A Compact Acoustic Communication Module for Remote Control Underwater

Abstract

This paper describes an end-to-end compact acoustic communication system designed for easy integration into remotely controlled underwater operations. The system supports up to 2048 commands that are encoded as 16 bit words. We present the design, hardware, and supporting algorithms for this system. A pulse-based FSK modulation scheme is presented, along with a method of demodulation requiring minimal processing power that leverages the Goertzel algorithm and dynamic peak detection. We packaged the system together with an intuitive user interface for remotely controlling an autonomous underwater vehicle. We evaluated this system in the pool and in the open ocean. We present the communication data collected during experiments using the system to control an underwater robot.

Exploration of underwater life with an acoustically controlled soft robotic fish

“…The chosen parameters support 2048 distinct messages with a data rate of one message per second at 20 bits/s. Further details on the algorithm can be found in (12).…”

“…How ever, the robot had limited thrust, could not withstand compression at depths of more than a meter, was not able to adjust its buoy ancy autonomously, and had no mechanism for underwater remote control and communication with a human diver. This paper also builds on our acoustic communication modem documented in (12), presenting its integration into SoFi and evaluating its ability to enable real-time interactive oceanic exploration. SoFi integrates and extends these previous works, achieving untethered swimming and remote control at a range of depths in complex environments.…”

“…Thus, we implemented a new low-power, low-cost, software-defined acoustic modem, represented schematically in Fig. 8 on the right and described in detail in (12).…”