Methods and systems for determining fleet trajectories to satisfy a sequence of coverage requirements

• US 9,014,957 B2
• Filed: 12/29/2012
• Issued: 04/21/2015
• Est. Priority Date: 12/29/2012
• Status: Expired due to Fees

• Current Assignee: Loon, LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Bonawitz, Keith Allen, Treuille, Adrien
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): WONG, YUEN H
• Application Number:
  US13/730,867
• Publication Number:
  US 20140188377A1
• Time in Patent Office: 843 Days
• Field of Search: 701/120, 709/201
• US Class Current: 701/120
• CPC Class Codes: B64B 1/58 Arrangements or construction of gas-bags; Filling arrangements
• CPC Class Codes: B64B 1/60 Gas-bags surrounded by separate containers of inert gas
• CPC Class Codes: B64U 10/30 Lighter-than-air aircraft, e.g. aerostatic aircraft
• CPC Class Codes: B64U 2101/20 for use as communications relays, e.g. high-altitude platforms
• CPC Class Codes: B64U 2201/102 adapted for flying in formations
• CPC Class Codes: B64U 50/31 generated by photovoltaics
• CPC Class Codes: G05D 1/104 involving a plurality of aircrafts, e.g. formation flying traffic control systems for aircraft G08G5/00
• CPC Class Codes: G06Q 10/047 Optimisation of routes or paths, e.g. travelling salesman problem
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
• CPC Class Codes: G08G 1/202 Dispatching vehicles on the basis of a location, e.g. taxi dispatching
• CPC Class Codes: G08G 5/0034 Assembly of a flight plan
• CPC Class Codes: G08G 5/0043 Traffic management of multiple aircrafts from the ground G08G5/003 takes precedence; data processing specially designed for resource management, e.g. scheduling or allocating time, human or machine resources G06Q10/06
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft
• CPC Class Codes: G08G 5/0091 for monitoring atmospheric conditions radar or analogous systems specially adapted for meteorological use G01S13/95; meteorology G01W
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform

Abstract

Methods and systems for determining trajectories for vehicles of a fleet of vehicles are provided. In one example, a method comprises receiving an initial location of one or more vehicles, and receiving a sequence of coverage requirements for a region and an associated period of time. The region may be divided into a plurality of landmarks and the period of time may be divided into a plurality of phases. The method also comprises determining for each of one or more phases and at least one respective landmark, a set of starting landmarks from which a vehicle could reach the respective landmark during the phase. The method further comprises determining which respective landmark that the vehicle should travel to during the one or more phases based on the sequence of coverage requirements and the set of starting landmarks for the one or more phases and the at least one respective landmark.

Claims

1. A method for a data network comprising:

receiving an initial location of one or more vehicles of a fleet of vehicles;

receiving a sequence of individual coverage requirements for a geographic region for the data network and an associated period of time, wherein the geographic region is divided into a plurality of landmarks and the associated period of time is divided into a plurality of phases, and wherein each individual coverage requirement of the sequence of individual coverage requirements corresponds to at least one respective phase of the plurality of phases and is indicative of a desired number of vehicles of the fleet of vehicles for one or more of the plurality of landmarks at an end of the at least one respective phase;

determining, by a processor, for each of one or more of the respective phases of the plurality of phases and for each of multiple respective ending landmarks of the plurality of landmarks, a set of starting landmarks corresponding to the respective phase and the respective ending landmark, wherein the set of starting landmarks comprises one or more landmarks of the plurality of landmarks from which the one or more vehicles of the fleet of vehicles could reach the respective ending landmark of the plurality of landmarks by traveling during the respective phase;

based on the initial locations of the one or more vehicles of the fleet of vehicles, the sequence of individual coverage requirements for the geographic region for the data network, and the determined set of starting landmarks for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, determining, by the processor, which landmark of the plurality of landmarks for a particular vehicle of the one or more vehicles of the fleet of vehicles to travel to during a respective phase of the one or more respective phases; and

instructing the particular vehicle to travel to the determined landmark during the respective phase.

