Abstract: The present invention provides a communication device and a communication method of an underwater vehicle, which use an electromagnetic field (electromagnetic wave), having a higher propagation speed than that of an acoustic wave, for communication between an underwater vehicle and a mother vessel or the like so as to allow real-time control of the underwater vehicle and the like and further to make the communication little sensitive to noise and the like. The communication device performs wireless communication between an underwater vehicle in water and an object on land or on water, and is configured to compress data to be transmitted and transmit/receive the compressed data by the use of a low-frequency electromagnetic field.

Abstract: The present invention provides a power unit of an underwater vehicle, which allows reduction in size and weight of a transformer for stepping down a power voltage of a power supply to increase a loading amount of a variety of devices with respect to the underwater vehicle, so as to obtain a favorable operating environment. The power unit is connected to the power supply through a cable and receives power through the cable. Further, the power unit comprises an electronic transformer having: a rectifier for rectifying a high-voltage alternate current power of the power supply into a direct current; a high-frequency converter for converting an output of the rectifier into a high-frequency alternate current; a transformer for stepping down an output voltage of the high-frequency converter; a rectifier for rectifying an output of the transformer into a direct current; and a control circuit for controlling the high-frequency converter.

Abstract: The present invention provides a power unit of an underwater vehicle, which allows reduction in size and weight of a transformer for stepping down a power voltage of a power supply to increase a loading amount of a variety of devices with respect to the underwater vehicle, so as to obtain a favorable operating environment. The power unit is connected to the power supply through a cable and receives power through the cable. Further, the power unit comprises an electronic transformer having: a rectifier for rectifying a high-voltage alternate current power of the power supply into a direct current; a high-frequency converter for converting an output of the rectifier into a high-frequency alternate current; a transformer for stepping down an output voltage of the high-frequency converter; a rectifier for rectifying an output of the transformer into a direct current; and a control circuit for controlling the high-frequency converter.

Abstract: The present invention provides a communication device and a communication method of an underwater vehicle, which use an electromagnetic field (electromagnetic wave), having a higher propagation speed than that of an acoustic wave, for communication between an underwater vehicle and a mother vessel or the like so as to allow real-time control of the underwater vehicle and the like and further to make the communication little sensitive to noise and the like. The communication device performs wireless communication between an underwater vehicle in water and an object on land or on water, and is configured to compress data to be transmitted and transmit/receive the compressed data by the use of a low-frequency electromagnetic field.