Abstract: A marine vessel steering system having a bus to which an autopilot interface unit (AIU) containing an autopilot function is coupled. The system having at least one steering location at which autopilot function controls are positioned and coupled through a cable (bus) interface unit (CIU) to the bus for communication with the AIU. In the event that more than one steering location seeks access to the bus, priority is established by an arbitration procedure between data frames transmitted from each steering location. A manual steering unit, such as a helm, is positioned at the main steering location and directly coupled to the AIU, wherein a switch selects between autopilot function rudder control and helm rudder control. Miniwheels, which operate in a manner similar to that of a helm, are positioned at steering locations remote to the main steering location which communicate with the AIU to switch between autopilot function control to miniwheel control.

Abstract: A marine vessel steering system having a bus to which an autopilot interface unit (AIU) containing an autopilot function is coupled. The system having at least one steering location at which autopilot function controls are positioned and coupled through a cable (bus) interface unit (CIU) to the bus for communication with the AIU. In the event that more than one steering location seeks access to the bus, priority is established by an arbitration procedure between data frames transmitted from each steering location. A manual steering unit, such as a helm, is positioned at the main steering location and directly coupled to the AIU, wherein a switch selects between autopilot function rudder control and helm rudder control. Miniwheels, which operate in a manner similar to that of a helm, are positioned at steering locations remote to the main steering location which communicate with the AIU to switch between autopilot function control to miniwheel control.

Abstract: A ship steering system has a multiplicity of selectable steering stations. A continuously rotating helm at each steering station generates digital rudder control signals which cause a predetermined rudder movement for each 360.degree. of helm rotation. Steering stations are selected through a multiplexer controlled at a command steering station. The steering system is operable from the command steering station in a plurality of modes, which includes auto-pilot, helm (full-follow-up), and tiller (non-follow-up). Helm and/or tiller modes of operation are available at steering stations remote from the command steering station. The system provides for an emergency takeover from the helm or autopilot modes by automatically establishing the tiller mode when the tiller stick is moved. When in the autopilot mode an alarm system provides an alert should the course deviate from a selected course tolerance.

Abstract: A digital mapping display system for an aircraft wherein map data from a mass memory unit is periodically loaded into RAM in the form of a cache memory in accordance with the aircraft trajectory. The cache memory is randomly addressable within the physical address space of a control processor, individual segments of the cache memory being loaded with map data and updated while other segments are being displayed, thereby avoiding the inherent delay of accessing the mass memory unit and addressing the entire RAM array. Parallel processing of map data and symbology facilitate a real-time display.

Abstract: A contour line generator for identifying and displaying real time elevation contour lines for use with a moving map display. A plurality of data points neighboring a selected data point are compared to determine the presence or absence of a contour line. An average elevation is computed and applied to address a contour memory, having stored therein the elevations at which contour lines are desired to be displayed. The resultant logic signals are applied dynamically to override normal display data when a contour line is to be generated. The system provides programability for flexibility in modifying contour line intervals.