Design of Multipoint Weighing in Three-Dimensional Object Center of Mass Measurement System Based on Raspberry Pi

Abstract

Electric motorcycles have a very simple machine construction consisting of a battery, controller and drive motor. The placement of these components affects the center of mass, where all the weight of the motor is centered in one meeting point or motor weight point. The problem of determining the position of the center of mass when converting a fuel motor to an electric motor is one of the things that must be resolved. To solve these problems, a center of a mass measurement system is made using the multipoint weighing method with four load cell sensors, the center of mass of an object can be determined by placing the measuring platform under the object to be measured and the position of the center of mass is obtained from the difference in mass measurements at the four load cell points. Sensor reading data is sent to Raspberry Pi from Arduino nano using serial communication and measurement results are displayed using Node-Red as a user interface. The Mass Center Measurement System was successfully implemented with the multipoint weighing method. The best position for mass measurement by varying the nominal load at the same interval is in the center of the platform with a percentage error rate of 0.00% and a repeatability value of 0.002. The results of testing the center of mass with validated objects obtained the percentage level of error of the measuring instrument below the permissible error limit of 10% and the percentage of success of measuring the center of mass of 95.39%. The measurement results of the motor center of mass before and after conversion obtained the deviation value of the center of mass based on the x coordinate of 2.24 cm, based on the y coordinate of 2.34 cm, and the height of the center of mass has a deviation of 1.53 cm. The position of the motor center of mass after conversion is still within the ideal area.