Abstract: A network architecture (100) that supports periodic and aperiodic data transmissions over a network databus. The network (100) comprising a plurality of Network Interface Controller (NIC) modules (120, 169) configured to communicate with each other with at least one of the modules acting as a master NIC modules (120) and configured to allocate data transmission bandwidth on the network databus (114) using a set of priority sequences stored in a table (158) accessible by the master NIC (154) within the master timing NIC module (120). The table (158) is used by the master NIC (120) to allocate bandwidth on the network databus (114) after transmission of periodic data and according to priority, length and frame sequence. In this way, aperiodic data from some NIC modules is guaranteed a certain amount of bandwidth on the network databus (114).

Abstract: A communications system capable of providing enhanced data integrity and reliability through redundant buses, and a network interface controller for use therewith. Redundant conductors conforming to well-known ethernet standards interconnect electronics components. Each component communicates with the conductors through a single network interface card (NIC). Each NIC comprises an ethernet compliant transceiver for each ethernet conductor in communication with the component. Microcontrollers embedded in each NIC synchronously and deterministically place data on the ethernet conductors according to a timing scheme stored in a non-volatile memory means. A heartbeat/power monitor is also provided to ensure that data cannot be transmitted in the event of a microcontroller failure. The communications system provides a high degree of redundancy and fault-tolerance and is therefore well-suited to critical applications in avionics communication.

Abstract: A self adaptive limiter for use in aircraft control systems during approach and landing is disclosed. Estimated flight path angle is continuously computed during the glidepath tracking phase until a predetermined lock altitude above ground when a nominal flight path angle is latched. Nominal vertical speed is continuously computed below the lock altitude as a function of the latched nominal flight path angle and ground speed of the aircraft. A vertical speed limit function is generated as a function of the nominal vertical speed and radio altitude. During approach and landing a pitch limit is computed from the vertical speed limit, vertical speed, ground speed, and pitch. When a pitch command to the autopilot exceeds the pitch limit(i.e. commands excessive pitch down attitude), it is limited to the pitch limit thus preventing the aircraft from descending below a safe altitude.

Abstract: An aircraft control system improves system flexibility, scalability, redundancy, and separation. The system uses a "virtual backplane" architecture which maximizes system flexibility and scalability and allows easy integration of new functions. The architecture comprises four major elements: processing modules; input and output modules (i.e. I/O modules); database modules; and an aircraft wide system network. Inter module communication occurs via the aircraft wide system network thereby eliminating the need for point to point communication and making modules independent of physical location or what modular units (MUs) they are in. Predetermined periodic and deterministic broadcast techniques improve the safety and communications efficiency of the system.

Abstract: An apparatus for providing asymmetrical torque-switching for an aircraft autopilot. The invention provides an increased amount of available pitch servo torque at high altitude. The direction of pitch of the aircraft is sensed. An increased amount of torque is provided for the pitch-up direction thereby providing more positive control of the aircraft.