Patent Application
20070272801
Referring to
For the configuration of recovery apparatus 20 in
Referring to
The parafoil 34, which is rectangular in shape, includes four separate control lines 36, 38, 40 and 42. Each separate control line 36, 38, 40 and 42 includes at its upper end a set of four attachment lines 44, 46, 48 and 50 and a connecting element 52 which secures each control line 36, 38, 40 or 42 to its associated set of attachment lines 44, 46, 48 and 50. The opposite ends of each set of attachment lines 44, 46, 48 and 50 are attached to the parafoil 34. As shown in
The opposite end of each control line 36, 38, 40 and 42 is attached to an electro-mechanical motor drive unit 60 for parafoil recovery system 30 which is illustrated in
At this time, it should be noted that other configurations of control lines and their associated motor drives may be utilized for flight control of the recovery apparatus 20 as recovery apparatus 20 descends to its designated landing site. For example, parafoil control lines can be arranged as a pair of control lines controlled by two motor drives or six control lines controlled by six motor drives. Furthermore, bracing structures may be used near parafoil recovery system 30 to keep control lines separated near the electro-mechanical motor drive unit 60.
It should also be noted that the sensor equipment package 24 includes a Radiosonde which is a unit designed for use in weather balloons that measures various atmospheric parameters and then transmits the measured atmospheric parameters to a fixed receiver. A radio frequency of 403 MHz is reserved for transmission of the measured atmospheric parameters to a fixed receiver by a Radiosonde. Sensor equipment package 24 may include electronics other than atmospheric sensors such as cell relays.
A Radiosonde is tied to a helium or hydrogen filled balloon, which lifts the device up through the atmosphere. The maximum altitude the balloon ascends to is determined by the size of the balloon or weight of the balloon material. Balloon sizes can range from about 150 grams to about 3000 grams. An 800 gram balloon will generally burst at about 100,000 feet or 30,000 meters due to lack of external pressure at that altitude. The weight of a Radiosonde is typically 250 grams and Radiosondes are commercially available from various sources such as Vaisala in Finland.
Referring to
Referring to
An extension line 31 connects the recovery system 30 to a spooler 33 within the recovery system support frame 35. Spooler 33 is attached to the base of support frame 35 and is designed to un-reel extension line 31 to allow for the deployment of the recovery system 30 and parafoil 34.
In the embodiment illustrated in
Referring to
Payload trajectory control in the air is accomplished by controlling the relative location of the parafoil 34 and the payload 24 and varying the angle of attack of the parafoil 34. Payload trajectory control in the air may, for example, be accomplished by lowering a portion of the back of parafoil 34. This requires shortening control lines 36 and 40. Further, payload trajectory control in the air may also be accomplished by lowering a portion of the front of parafoil 34. This requires shortening control lines 38 and 42.
Referring to
The guidance control device 72 includes a microprocessor with adaptive guidance algorithms for continuous flight path control of recovery system 30 to a designated landing area. Examples of such algorithms are Kalman filters which can be adaptively modified as flight dynamics for recovery system 30 change from one moment to the next including changes caused by winds, insuring that recovery system 30 travels an optimal flight path to a designated landing area. Guidance control device 72 continuously updates flight dynamics information received from GPS receiver 66.
As shown in
The GPS data continuously calculated by GPS receiver 66 is transferred via an electrical cable 70 to a guidance control device 72. The guidance control device 72 then continuously processes the GPS position and flight dynamics data with a microprocessor containing flight control algorithms which calculates a continuously updated optimal flight path, generating a plurality of digital positioning commands/signals which are converted to an analog format prior to being supplied to a plurality of servo motors 74 and 76. The guidance control device includes a digital to analog converter board to convert the digital signals to an analog format. Electrical cables 78 connect each of the plurality of servo motors 74 and 76 to guidance control device 72.
The microprocessor in guidance control device 72 continuously receives position and velocity (including decent rate) updates from GPS receiver 66 and calculates an updated optimal flight path including corrections for wind. These calculations are then used to correctly maneuver parafoil 34 via servo motors 74 and 76.
At this time it should be noted that guidance control device 72 may be a commercial available light weight, compact, impact resistant digital computer or microprocessor.
The plurality of servo motors each have a shaft and a capstan/spool attached to the shaft of the servo motor. As shown in
The capstan 84 rotates in the clockwise direction to lengthen/extend control line 38 and in the counterclockwise direction to shorten/retract control line 38 (as indicated by arrow 88). The capstan 80 rotates in the counterclockwise direction to lengthen/extend control line 36 and in the clockwise direction to shorten/retract control line 36 (as indicated by arrow 90).
There is a rechargeable battery/power supply 92 mounted within support structure 68 which is connected to guidance control device 72 by an electrical cable 94 to supply power to guidance control device 72. Power for the servos 74 and 76 is routed through guidance control device 72 and electrical cables 78 to each servo 74 and 76. Power for recharging the battery 92 is generally provided by a recharging station at ground facility.
The recovery system 30 also includes a beacon 100 which has an antenna 102 for transmitting radio frequency signals to the ground station. These radio frequency signals provide data relating to the altitude of recovery system 30, the rate of descent of recovery system 30, direction of flight of recovery system 30 and the current position of recovery system 30 including its latitude and longitude. this information is used by the ground station personnel to track recovery system 30 and identify the approximate landing site, while beacon 100 provides continuous transmission to recovery personnel.
During the flight of recovery system 30, signals from beacon 100 may be used by ground station personnel to compute flight trajectory and override guidance control device if necessary. For example, ground station personnel may want to change the landing site stored in the microprocessor of device 72 to a different landing site by overriding the decisions made by the microprocessor to control the flight path of parafoil 34.
Computers at the ground station process beacon 100 signal data calculating new optimal flight path and a rate of descent which is then transmitted to the guidance control device 72. An electrical cable 103 connects the guidance control device 72 to beacon 100.
Upon receiving new flight trajectory information from the ground station, the guidance control device 72 generates new positioning signals which are supplied to the servos for each of the control lines 36, 38, 40, and 42 adjusting the length of each of the control lines 36, 38, 40, and 42 as required to steer the parafoil recovery system 30 on a flight path which allows for a gentle touchdown and soft landing of payload 24.
From the foregoing, it may readily be seen that the present invention comprises a new, unique and exceedingly useful parafoil recovery system which constitutes a considerable improvement over the known prior art. Many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
