WO2020160471A1

WO2020160471A1 - Aircraft weight and balance measurement system and method

Info

Publication number: WO2020160471A1
Application number: PCT/US2020/016210
Authority: WO
Inventors: Scot CARPENTER
Original assignee: Teledyne Controls, Llc
Priority date: 2019-01-31
Filing date: 2020-01-31
Publication date: 2020-08-06

Abstract

An aircraft weight and balance measurement system and method comprises an identification means which enables each person (12) and/or object (16) boarding an aircraft to be tracked, and their weight to be known or estimated. A processing system receives data from the identification means and produces an operational weight and balance calculation for the aircraft. The identification means may consist of an array of cameras (10), at least one of which images each person (12) and/or object (16) as they board the aircraft; other cameras are located throughout the cabin to enable each person/ object to be tracked once onboard. The system may further include a weighing pad (18) arranged to weigh each person (12) and/or object (16) as they board the aircraft, with the measured weights provided to the processing system.

Description

AIRCRAFT WEIGHT AND BALANCE

MEASUREMENT SYSTEM AND METHOD

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 62/799,323, filed January 31, 2019.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] This invention relates generally to systems and methods for maintaining aircraft stability.

Description of the Related Art

[0003] Weight and Balance are two critical factors affecting the safe and efficient operation of an aircraft, in terms of the craft’s stability, control, and efficient aerodynamic configuration. Under current practice, an airplane manufacturer provides the allowable Center of Gravity (CG) and Mean Aerodynamic Chord (MAC) envelope to the plane’s operator, usually in the aircraft Type Certificate Data Sheet. The airplane operator then controls operational weight and balance to maintain a proper CG for continued safe flight. Stability of the airplane is dependent on CG being forward of the center of lift, which requires a“tail down” aerodynamic force to ensure stability.

[0004] The calculated MAC for each flight indicates if the airplane is in a safe configuration (from Take-Off to Touchdown - i.e., desirable nose heavy condition in the event of an airplane stall condition). Within the allowable MAC range, there are performance/fuel bum considerations. For example, if an airplane is nose heavy, it will burn more fuel. If loaded with a bias toward being tail heavy (but within safe limits), fuel burn is reduced due to their being less drag.

[0005] Each airplane operator produces a Weight and Balance Substantiation report that, among other things, establishes the passenger compartment and crew configuration and weight. Since most commercial airplane operators do not directly weigh passengers due to time constraints, they use assumed weights (for males and females) that are published and approved by the regulatory authorities. Because airplane operators do not weigh individual passengers, the substantiation report details the balance condition average-weighted passenger/crew throughout the cabin. However, due to the shortcomings of this process:

1. The true operational weight and balance (W&B) of the airplane is not known;

2. The optimal airplane configuration to obtain fuel savings is not realized (e.g., seat assignments, ballast fuel placement, en route fuel tank transfers, horizontal stabilizer position);

3. Less economical operational procedures, or altered procedures, may come into effect as it relates to takeoff performance, maximum allowed payload, and other factors dependent of the airplanes W&B, and

4. Flight delays occur for smaller aircraft that are required to reposition passengers to achieve the required operational CG- a procedure that is fraught with errors and/or disarray.

SUMMARY OF THE INVENTION

[0006] An aircraft weight and balance (W&B) measurement system and method is presented which addresses some of the problems noted above.

[0007] The present system comprises an identification means which enables each person and/or object boarding an aircraft to be tracked, and their weight to be known or estimated. A processing system receives data from the identifications means and produces an operational weight and balance calculation for the aircraft.

[0008] Several possible configurations of the W&B measurement system are described herein. For example, the identification means may consist only of an array of cameras, at least one of which images each person and/or object as they board the aircraft. The system may further include a weighing pad arranged to weigh each person and/or object as they board the aircraft, with the measured weights provided to the processing system. Yet another possibility is to provide a plurality of weight sensors in respective seats on the aircraft, such as a low-power strain gage on the bottom of each seat cushion, with each weight sensor arranged to weigh the occupant of the seat and provide the weight to the processing system. Weight sensors might also be employed in the aircraft’s overhead bins, to provide more accuracy with respect to the aircraft’ s weight and balance. [0009] One possible alternative identification means requires that respective RFID devices be associated with each person and/or object boarding the aircraft. A weighing pad could then be arranged to weigh each person boarding the aircraft, with the weight data associated to pre assigned seat locations.

