Evaluation of motion characteristics using absolute sensors

Abstract

Definition of movement trajectories using absolute sensors is a challenging problem in various application fields due to the appearing additive errors. For the trajectory definition, most often used Inertial measurement units (IMU) consisting of accelerometers, gyroscopes, and magnetometers require the implementation of sensor fusion algorithms and complex data processing. In this research, we investigated the possibility to use cheap 3-axis accelerometer for movement trajectory definition and reproduction. Six degrees of freedom industrial articulated robot was used as a source of ideal trajectories. Obtained results show that using 3-axis accelerometer and relatively simple data processing; raw data mean value offset correction and double integration it is possible to define 2D and 3D trajectories in respect of reference point. In our case, the maximum reproduction error did not exceed 21 mm for, 314 mm length 2D trajectory, and correspondingly 7 mm for the 3D trajectory of the same length. Also, we defined that reproduction errors are proportional to the length of trajectory in the separately taken axis.