sUAS Training
Lost Link
Expected = continues with mission Not expected o Continue with mission for a short time waiting for link to re-establish o Hovers in area for short time o Returns to home First seeks desired sltitude Returens to home Loiters or hovers at selected altitude for pre-selected tiem Autoland after pre-selected tiem o Should be tested daily
o Crosstracking
How quickly the AV returns to the straight line path if it overshoots
o Bank turning mode:
The AV cuts the corner or hits the waypoint without slowing down. It overshoots the tracking line
o Adaptive coordinated turning mode
The AV cuts the corner, but slows down just before turning to stay on-track better
GCS o Elevated mode
The helicopter altitude is the same as elevation according to Google Map. • Altitude sensor can be affected by weather conditions so an offset of altitude is necessary
GCS-- Normal Height
the system records the helicopter at 0 height reference point above • (+) value means above ground • (-) value means below ground
Auto Pilot Components
(CGI BAG FP) • Compass • GPS • IMU • Barometric Pressure Sensor • Accelerometer • Gyro • Flight Controller • Pitot/Static
Components of Air Vehicle
(PAGE IF AE) • Propulsion (covered in Class #5) • Auto Pilot • Generators • Electrical System • IMU/ GPS • Flight Controller • Attitude Flight Stabilization System (AFSS) • Electrical Speed Control
o Fixed-point mode
(helicopters only) Aircraft fly to the first fixed point accurately, then stay at the fixed point and then fly to the next fixed point.
Types of Sensors
Electro-Optical (EO)
Aliasing to reduce jaggies
Software will smooth images by combine image pixels with adjoining pixels to smooth edges
Blooming
When a pixel color over flows into surrounding pixels Over exposing pixels
IC 2-cycle vs. 4-cycle
• 2-cycle • 4-cycle o 4 strokes Compression stroke Power stroke Intake stroke Exhaust stroke o 2 motions: up and down
Difference between Accelerometer and Gyro
• Accelerometer o Always know which way is up o No error, uses gravity as a baseline o Cannot not measure yaw, which is not affected by gravity • Gyro o Susceptible to drift o Good for instantaneous information • Gyro good for short term changes • Accelerometer good for long term changes • Compass or GPS good for long term changes to yaw
Small UAS architecture
• Air Vehicle • GCS • Payload • Wireless Links
ESC Programmer
• Auto cut off at low voltage o May want to shut off if you have a monitoring system to warn of low voltage Helicopter/Multi-copter = disable, allow battery to run down Fixed wing = enable, airplanes can glide
Battery C-Rating
• C-rating vary from 10C to 65C+ • C-rating tells the discharge rate o 2200mah battery with 20C rating has continuous use rating of 2.2 x 20 = 44amps • C-rating is an indication of quality o Higher C-rating = higher quality • Use high C-rating • Make sure discharge rate is high
Electric Propulsion Systems
• Need a Matched Set o Electric Motor Avoid cheaper motors • Tend to fail/overheat o Electronic speed Control Operates electric motor Converts from DC to AC • Most operate on AC o Propeller o Battery Rated in watts/millihours o Connectors Want to over-size to avoid voltage and amp loss o Watt/Amp Meter Sends real time data while flying
GPS
• Not available indoors, requires a GPS repeater to direct the info towards indoors • Want 7 or more satellites, not 4 like general aviation • Does not drift long term • Can be imprecise due to slow 10Hz refresh rate
Lipo Battery Care
• Number each battery • Keep record of every cycle o Time used o Mah used • Write down the min. and max. voltages on the battery
Sensor data rates
• Range from a typical low of .3 fps ( 1 photo every 3.5 secs) o Slower airspeed to reduce blur • to a high of 120 fps for video
Electric Speed Controllers (ESC)
• Rated by Volts and Amps • Volt Rating: 2-6 cell battery 8-24V • Amp Rating: 40A continuous, 55A burst up to 10 seconds • BEC (Battery Eliminator Circuit) 3A/5V o Get some low voltage from battery without tapping into battery again o Regulates the voltage
Battery Capacity
• Rating are usually fairly accurate • Battery should be discharged no more than 80% o Will damage battery • No advantage to 1P vs. 2P or more • Know your cruise current • 5 am cruise with 2200 mah means o 22./5 x 80% x 60 =21 min. • Second battery in parallel will offer less than double the time due to extra weight especially in a copter. • Gene uses a timer to help to judge battery level
IMU
• Reports o Velocity o Orientation o G-Forces • Uses: o 3 Accelerometers o 3 Gyros o GPS o Pitot/Static o Barometric Pressure Measurements
Advantages of 2-cycle
Higher rpm • smaller size • lighter for same cc • more power for same cc • very high power to weight • less parts • less maintenance • starts easier
