Navigation support system for electric boat

Abstract

The electric boat named "RAICHO-I" has been developed by Tokyo University Marine Science and Technology. The possible cruising time of this boat is still short compared with conventional same size boats. Currently, the operator has to estimate empirically the possible cruising time from weather (wind direction and power), state of waves (wave height and tide), voltage and State of Charge (SOC) of batteries. The situation of battery loss has to be avoided from the view point of operational safety. In order to solve this problem, a Navigation Support System (NSS) that has the following 2 functions is developed. 1) The recommended speed and possible cruising distance are calculated and displayed by using information such as the desired cruising distance and time, SOC etc. 2) The output power (motor and invertor output power) can be restricted automatically when SOC is not enough to achieve the desired operation. In this paper, in order to realize these functions, the estimation algorithm based on the analysis of the actual cruising data, the motion characteristics of ship and the battery discharge characteristics is derived. The prototype of the display system for boat operators is proposed. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).