Abstract
In this research, we propose a method or a device which can detect the correct position of the gravity center of a lifted object. This method uses four strain sensors to measure the tensile strains of four wires for estimating the gravity center quickly and automatically. However, due to the different lengths of four wires and different sensor behaviors, it is difficult to identify the correct location of the gravity center. This problem is overcome by proposing a new method to calibrate the measured data. First, the correction factors of the four strain sensors are obtained by a trial test in which the gravity center is located at the center of the lifted object Then, these factors are applied to correct the measured strains in practical cases where the center of gravity deviates from the center of the object
