2011 IEEE Conference on Sustainable Utilization and Development in Engineering and Technology (STUDENT) The University of Nottingham, Semenyih, Selangor, Malaysia. 20-21 October 2011.
A Semi-Automated Floor Tiling Robotic System *
M. K. A., Ahamed Khan, K. I. Saharuddin
I. Elamvazuthi, P. Vasant
Univesiti Industri Selangor Kampus Bestari Jaya, Jalan Timur Tambahan Selangor Darul Ehsan *
[email protected]
Universiti Teknologi PETRONAS Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan
Abstract—This paper discusses the configuration of a semi-
automated robotic tiling system for floor-tile installation of residential and commercial buildings. The research is motivated by the need to reduce the human fatigue, installation time, cost and while maintaining consistent quality. The technical solution that is deemed feasible and capable of addressing the above mentioned issues is an electrically-powered semi-automated robotic system with omni-directional locomotive capability. The design parameters and system performance are discussed.
II.
TILING PROCESS
The manual tiling involves several processes such as preparing the surface, preparing the tiles, laying the tiles and completion of installation. The process flow is shown in Figure 1 and illustrated in Figure 2.
Keywords: robotic system, floor tile, design parameters, system performance
I.
INTRODUCTION
Robots have been used in a vast range of industries for many different applications such as assembly, cutting, deburring, grinding, polishing, handling, palletising, sealing and gluing, spraying, painting, coating, welding, etc. However, its use in construction has been very limited due to various limitations such as unstructured, dynamic nature of the construction site, the hazards and difficulties presented by temporary works, weather. In the case of buildings, the development of a systematized approach to construction using largely dry, prefabricated components delivered just-in-time has advanced the degree of automation [1-2]. The literature has shown that there is limited use of robots in the construction sector, especially in the tile installation as indicated in [3-9]. It revealed that the use of vision systems and autonomous navigation have not increased productivity substantially. In addition, not much information could be gathered on the use of technology and the overall cost. The current floor tiles installation process that is carried out by skilled human installers has many shortcomings such as human fatigue, low productivity and too time consuming [10]. In view of this, a study was carried out to minimise or to overcome the problems. The main objective of study was to design and develop a semi-automated prototype system for installation of floor tiles. The rest of the paper is organized as follows: Section II discusses the manual tiling process, followed by the description of the system design in section III. Analysis and discussion is provided in section IV, and finally conclusions are drawn in section V.
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Figure 1. Flowchart of installation process
(a)
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statement of what design must achieve or accomplish. These requirements provide designers with working tools and guidance throughout the design process. There are two sources of information for functional requirements. An external source includes customer specifications, industry standards, and product feedback; and an internal source includes marketing, sales requirements, and product development requirements [1112]. For this study, external source, i.e., the plant survey provided the input for functional requirements specifications. The system requirements are presented in Table I. (b)
TABLE I.
Specifications Tiling productivity System affordability Operation of Machine Assembly of Machine Troubleshooting Components (c)
(d) Figure 2. Floor tiles installation process
At the ‘preparing the surface’ process (as shown in figure 2(a)), old floor covering or paint is removed and the surface is cleared of dust and loose particles. If a waterproof membrane or other backing surface is required, it is installed. Then, at the ‘preparing the tiles’ process (as shown in figure 2(b)), to ensure even shading, tiles from different cartons are mixed. Next, at the ‘Laying the Tiles’ process (as shown in figure 2(c)), mortar or adhesive is applied and combed with a notched trowel over one area at a time. Tiles are individually pressed in place and beaten in with a rubber. At the ‘the finished installation’ process (as shown in figure 2(d)), heavy traffic should be avoided on newly tiled floors for three to four days following installation to prevent any loosening or dislocation of the tiles. This then completes the floor tiles installation process. III.
FUNTIONAL REQUIREMENTS
Description should be able to achieve double the current productivity should be cheap and affordable by contractors user friendly and easy to use ease of assembly maintenance of the machine should not be complicated should be sourced locally
Based on the functional requirements outlined in Table I, the tiling robot does not need to be autonomous, as it is not the intention to make tillers superfluous, but to assist them. Requiring the robot to be capable of doing everything, including edges and other difficult jobs, will increase complexity and cost price in a non-proportional way. For this reason, the tiling robot will tile the large areas but leave the edges and difficult niches to be tiled manually by a skilled tiler. Furthermore, at this stage, the robot is being supplied with assessed tiles by an (assistant) tiler. A future possibility is appending the robot with an on-board tile assessment system. Even the extension to an autonomous robot could be possible as indicated in [13]. The semi-automated system was designed and developed as per the above mentioned requirements. Figure 3 shows the overall view of the system. It comprises of mechanical and control subsystems.
SYSTEM DESIGN
Functional requirement specification is a resource for what the product must be able to accomplish when it is completed. It generally refers to the broad needs and wants of the entity as well as the users of the product. They represent an overall
Figure 3. System configuration diagram
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The mechanical sub-system comprises of 6 major parts; namely, frame, control panel, compactor, tile loader, shaft conveyor and tile tray. The loader loads tile on the conveyor. (as shown in Figure 4 (a)), the conveyor moves the tiles to the tile tray (as shown in Figure 4 (b)), and the tile tray that lays down the tiles on floor (as shown in Figure 4 (c)).
IV.
ANALYSES AND DISCUSSION
Typically, ceramic floor tiles comes in various sizes such as 20 cm x 20 cm, 30 cm x 30cm, 40 cm x 40cm and 45cm x 45cm. In this project, 30 cm x 30 cm tiles were used. The semi automated robotic system for the installation of floor tiles focused mainly on how the tiles can be laid down on the floor with accurate position with the other tiles. Several analyses have been done. Figure 5 shows the sketch of the inclination of tile tray. Represents as tile tray
Certain degrees (a)
Figure 4. Tile try with angle inclination
The results of the experiments are shown in Table II. Factors such as speed, force and resistance were taken in considerations in the experiments. These factors play an important role in ensuring that the Tile tray can be laid down accurately with the other tiles. TABLE II.
(b) Degree 30 50 60
Speed Slow Fast Faster
PARAMETERS
Parameters Force Resistance High High Moderate Moderate Less Less
From Table II, it can be seen that at higher degree of inclination, the speed of the tile increases, and as a result, the tile will safely lay down on the floor in accurate position. Several trials were conducted to compare the productivity of the prototype system to human labour. The results are tabulated in Table III. TABLE III. Performance comparison (c)
Tasks
Figure 4. System configuration illustration
The control subsystem comprises of three major parts; namely, control panel, junction box and external components. The control panel contains switches, whereas the junction box contains relays, and the external components are DC motors.
Lay down one tile on the floor Compacting tile on the floor Movement to the next Tile Total time taken
Tiling Manual Machine Tiling (in seconds) 3 5 4
6
7
8
14
19
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From Table III, it could be found that the Robotic System performed better than manual tiling. Although, Table IV gives an overview of permissible tolerances in joint-width of tiles, the average tiling quality is still assessed visually. TABLE IV. Alignment Tolerance for Average Tiling Quality [13] Tile
Description Deviation of the adjoining tiles w.r.t. the tiling grid
Standards < 1.5 mm
Divergence of a row of tiles w.r.t. the tiling grid Divergence of the joint width over a length of 2 m
< 3.0 mm/m and overall
