is difficult for the workers to access the exterior wall of building. Therefore, the maintenance system of high-rise building stands out as being important issues to be developed, so that a variety of robot systems have been developed to accomplish the building-wall maintenance works. In this paper, the maintenance robots are classified in painting, inspecting, cleaning systems according to the maintenance works. Then, their locomotion and adhesion mechanisms are analyzed including their applicability to the real maintenance works. This study can be used to develop maintenance robotic system that is more efficient and stable than existing ones.
Maintenance works for current high-rise buildings significantly depend on human labor, unlike other construction processes that are gradually being automated. Herein, this paper proposes robotic building maintenance system using motion control, in specific, reducing a system jerk which is directly subjected to improve the process performance and economic feasibility. The sensor for detecting straight and curvature section of the building facade, moreover rail-joint segment can be detected and be utilized for reducing jerk of the system. Analysis of the proposed system error caused by excessive vibration, e.g. jerk motion is introduced. To enhance the stability and safety of the system, herein, the strategy is proposed for enhancing the performance of the system based on anti-jerk motion control algorithm which comes out increasing the stability and sustainability of the integrated system, as well.
Down through the years, human needs and desires have required a robot system to work at hazardous environments instead. Current painting task is costly and laborious, and it exposes workers to significant health and safety risks. Automation system offers potential improvement in this area and is especially well suited to the outer-wall painting tasks in concrete structures. This paper introduces the result of gondola-type building management robot(G-BMR) platform and mechanism for moving/tasking on building outer-wall for the outer-wall painting. Its technical and economic feasibility are conducted, and it is concluded that developing G-BMR is physically and economically feasible in this research. And we discuss about the future of G-BMR and automation in construction field.
Demand for high-rising building has arisen. However, its maintenance is usually executed by labour. It could have a severe problem. We proposed a gondola robot to solve it. In this paper, we designed a height estimation sensor for this gondola. It is consist of pan-tilt unit, ARS sensor, and laser sensor. The pan-tilt unit keeps the laser sensor to indicate the gravity direction by referencing the ARS. The laser sensor’s range is vertical distance from gondola to ground. However, if there is an obstacle under the gondola, the distance includes its height. To filter it out, we apply a Kalman filter for the height estimation. If the estimated height is changed extremely, the filter decides that there is an obstacle. Then, it remembers the height of obstacle. Other extreme changes of height estimations are reflected. The experimental results using the proposed sensor system show detail flow of the height estimation.
Due to the development of technology, there is a considerable increase in the number of skyscrapers in the world. Accordingly, there are rapid growing requests about maintenances such as cleaning, painting, and inspection. However, it is extremely dangerous working the walls of buildings, and crashes from buildings have accounted for large proportion of constructional accidents. Especially, as the number of buildings with irregular shapes increases, the accident rate during the maintenance work increases each year, and most of the accidents lead to death. An alternative solution must be developed with the commercialization of automatic systems. In this research, a fundamental research has been conducted for drafting and commercializing an automation tool that is carried in the built-in guide system, which can perform cleaning.
In this study, we carried out the each lines of section, using GC (green silicon carbide) whetstone, the SCM415 material which separated by after and before heat treatments process, in 3+2 axis machining centers for integrated grinding after cutting end mill works, the spindle speed 8000 rpm and feed rate 150 mm/min. For the analysis of the centerline average roughness (Ra), we measured by 10 steps stages. Using Finite element analysis, we found the result of the load analysis effect of the assembly parts, when applied the 11 kg’s load on both side of the ATC (Automatic tool change) arm. The result is as follows. For the centerline average roughness (Ra) in the non-heat treatment work pieces, are appeared the most favorable in the tenth section are 0.510 ㎛, that were shown in the near the straight line section which is the smallest deformation of curve. In addition, the bad surface roughness appears on the path is to long by changing angle, the more inclined depth of cut, because the chip discharging is not smoothly.
In this paper, the characteristics of ablation processing of the eagle glass by pico-second laser are investigated. The laser ablation is used to process micro forms on materials. The ablation causes little thermal effect and little burr on the surface of eagle glass. In order to examine the characteristics of panic cracks, experiments are conducted under various cutting conditions such as a frequency of 600 kHz, laser powers, scan speeds and number of scan(NS). To minimize the panic cracks, the specimens are heated at 30℃, 45℃, and 60℃ for ten minutes respectively and then they are broken by hands. Laser powers, NS and scan speeds have an effect on glass cutting results. The ablation depths increase with an increase in the laser power and NS whereas the panic cracks decrease with an increase in scan speed. The high temperature on processed specimens reduces the panic cracks and makes good results of laser cutting. The optimal condition for eagle glass laser cutting is found to be at 30 W of laser power, 3 mm/s of scan speed and 500 of NS, respectively.
