摘要: |
This paper describes a ship steering system that provides a means to accurately steer a ship along a prescribed track such as a rhumb line, for indefinite distances. This is accomplished by applying frequent heading corrections via a trackkeeping interface to the ship's autopilot, based on best present ship position data (BPP) and the prescribed track. Best present position is obtained from an integrated navigation positioning system. The navigation positioning system computer provides best present position as frequently as required, by integrating position data from land based Loran stations, satellite based GPS, an inertial navigation system and dead reckon aids. The prescribed track usually specified as a rhumb line equation for survey applications generally may be described by any desired mathematical representation. The best present position and the mathematical representation of the track used to compute the off-track distance of the ship from the track. The off-track distance is used to develop proportional and integral heading corrections, which are applied to the autopilot by way of the track-keeping interface. The paper includes system performance results of in-house simulations and shipboard operation.... Command, control and communications, Sonarray shipriders and factory support. |