[0010] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a diagram illustrating one possible embodiment of a W&B system per the present invention.

[0012] FIG. 2a is a flow chart illustrating a prior art method of determining W&B on an aircraft.

[0013] FIG. 2b is a flow chart illustrating a method of determining W&B on an aircraft per the present invention.

[0014] FIG. 3 a is a block diagram of one possible embodiment of a W&B system per the present invention which is integrated with the aircraft.

[0015] FIG. 3b is a block diagram of one possible embodiment of a W&B system per the present invention wherein some of the system components are off-aircraft.

[0016] FIG. 4 is a flow chart illustrating an image processing method as might be used with a W&B system per the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The present aircraft W&B measurement system and method determines the weight and balance of an aircraft while on the ground or in flight. The system comprises a measurement subsystem including at least one identification means, such as a camera or array of cameras, which enables each person and/or object boarding an aircraft to be tracked and their weight to be known or estimated. In a preferred embodiment, the system includes a sensor, such as a weighing pad, configured to measure a physical property of each person and/or object. Assuming the system is configured with a camera and weighing pad, the system includes a processor for receiving data from the camera and weighing pad. Software on the processor analyzes the entities being weighed and applies a unique identifier (or label) to unique characteristics or features obtained from the camera imagery, and for each entity that has been uniquely labeled, the weight determined by the weighing pad is associated. The system is preferably arranged to continuously monitor and track the unique entities from a plurality of cameras within the aircraft. The software preferably further determines the location of each unique entity within the aircraft, with each aircraft location having a pre-defined location identifiable to a reference datum. The software is preferably arranged to output the effect of each entity on the aircraft’s W&B by multiplying the weight of the entity against the distance of the reference datum (moment x arm), to determine the aircraft’s W&B in terms of CG, and may further determine Lift relative to other known weight factors.

[0018] The present aircraft W&B system and method comprises an identification means which enables each person and/or object (“person/object”) boarding an aircraft to be tracked and their weight to be known or estimated. One possible basic configuration is illustrated in FIG 1. Here, the identification means comprises a camera system 10 that acquires imagery of each person 12, typically as they enter the aircraft’s fuselage 14. The system would typically also be arranged to acquire imagery of each person’s carry-on 16 (or any bulky object being conveyed by the person), if any. The system also includes a processing system (not shown in FIG. 1) which receives data from the identifications means and produces an operational weight and balance calculation for the aircraft.

[0019] When the identifications means is a camera system, it would typically comprise an array of cameras, at least one of which images each person and/or object as they board the aircraft; other cameras would typically be located throughout the cabin, to enable each person/object to be tracked once onboard. The cameras would typically operate in the visual or infrared areas of the electromagnetic spectrum. The cameras in the array are preferably fixed, with their baseline fields-of-view (FOVs) referenced to known aircraft locations. When the system employs only cameras and a processing system (i.e., no weighing means), the weight of each person/object boarding the aircraft would be estimated based on the images detected by the cameras.

[0020] In a preferred embodiment, the system of FIG. 1 would also include at least one weighing pad 18 arranged to weigh each person 12 and/or object 16 as they board the aircraft, with the weighing pad arranged to provide the measured weights to the processing system. Note that weight sensors might also be provided in respective seats on the aircraft (not shown), with each weight sensor arranged to weigh the seat’s occupant and provide the weight to the processing system. Similarly, weight sensors might also be provided in respective overhead bins on the aircraft (not shown), with each weight sensor arranged to weigh the bin’s contents and provide the weights to the processing system. Note that, if weight sensors are provided at each seat, a camera system may be unnecessary.

