초록 ▼

A guided parafoil system for delivering lightweight payloads provides an accurate, small and low-cost delivery system for small payloads such as chemical sensor packages. The delivery system is adapted to fit along with the payload within a standardized canister. The delivery system includes a paraf

A guided parafoil system for delivering lightweight payloads provides an accurate, small and low-cost delivery system for small payloads such as chemical sensor packages. The delivery system is adapted to fit along with the payload within a standardized canister. The delivery system includes a parafoil and a guidance control system that includes a global positioning system (GPS) receiver and an electronic compass to detect a deviation and bearing from a desired target. The parafoil is guided by a single motor that turns the parafoil in a horizontal direction perpendicular to the current direction of travel in response to deviations detected from a desired course. The desired course is initially linear until the system reaches a predetermined horizontal radius from the target and then the course becomes a circular path around and above the target.

대표청구항 ▼

1. A guided payload delivery system for delivering a payload to a target on the ground, comprising:a parafoil for reducing a rate of fall of said payload, said parafoil including a first set of control cables for controlling drag on a right side of said parafoil and a second set of cables for contro

1. A guided payload delivery system for delivering a payload to a target on the ground, comprising:a parafoil for reducing a rate of fall of said payload, said parafoil including a first set of control cables for controlling drag on a right side of said parafoil and a second set of cables for controlling drag on a second side of said parafoil;a location sensor for determining a physical position of said delivery system;a horizontal bearing sensor for determining a horizontal bearing of said delivery system;a guidance control coupled to said location sensor and said horizontal bearing sensor for computing a deviation of a trajectory of said physical position from a cylinder extending axially above said target and having a predetermined diameter; anda motor coupled to said guidance control for shortening one of said first set of cables and said second set of cables and lengthening another one of said first set of cables and said second set of cables, in response to said guidance control computing that said trajectory deviates from said cylinder, wherein said shortened set of cables is selected in conformity with a sign of said deviation, whereby said system is guided to land near said target. 2. The guided parafoil delivery system of claim 1, wherein a radius of said cylinder is substantially equal to 100 feet. 3. The guided parafoil delivery system of claim 1, wherein said motor is a single motor that provides all guidance mechanical control for said parafoil. 4. The guided parafoil delivery system of claim 1, wherein said location sensor is a global positioning system (GPS) receiver. 5. The guided parafoil delivery system of claim 1, wherein said horizontal bearing sensor is an electronic compass. 6. The guided parafoil delivery system of claim 1, wherein said guidance control computes a magnitude of said deviation and wherein said shortening and lengthening are applied in proportion to a magnitude of said deviation. 7. The guided parafoil delivery system of claim 1, wherein said system is adapted to fit along with said payload within a container having dimensions substantially less than or equal to one foot per side. 8. The guided parafoil delivery system of claim 1, further comprising:a guidance system container mechanically coupled to said parafoil, wherein said guidance system container contains said guidance control and said motor;a parafoil cover disposed over said parafoil at an end of said guidance system container prior to deployment, and wherein said parafoil cover is ejected during deployment of said parafoil; anda sensor for detecting ejection of said parafoil cover, wherein said sensor is coupled to said guidance control for activating said computing, whereby said motor is activated only after said deployment. 9. The guided parafoil delivery system of claim 1, further comprising:a guidance system container mechanically coupled to said parafoil, wherein said guidance system container contains said guidance control and said motor; anda payload container for enclosing said payload, wherein said payload container and said guidance system container are held in proximity with said payload container prior to deployment, wherein said payload container and said guidance system container separate after deployment, wherein said system further comprises a sensor for detecting separation of said guidance system container and said payload container, and wherein said sensor is coupled to said guidance control for activating said computing, whereby said motor is activated only after said deployment. 10. The guided parafoil delivery system of claim 1, wherein said system further comprises:a guidance system container mechanically coupled to said parafoil, wherein said guidance system container contains said guidance control, said motor and said horizontal bearing sensor; anda payload container mechanically coupled to said parafoil for containing said payload, and wherein said location sensor is a global positioning system (GPS) re ceiver mounted on said payload container and electrically coupled to said guidance control via one or more cables connected between said payload container and said guidance system container. 11. The guided parafoil delivery system of claim 1, wherein said system further comprises a zero position sensor coupled to said motor and further coupled to said guidance control for determining a zero position of said motor, whereby a position of balanced dispensed length of said first set of cables and said second set of cables is detected. 12. The guided parafoil delivery system of claim 1, further comprising a motor control coupled to said motor and further coupled to said guidance control for providing control of said motor in response to instructions received from said guidance control. 13. The guided parafoil delivery system of claim 12, further comprising a shaft position sensor mechanically coupled to said motor, and electrically coupled to said motor control, whereby said motor control controls a rate of said shortening and lengthening. 14. The guided parafoil delivery system of claim 1, wherein said guidance control computes a rate of change of said horizontal bearing, wherein said guidance control further detects when said rate of change of said horizontal bearing exceeds a threshold, and wherein said guidance control sets a length of said first set of cables and said second set of cables to a zero position in response to said guidance control detecting that said rate of change exceeds said threshold. 15. A method for delivering a payload to a target on the ground, comprising:deploying a parafoil mechanically coupled to said payload and further coupled to a guidance system;receiving a physical position of said payload from a location sensor;receiving a horizontal bearing of said payload from a horizontal bearing sensor;computing a deviation of a trajectory of said physical position and said horizontal bearing from a cylinder extending axially above said target and having a predetermined radius; andin response to computing that said trajectory deviates from said cylinder, shortening one of said first set of cables and said second set of cables and lengthening another one of said first set of cables and said second set of cables, wherein said shortened set of cables is selected in conformity with a sign of said deviation, whereby said system is guided to land near said target. 16. The method of claim 15, wherein said receiving a physical position receives said physical position via a global positioning system (GPS) receiver. 17. The method of claim 15, wherein said receiving a horizontal bearing receives said horizontal bearing from an electronic compass. 18. The method of claim 15, wherein said computing computes a magnitude of said deviation and wherein said shortening and lengthening are applied in proportion to a magnitude of said deviation. 19. The method of claim 15, further comprising sensing that said parafoil has been deployed, and wherein said computing is commenced in response to said sensing, wherein said shortening and lengthening are applied only after deployment. 20. The method of claim 15, further comprising:calculating a rate of change of said horizontal position;determining whether or not said rate of change has exceeded a threshold to detect an undesirable flight condition; andin response to determining that said rate of change has exceeded a threshold, setting a length of said first set of cables and said second set of cables to a zero position.