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SoLong Solar-Electric UAV 48 hour flight
The era of silent, zero emission flight is upon us. Never run out of fuel again. http://www.acpropulsion.com/whats_new.htm AC Propulsion SoLong UAV Flies for 48 Hours on Sunlight Two Nights Aloft Opens New Era of Sustainable Flight Desert Center, California Friday, June 3, 2005 An airplane that never needs to land might sound impossible, but it is closer to reality now that AC Propulsion’s SoLong has completed a two-day flight fueled only by energy from the sun. SoLong took off at 4:08 PM, Wednesday, June 1 from the sun-baked runway at Desert Center Airport just east of Eagle Mountain in California’s Colorado desert. It remained aloft until Friday when it skidded to a stop at 4:24 PM after 48 hours and 16 minutes in the air. During that time it had fully recharged its batteries during the day and then flown through the night on battery power. Twice. Nothing, save the flagging energy of its pilots on the ground, kept the SoLong from flying for another two days, or ten, or a whole month. The SoLong is an electric-powered UAV (unmanned aerial vehicle) that collects solar energy from photo-voltaic arrays laminated into its wings. It uses energy so efficiently that it can gather enough energy during the day to keep flying all night. Remaining aloft for two nights is the milestone for sustainable flight. One night is possible just by discharging the batteries, but two or more nights means that the plane has to fully recoup and store the energy used at night while flying in the sunlight the following day. Once that is achieved, the cycle can repeat continually, and keep the plane airborne indefinitely. “We flew 24 hours in April”, said Alan Cocconi, SoLong’s creator and chief pilot, “but we split the night in two, flying midnight to midnight. That was a warm up for this flight. It showed us that we were getting enough solar energy during the day but we didn’t have quite enough battery to takes us through the night. Just last week I got new Sanyo high-capacity Li Ion cells. That made the difference” Cocconi is founder, Chairman, and Chief Engineer of AC Propulsion, Inc., a San Dimas, CA-based R&D shop that specializes in high-efficiency electric propulsion. Efficiency is the key to SoLong’s success. The power system includes a high efficiency electric motor driven by a patented split-phase power controller developed by AC Propulsion. The controller gives high power for takeoff and maintains high efficiency even at the low power levels used in steady flight. A variable pitch propeller allows tuning for maximum propulsion efficiency under varying flight conditions. Solar cells that convert solar energy to electricity with an efficiency of 20% are controlled by proprietary peak power tracking software that makes best use of the photovoltaic energy. Much of that energy goes to charge the Li-ion battery pack that powers the motor and a separate pack for the controls and communications. With a charge discharge cycle efficiency over 95%, the Li-ion batteries do not squander the bounty from the solar cells, and at 220 Wh/kg, the Sanyo cells pack a lot of energy without much weight. Still, the battery makes up 44% of the aircraft’s total weight because the air frame uses efficient structure and composite materials so it is light but still strong enough to withstand 30 mph winds. The 6 servos that move the control surfaces use special electronics that were developed for this mission by AC Propulsion to reduce power consumption and to extend durability. “Every system and part on the SoLong was designed to minimize weight and drag, and maximize efficiency” Cocconi stated. He continued, “of course that is true of just about every airplane, but with the SoLong the entire mission depends on efficiency. We had to push everything to the limit.” That included the pilots who flew SoLong from the 5 ft x 8 ft trailer that serves as SoLong’s ground station. Led by Cocconi, the team of crack radio-control and hang glider pilots took turns monitoring flight conditions from the twenty three channels of telemetry plus GPS navigation and video downlink data available in the ground station. The pilot’s job is to find updrafts, avoid downdrafts, and make judicious use of the battery power to maintain altitude and find “good air” that will lift the plane. The energy budget requires riding thermals with the motor off as much as possible during the day. With the motor off, the entire output from the solar wings goes into the battery. The energy margins are so thin, and the weather so dauntingly capricious that the pilot must focus intently, always trying to bank energy, either as battery charge or altitude, that can be drawn upon to get the plane out of trouble when the air turns bad. After 46 hours, with the critical achievement of two nights flown already in the bag, the air did turn bad. In bright clear skies, SoLong flew into an invisible but huge mass of down rushing air that seemed inescapable no matter which direction she flew. Sinking at 5 meters per second even full power was not sufficient to check the descent, SoLong’s altitude reserve diminished rapidly. An abortive early landing seemed a possibility until Cocconi, drawing on 30 years of piloting experience, determination borne of exhaustion, and perhaps some good luck too, found less treacherous air at low altitude. The atmospheric disturbance lasted a total of 20 minutes, and the SoLong was restored on a course of energy equilibrium. The first mission of any flight is to land the plane safely. This is no less true because the SoLong’s pilots remain on the ground. SoLong represents 4 years of work by Alan Cocconi to develop light, strong, and efficient aircraft, control, and propulsion systems. SoLong herself took him the more than a year to build and test. The funding was his own. The consequences of pilot error or system failure would be devastating. But still there is no margin to make the plane stronger than it has to be, or easier to fly, or to add a few extra batteries. The balance points between strength and weight, between stability and drag, between energy and power make a very fine line. On one side of that line are airplanes that cannot fly through the night. On the other side are airplanes that fall from the sky. Many efforts, some extremely well-funded, have tried to find the balance that will keep a solar-powered airplane plane in the air for two consecutive nights. Until today, not one had found it. By three o’clock with good air and full batteries, the 48th hour became a formality