A Novel Control Method of A Soft Exosuit with Plantar Pressure Sensors

Abstract

Soft Exosuit is a kind of Lower-limb wearable robots to augment and assist the wearer's performance. Recently, our team developed a cable-driven wearable robot named SIAT Soft Exosuit (SSEX) which can transmit assistive force to wearer's body. Natural gait feature extraction is the key to control a Soft Exosuit. In this paper, we propose a method to obtain the gait feature by plantar pressure sensors which measure the force load on a shoe insole. The system can detect the gait event accurately and reliably in real time which is the onset time of assistance for hip extension. Then we use IMUs to get the hip joint angle during hip extension which can help us calculate the variation of cable length and motor position profile. There are also two load cells in our system to make a feedback and get us desired assistant force. To achieve a desired active force, the control system adapt a way based on learning iterative control.