US 5,377,109 A · Failsafe digital bus to analog protocol converter system

Abstract

A failsafe avionics interface unit serves as a protocol converter system for translating data for control purposes from a digital communication bus to an analog control channel as an upgrade or interface to an existing analog control system. The avionics interface unit includes digital interface bus logic, a digital data processor module, an analog interface, and a mode selection circuit. Data communicated over the digital interface bus is periodically translated into equivalent analog control signals. For safety purposes, the avionics interface unit ensures the integrity of the system by repetitively looping back or wrapping the digital equivalents of the analog output signals and comparing them to commanded digital control values. The protocol converter system additionally monitors communications over the digital data bus for data continuity. If the difference between a wrapped digital equivalent of an analog output signal and an expected value exceeds tolerable limits or if communication fails, the system disconnects its interface from control using redundant software and hardware and returns control to the analog control system.

Claims45

Dependent claims

A protocol converter system comprising:

a digital interface circuit which is adapted for connection to a digital data bus, the digital interface circuit receiving flight control information from the digital data bus and operating in response to the received flight control information to output at least one first digital flight control signal representing the received flight control information;
an analog interface circuit coupled to receive at least one second digital flight control signal from a digital data processor, the analog interface circuit operating in response to each received second digital flight control signal to generate and output an analog flight control signal commanding an aircraft analog flight control computer to execute a maneuver commanded by the received second digital flight control signal;
and
the digital data processor coupled to receive the at least one first digital flight control signal from the digital interface circuit, the digital data processor generating and outputting in response to each received first digital flight control signal one of the at least one second digital flight control signals representing the flight control information represented by the first digital flight control signal.

1 more element

A protocol converter system comprising:

a digital interface circuit which is adapted for connection to a digital data bus, the digital interface circuit receiving from the digital data bus flight control information generated by a digital avionics computer and operating in response to the received flight control information to output at least one first digital flight control signal representing the received flight control information;
an analog interface circuit coupled to receive at least one second digital flight control signal from a digital data processor, the analog interface circuit operating in response to each received second digital flight control signal to generate and output an analog flight control signal commanding an aircraft analog flight control computer to execute a maneuver commanded by the received second digital flight control signal;
and
the digital data processor coupled to receive from the digital interface circuit the at least one first digital flight control signal generated by the digital avionics computer, the digital data processor generating and outputting in response to each received first digital flight control signal one of the at least one second digital flight control signals representing the flight control information of the first digital flight control signal.

1 more element

A protocol converter system coupled between at least one digital data bus and an aircraft analog flight control computer, the at least one digital data bus communicating with a digital avionics computer, the protocol converter system comprising:

a digital interface circuit which is adapted for connection to the at least one digital data bus, the digital interface circuit receiving from said digital data bus flight control information generated by a digital avionics computer and operating in response to the received flight control information to output at least one first digital flight control signal representing the received flight control information;
an analog interface circuit coupled to receive at least one second digital flight control signal from a digital data processor, the analog interface circuit operating in response to each received second digital flight control signal to generate and output an analog flight control signal commanding an aircraft analog flight control computer to execute a maneuver commanded by the received second digital flight control signal;
and
the digital data processor including a nonvolatile memory which stores instructions received from the digital data bus, the digital data processor executing the instructions stored in the nonvolatile memory, the digital data processor being coupled to receive from the digital interface circuit the at least one first digital flight control signal generated by the digital avionics computer, and the digital data processor generating and outputting in response to each received first digital flight control signal one of the at least one second digital flight control signals representing the flight control information represented by the first digital flight control signal.

1 more element

a digital interface circuit which is adapted for coupling to the at least one digital data bus, the digital interface circuit receiving over said digital data bus avionics information generated by the digital avionics computer and operating in response to the received avionics information to output at least one first digital flight control signal representing the received flight control information;
an analog interface circuit coupled to receive at least one second digital flight control signal from a digital data processor, the analog interface circuit operating in response to each received second digital flight control signal to generate and output an analog flight control signal commanding an aircraft analog flight control computer to execute a maneuver commanded by the received second digital flight control signal;
the digital data processor coupled to receive from the digital interface circuit the at least one first digital flight control signal carrying the flight control information generated by the digital avionics computer, the digital data processor generating and outputting in response to each received first digital flight control signal one of the at least one second digital flight control signals representing the flight control information of the first received digital flight control signal;
and
an analog sample circuit coupled to receive at least one analog wraparound signal provided by the aircraft analog flight control computer and coupled to the digital data processor, the analog sample circuit converting each received analog wraparound signal to a digital value and communicating the digital value to the digital data processor, the digital data processor storing each digital value and communicating each digital value to the digital data bus for communicating to the digital avionics computer in response to a request received from the digital data bus.

2 more elements

An avionics system comprising:

a digital data bus;
a digital avionics computer coupled to communicate over the digital data bus, the digital avionics computer providing digital flight control information and receiving digital representation of analog wraparound signals generated by an aircraft analog flight control computer;
a protocol converter system that is coupled to communicate with the digital avionics computer using the digital data bus, the protocol converter system receiving digital communications from the avionics computer and translating the received digital communications into at least one analog flight control signal representing the received digital communications, the protocol converter system sampling and storing digital representations of analog wraparound control signals generated by the analog flight control computer and communicating upon demand by the digital avionics computer these digital representations of analog wraparound control signals over the digital data bus;
and
the aircraft analog flight control computer coupled to receive at least one analog flight control signal from the protocol converter system, the aircraft analog flight computer operating in response to each received analog flight control signal to generate two identical analog flight control signals, wherein the first said analog flight control signal is coupled command a mechanical actuator to execute a commanded maneuver and the second analog flight control signal is the analog wraparound signal that is received by the protocol converter system.

2 more elements

Dependencies are inferred from the claim text.

Failsafe digital bus to analog protocol converter system

Life of this patent

Failsafe digital bus to analog protocol converter system

Life of this patent

Abstract

Claims45