Battery-free underwater navigation system developed by MIT

MIT has developed a new navigation system for underwater use. This system is intended to realize the direction guidance of GPS on the ground and in the air in the water.

GPS rarely touches underwater. Electromagnetic waves and water do not work well. That’s why submarines use sonar and the like. Sonars measure reflections from the seabed and other underwater objects that emit sound waves. However, voice signal methods including sonar generally consume a lot of power. Therefore, there is great potential for a battery-free system developed by MIT.

GPS is a power-efficient system that has greatly changed the way it travels from car navigation to smartphone maps. A limitation of current underwater navigation technology is the need for a large, fast-consuming battery pack to drive a sound wave generating and transmitting device. The new battery-free voice navigation system using the MIT system does not produce sound directly, but uses ambient signals.

The piezoelectric materials used by the system are subjected to mechanical stress to generate electric charges. Stress arises from the impact of sound on the material. The research team squeezed out a method of converting sound wave information into a binary code at the center using piezoelectric materials and used it to measure the surrounding seawater temperature and salt content, but it was theorized that it was used for positioning.

Of course, it’s not as easy as you might think. Because sound can return from unexpected angles reflected from various underwater surfaces. However, the research team coped with this problem with a method called frequency hopping and collected information over a wide range of wavelengths. As this works in the deep sea, the research team is working on ways to increase efficiency even in shallow water noise environments. In addition, based on the same technology as this system, in the future version, the goal is to improve the efficiency of submarine mapping by future robotic exploration submarines, and enable all automatic monitoring and underwater navigation. Related information can be found here .