Abstract
A flexible optical intensity sensor is designed in this study to address the poor adaptability of fixed-value parameters in exoskeleton research, which makes it difficult to handle system changes and uncertainties. The light transmission portion of the sensor is made of TPU and PET, exhibiting flexibility and bendable deformation characteristics, as well as good sensitivity, anti-interference capability, and stability. The flexible optical sensor is fixed on the side of the binding device, which is installed on the biceps brachii to collect the optical intensity loss signals after sensor bending. By utilizing this method, parameters such as the cross-sectional radius, arm centroid, and moment of inertia can be estimated in real-time. Finally, the estimated radius values are compared with theoretical values, and the accuracy is verified by combining the kinematic model. Experimental results demonstrate that the proposed method achieves a parameter information error of less than 8.63% and a stability better than 4.3%. Compared to the traditional fixed parameter method, the stability has improved by 25.06%, and the accuracy has improved by 9.04%.
