Vehicle condition monitoring system

#This invention relates generally to vehicle maintenance systems and, more specifically, to data acquisition relating to vehicle condition.

#Total life cycle costs for vehicles includes costs for operating and maintaining the vehicles. In many instances, vehicles must be inspected before maintenance can be performed on the vehicles.

#A significant portion of the cost of inspecting vehicles, such as aircraft, for corrosion, stress or other damage is associated with obtaining access to hidden parts of the vehicle's structure. For example, for a 747-400 commercial transport aircraft over 36,000 labor hours are spent inspecting the aircraft for fatigue cracks and corrosion. Of these, 25,000 hours are spent inspecting for corrosion. Over 21,000 hours or 84% of these hours are spent gaining access to hard to inspect areas, and only 16% or 4000 hours are spent doing the actual inspection. In addition, added costs are associated with incidental damage that may be inflicted upon the structure while gaining access to hidden areas.

#The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.

#FIG. 1 illustrates components of the present invention implemented in an aircraft;

#FIG. 2 illustrates the components of a data acquisition unit implemented within a vehicle; and

#The present invention provides a system and method for acquiring vehicle condition information in a non-intrusive, efficient manner for allowing damage and usage analysis. As shown in FIG. 1, a condition data acquisition system 20 is located in a vehicle 21 and includes one or more sensors 22 electrically or optically coupled to a data acquisition unit 26. The sensors 22 generate electrical or photonic signals that reflect a condition in which the sensors 22 were designed to detect. The data acquisition unit 26 acquires the electrical or photonics signals from the sensors 22 and processes the received electrical or photonics signals for analysis by a structural condition management system 30 that is external to the vehicle. The data acquisition unit 26 may perform some diagnostic or prognostic preprocessing of the received signals based on the type of signal received and a predefined test to be performed on the received signals. It will be appreciated that the structural condition management system 30 is a system that is presently used in many vehicle continued maintenance programs, such as that used in the airline industry. The present invention provides an electrical or wireless connection between the data acquisition unit 26 and the structural condition management system 30 for allowing the delivery of the sensed electrical or photonics signals from the data acquisition unit 26 to the structural condition management system 30. It will be appreciated that the vehicle can be an aircraft, spacecraft, launch vehicle, seaborne or undersea vessel, or ground-based vehicle.

#A number of digital signal processing algorithms are available to be coded into the data acquisition unit 26 to perform functions such as filtering and data compression, Fourier transforms, power spectral density calculations on dynamic data, and diagnosis of the sensed structural component such as fatigue life and usage, overload conditions and environmental exposures, etc. The structure condition management system 30 is a computer system such as a laptop or personal computer that takes the sensor data and the coded processing algorithms and performs additional diagnostics assessments of the structural condition (health). The structure condition management system 30 includes prognostics algorithms that assess the current state (health) of the vehicle 21 to predict the condition at some future time given some assumed loading, usage, scenario, or environmental exposure. The prognostics algorithms can include crack growth or strain-life models, corrosion damage predictive models, or other residual strength and life predictive models. The structure condition management system 30 then stores the data in a format specified by vehicle maintenance personnel for the purpose of planning future maintenance actions.

#Some of the sensors 22 are prepositioned in the vehicle in hidden locations that would require physical deconstruction of the vehicle for proper condition inspection to be completed using known inspection methods. [This refers to prior inspection methods] The sensors 22 are suitable off-the-shelf micro-electromechanical devices (MEMS), or extrinsic Fabry-Perot interferometric (EFPI), long-period grating (LPG), and fiber Bragg grating (FBG) fiber optic sensors. The sensors 22 suitably include corrosion, humidity, pH, chloride ion (Cl−), metal ion, temperature, acceleration, stress, strain, pressure, load, and force sensors. Fiber optic sensors are relatively tolerant or immune to the effects of high-temperature, high-electromagnetic interference (EMI), and highly corrosive environments. In one non-limiting example, the sensor is an LPG fiber optic moisture sensor that is located in areas of a vehicle where water can pool or cause problems, such as under floors of lavatories and galleys, inside insulation around doors, and in bilge areas.