Browsing by Author "Wanniarachchi, WKIL"

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    Development of a low-cost automated micro dispense digital goniometric device with drop shape analysis
    (IEEE, 2018-05) Senarathna, RMDM; Wanniarachchi, WKIL; Jayawardhana, S; Rathnaweera, DR; Chathuranga, D
    Accurate measurement of contact angles can define fluid dynamics, surface material properties and contribute to the development of micro/nanofluidic devices. The drop shape analysis technique was developed to accurately determine the contact angle and surface tension of a liquid drop on a solid surface. The technique involves capturing a reflected image of the drop profile, acquiring coordinate points along the contour and finding the mathematical best-fit accordingly. Many conventional equipment utilizes this method through manual acquisition and analysis of data. This is an arduous, time consuming task which can introduce inaccuracies. Nevertheless, partially automated equipment can be prohibitively expensive. Here its shown that by utilizing embedded system development techniques, both the imaging and profile analyzing tasks as well as the liquid dispenser can be automated and precisely controlled by a computer application at a fraction of the cost of a commercial unit. The developed system also facilitates sample stage tilting which can provide information on dynamic liquid profiles to determine advancing and receding contact angles. Importantly the device is capable of dispensing and analyzing less than 5 nl volumes of liquid. Such measurements are becoming increasingly important in the understanding of areas such as superhydrophobicity and microfluidic devices.
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    Vision based office assistant robot system for indoor office environment
    (Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa, Sri Lanka, 2018) Diddeniya, SIAP; Adikari, AMSB; Gunasinghe, HN; De Silva, PRS; Ganegoda, NC; Wanniarachchi, WKIL; Wijesiriwardana, CP
    This paper presents an office assistant robot that can be used in an unstructured indoor office environment. Among many technologies available, we used free and open source software and inexpensive sensors and materials to build the low cost but accurate robot. Robotic Operating System (ROS) indigo was used as the ground operating system on Ubuntu 14.04. The mobile robot, iRobot Create 2 was used as the basic robot and a structure was built to carry a mini-laptop and PrimeSense 3D vision sensor. A workstation computer was used as the central location PC which was kept still and map of office environment is built on it. User is able to give commands to the system via voice and virtual keys by the developed Android application (App). These three units, mobile robot, central workstation and Android devices, communicates through a Wi-Fi connection. The proposed robot could deliver documents or parcels in between office members according to the user commands. We allowed the robot to navigate autonomously and randomly between users and monitored its accuracy by looking at the completion of the route to a target user. Results show that the office assistant delivery robot has above 92% of accuracy in delivery process for a valid user input.