to make a numerical milestone – two full days in the air. The network film crew arrived to record SoLong’s historic landing and the jubilation, showing through the fatigue, on the pilots’ faces. Steve Bellknap, Jerry Bridgeman, David Fee, “RCDave” Freund, Chuck Grim and Steve Neu had all ably assisted Alan Cocconi in piloting the SoLong over its record setting flight. They had helped accomplish something never done before, and in doing it the first time, they made it easier to do the next time and then again, and again. Now, it is within the realm of reality that airplanes flying sustainably on rays from the sun may become commonplace, may become useful tools in the service of humans and their environment. SoLong Specifications Wingspan 4.75m Wing area 1.50 m2 Mass 12.6 kg Power sources 120 Sanyo 18650 Li-Ion cells 76 Sunpower A300 solar cells Solar panel nom. power 225 W Battery mass 5.50 kg Max motor power 800W Min electrical power for level flight 95W Stored energy 1200Wh Speed range 27 to 50 mph Max. climb rate 2.5 m/s Control and telemetry range 8,000 m Contact: |
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SoLong Solar-Electric UAV 48 hour flight
Larry Dighera opined
I ran across this flight earlier. there is less here than meets the eye. During the day the pilots, all of whom are experienced RC glider pilots, used thermals so all the solar power collected could be used to charge the batteries for the night time. If the aircraft had had to circle over the same spot, the flight would have been much shorter. Solar cell efficiency and battery storage density need to at least double before true stay aloft forever is going to happen. The era of silent, zero emission flight is upon us. Never run out of fuel again. http://www.acpropulsion.com/whats_new.htm AC Propulsion SoLong UAV Flies for 48 Hours on Sunlight Two Nights Aloft Opens New Era of Sustainable Flight Desert Center, California Friday, June 3, 2005 An airplane that never needs to land might sound impossible, but it is closer to reality now that AC Propulsion’s SoLong has completed a two-day flight fueled only by energy from the sun. SoLong took off at 4:08 PM, Wednesday, June 1 from the sun-baked runway at Desert Center Airport just east of Eagle Mountain in California’s Colorado desert. It remained aloft until Friday when it skidded to a stop at 4:24 PM after 48 hours and 16 minutes in the air. During that time it had fully recharged its batteries during the day and then flown through the night on battery power. Twice. Nothing, save the flagging energy of its pilots on the ground, kept the SoLong from flying for another two days, or ten, or a whole month. The SoLong is an electric-powered UAV (unmanned aerial vehicle) that collects solar energy from photo-voltaic arrays laminated into its wings. It uses energy so efficiently that it can gather enough energy during the day to keep flying all night. Remaining aloft for two nights is the milestone for sustainable flight. One night is possible just by discharging the batteries, but two or more nights means that the plane has to fully recoup and store the energy used at night while flying in the sunlight the following day. Once that is achieved, the cycle can repeat continually, and keep the plane airborne indefinitely. “We flew 24 hours in April”, said Alan Cocconi, SoLong’s creator and chief pilot, “but we split the night in two, flying midnight to midnight. That was a warm up for this flight. It showed us that we were getting enough solar energy during the day but we didn’t have quite enough battery to takes us through the night. Just last week I got new Sanyo high-capacity Li Ion cells. That made the difference” Cocconi is founder, Chairman, and Chief Engineer of AC Propulsion, Inc., a San Dimas, CA-based R&D shop that specializes in high-efficiency electric propulsion. Efficiency is the key to SoLong’s success. The power system includes a high efficiency electric motor driven by a patented split-phase power controller developed by AC Propulsion. The controller gives high power for takeoff and maintains high efficiency even at the low power levels used in steady flight. A variable pitch propeller allows tuning for maximum propulsion efficiency under varying flight conditions. Solar cells that convert solar energy to electricity with an efficiency of 20% are controlled by proprietary peak power tracking software that makes best use of the photovoltaic energy. Much of that energy goes to charge the Li-ion battery pack that powers the motor and a separate pack for the controls and communications. With a charge discharge cycle efficiency over 95%, the Li-ion batteries do not squander the bounty from the solar cells, and at 220 Wh/kg, the Sanyo cells pack a lot of energy without much weight. Still, the battery makes up 44% of the aircraft’s total weight because the air frame uses efficient structure and composite materials so it is light but still strong enough to withstand 30 mph winds. The 6 servos that move the control surfaces use special electronics that were developed for this mission by AC Propulsion to reduce power consumption and to extend durability. “Every system and part on the SoLong was designed to minimize weight and drag, and maximize efficiency” Cocconi stated. He continued, “of course that is true of just about every airplane, but with the SoLong the entire mission depends on efficiency. We had to push everything to the limit.” That included the pilots who flew SoLong from the 5 ft x 8 ft trailer that serves as SoLong’s ground station. Led by Cocconi, the team of crack radio-control and hang glider pilots took turns monitoring flight conditions from the twenty three channels of telemetry plus GPS navigation and video downlink data available in the ground station. The pilot’s job is to find updrafts, avoid downdrafts, and make judicious use of the battery power to maintain altitude and find “good air” that will lift the plane. The energy budget requires riding thermals with the motor off as much as possible during the day. With the motor off, the entire output from the solar wings goes into the battery. The energy margins are so thin, and the weather so dauntingly capricious that the pilot must focus intently, always trying to bank energy, either as battery charge or altitude, that can be drawn upon to get the plane out of trouble when the air turns bad. After 46 hours, with the critical achievement of two nights flown already in the bag, the air did turn bad. In bright clear skies, SoLong flew into an invisible but huge mass of down rushing air that seemed inescapable no