The present invention relates to diagnostic engine data, and more specifically, the storage and retrieval of diagnostic engine data.
Engine controllers employed on aircraft store diagnostic data such as oil levels and various temperature readings to be later retrieved and analyzed for maintenance purposes. Typically, the diagnostic data is stored to non-volatile memory that preserves the data without a constant supply of power. However, power is required to retrieve the data from the non-volatile memory. In prior systems, a ground-based computer such as the Common Engine Transfer System (CETS) computer would be connected to the engine controller and an external power supply (such as a battery) provides power to the engine controller normally provided by an internal power source.
A method is provided for storing and retrieving engine data in an electronic engine control system that includes a processor, a data controller, and a non-volatile memory. During an engine operation, power is supplied to the processor, the data controller, and the non-volatile memory from an engine power source. Sensor data is received at the processor. The sensor data is supplied to the data controller for storage in the non-volatile memory. During data retrieval, power is supplied to the data controller and the non-volatile memory from a USB communications channel. The data controller retrieves the saved sensor data from the non-volatile memory and the sensor data is provided to the universal serial bus (USB) communications channel.
In another embodiment, an electronic engine control has a processor, a non-volatile memory, a USB communications channel, data controller, and a computing device. The processor is adapted to receive engine data from engine sensors. The non-volatile memory is adapted to store engine data. The data controller is adapted to receive engine data from the processor and provide the engine data to a non-volatile memory. The data controller is further adapted to retrieve the data from the non-volatile memory and provide it a USB communications channel. The computing device is connected to the electronic engine controller and configured to receive engine data from the USB communication channel. The data controller and the non-volatile memory are capable of being powered from the computing device.
An alternate embodiment is an engine data interface. The interface includes an interface connector a low power non-volatile memory, and a low power data controller. The interface connector has a power input, a ground input, and data conductor inputs. The low power data controller is adapted to supply data residing in the low power non-volatile memory to the data conductor inputs. The low power non-volatile memory and the low power data controller are adapted to draw power from the power and ground inputs supplied by a computing device connected to the interface connector.
The present invention is directed to an electronic engine controller that stores diagnostic data received from a processor to non-volatile memory during normal operation. During a maintenance retrieval operation, internal power provided by the engine is not available. Sufficient power is drawn from the communication channel to power the non-volatile memory such that the diagnostic information can be retrieved without relying on a separate external power supply.
In the embodiment shown in
During engine operations, CPU 56, data controller 64a, and non-volatile memory 66 are powered from an internal source derived from the engine. For retrieval of the data stored in non-volatile memory 66, engine power is not available. Data controller 64a and non-volatile memory 66 are powered from computer 50 eliminating the need for a separate battery.
There are significant power constraints in order to be able to power the electronic engine control from the USB port on the computer. There are also constraints presented from the environment where the device operates. A jet engine is subject to heat and vibration profiles not typically seen by USB devices.
USB is capable of providing 100 mA of current during initialization and 500 mA of total current to a device plugged into a USB port on a computing device. This is well below the requirements to supply power to all of the components of the electronic engine controller 12a (e.g. CPO 56, data controller 64a, non-volatile memory 66, etc). The present invention addresses this by making data controller 64a and non-volatile memory 66 capable of being independently powered from the USB connection 68. In this way, data may be retrieved from non-volatile memory 66 without having to supply power sufficient to operate all components of electronic engine controller 12a.
When the CPU 56 is turned off, all the signal lines (address lines 58, data lines 60, and control lines 62) between it and data controller 64a will be grounded. Positioning data controller 64a between CPU 56 and non-volatile memory 66 allows continued accessibility of the data stored in memory over USB connection 68. Keeping CPU 56 and the remainder of electronic engine controller 12a powered off reduces the power consumption to meet the available power requirements from the USB communications channel. This enables downloading engine data information with a simple USB connection. No additional battery is needed to power the entire electronic engine control.
Data controller 64a can provide two way access to non-volatile memory 66 over USB connection 68. This means that computer 20 can deposit instructions on non-volatile memory 66 for later operations such as system maintenance and fault clearing. When the CPU 56 is powered on again, it reads the memory and determines if any instructions have been saved to the non-volatile memory. Saved instructions are then carried out by CPU 56.
Non-volatile memory 66 can be configured to appear as a mass storage device on computer 20 like many readily available USB thumb drive devices. This provides for compatibility with a wide range of software applications running on computer 20 connected to electronic engine controller 12a. To prevent unauthorized access or storage of improper information, non-volatile memory 66 can be alternatively configured to have a special type identifier which requires a special driver provided by the device manufacturer. This ensures that non-volatile memory 66 is accessed for the proper purposes by authorized personnel. The use of NAND flash further facilitates compatibility with existing software architectures because it natively supports bad sector management, mapping of logical to physical storage addresses, and cell wear management.
In addition to the power restrictions from the USB requirements, the device operates in the environmental conditions present on a jet engine. Military grade electronics are preferable in this operating environment due to the expected wide temperature ranges. Commercial grade electronics have a rating of 0° to 70° C. Industrial grade parts are rated at −40° to 85° C. Military grade parts are rated at −55° to 125° C. To implement the present invention in such an environment, it may be necessary to use an integrated circuit for the data controller with a suitable temperature rating to provide needed functionality. Another method of ensuring proper operation is to test components at 125° C. to verify proper operation where the manufacturer rating is not sufficient and there are no alternatives.
Vibration profiles are also significantly different than in consumer electronics often using a quad flat pack no leads (QFN) or very fine ball grid array (VFBGA) packaging. A more rugged quad flat pack (QFP) package is preferable to ensure proper operation.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Contract No. F33365a7-99D-2051 awarded by the United States Air Force.