A polypropylene film was ablated using a CO₂ laser, Ti-sapphire femtosecond laser, and UV nanosecond laser. For modified atmosphere packaging, polypropylene films were ablated by laser pulse with different pulse energies and measured on an optical microscope. Also, we observed the shelf life of a banana contained within packaging of a breathable zipper bag. As a result, we have demonstrated that the breathable film can efficiently extend the shelf life of respiring foods, particularly fresh fruits and vegetables. The development of breathable film laser microfabrication system will more useful for industrial applications.
We developed inkjet based measurement system for micro-droplet behavior on a substrate. By using the inkjet dispenser, a droplet, which is as small as few pico-liter in volume, can be jetted and the amount can be controlled. After jetting, the droplet image on the substrate is acquired from side view camera. Then, droplet profile is extracted to measure droplet volume, contact angle and evaporation characteristics. Also top view image of the droplet is acquired for better understanding of droplet shape. The previous contact angle measurement method has limitations since it mainly measures the ratio of height and contact diameter of droplet on a substrate. Unlike previous measurement system, our proposed method has advantages because various behavior of droplet on substrate can be effectively analyzed by extracting the droplet profile.
Nowadays in building construction field, workers become aged and avoid dirty, difficult, and dangerous work. Above all, a person who is in charge of beam assembling work in high and narrow space just relies on safety belt. So these workers should be highly trained. This paper deals with a new locomotion robot that can take this in charge, which will be able to provide less labor costs, less time to build a building and safer environments for workers. The geometric features of steel structure in building construction were carefully analyzed and developed a locomotion mechanism optimized to it. The robot was designed to be rugged, strong, and fast rather than having excessive mobility. Feasibility of the developed robot was verified through experiments.
Stair climbing is one of critical issues for field robots to widen applicable areas. This paper presents optimal design on kinematic parameters of a new robotic platform for stair climbing. The robotic platform climbs various stairs by body-flip locomotion with caterpillar type main platform. Kinematic parameters such as platform length, platform height, and caterpillar rotation speed are optimized to maximize stair-climbing stability. Three types of stairs are used to simulate typical user conditions. The optimal design process is conducted based on Taguchi methodology, and resulting parameters with optimized objective function are presented. In near future, a prototype is assembled for real environment testing.
Bending motion has been used in the surgical instruments with bending structures and tendon mechanisms. A simplified bending angle amplification ratio between the proximal and distal bending joint was derived in this article. The bending structure of disk and rib in the proximal joint was analyzed based on finite element method with an emphasis on the circumferential uniformity of bending stiffness. Regarding the distal joint, optimal design and sensitivity analysis was done with four design variables of outer and inner diameter, rib height and rib width while maximizing the deformation under the stress distribution below the yield stress. Outer diameter and rib width are most critical to maximum deformation as the outer diameter and inner diameters are so to maximum equivalent stress.
This study was to compare a domestic comfort shoes to the popular import(SAS<SUP>®</SUP>) to gain a better understanding in biomechanical characteristics for shoe design for the elderly. For each shoe type, morphologic dimensions, shock absorption, and flexibility were assessed. From subjects(n = 20, 72.4±5.5 years, 67.7±7.9 kg), mean peak pressure(MPP) and contact area(CA) at the plantar surface were analyzed. The domestic shoes reflecting anatomic contour of the plantar surfaces of Asians resulted in wider CA(by 30.4 cm²), higher shock absorption(by 2.4%) and stiffness(by 0.5 N/mm) than the import. With the domestic shoes, significantly less MPPs were found at the forefoot(by 42~49%) regions(p < .05) and higher CA was noted additionally at hallux and lessor toes(by 26~63%). More anatomically-contoured insole and favorable mechanical characteristics may help reduce the plantar pressures more effectively and more evenly, especially across the central forefoot and midfoot regions of the plantar surface, especially for the design of the comfort shoes for the elderly.
The aim of this study was to develop and verify gait training system for post-stroke hemiplegia patients with step length asymmetry. Most post-stroke hemiplegic patients show gait asymmetry and weight shifting training has been suggested as a useful method for improving the walking ability. However, verbal cue by physical therapist may be not effective. Therefore, our weight shift training system was designed to give a feedback to patients through precise plantar pressure and center of pressure (COP) measurement. This weight shifting biofeedback training system is composed of F-Scan plantar pressure measurement system and software development kit (SDK) for Windows operating system. Two post-stroke patients with step length asymmetry were enrolled in this study. After training for six weeks, the weight shift score and step length ratio of two all patients were improved and approached to them of non-disabled. This system developed in this study may improve the step length asymmetry, and therefore this system is also expected to improve a walking ability in hemiplegic patients.