Design, Manufacture, and Testing of a Low-Cost Force Platform with 3-Axis Load Cell

Abstract

Abstract Force platform is an instrument to measure Ground Reaction Force (GRF) and locate Center of Pressure (CoP) in motion analysis. Although it is very useful, the cost of the commercially available force platform is relatively high. Therefore, the objective of this work is to develop a low-cost force platform with 3-axis load cell. The development was initiated with Design Requirement and Objective (DR&O) of the force platform. To measure the force, four 3-axis loadcells were placed in each corner of the force platform to measure a maximum force of 1500 N. The dimension of the aluminum 5058 force platform was 500 x 500 mm. After the manufacturing process, the force platform was calibrated to obtain 12 correction factors for the four loadcells in the three-axes. It was obtained that the RMSE of the correction factors was 0.87% in z direction and lower than 2% for x and y direction of GRF. The CoP was also tested to ensure the functionality of the developed force platform. The RMSE errors for the CoP were 5 mm and 5.9 mm in x and y coordinates, respectively. With relatively small RMSE, the force platform could be used to obtain GRF and locate the CoP in gait analysis.