[0021] The processing system would typically be arranged to execute associated software, with the processing system and software arranged to identify and store physically unique features of each person/object boarding the plane, and to associate the features to a unique identification. In practice, the processing system would include a software (SW) component that processes, tags, and stores key features of the person/object for use by a SW tracking function. The SW tracking function can be arranged to identify the position of the person/object within the cabin (seat or station number), using multiple cameras within the aircraft cabin. A SW function outputs the person/object location on the airplane (frame/seat/datum), as well as the passenger/object weight if the system employs a weighing pad 18. Another SW function then estimates weight and balance via a cumulative arm x moment calculation. These steps are preferably repeated continuously so that aircraft W&B is always up-to-date. The processing system is preferably further arranged to calculate a moment-of-force value using the weight data and cumulative arm x moment calculation.

[0022] The prior art method, illustrated in FIG. 2A, requires collection of various data (30) that is necessary to calculate the aircraft’s CG (32) and determine its W&B (34). Since most commercial airplane operators do not directly weigh passengers due to time constraints, they use assumed weights that are published and approved by the regulatory authorities. The use of assumed weights is proven effective for safe operation, but not knowing the true weight and balance may, in some cases, prohibit using more economical aircraft performance configurations that reduce fuel consumption or provide increased load carrying capacity.

[0023] A flow chart of an embodiment of the present method which includes a weighing step is shown in FIG. 2B. Camera imagery is acquired in step 40, and unique features of each person/object is identified (or labeled) from the imagery and stored (42). The person/object is weighed (44), and the weight is associated with the person/object (46). Other data may be received from other systems (48); then, calculations using actual weights are performed (50) (e.g., weight x arm = moment; sum of moments / sum of weights = CG; etc.). If loading is not completed (52), steps 40-50 are repeated for the next person/object. When loading is complete, the aircraft’s CG is determined (54) and may be output (56) to external systems such as an operations center. Note that the processing system may be further arranged to receive additional moment arm data from other systems or by manual input, which could also be included when calculating the CG for the entire aircraft.

[0024] Using a camera system as described herein preferably supports a two stage process: 1) a camera array around the weighing pad is used to collect unique identifiers for each entity; and 2) a camera array around the cabin is used to track each entity to their final location (seat/storage compartment) by matching against their unique identifiers. Stage 1 is expected to require a clear view of each entity in at least a plurality of images. Stage 2 is expected to require tracking entities through occlusions and determine that an entity has reached its final location. In some cases, it is expected that the camera system may, for a number of reasons, lose and re acquire objects as they move into and out of their FOVs (or encounter obstructed views) during the load procedures.

[0025] Block diagrams of two possible embodiments of the present aircraft W&B system are shown in FIGs. 3 A and 3B. FIG. 3 A depicts a system which is fully integrated with the aircraft, while FIG. 3B illustrates a hybrid system in which some elements of the system may not be installed on the aircraft, but which relay certain data to the airplane subsystem; for example, a camera system and a weighing pad could be located external to the aircraft, with data from the weighing pad and camera system relayed to one or more systems on the aircraft, preferably wirelessly. Each of the numbered items in FIGs. 3A and 3B are described in more detail below.

[0026] Image Sensor (Camera) - 1

[0027] The image sensors may provide image detection in visual, IR, or other areas of the electromagnetic spectrum. The camera may encode the sensor data with values that, in later processing, relate to unique patterns or values that correspond to identifiable features, colors, shapes, etc. that can be classified, labeled, stored and retrieved using computer software. Some or all of the image sensors located on the aircraft determine a tracked object’s location. However, pre-processed entity feature data (or pre-composed labelled data) may be transferred to the aircraft before entering the airplane. As shown in FIG. 3B, one or more image sensors might also be located off-aircraft, such as in the boarding area.

[0028] Weighing Sensor - 2 [0029] A device used to weigh the person/object(s) of interest to the system. There may be one weighing sensor located at a single boarding point, or multiple weighing sensors located at multiple entry points (in the case of large airplanes). It is envisioned that the weighing sensor - typically a load cell - may determine the weight at discrete contact areas within the load cell area (to facilitate discrimination of multiple entities or objects contacting the load cell), and a total weight for all contact points. The load cell would preferably contain a“zeroing” calibration function.

