Experimental Investigation of a New Wake Monitoring Method Based on Underwater Thermal Tactile

The intrusions of unauthorized underwater vehicles and ships have a negative impact on marine protected areas. Therefore, it is necessary to develop monitoring methods to reduce the occurrence of illegal intrusions. This research creatively proposes a thermal tactile wake sensing method based on the micro-thermoelectric generator for monitoring the wake of underwater moving objects. The wake monitoring theory model based on the mechanism of the thermoelectric generator is established, and a sensor prototype is designed. Experimental studies are conducted in specific orientations to verify the feasibility of this method in identifying the orientation of underwater moving objects. The experimental results indicate that when the underwater propeller passes by the prototype, the conclusion drawn from comparing the output voltages of the thermal tactile units on different surfaces of the prototype aligns with the theoretical model. In addition, a comparative experiment between the propeller and fish is conducted. The experimental results show that when the propeller speed is 200 r/min and the forward velocity is 0.1 m/s, the prototype can distinguish between the wakes of the above two types of underwater moving objects within 20–30 s. By combining the results of both types of experiments, it is demonstrated that this method can identify the orientation of underwater moving objects by sensing their wakes while excluding interference from the wakes of fish. The thermotactic wake sensing method proposed in this research has great potential for application in marine protected areas.