2. The method of claim 1, wherein the one or more vehicles of the fleet of vehicles include a balloon within the data network that is operable to provide data communication via optical or radio-frequency (RF) links.

3. The method of claim 2, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises determining one or more landmarks of the plurality of landmarks from which the balloon could reach the respective ending landmark of the plurality of landmarks by following one or more estimated winds at one or more altitudes during the respective phase.

4. The method of claim 3, further comprising determining the one or more estimated winds based on wind data received from one or more balloons.

5. The method of claim 1, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks, the set of starting landmarks comprises:

determining, by the processor, for each respective phase and each respective ending landmark of the plurality of landmarks, a minimum distance from the respective ending landmark of the plurality of landmarks that the one or more vehicles could reach when starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling during the respective phase, and

determining the set of starting landmarks for the respective phase and the respective ending landmark of the plurality of landmarks based on comparisons between the determined minimum distances for the respective ending landmark of the plurality of landmarks and a threshold distance.

6. The method of claim 5, further comprising determining, by the processor, which landmark of the plurality of landmarks for the particular vehicle to travel to during the respective phase based on the determined minimum distances for each respective ending landmark of the plurality of landmarks.

7. The method of claim 1, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining, by the processor, for each respective phase and each respective ending landmark of the plurality of landmarks, a confidence measure that is indicative of whether the one or more vehicles could reach the respective ending landmark of the plurality of landmarks when starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling during the respective phase, and

determining the set of starting landmarks for the respective phase and the respective ending landmark of the plurality of landmarks based on comparisons between the determined confidence measures for the respective ending landmark of the plurality of landmarks and a confidence threshold.

8. The method of claim 7, further comprising determining, by the processor, which landmark for the particular vehicle to travel to during the respective phase based on the determined confidence measures for each respective ending landmark of the plurality of landmarks.

9. The method of claim 1, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining, by the processor, for each respective phase and each respective ending landmark, a cost value associated with the one or more vehicles starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling to the respective ending landmark of the plurality of landmarks during the respective phase; and

determining the set of starting landmarks for the respective phase and the respective ending landmark of the plurality of landmarks based on comparisons between the determined cost values for the respective ending landmark of the plurality of landmarks and a cost threshold.

10. The method of claim 1, further comprising determining which landmark of the plurality of landmarks for the particular vehicle to travel to during the respective phase by minimizing a linear objective function.

11. A non-transitory computer-readable storage medium having stored therein instructions, that when executed by a computing device in a data network, cause the computing device to perform functions comprising:

receiving an initial location of one or more vehicles of a fleet of vehicles;

receiving a sequence of individual coverage requirements for a geographic region for the data network and an associated period of time, wherein the geographic region is divided into a plurality of landmarks and the associated period of time is divided into a plurality of phases, and wherein each individual coverage requirement of the sequence of individual coverage requirements corresponds to at least one respective phase of the plurality of phases and is indicative of a desired number of vehicles of the fleet of vehicles for one or more of the plurality of landmarks at an end of the at least one respective phase;

determining for each of one or more of the respective phases of the plurality of phases and for each of multiple respective ending landmarks of the plurality of landmarks, a set of starting landmarks corresponding to the respective phase and the respective ending landmark of the plurality of landmarks, wherein the set of starting landmarks comprises one or more landmarks of the plurality of landmarks from which the one or more vehicles of the fleet of vehicles could reach the respective ending landmark of the plurality of landmarks by traveling during the respective phase;

based on the initial locations of the one or more vehicles of the fleet of vehicles, the sequence of individual coverage requirements, and the determined set of starting landmarks for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, determining which landmark of the plurality of landmarks for a particular vehicle of the one or more vehicles of the fleet of vehicles to travel to during a respective phase of the one or more respective phases; and

instructing the particular vehicle of the one or more vehicles of the fleet of vehicles to travel to the determined landmark of the plurality of landmarks during the respective phase.