[0030] FIG. 3B embodiment: while desirable to have the weighing sensor as part of the aircraft system, it could alternatively be off-aircraft (e.g. near the boarding gate) as part of an extended system that performs the person/object weighing and feature extraction and labeling functions (i.e., identifying unique features associated with an entity for tracking under a unique ID or label) before boarding the airplane. In this case, the aircraft imaging system would typically perform look-up and match functions to perform tracking against precomputed data.

[0031] Data I/O - 3

[0032] This represents various aircraft data interfaces used to provide required input or output. All commercial airplanes provide standard data busses used to transfer various information between subsystems.

[0033] FIG. 3 A: as part of a completely integrated system, it is envisioned that some data could automatically be retrieved from the airplane data bus to the processing system (computer 5) and used to perform the weight and balance computation. Examples of this type of data include:

• Airplane fuel quantity data

• Aircraft type and Aircraft ID

• Aircraft Load Manifest or other data retrievable from other airplane subsystems

• Airplane specification data or precomputed data such as Zero-Fuel Weight, Gross Weight, etc. that may be available from another sub-system - such as the Flight Management Computer

[0034] The data input described above may also be direct-entered into the system manually by flight or support crew via terminal (such as a Multi-Function Display Unit (see block 4, below), or an Electronic Flight Bag. Remote Input may also occur through off-board data links.

[0035] The outputs produced by the present system may include:

• Human Interface Display (HID) command data (such as manual input) • System state information

• Results of the calculations

• Errors

[0036] HID - 4

A HID may be included to provides a means for an individual to input or view system control (menu) data, as well as output from the system as described in Data I/O 3.

[0037] Computer - 5

The computer provides data acquisition and processing necessary to perform some of the functions described herein. It would typically contain a processor (6), memory, storage, input/output interfaces, operating systems, and software applications. Processor 6 would typically contain the image software, static data pertaining to airplane specifications, mission data pertaining to the current operations (such as fuel load), and the primary weight and balance calculation software. A Sensor Acquisition/Data I/O block (7) would typically be part of the computer system, and serves to provide a data interface to aircraft sub-systems.

[0038] Another possible identification means that might be employed by the present system is an RFID device, with respective RFID devices associated with each person and/or object boarding the aircraft. For example, an RFID may be printed on a passenger’s boarding pass. A weighing pad may also be provided and arranged to weigh each person boarding the aircraft, with the weight data associated to pre-assigned seat locations.

[0039] Assuming a system which includes one or more cameras and a weighing pad as described above, one possible method of processing images obtained by the cameras is shown in FIG. 4. In step 60, a person/object is weighed on a weighing pad. A camera(s) scans the entity on the weighing pad and creates a unique ID according to unique features (62). The weight and unique ID are associated and stored (64). A camera in the aircraft cabin (“Camera N”) provides imaging of the cabin to the system’s processor (66). Each imaged entity is followed to its final location (68). In step 70, system software processes the camera images, and scans and isolates individual entities, to match each with the stored unique features. If the entity with a unique ID from step 62 matches the entity isolated in step 70, the process moves forward; if not, steps 68 and 70 are repeated (step 72).

[0040] If there is a match in step 72, the position of the matched object is determined according to pre-defined reference locations (step 74). The current moment/arm of the matched object is then calculated (step 76), and the cumulative CG for all matched objects acquired during the load process is calculated (step 78). The resulting data is then output to other aircraft systems as necessary (step 80).

[0041] The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention as defined in the appended claims.

Claims

I CLAIM:

1. An aircraft weight and balance measurement system, comprising:

an identification means which enables each person and/or object boarding an aircraft to be tracked and their weight to be known or estimated; and

a processing system which receives data from said identifications means and produces an operational weight and balance calculation for said aircraft.

2. The system of claim 1 , wherein said identification means is an array of cameras, at least one of which images each person and/or object as they board said aircraft.

3. The system of claim 2, wherein at least one of said cameras operates in the visual or infrared areas of the electromagnetic spectrum.

4. The system of claim 2, wherein the cameras in said array are fixed and their baseline fields-of-view are referenced to known aircraft locations.

