Galvanically isolated gas sensing system for aerospace applications
An aircraft sensing system includes a power and communications module, a sensor module in optical communication with the power and communications module, the sensor module being disposed in an at least partially enclosed space within the aircraft, and at least one gas sensor in communication with the sensor module, the at least one gas sensor being disposed in the at least partially enclosed space. The at least one gas sensor is configured to sense at least one flammable gas species or non-flammable gas species, and the sensor module and the at least one gas sensor are galvanically isolated from the power and communications module.
1 . An aircraft sensing system comprising:
a power and communications module;
a sensor module in optical communication with the power and communications module, the sensor module being disposed in an at least partially enclosed space within the aircraft;
a first gas sensor in communication with the sensor module via a first fiber optic line, the first gas sensor being disposed in the at least partially enclosed space; and
a second gas sensor in communication with the sensor module via a second fiber optic line, the second gas sensor being disposed in the at least partially enclosed space,
wherein the sensor module is configured to condition signals from each of the first and second gas sensors, and to provide voltage isolated regulated power to each of the first and second gas sensors;
wherein the sensor module is configured to intake non-electrical signals from the first fiber optic line and the second fiber optic line, and send an output signal to the power and communications module via optical communication via a single communication fiber optic line; and
wherein the sensor module, the first gas sensor, and the second gas sensor are galvanically isolated from the power and communications module.
2 . The system of claim 1 , wherein the power and communications module is in communication with a power source configured to supply electrical power to the power and communications module.
3 . The system of claim 2 , wherein the power and communications module is configured to convert the electrical power to an optical power signal.
4 . The system of claim 3 , wherein the power and communications module is configured to supply the optical power signal to the sensor module via a first fiber optic cable.
5 . The system of claim 4 , wherein the power and communications module is configured to bidirectionally communicate with the sensor module via at least one fiber optic cable.
6 . The system of claim 3 , wherein the sensor module comprises a photovoltaic power converter for converting the optical power signal to an electrical power signal to power the at least one sensor.
7 . The system of claim 1 , wherein the sensor module further comprises:
a signal conditioner; and
an analog-to-digital converter.
8 . The system of claim 1 , wherein the first and second gas sensors are one of an electrochemical sensor, metal oxide sensor, catalytic bead sensor, and optical sensor.
9 . The system of claim 1 , wherein the at least partially enclosed space is one of a cargo bay, a fuel tank, a gas turbine engine, a cabin, and a cockpit.
10 . The system of claim 9 , wherein the power and communications module is located outside of the at least partially enclosed space.
11 . The system of claim 1 , wherein the sensor module receives only optical signals from the power and communications module.
12 . The system of claim 1 , wherein the first gas sensor is configured to sense a first flammable gas species, and wherein the second gas sensor is configured to sense multiple flammable gas species, all of the multiple flammable gas species different from the first flammable gas species.
13 . The system of claim 12 , wherein the first flammable gas species is at least one of hydrogen, carbon monoxide, and a hydrocarbon gas.
14 . The system of claim 12 , wherein the system is configured to alarm when the first flammable gas species or toxic gas species reaches a threshold concentration.
15 . The system of claim 12 , wherein the system is configured to alarm when a concentration of the first flammable gas species changes at a predetermined rate.
16 . The system of claim 1 , wherein the sensor module is in optical communication with the power and communications module via an optical power line, an optical signal transmission line, and an optical signal receiver line.