# US 8,788,127 B1 · Precision airdrop terminal seeker > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,127 B1 - Document ID: US8788127B1 - Status: Granted - Kind: B1 - Application number: 13/221,468 - Filed: 2011-08-30 - Granted: 2014-07-22 - Earliest claimed: 2011-08-30 - Assignees: The Boeing Company - Applicants: Dale F. Waldo; David Ray Riley; Thomas Lyman Weaver - Inventors: Dale F. Waldo; David Ray Riley; Thomas Lyman Weaver - Web page: https://patentgrep.com/patent/US8788127B1 ## CPC - B64D 1/02: Dropping, ejecting, or releasing articles (jettisonable fuel reservoirs B64D37/12) - B64D 1/08: the articles being load-carrying devices - G05D 1/105: {specially adapted for unpowered flight, e.g. glider, parachuting, forced landing (parachutes per se B64D17/00)} - B64F 1/20: Arrangement of optical beacons - F21W 2111/00: Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00 - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - B64F: GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR - F21W: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS ## Abstract A beacon receiving system on a pallet of a container cargo bundle is airdropped from a cargo airplane. The beacon receiving system comprises a sensor that detects during descent a beacon signal generated from a beacon placed at the target drop location. The sensor provides signals to a microcontroller that ascertains an angle at which the beacon signal is received. An inertial measurement unit provides signals indicating a tilt of the pallet during descent, which is used by the microcontroller to determine an offset angle of the received beacon signal. This information is used to steer the container cargo bundle during descent to achieve high precision in landing at the desired target drop location. The beacon signal may comprises a modulated light signal which can be distinguished by the sensor from other light sources. ## Claims ### Claim 1 A system for targeting airdropped cargo delivery comprising: a sensor configured to be integrated into a pallet of a container delivery system (“CDS”) bundle, wherein the sensor is able to detect a beacon signal of a specified electromagnetic wavelength spectrum directed in an upward direction from ground, said sensor further configured to generate a first set of reference signals associated with the beacon signal; an inertial reference unit configured to be integrated into the pallet and generate a second set of reference signals corresponding to a tilt of the pallet; a microcontroller configured to receive the first set of reference signals, receive the second set of reference signals, and use the first set of reference signals and the second set of reference signals to ascertain an offset angle of the beacon signal, and provide the offset angle for steering the pallet to the beacon signal; and a beacon signal generator, configured to be placed at a drop location and generate the beacon signal of the specified electromagnetic wavelength spectrum. ### Claim 2 (depends on 1) The system of claim 1, wherein the electromagnetic wavelength spectrum comprises a visible wavelength spectrum. ### Claim 3 (depends on 1) The system of claim 1, wherein the inertial reference unit provides the second set of reference signals comprising a two orthogonal values representing a corresponding tilt of the pallet in an X and Y direction. ### Claim 4 (depends on 3) The system of claim 3, wherein the sensor provides the first set of reference signals comprising two orthogonal values representing corresponding angles of the beacon relative to the pallet in the X and Y direction. ### Claim 5 (depends on 3) The system of claim 3, wherein the sensor is a quadrant sensor and the first set of reference signals comprises four signals. ### Claim 6 (depends on 1) The system of claim 1, wherein the beacon signal generator comprises a plurality of LEDS and a modulator for generating the beacon signal with a periodic duty cycle. ### Claim 7 (depends on 1) The system of claim 1, further comprising an altitude sensor wherein the processor is configured to ascertain the relative angle of the beacon signal below a threshold altitude. ### Claim 8 (depends on 1) The system of claim 1, wherein the beacon signal is a pulsed beacon signal with a frequency, and the processor is configured to detect the pulsed beacon signal at the frequency. ### Claim 9 A system comprising: a sensor configured to be integrated with a pallet of a container delivery system (“CDS”) bundle, wherein the sensor is able to detect a beacon signal of a specified electromagnetic wavelength spectrum directed in an upward direction from ground, said sensor further configured to generate a first set of reference signals; an inertial reference unit configured to be integrated into the pallet configured to generate a second set of reference signals; and a microcontroller configured to receive the first set of reference signals and the second set of reference signals and ascertain an offset angle of the beacon signal, wherein the microcontroller is configured to generate data used to adjust steering of the CDS bundle during descent. ### Claim 10 (depends on 9) The system of claim 9, further comprising: the pallet, into which the sensor and the inertial reference unit are integrated. ### Claim 11 (depends on 9) The system of claim 9, wherein the sensor comprises a quad sensor providing four output signals. ### Claim 12 (depends on 11) The system of claim 11, wherein the microcontroller is configured to receive the four output signals from the sensor. ### Claim 13 (depends on 9) The system of claim 9, wherein the specified electromagnetic wavelength spectrum comprises a visible electromagnetic wavelength. ### Claim 14 (depends on 9) The system of claim 9, wherein the sensor is configured to receive spectrum in an infrared electromagnetic wavelength. ### Claim 15 A method for controlling the descent of an airdropped container delivery system (“CDS”) bundle pallet comprising: receiving a beacon signal emanating from the ground at a beacon sensor integrated into the CDS bundle pallet; determining a tilt of a CDS bundle pallet from an inertial measurement unit; determining an angle of the beacon signal as received by the beacon sensor; and determining an offset angle of the beacon signal from the tilt of the CDS bundle pallet and the angle of the beacon signal. ### Claim 16 (depends on 15) The method of claim 15, further comprising adjusting a direction of the CDS bundle pallet based in part on the offset angle. ### Claim 17 (depends on 16) The method of claim 16 wherein determining a tilt comprises determining tilt in two orthogonal directions. ### Claim 18 (depends on 17) The method of claim 17 wherein determining the angle of the beacon signal comprises determining the angle of the beacon signal in two orthogonal directions. ### Claim 19 (depends on 18) The method of claim 18, further comprising determining an altitude, and upon determining that the altitude is below a threshold performing the operation of determining the offset angle of the beacon signal. ### Claim 20 (depends on 15) The method of claim 15, wherein receiving the beacon signal from the beacon sensor comprises receiving four signals from a quadrant signal detector.