matter which direction she flew. Sinking at 5 meters per second even full power was not sufficient to check the descent, SoLong’s altitude reserve diminished rapidly. An abortive early landing seemed a possibility until Cocconi, drawing on 30 years of piloting experience, determination borne of exhaustion, and perhaps some good luck too, found less treacherous air at low altitude. The atmospheric disturbance lasted a total of 20 minutes, and the SoLong was restored on a course of energy equilibrium. The first mission of any flight is to land the plane safely. This is no less true because the SoLong’s pilots remain on the ground. SoLong represents 4 years of work by Alan Cocconi to develop light, strong, and efficient aircraft, control, and propulsion systems. SoLong herself took him the more than a year to build and test. The funding was his own. The consequences of pilot error or system failure would be devastating. But still there is no margin to make the plane stronger than it has to be, or easier to fly, or to add a few extra batteries. The balance points between strength and weight, between stability and drag, between energy and power make a very fine line. On one side of that line are airplanes that cannot fly through the night. On the other side are airplanes that fall from the sky. Many efforts, some extremely well-funded, have tried to find the balance that will keep a solar-powered airplane plane in the air for two consecutive nights. Until today, not one had found it. By three o’clock with good air and full batteries, the 48th hour became a formality to make a numerical milestone – two full days in the air. The network film crew arrived to record SoLong’s historic landing and the jubilation, showing through the fatigue, on the pilots’ faces. Steve Bellknap, Jerry Bridgeman, David Fee, “RCDave” Freund, Chuck Grim and Steve Neu had all ably assisted Alan Cocconi in piloting the SoLong over its record setting flight. They had helped accomplish something never done before, and in doing it the first time, they made it easier to do the next time and then again, and again. Now, it is within the realm of reality that airplanes flying sustainably on rays from the sun may become commonplace, may become useful tools in the service of humans and their environment. SoLong Specifications Wingspan 4.75m Wing area 1.50 m2 Mass 12.6 kg Power sources 120 Sanyo 18650 Li-Ion cells 76 Sunpower A300 solar cells Solar panel nom. power 225 W Battery mass 5.50 kg Max motor power 800W Min electrical power for level flight 95W Stored energy 1200Wh Speed range 27 to 50 mph Max. climb rate 2.5 m/s Control and telemetry range 8,000 m Contact: -ash Cthulhu in 2005! Why wait for nature? |
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SoLong Solar-Electric UAV 48 hour flight
On 19 Oct 2005 20:47:6 -0500, "Ash Wyllie" wrote in
:: Larry Dighera opined I ran across this flight earlier. there is less here than meets the eye. During the day the pilots, all of whom are experienced RC glider pilots, used thermals so all the solar power collected could be used to charge the batteries for the night time. Where did you get that bit of information? If the aircraft had had to circle over the same spot, the flight would have been much shorter. Agreed, if atmospheric convective lift was indeed used to sustain the aircraft during daylight hours. While it's still solar power, but not photovoltaic, it would not be of practical use for sustaining the aircraft indefinitely. Solar cell efficiency and battery storage density need to at least double before true stay aloft forever is going to happen. How did you calculate that factor? Triple-Junction Gallium Arsenide solar cells with efficiencies of about 31% under terrestrial conditions are the most efficient of which I am awa http://www.boeing.com/news/releases/...r_030725s.html HIGH-EFFICIENCY SOLAR CELLS July 25, 2003 News Release A Spectrolab, Inc. associate places wafers on platters for epitaxial growth. The wafers are then fabricated into solar cells that will be capable of an unprecedented 36.9 percent efficiency in converting sunlight to energy when exposed to concentrated sunlight. Spectrolab, a Boeing subsidiary, uses these state-of-the-art photovoltaic solar cells in concentrator modules of various sizes and power-generating capabilities. Several modules are already being tested throughout the world by photovoltaic concentrator system manufacturers. These Spectrolab products could be part of terrestrial systems that dramatically reduce the cost of generating electricity from solar energy. Contact: Spectrolab, Inc. Public Relations Department P.O. Box 92919 (S10/S323) Los Angeles, CA 90009 Public Relations (310) 364-6363 www.boeing.com/satellite http://www.spectrolab.com/ Triple-Junction with a minimum average efficiency of 26.5%) developed and manufactured at Spectrolab. Ultra-Triple-Junction solar cells, with a minimum average efficiency of 28.3%, are now in production http://www.spectrolab.com/stores/ Spectrolab has a variety of solar cells in inventory and available in limited quantities. Some of these solar cells are rejects from the production line, others are surplus material from space programs. All are limited to small batches and sold on a first-come first-serve basis. Improved Triple-Junction Gallium Arsenide with efficiencies of about 26.8% (AM0) or about 31% under terrestrial conditions. Some of these solar cells are in excellent condition while others are functionally limited to a certain type of application. Call Mike Kalachian at (818) 898-7540 or send an e-mail to: Mike Kalachian to inquire about what is currently available. If you are ready to place an order, please download the appropriate form, fill it out appropriately and fax it to Mr. Kalachian's attention at: (818) 361-5102 The era of silent, zero emission flight is upon us. Never run out of fuel again. http://www.acpropulsion.com/whats_new.htm AC Propulsion SoLong UAV Flies for 48 Hours on Sunlight Two Nights Aloft Opens New Era of Sustainable Flight [...] |
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SoLong Solar-Electric UAV 48 hour flight
Larry Dighera opined
