| 摘要 |
A heading change unit for a ship's autopilot gyrocompass that provides a heading error signal to produce a proportional rudder control signal. An operator enters a heading change which causes an up/down counter (33, 34) to be incremented or decremented in accordance with the heading change order. The counter (33, 34) is also responsive to a step heading input signal. The counter is referenced to a zero value and converted to an analogue control signal by a digital-to-analogue converter (36). As the ship turns towards the new heading, the changing step heading input will cause the counter (33, 34) to count back to zero. The displayed (48) amount of heading error or ordered heading change is generated by converting the analogue heading error signal to a digital encoded format (30) which controls a display. The heading error signal is generated in the form of a parallel twelve bit binary code which represents integer degree changes and 1/6 degree fractional changes. |