12. The non-transitory computer-readable storage medium of claim 11, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining for each respective phase and each respective ending landmark, a minimum distance from the respective ending landmark that the one or more vehicles could reach when starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling during the respective phase, and

determining the set of starting landmarks for the respective phase and the respective ending landmark based on comparisons between the determined minimum distances for the respective ending landmark of the plurality of landmarks and a threshold distance.

13. The non-transitory computer-readable storage medium of claim 11, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining for each respective phase and each respective ending landmark, a confidence measure that is indicative of whether the one or more vehicles could reach the respective ending landmark of the plurality of landmarks when starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling during the respective phase, and

determining the set of starting landmarks for the respective phase and the respective ending landmark based on comparisons between the determined confidence measures for the respective ending landmark of the plurality of landmarks and a confidence threshold.

14. The non-transitory computer-readable storage medium of claim 11, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining, for each respective phase and each respective ending landmark, a cost value associated with the one or more vehicles starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling to the at lest one respective ending landmark of the plurality of landmarks during the respective phase; and

determining the set of starting landmarks for the respective phase and the respective ending landmark based on comparisons between the determined cost values for the respective ending landmark of the plurality of landmarks and a cost threshold.

15. A system for a data network, comprising:

at least one processor; and

data storage comprising program instructions executable by the at least one processor to cause the system to perform functions comprising;

receiving an initial location of one or more vehicles of a fleet of vehicles;

receiving a sequence of individual coverage requirements for a geographic region for the data network and an associated period of time, wherein the geographic region for the data network is divided into a plurality of landmarks and the associated period of time is divided into a plurality of phases, and wherein each individual coverage requirement of the sequence of individual coverage requirements corresponds to at least one respective phase of the plurality of phases and is indicative of a desired number of vehicles of the fleet of vehicles for one or more of the plurality of landmarks at an end of the at least one respective phase;

determining for each of one or more of the respective phases of the plurality of phases and for each of multiple respective ending landmarks of the plurality of landmarks, a set of starting landmarks corresponding to the respective phase and the respective ending landmark of the plurality of landmarks, wherein the set of starting landmarks comprises one or more landmarks of the plurality of landmarks from which the one or more vehicles of the fleet of vehicles could reach the respective ending landmark of the plurality of landmarks by traveling during the respective phase;

based on the initial locations of the one or more vehicles of the fleet of vehicles, the sequence of coverage requirements, and the determined set of starting landmarks for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, determining which landmark of the plurality of landmarks for a particular vehicle of the one or more vehicles of the fleet of vehicles to travel to during a respective phase of the one or more respective phases; and

instructing the particular vehicle of the one or more vehicles of the fleet of vehicles to travel to the determined landmark of the plurality of landmarks during the respective phase.

16. The system of claim 15, wherein the one or more vehicles of the fleet of vehicles include a balloon within the data network that is operable to provide data communication via optical or radio-frequency (RF) links.

17. The system of claim 16, wherein determining, for each of the one or more respective phases and each of the multiple respective ending landmarks of the plurality of landmarks, the set of starting landmarks comprises:

determining for each respective phase and each respective ending landmark of the plurality of landmarks, a minimum distance from the respective ending landmark of the plurality of landmarks that the one or more vehicles could reach when starting from each of multiple given landmarks of the plurality of landmarks respectively and traveling during the respective phase, and

determining the set of starting landmarks for the respective phase and the respective ending landmark based on comparisons between the determined minimum distances for the respective ending landmark of the plurality of landmarks and a threshold distance.

18. The system of claim 17, wherein the functions further comprise determining which landmark of the plurality of landmarks for the particular vehicle to travel to during the respective phase based on the determined minimum distances for each respective ending landmark of the plurality of landmarks.