On 19 Oct 2005 20:47:6 -0500, "Ash Wyllie" wrote in :: Larry Dighera opined I ran across this flight earlier. there is less here than meets the eye. During the day the pilots, all of whom are experienced RC glider pilots, used thermals so all the solar power collected could be used to charge the batteries for the night time. Where did you get that bit of information? Aviation Wek and Space Technologies, IIRC. I probably didn't keep that issue. If the aircraft had had to circle over the same spot, the flight would have been much shorter. Agreed, if atmospheric convective lift was indeed used to sustain the aircraft during daylight hours. While it's still solar power, but not photovoltaic, it would not be of practical use for sustaining the aircraft indefinitely. Solar cell efficiency and battery storage density need to at least double before true stay aloft forever is going to happen. How did you calculate that factor? It was in the article. Triple-Junction Gallium Arsenide solar cells with efficiencies of about 31% under terrestrial conditions are the most efficient of which I am awa http://www.boeing.com/news/releases/...r_030725s.html HIGH-EFFICIENCY SOLAR CELLS July 25, 2003 News Release A Spectrolab, Inc. associate places wafers on platters for epitaxial growth. The wafers are then fabricated into solar cells that will be capable of an unprecedented 36.9 percent efficiency in converting sunlight to energy when exposed to concentrated sunlight. Spectrolab, a Boeing subsidiary, uses these state-of-the-art photovoltaic solar cells in concentrator modules of various sizes and power-generating capabilities. Several modules are already being tested throughout the world by photovoltaic concentrator system manufacturers. These Spectrolab products could be part of terrestrial systems that dramatically reduce the cost of generating electricity from solar energy. Contact: Spectrolab, Inc. Public Relations Department P.O. Box 92919 (S10/S323) Los Angeles, CA 90009 Public Relations (310) 364-6363 www.boeing.com/satellite http://www.spectrolab.com/ Triple-Junction with a minimum average efficiency of 26.5%) developed and manufactured at Spectrolab. Ultra-Triple-Junction solar cells, with a minimum average efficiency of 28.3%, are now in production http://www.spectrolab.com/stores/ Spectrolab has a variety of solar cells in inventory and available in limited quantities. Some of these solar cells are rejects from the production line, others are surplus material from space programs. All are limited to small batches and sold on a first-come first-serve basis. Improved Triple-Junction Gallium Arsenide with efficiencies of about 26.8% (AM0) or about 31% under terrestrial conditions. Some of these solar cells are in excellent condition while others are functionally limited to a certain type of application. Call Mike Kalachian at (818) 898-7540 or send an e-mail to: Mike Kalachian to inquire about what is currently available. If you are ready to place an order, please download the appropriate form, fill it out appropriately and fax it to Mr. Kalachian's attention at: (818) 361-5102 Weight and flexibility arealso important as well. It's not that the goal is impossible, just a little bit off. The era of silent, zero emission flight is upon us. Never run out of fuel again. http://www.acpropulsion.com/whats_new.htm AC Propulsion SoLong UAV Flies for 48 Hours on Sunlight Two Nights Aloft Opens New Era of Sustainable Flight [...] -ash Cthulhu in 2005! Why wait for nature? |
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SoLong Solar-Electric UAV 48 hour flight
On 20 Oct 2005 15:46:26 -0500, "Ash Wyllie" wrote in
:: Larry Dighera opined On 19 Oct 2005 20:47:6 -0500, "Ash Wyllie" wrote in :: Larry Dighera opined I ran across this flight earlier. there is less here than meets the eye. During the day the pilots, all of whom are experienced RC glider pilots, used thermals so all the solar power collected could be used to charge the batteries for the night time. Where did you get that bit of information? Aviation Wek and Space Technologies, IIRC. I probably didn't keep that issue. Thanks for the pointer. There is a lot more information in that article: http://www.aviationweek.com/avnow/se...2F06275p01.xml SoLong Solar-Powered Drone Stays Aloft for 48 Hr. By Michael A. Dornheim 06/26/2005 03:05:12 PM PERPETUAL MOTION People have long dreamed of perpetual flight, and the tipping point was reached earlier this month when a solar-powered drone stayed aloft for 48 hr. It showed that enough energy could be stored during the day to fly the aircraft at night, for at least several days. All that's needed are small, near-term improvements in technology to tip this feat into flights lasting reliably for months. One application, albeit much harder, would be as a radio tower in the sky, giving line-of-sight access across a city. AC Propulsion, a small research company in San Dimas, Calif., made the flight after several years of dedicated effort by its founder, Alan G. Cocconi. Semi-perpetual flight has been sought after for years, most notably by AeroVironment and its solar-powered Helios drone with fuel cell storage (AW&ST Feb. 28, 2000, p. 58). More recently the company has been working on a pure fuel cell week-long flier (see p. 52). But AC Propulsion used lithium-ion laptop computer batteries for storage instead of fuel cells, as well as an overall simpler approach, to become the first to fly through two full nights under solar power (AW&ST Sept. 15, 2003, p. 66). It's a friendly rivalry, as Cocconi has been an important collaborator on several AeroVironment projects. The aircraft is called SoLong and is a powered sailplane of Cocconi's own design with solar cells built into the wing. It weighs 28.2 lb., has a 15.6-ft. span, and takes off with its own 1-hp. motor from a wheeled dolly. The control system includes a sophisticated autopilot with inertial, barometric and GPS references; a television camera gives an over-the-nose pilot's-eye view. It's easy to dismiss the project due to the small size of the aircraft and the 5 X 8-ft. ground station, but the flight system is equal to those many times larger. Still, Cocconi is quick to point out the limitations of the achievement. There was no mission flexibility. The six skilled glider pilots were focused only on soaring to keep the motor off most of the day in order to put more solar power into the battery. No payload was carried, though the TV camera is good for simple reconnaissance. A mostly cloud-free sky on a long summer day and reasonable weather were required. But the flight probably could have lasted a third night, and perhaps a fourth and a fifth. Cocconi landed after 48 hr. 16 min. because the pilots were exhausted, not because the battery was low on juice. The flight started at 4:08 p.m. PDT June 1 with a charged battery; two days later at that time, the charge was down less than 5%. The landing was made at 4:24 p.m. at the Desert Center airport operating base in southeastern California. SoLong is reasonably tough. It has