DEVELOPMENT OF A VERTICAL CYLINDRICAL TANK VOLUME MEASUREMENT SYSTEM USING ULTRASOUND RANGING SCANNER

• Main Author: Sutanto, Willi
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65520
• Institution: Institut Teknologi Bandung

The measurement system developed in this study offers an alternative option in measuring the volume of a vertical cylindrical tank or TUTSIT. In contrast to national methods such as the Strapping method and most optical methods which are carried out outside the tank with limited measuring points, the measurement system is imitating the concept of volume measurement using the 3D laser scanner method. In this system, measurements are done in the tank by scanning the area in the tank using a scanner that can rotate 360o continuously and automatically. The purpose of the scan is to obtain a very large number of measurement points compared to the Strapping and optical methods, although they are still less than the 3D laser scanner method. Unlike the 3D laser scanner, which is a very expensive commercial tool and is used for site and building surveys, this measurement system uses a prototype ultrasound ranging based scanner designed using affordable components. This scanner has main components such as an Arduino UNO R3 microcontroller, three ultrasonic transducers and a DHT sensor. Two ultrasonic transducers (US-1 and US-2) were positioned horizontally and opposite each other to measure the radius while the remaining one transducer (US-3) was mounted vertically downwards to measure the height of the scanner from the bottom of the tank. The DHT sensor is used to detect temperature and humidity conditions during scanning. The scanner is equipped with two spirit buble level that attach to the scanner to ensure scanning is performed in a perfect level position. In addition, to assist in moving the height position during measurement, the scanner is mounted on a tripod stand. To be able to scan by rotating 360o, the US-1 and US-2 transducers are mounted on a bearing mounted support and are connected to the stepper motor through two gears connected by a timing belt. The number of measurement points in one scan is 325 points. Scans were performed at 6 elevation positions at course I and II. Based on the results of the Strapping method, each course has an average height of about 151.10 cm and 152.40 cm with an average diameter of 403.76 cm for course I and 403.65 cm for course II. The purpose of this scan is to obtain inner radius data of the tank. Furthermore, the data will be processed to eliminate gross errors and outliers from the data. After that, the data will be fitted using the RANSAC fitting method to obtain a circular model that represents the cross section in the tank. The fitting results two circle models because the data fitted were done on US-1 and US-2 data separately. In addition to the circle model, the fitting method produces radius and center point of the circle. The radius is used to determine the diameter of the inner circle and the volume of the tank. The measured tank volume is estimated by multiplying the area of the circle using the diameter measured by the height measured by the Strapping method. The measurement error of the scanned tank volume compared to the Strapping method is -558.78 dm3 or about -1.44% for the US-1 scan, -547.46 dm3 or about -1.41% for the US-2 scan, and -599.01 dm3 or about -1.44% for the use of the diameter of the sum of the fitting radii of US-1 and US-2.