Traffic alert and collision avoidance coding system
First Claim
1. A traffic alert and collision avoidance system for preventing the collision of vehicles within an airspace, said system comprising:
- (a) a navigation signal generating network that emits navigational signals suitable for determining the position of a vehicle receiving the navigational signals; and
(b) a plurality of vehicles,(i) each of said vehicles including a transmitter for;
receiving navigational signals generated by the navigation signal generating network;
determining the actual position of the vehicle based on the received navigational signals;
determining an airspace volume element that forms part of a grid of volume elements within which the vehicle is located; and
transmitting a collision avoidance signal that includes a navigation message containing data describing the actual position of the vehicle and a volume element code assigned to the airspace volume element within which said vehicle is located; and
(ii) at least some of said vehicles including a receiver for receiving the collision avoidance signals produced by the transmitters of other vehicles, said receiver;
selecting which received collision avoidance signals to evaluate based on the volume element code contained in the received collision avoidance signals;
evaluating the selected collision avoidance signals to determine the range between the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals based on the actual position data contained in the navigation message of the selected collision avoidance signals and the actual position of the vehicle receiving the selected collision avoidance signals; and
generating a warning if the range between any of the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals indicates a potential collision between the vehicles.
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Accused Products
Abstract
A system for coding and transmitting traffic alert and collision avoidance data between vehicles (A, B and C) traveling within a given airspace (12). The airspace is divided into a grid of volume elements (14a, 14b . . . 14i), each of which is assigned a unique pseudonoise (PN) code. A vehicle (A) traveling through the airspace determines its position using signals from Global Positioning System (GPS) satellites. The vehicle'"'"'s position places it within one of the volume elements in the airspace. A Traffic Alert and Collision Avoidance System (TCAS) transmitter (38) on the vehicle creates a navigation message that describes the position of the vehicle. A collision avoidance signal is then generated by modulating a carrier signal with the PN code representing the volume element containing the transmitting vehicle and with the navigation message. The collision avoidance signal is transmitted on a common communications channel using time-multiplexing based on a pseudorandom sequence. Other vehicles operating within the same airspace use a TCAS receiver to receive the collision avoidance signals broadcast from each vehicle. Each receiving vehicle in the airspace only tracks collision avoidance signals produced by vehicles located in its own and surrounding volume elements to determine if an impending collision is likely. Specifically, only the navigation messages from vehicles in the same or surrounding volume elements are decoded to determine the position of the other vehicles. Based on calculated vehicle paths, a warning of an impending collision or instructions on how to avoid a collision are provided to the operator of the receiving vehicle.
184 Citations
49 Claims
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1. A traffic alert and collision avoidance system for preventing the collision of vehicles within an airspace, said system comprising:
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(a) a navigation signal generating network that emits navigational signals suitable for determining the position of a vehicle receiving the navigational signals; and (b) a plurality of vehicles, (i) each of said vehicles including a transmitter for;
receiving navigational signals generated by the navigation signal generating network;
determining the actual position of the vehicle based on the received navigational signals;
determining an airspace volume element that forms part of a grid of volume elements within which the vehicle is located; and
transmitting a collision avoidance signal that includes a navigation message containing data describing the actual position of the vehicle and a volume element code assigned to the airspace volume element within which said vehicle is located; and(ii) at least some of said vehicles including a receiver for receiving the collision avoidance signals produced by the transmitters of other vehicles, said receiver;
selecting which received collision avoidance signals to evaluate based on the volume element code contained in the received collision avoidance signals;
evaluating the selected collision avoidance signals to determine the range between the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals based on the actual position data contained in the navigation message of the selected collision avoidance signals and the actual position of the vehicle receiving the selected collision avoidance signals; and
generating a warning if the range between any of the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals indicates a potential collision between the vehicles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A traffic alert and collision avoidance transmitter for broadcasting a collision avoidance signal from a moving vehicle, said traffic alert and collision avoidance transmitter comprising:
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(a) navigational means for determining the actual position of a vehicle containing the transmitter based on navigation signals produced by a navigation signal generating network; (b) a navigation message generator for creating a navigation message that contains data describing the actual position of the vehicle; (c) a volume element code generator for generating a unique code assigned to an airspace volume element of a grid of airspace volume elements within which the vehicle is located based on the actual position of the vehicle; (d) a carrier signal generator for generating a carrier signal; (e) a modulator for modulating the carrier signal by the navigation message and the volume element code to produce a collision avoidance signal; and (f) transmitting means for transmitting the collision avoidance signal. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A traffic alert and collision avoidance receiver for receiving and decoding a collision avoidance message, said traffic alert and collision avoidance receiver comprising:
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(a) navigational means for determining the actual position of a vehicle containing the receiver based on signals produced by a navigation signal generating network; and (b) receiving means for; (i) receiving collision avoidance signals transmitted by other vehicles, the collision avoidance signals containing a navigation message containing data describing the position of the vehicle transmitting the collision avoidance signal and an airspace volume element code describing the airspace volume element of a grid of airspace volume elements within which the transmitting vehicle is located; (ii) distinguishing collision avoidance signals produced by vehicles located in the same airspace volume element or airspace volume elements surrounding the airspace volume element in which the vehicle containing the receiver is located from collision avoidance signals produced by vehicles located in other airspace volume elements based on the airspace volume element code contained in the received collision avoidance signals; (iii) decoding the navigation message contained in the collision avoidance signals produced by vehicles located in the same airspace volume element or the airspace volume elements surrounding the airspace volume element in which the vehicle containing the receiver is located in order to determine the position of said vehicles; and (iv) alerting an operator of the vehicle containing the receiver to the location of vehicles located in the same airspace volume element or the airspace volume elements surrounding the airspace volume element in which the vehicle containing the receiver is located. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42)
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43. A method of preventing a collision between a plurality of vehicles operating within an airspace, the method comprising:
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(a) establishing a grid of volume elements within the airspace, each volume element within the grid of volume elements being assigned a unique volume element code; (b) causing each of the plurality of vehicles to generate and transmit a collision avoidance signal, the collision avoidance signal transmitted by each vehicle comprising a navigation message containing data describing a position of the vehicle generating the collision avoidance signal and the unique volume element code corresponding to the volume element in which the vehicle generating the collision avoidance signal is located; and (c) causing some of the plurality of vehicles to receive the collision avoidance signals transmitted by the plurality of vehicles, each of the vehicles receiving the collision avoidance signals; (i) selecting which received collision avoidance signals to evaluate based on the volume element code contained in the received collision avoidance signals; (ii) evaluating the selected collision avoidance signals to determine the range between the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals based on the position data contained in the navigation message of the selected collision avoidance signals and the position of the vehicle receiving the selected collision avoidance signals; and (iii) generating a warning if the range between any of the vehicles transmitting the selected collision avoidance signals and the vehicle receiving the selected collision avoidance signals indicates a potential collision between the vehicles. - View Dependent Claims (44, 45, 46, 47, 48, 49)
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Specification