been flown in 30-mph. winds and desert turbulence, and has landed at night with the aid of a pair of 1/2-watt LED "landing lights" in the wing and a set of $2 runway edge lights. The aircraft has flown more than 250 hr. in 60+ flights without being seriously damaged--not bad for a drone. AC Propulsion's multiday flight effort was self-funded and hence less ambitious than AeroVironment's, which was covered by multimillion-dollar contracts from NASA. Helios performance was challenging because it operated in the thin air at 50,000 ft., where more power is needed to loiter because of the high true airspeeds. The benefits of that altitude are that it is above the clouds and the winds are fairly low. Cocconi has an easier job loitering near sea level, though his drone has to be stronger to withstand the frequent turbulence there. Helios could carry some payload, and SoLong hasn't. Helios' regenerative fuel cells were a major headache, and AeroVironment and its contractors were not able to make them work. SoLong's battery has less energy per pound--but it works. Helios was destroyed in a crash in June 2003 (AW&ST Sept. 27, 2004, p. 59). Rather than trying to do everything at once, Cocconi decided to focus on the simplest path to multi-day flight, then build from there. He estimates he spent $20,000-30,000 developing SoLong during a two-year period, the majority of it full-time. Key parameters for endurance are the energy density of the batteries, the efficiency of the solar cells, and other efficiencies such as round-trip battery storage and motor economy at loiter thrust. These are on top of the usual parameters like lift-to-drag ratio, structural weight and propeller efficiency. Technology is improving in two key areas--the solar cells and the batteries. Cocconi made the first 24-hr. flight here with SoLong on Apr. 21-22, comprising two half-nights (AW&ST May 2, p. 19). The 100-cell, 800 watt-hr. battery was not quite big enough for a full night and could not absorb all the day's solar energy. It used LG Chem 18650-size lithium-ion laptop cells storing 185 watt-hr. per kilogram. In late May, Cocconi received Sanyo 18650 cells that could hold 214 watt-hr./kg., a 15% improvement. That, and increasing the battery to 120 cells, tipped performance to the current edge of being barely capable of multi-day flights. The pace of battery improvement has indeed been rapid. SoLong is now fitted with Sunpower A300 single-crystal silicon solar cells about 20% efficient. Each wing has a series string of 38 cells and they cover a total of about 13 sq. ft. producing a nominal 225 watts. They weigh about 2.3 lb. Bending the thin silicon cells to fit the wing contour is tricky and Cocconi has devised techniques to avoid breaking them. "It's like bending a 5-in. square of microscope slide glass," he says. Right now, 28% efficient space-grade cells are available, making 40% more power, but cost about 100 times as much. Covering the wing with them would cost about $150,000, Cocconi says. But that boost in power, along with the next generation of laptop batteries, would make SoLong a no-brainer multi-day airplane with no glider soaring required. Solar cell prices can only go down, and the reality of this craft is close. SoLong was recently modified to include a variable-pitch propeller, and inflight tuning has gained about 10% propeller efficiency. A load cell in the motor mounts, cannibalized from a postal scale, sends real-time thrust readings back to the ground. Pitch is automatically scheduled in flight but can be manually tweaked. The 23-in. prop folds back when not in use. An important factor is to maintain motor efficiency when operating at low loiter power settings. Maximum input is 800 watts for 1-hp. output, but minimum loiter is 95 watts. Cocconi built a special nine-phase motor controller that is 88% efficient at loiter power, including motor geartrain losses, instead of a typical 70-75%. The hollow wings are ribless with stiff sandwich skins to hold the airfoil shape. The solar cells are under the fiberglass outer skin. The fuselage is made of Kevlar and carbon-fiber composites. The lift-to-drag ratio is roughly 20, and the loiter speed is about 28 mph., or 2-3 mph. above stall speed. The autopilot can fly a constant lift coefficient to ease operating on the edge of stall. The ground station plots areas of rising and falling air from telemetry, giving a map to assist the pilots. On the first day, they were aggressively hand-flying to seek the best air; but when they tired on the second day, they would usually tell the autopilot to orbit a GPS waypoint at a defined radius in a good area. The second night was more turbulent and difficult than the first. An ingenious barometric roll sensor picks up static pressures near both wingtips and calculates the bank angle by measuring the flow due to differential pressure between the wingtips. Running the autopilot, flight controls, strobe lights and 5-mi.-range, 23-channel telemetry and TV transmitter takes only 7 watts. Cocconi would like to build a larger aircraft that can fly higher, but both those objectives would make the job more difficult and require bigger improvements in solar cell efficiency, battery energy density and lightweight structure. And that would make him face more of the problems that were tackled by Helios. Energy Budget Per Day (June 1-3 at 33.75 deg. N. Lat.) (estimated by Aviation Week & Space Technology) BATTERY CHARGING (approx. 9 a.m. to 7 p.m. 10 hr.) Solar power in 1.55 kw.-hr. used to charge battery 1.1-1.2 kw.-hr. used for housekeeping(7 watts X 10 hr.) 0.07 kw.-hr. used for motor (95 watts X ~4 hr.) 0.38 kw.-hr. BATTERY DISCHARGING (approx. 7 p.m. to 9 a.m. 14 hr.) Available in battery 1.2 kw.-hr. used for housekeeping (7 watts X 14 hr.) 0.1 kw.-hr. used for motor (95 watts X ~9.5-11.0 hr.) 0.9-1.05 kw.-hr. DIMENSIONS Wingspan 15.6 ft. Wing area 16.1 sq. ft. WEIGHTS Gross weight 28.2 lb. Battery 12.3 lb. Solar cells 2.3 lb. COMPONENTS Battery 120 Sanyo 18650 Li-Ion cells Battery capacity 1,200 watt-hr. Solar array 76 Sunpower A300 solar cells Nominal solar power 225 watts Powerplant Kontronik 800-watt electric PERFORMANCE Speed range 28-50 mph. Min. loiter power 95 watts Max. climb rate 490 fpm. (Battery power alone can climb to approx. 50,000 ft.) Control and telemetry range 5 mi. |
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SoLong Solar-Electric UAV 48 hour flight
HELLO SIR|GE i saw ur plane it seems to be very nice implementation but whether ur plane motor(800watt) produced enough thrust to encounter 12 kg weight.i hope best reply from u.
