Energy consumption evaluation of a lower limb active orthosis using stochastic analysis

摘要

This work presents an method to estimate the usage of energy consumption over time in electric actuators of an active orthosis, based on the concepts of stochastic processes. The presented method can be also applied in actuators of robotic manipulators. Active orthosis are robotic devices that assist people with some degree of the spinal cord injury. Active orthoses generally control the hip and knee joints movements through mechanical and electrical actuators. In some cases the device give the user the ability to select any desired movement, such as walking, sitting and standup, up and down stairs. For the most efficient execution of these movements it is important to analyse the evolution or estimate the energy consumption. For this, a board with Hall effect current sensors was used to acquire the data measured at each instant of the actuators. In addition, it is necessary to observe how energy is distributed in the frequency domain, and how its spectral density analysis is performed. The proposed work reinforces the importance of energy consumption analysis of rotational electric actuators that are responsible for driving the joints movements of lower limbs active orthosis.