A fuzzy logic based terrain identification approach to prosthesis control using multi-sensor fusion

This paper presents a fuzzy logic based terrain identification method using multi-sensor fusion for powered prosthesis control. Five locomotion features including rising time of ground reaction force, sequence of foot strike on ground, foot inclination angle during stance, shank inclination angle at toe-off and maximal shank inclination angle during swing are selected to identify different terrains. These features are measured by fusion of two gyroscopes, two accelerometers, two force sensitive resistors and a timer. Based on the features, a fuzzy logic identification method is developed to identify level-ground, stair ascent, stair descent, upslope and downslope online in real time. Average identification accuracy higher than 97.5% is obtained in experiments of five able-bodied subjects and a transtibial amputee. Continuous identification results show the prospect of using the proposed method to realize real-time terrain identification of powered prostheses.