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SoLong Solar-Electric UAV 48 hour flight
http://www.acpropulsion.com/products-drivesystem.html Drive Systems Since 1992, AC Propulsion has been a leader in development of drive systems which lead the industry in power density and efficiency. Products ranging from 80kW to over 200kW (268 hp) motor output have been built for spirited driving while maximizing vehicle range. Our custom designed induction motors feature high efficiency over a broad operating range, thus achieving drive cycle efficiency comparable to the best PM machines. Smooth and comprehensive energy recovery is provided through traction-controlled regenerative braking. ACP technology includes drive systems that feature an Integrated "Reductive" Charger that delivers up to 18kW of charge power for reduced charger cost, reduced weight and reduced charge time. AC Propulsion designs and engineers drives systems for OEM vehicle companies. Our latest generation is designed to meet the stringent demands of customers for performance, reliability, environmental ruggedness and cost. Our sister company, eMotor Advance, located in Beijing, China, is prepared to provide serial production units to customers worldwide. drive system engine overview Dynamometer Testing Gen 2 Motor Gen 4 Motor with Integrated Inverter Motor with Top Mount Integrated Inverter ================================================== ================= http://machinedesign.com/news/solar-...-days-straight Solar-powered UAV flies two days straight An electric-motor driven UAV (unmanned aerial vehicle) recently completed a 48-hr nonstop test flight using only solar energy. Aug 18, 2005 Machine Design Staff | Machine Design INSHARE COMMENTS 0 The SoLong unmanned aerial vehicle from AC Propulsion recently flew over 48 hr nonstop fueled only by solar energy. The plane sports a wingspan of 4.75 m and weighs 12.6 kg. The SoLong unmanned aerial vehicle from AC Propulsion recently flew over 48 hr nonstop fueled only by solar energy. The plane sports a wingspan of 4.75 m and weighs 12.6 kg. The two-day test demonstrated the feasibility of sustainable flight using solar-electric power. The test flight of the SoLong solar-powered aircraft by AC Propulsion Inc., San Dimas, Calif., was more a test of endurance for its seven ground-based pilots than the craft. The fatigued team, lead by AC Propulsion's chief engineer and SoLong's designer Alan Cocconi, brought the flight to a successful touchdown 48 hr and 11 min after takeoff. The 48-hr mark was mere formality as SoLong could stay flying indefinitely. Power from 76 SunPower Corp. (Sunnyvale, Calif.) solar cells supply the plane's energy. Power distribution among the onboard systems is controlled by management software developed by Cocconi. During daylight flight the nominal 225-W solar array powers all systems and recharges 120 Li-ion cells from Sanyo Corp. The Li-ion cells fulfill the craft's energy demand at night. Propulsion comes from a high-efficiency electric motor driven by a split-phase power controller developed by AC Propulsion. A variable-pitch propeller fine-tunes thrust for different rpm and power settings using a load cell for in-flight thrust measurements. An earlier 24-hr test flight showed the original battery reserve couldn't keep the craft airborne. "We split the first test flight's night in two, flying midnight to midnight," said Cocconi. "We were getting enough solar energy during the day but we didn't have quite enough battery to take us through the night." The Sanyo cells pack 220 W-hr/kg and have a charge-discharge efficiency of over 95%. "That made the difference," Cocconi stated, allowing the SoLong to pass the 48-hr mark. Twelve PIC18 microcontrollers from Microchip Technology Inc., Chandler, Ariz., control and monitor all vehicle systems. Systems under control of the PICs include the autopilot, motor drive, power tracker, six servomotors, the battery monitor, and a tracking downlink antenna. For example, the autopilot controller decodes 13 PWM control signals from the uplink receiver, inputs serial data from the GPS module, and monitors 23 analog sensor channels. Data from all systems and a live video feed from the "cockpit" telemeter to the pilots on the ground. Two servo positioners driven by another PIC18 microcontroller keep the telemetry-link antenna pointed towards the same ground position. The PIC18 computes servosettings using signals from the plane's autopilot and GPS. Efficiency is the key to SoLong's success. Even so, the energy budget required riding thermals with the motor off as much as possible during the day. The variable-pitch propeller folds flat against the fuselage during motor-off flight to minimize drag. SoLong pilots must always try to bank energy, either in the form of stored solar-electric power or aircraft altitude. Pilots draw against either to keep the plane in the air when conditions turn sour. MAKE CONTACT: AC Propulsion Inc., (909) 592-5399, acpropulsion.com Microchip Technology Inc., (480) 792-7200, microchip.com Sanyo Corp., (619) 661-4888, sanyo.com SunPower Corp., (408) 991-0900, sunpowercorp.com ------------------------------------------------------------------------------- http://aviationweek.com/awin/solong-...ys-aloft-48-hr SoLong Solar-Powered Drone Stays Aloft for 48 Hr. SoLong airplane, with lithium-ion batteries to store energy, flies through two nights on solar power. Better batteries are soon to come. Jun 27, 2005 MICHAEL A. DORNHEIM | Aviation Week & Space Technology People have long dreamed of perpetual flight, and the tipping point was reached earlier this month when a solar-powered drone stayed aloft for 48 hr. It showed that enough energy could be stored during the day to fly the aircraft at night, for at least several days. All that's needed are small, near-term improvements in technology to tip this feat into flights lasting reliably for months. One application, albeit much harder, would be as a radio tower in the sky, giving line-of-sight ... THIS CONTENT REQUIRES SUBSCRIPTION ACCESS ================================================== =============================== https://xpda.com/junkmail/junk173/AC...2005-06-05.pdf AC Propulsion’s Solar Electric