5. The system of claim 2, wherein said processing system executes associated software, said processing system and software arranged to identify and store physically unique features of persons and/or objects boarding said plane, and to associate said features to a unique identification (or label).

6. The system of claim 2, arranged such that the weight of each person and/or object boarding said aircraft is estimated based on said image from said at least one camera.

7. The system of claim 2, further comprising at least one weighing pad arranged to weigh each person and/or object as they board said aircraft, said weighing pad arranged to provide said weights to said processing system.

8. The system of claim 1, further comprising a plurality of weight sensors in respective seats on said aircraft, each weight sensor arranged to weigh the occupant of said seat and provide said weight to said processing system.

9. The system of claim 8, further comprising a plurality of weight sensors in respective overhead bins on said aircraft, each weight sensor arranged to weigh the contents of said bin and provide said weights to said processing system.

10. The system of claim 1, wherein said identification means comprises respective RFID devices associated with each person and/or object boarding said aircraft.

11. The system of claim 10, further comprising a weighing pad arranged to weigh each person boarding said aircraft, said weight data associated to pre-assigned seat locations.

12. An aircraft weight and balance estimation system, comprising:

a weighing pad arranged to weigh each person and/or object as they board an aircraft;

a camera system that, while said person is on said weighing pad, acquires imagery of the person and/or object;

a processing system which receives data from said weighing pad and camera system, and is arranged to process, tag, and store key features of the person/carry-on;

an array of cameras within the cabin of said aircraft, each of which is fixed and has a baseline field-of-view referenced to known aircraft locations;

said processing system further arranged to track the position of each person and/or object within said cabin and to output weight and position data for each person and/or object on said aircraft;

said processing system further arranged to estimate weight and balance for said aircraft via a cumulative arm x moment calculation.

13. The system of claim 12, wherein said processing system is arranged to continuously perform said tracking and estimating functions.

14. The system of claim 12, wherein said processing system is further arranged to calculate a moment-of-force value using said weight data and said cumulative arm x moment calculation.

15. The system of claim 12, wherein said processing system is further arranged to receive additional moment arm data from other systems or by manual input, and to calculate the Center-Of-Gravity for the entire aircraft.

16. The system of claim 12, wherein said processing system is further arranged to output the calculated Center-Of Gravity to one or more additional systems.

17. The system of claim 12, wherein said weighing pad and camera system are located within and are integrated with said aircraft.

18. The system of claim 12, wherein said weighing pad and camera system are located external to said aircraft, and data from said weighing pad and camera system is relayed to one or more systems on said aircraft.

19. An aircraft weight and balance estimation system, comprising:

a plurality of weight sensors in respective seats on said aircraft, each weight sensor arranged to weigh the occupant of said seat;

a processing system which receives data from said weight sensors and camera system, and is arranged to process, tag, and store key features of the person/carry-on;

said processing system further arranged to track the position of each person and/or object within said cabin and to output weight and position data for each person and/or object on said aircraft; said processing system further arranged to estimate weight and balance for said aircraft via a cumulative arm x moment calculation.

20. The system of claim 19, further comprising a plurality of weight sensors in respective overhead bins on said aircraft, each weight sensor arranged to weigh the contents of said bin and provide said weights to said processing system.

21. A method of determining Center-Of-Gravity on an aircraft, comprising:

acquiring imagery of a person and/or object boarding an aircraft;

weighing said person and/or object;

repeating said acquiring, identifying, and weighing steps for additional persons and/or objects boarding said aircraft;

tracking said persons and/or objects while aboard the aircraft to determine their locations; and

calculating Center-Of-Gravity for said aircraft based on said weight and location data.

22. The method of claim 21, further comprising:

receiving additional weight and location data from other aircraft systems for other objects aboard said aircraft, and

including said additional weight and location data when calculating said Center

Of-Gravity.

23. The method of claim 21, further comprising providing said calculated Center- of-Gravity to other aircraft systems.

24. The method of claim 21, wherein an array of cameras within said aircraft provides imaging with which to track said persons and/or objects while aboard the aircraft to determine their locations.