Abstract:The complex and variable underwater environment can greatly interfere with the normal movement and perception of underwater information of bionic robotic fish, and the deformation of fins plays a key role in generating propulsive force. However, little research has been conducted on how fins use their sensory information to identify and predict propulsive force. In order to solve this problem, a flexible fish fin-like composite sensor is developed, which based on piezoelectric/piezoresistive dual sensing mode, and produced by integrating a piezoelectric and piezoresistive layer on a flexible sensor, and a method is proposed to predict the propulsive force generated by the fish fin based on the composite sensor. A propulsive force prediction model is established and trained, which is based on BP artificial neural network , and the prediction accuracy of the model is improved by screening and optimizing the input layer date through Pearson correlation analysis. The experimental results demonstrate that the propulsive force prediction is effective and feasible, which based on BP neural network and Pearson correlation analysis for the combination of multiple sensing layers, and also provides a new way to improve the underwater sensing capability of the machine fish.