Powered SoLong UAV June 5, 2005 Alan Cocconi with SoLong at El Mirage Dry Lake in California Steve Neu SoLong landing at the end of its 48 hour flight at Desert Center 441 Borrego Court San Dimas, CA 91773 909 592 5399 www.acpropulsion.com AC Propulsion SoLong UAV June 5, 2005 Background AC Propulsion is a small R&D and manufacturing company specializing in high performance electric drives and vehicles. Since 1991 most of the projects have been automotive, and AC Propulsion has established itself as an industry leader in the field of high performance AC drives and integrated battery-charging systems. The self funded SoLong UAV project builds on this electric propulsion expertise and has produced a small, inexpensive and rugged UAV that has demonstrated multi-day solar powered flight on June 1-3, 2005. Applications The long endurance electric powered SoLong is a unique platform that can be adapted to a variety of remote sensing applications. Its moderate size, the quiet and clean electric propulsion and GPS navigation make it a practical alternative to other available UAVs. The airframe and propulsion system can be easily scaled up or down to accommodate various missions and the R&D effort is continuing towards a fully autonomous UAV data gathering “appliance” with automated launch and recovery. AC Propulsion is eager to find partners and or customers for non-military applications. SoLong specifications Wingspan 4.75m Wing area 1.50 m2 Mass 12.8 kg Power sources 120 Sanyo 18650 LI-Ion cells and 76 Sunpower A300 solar cells Solar panel nom. power 225 W Battery mass 5.6 kg Max motor power 800W Min electrical power for level flight 95W Stored energy 1200Wh Speed range 27 to 50 mph Max. climb rate 2.5 m/s Control and telemetry range 8,000 m 2 AC Propulsion SoLong UAV June 5, 2005 SoLong takes off from a simple wheeled dolly, lands on its belly skid Avionics (above) and propulsion battery (below) fit within 15 cm diameter fuselage. Propeller folds during non-powered flight 3 AC Propulsion SoLong UAV June 5, 2005 Construction Fuselage Kevlar epoxy monocoque with carbon boom. Wings Carbon, Kevlar and glass epoxy composite sandwich with molded in place solar cells using CNC machined aluminum molds. Propeller Molded carbon epoxy with an in-flight adjustable pitch hub and a load cell for inflight thrust measurement. 225 W solar array is molded into the wing surface CNC-machined wing molds provide accurate profile For construction of wing and bonding of solar cells 4 AC Propulsion SoLong UAV June 5, 2005 Avionics 2.4 GHz video and data downlink with 23 channels of telemetry plus GPS nav. data (position, velocity, waypoints etc.) AC Propulsion developed autopilot with differential pressure for wing leveling, 3 axis gyros, accelerometers, and barometric pressure for stability augmentation and pitot pressure for airspeed hold. Ublox OEM GPS module for position information Microchip 8 bit processor running assembly language code for all control and navigation processing. High efficiency AC Propulsion developed digital amplifiers for the 6 control surface servos Propulsion AC Propulsion 9 phase motor drive with 88% minimum DC to motor shaft efficiency over the 60 to 800W range. Kontronik Tango 45-06 3 phase brushless ironless motor with 4.2:1 planetary gear reduction turning a 23 inch folding, variable pitch propeller. 30 volt Li-Ion battery pack of 120 Sanyo 18650 cells 76 Sunpower A300 solar cells. AC Propulsion 300W 4 phase peak power tracker weighing 100g and operating at 98% efficiency. 5 AC Propulsion SoLong UAV June 5, 2005 Ground Station A 5ft by 8ft utility trailer with GPS aimed tracking downlink antenna and 3 computer screens display live video feed and flight instruments, GPS waypoints and altitude coded flight path overlaid on a moving topo map or satellite imagery, and the third is multi function backup. The UAV flight and navigation is controlled using a modified RC model transmitter. The flight and landing is controlled from inside the trailer. Navigation waypoints can be downloaded before flight or set and moved while airborne. Telemetry allows display and monitoring of solar power capture, energy use, battery state of charge and real-time propulsion efficiency. Ground station trailer with 2 axis tracking antenna 6 AC Propulsion SoLong UAV June 5, 2005 Flight screen with live video feed, instrumentation and telemetry Navigation screen displays waypoints and flight path. Trace color indicates rate of climb. 7 AC Propulsion SoLong UAV June 5, 2005 Flight Tests The present prototype has had over 60 flights and 250 hours since July 2004 and is the latest of a series of UAVs designed and flown since 1983 by Alan Cocconi, chairman of AC Propulsion. The SoLong has been operated safely in winds of up to 30 mph and has been flown for many hours at night and has landed in full darkness with only runway marker lights. SoLong flew continuously for 48 hours and 11 minutes on June 1-3, 2005, demonstrating sustainable solar electric flight. 48 hour flight pilots. From left to right:, David Fee, Jerry Bridgeman, Alan Cocconi, Chuck Grim, “RCDave” Freund and Steve Neu Contact Information AC Propulsion 441 Borrego Ct San Dimas CA 91773 Tel: (909) 592 5399 Email: Website: acpropulsion.com 8 ================================================== =========== http://www.alternative-energy-news.i...lane-concepts/ THE 10 BEST SOLAR AIRPLANE CONCEPTS Posted in Solar Power | Transportation Solar Airplane Concepts Recently we posted an article announcing the production of a portable solar charger for airplane avionics. At the end of that article we asked if you thought airplanes could one day be powered by solar. Since then we discovered a whole slew of existing solar airplane concepts and projects that we thought we’d share with you. Click through the following links to visit the related websites. At the bottom of this article you’ll find another opportunity to vote your opinion and leave your comments about the feasibility of solar powered flight. Helios The Helios Prototype solar-electric flying wing was one of several remotely piloted aircraft, also known as uninhabited aerial vehicles or UAVs, that were developed as technology demonstrators under the now-concluded Environmental Research Aircraft and Sensor Technology (ERAST) project. Prior to its loss in an in-flight mishap in June 2003, the Helios Prototype set a world altitude record for propeller-driven aircraft of almost 97,000 feet. Pathfinder Pathfinder was first developed for a now-cancelled classified government program in the early 1980’s to develop a high-altitude, long-endurance aircraft for surveillance purposes. Known as the HALSOL (for High-Altitude SOLar) aircraft, its eight electric motors — later reduced to six — were first powered by batteries. After that project was cancelled, the aircraft was placed in storage for 10 years before being resurrected for a brief program under the auspices of the Ballistic Missile Defense Organization (BMDO) in 1993. With the addition of small solar arrays, five low-altitude checkout flights were flown under the BMDO program at NASA Dryden in the fall of 1993 and early 1994 on a combination of solar and battery power. Centurion The Centurion is a lightweight, solar-powered, remotely piloted flying wing aircraft that is demonstrating the technology of applying solar power for long-duration, high-altitude flight. It is considered to be a prototype technology demonstrator for a future fleet of solar-powered aircraft that could stay airborne for weeks or months on scientific sampling and imaging missions or while serving as telecommunications relay platforms. Although it shares many of the design concepts of the Pathfinder, the Centurion has a wingspan of 206 feet, more than twice the 98-foot span of the original Pathfinder and 70-percent longer than the Pathfinder-Plus’ 121-foot span. Hy-Bird The “Hy-Bird” project plans to fly around the world with a 100% clean electric airplane powered only by renewable energies: solar energy and hydrogen. The goal is to design an airplane, which will use only renewable energies with no greenhouse gas emission, and, to decrease dramatically noise pollution, which airplanes do normally engender.Indeed, photovoltaic cells affixed on the wing and on the horizontal tail will supply sufficient energy for the take off and for on-board power supply. Besides, a fuel cell will fuel the aircraft for cruise flight. An electric engine (more silent than heat engines) will propel Hy-Bird. Inhabitat Article Solar Impulse After four years of research, studies, calculations and simulations, the Solar Impulse project has entered a concrete phase with the construction of an initial prototype with a 61-metre wingspan, referred to by its registration number “HB-SIA”. Its mission is to verify the working hypotheses in practice and to validate the selected construction technologies and procedures. If the results are conclusive, it could make a 36-hour flight – the equivalent of a complete day-night-day cycle – in 2009 without any fuel. EcoGeek Article Solar Challenger Eric Raymond’s dream of a solar powered airplane began in 1979, when Larry Mauro demonstrated his solar powered ultralight glider, named SOLAR RISER. Eric began construction of his design in late 1986. Progress was slow until 1988, when support was found in Japan. With the help of Sanyo and several other corporations the SUNSEEKER was test flown at the end on 1989 as a glider. The motor and prop mechanism were not satisfactory, so an A.C. brushless motor and a folding prop were installed. After many long test flights, a series of flights were initiated across the country. During August of 1990, The SUNSEEKER crossed the country in 21 flights, with 121 hours in the air. Sky Sailor The Sky-Sailor would be carried to Mars in a small aeroshell that would be attached to a carrier spacecraft. Upon reaching the red planet, the aeroshell would be released for direct entry into the Martian atmosphere. From this point, the operations could be decomposed in different phases. It can cover a distance of ~1700 km during a 12-hour period. This allows the airplane to reach many different areas of interest. The exploration mission will end when the airplane crashes normally due to the batteries life cycle and dust deposition on solar panels. Solong Solar UAV The SoLong is an electric-powered UAV (unmanned aerial vehicle) that collects solar energy from photo-voltaic arrays laminated into its wings. It uses energy so efficiently that it can fly all night on energy it gathers from the sun during the day. Remaining aloft for two nights is the milestone for sustainable flight. One night is possible just by discharging the batteries, but two or more nights means that the plane has to fully recoup and store the energy used at night while flying in the sunlight the following day. Once that is achieved, the cycle can repeat continually, and keep the plane airborne indefinitely. Solar Powered Plane Called the Zephyr, it’s an aircraft that can fly continuously using nothing but solar power and “low drag aerodynamics”. The combination of solar panels on the upper wing surface and rechargeable batteries allows Zephyr to be flown for many weeks and even months. The first flight trial of the Zephyr were conducted recently by QinetiQ in White Sands Missile Range, New Mexico. Two aircraft were flown for four and a half and six hours respectively, the maximum flight times permitted under range restrictions. Venus Explorer Concept A Venus exploration aircraft, sized to fit in a small aeroshell for a “Discovery” class scientific mission, has been designed and analyzed at the NASA Glenn Research Center. For an exploratory aircraft to remain continually illuminated by sunlight, it would have to be capable of sustained flight at or above the wind speed, about 95 m/sec at the cloud-top level. The analysis concluded that, at typical flight altitudes above the cloud layer (65 to 75 km above the surface), a small aircraft powered by solar energy could fly continuously in the atmosphere of Venus. At this altitude, the atmospheric pressure is similar to pressure at terrestrial flight altitudes. On Sun, 25 Sep 2016 07:54:42 -0700 (PDT), wrote: HELLO SIR|GE i saw ur plane it seems to be very nice implementation but whether ur plane motor(800watt) produced enough thrust to encounter 12 kg weight.i hope best reply from u. |
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