Lithium Polymer Disadvantages
o Can very easily blow up and start a fire like a sparkler which burns at a very high temperature and cannot be extinguished o When fully charged, is extremely volatile. Worse than gasoline. Simply dropping it from a table onto a hard surface can set it off o if overcharged, it can blow up o if shorted out, it can blow up o Each cell must be monitored when charging to avoid being overcharged when more than one cell is in series which is always the case. Cells in parallel can be monitored as a group, not individually o Does not like being stored a fully charged. Cycle life is shortened if stored fully charged Store at a half charge o cannot be fully discharged or will stop working o can get quite expensive and large sizes o High end chargers can get expensive o are easily damaged in crash
Missing pixel estimation
o Combination of three color Ex. Cyan, magenta, green Ex. Red , blue, green o Fewer pixels will be less accurate because camera is trying make sense of color with less information
o Whip antanne
o Do not point directly at AV Output like a doughnut, signal in all directions
Electric Motors
o Good idea to oversize motor, to run at less than maximum capacity • Size everything else according to the size of motor
Lithium Polymer Advantages
o High power to weight (Li-Ion is a little better) o High burst output (up to 65C) o Hundreds or thousands of cycles o Inexpensive charging system o Inexpensive for a battery o Decent charge times of 20min - 1 hour o Reliably predict remaining capacity by voltage o Maintains its charge state for a very long time o Slowly degrade
• Emergency Terminology
o Land as soon as Practical RTH o Land as soon as possible Land at nearest and safest LZ o Controlled crash landing No safe LZ available • Crash land in minimal risk area • Hit something soft • Avoid people and property • Avoid wires o Urgent condition Not critical (yet anyway) Radio call is "pan pan pan" o Distress Condition Critical now Radio call is "may day, may day, may day" o Responsibilities PIC or mission Commander is responsible for pre-brief to all personal involved Possess a pre-accident/emergency procedure plan • Review emergency checklist before TO Emergency Procedures • First priority is to recover AV as safely as possible • Take action to recover the sUAS per pilot operation manual • Notify all team members • PIC is to document the sequence of events • Inform ATC of situation should immediate action not resolve the issue o Report last known altitude, heading and location o Call ATC by telephone if radio com is lost o 121.5 o Squawk 7700
• Rechargeable battery types
o Lead acid Car battery • Used to charge small batteries High discharge and charge rate Store fully charged 600 amp battery does not have 600 amp hours • Delivers a lot of current in short period of time o 30 seconds • More like 20-30 amp-hours Charging four 5-amp batteries simultaneously will drain battery completely • Keep car running • Alternator puts out 120 amps o Ni-Cad Look like normal household batteries 1000 or more chargers Replaced by Lithium batteries o Ni-MH Similar to Ni-Cad o Li-Ion Look like AA battery Double voltage or more of Nickel (Ni) batteries Low charge/discharge rate = 1C = 5amps Used on smaller UAVs o Li-poly Similar chemistry to Li-Ion Made to avoid overheating like Li-Ion • Packs made of plastic Made in various sizes Allow for a full burst of amps without damaging battery o Li-Fe Weighs about 50% more than Li-poly • Safer, but not typically used because of weight
• Operations requiring a pilot certificate
o The PIC shall hold, at a minimum, an FAA pilot certificate under the following circumstances: all operations approved for conduct in class A, C, D, and E airspace all operations conducted under IFR all operations approved for nighttime operations all operations conducted at joint use or public airfields all operations conducted beyond line of sight anytime the FAA has determine the need based on the UAS characteristic, mission profile, or other operational parameters note: the FAA may require specific aircraft category and class ratings and manned aircraft depending on the UAS seeking approval and the characteristics of its flight control interface o Operations not requiring a pilot certification: The PIC may not be required to hold a pilot certificate for operations approved and conducted solely within visual line sites in class G airspace. For the PIC to be exempt from the pilot certificate requirement the following conditions must exist in the alternate compliance method described below must be followed: • the operation is conducted in a sparsely populated location, and, • The operation is conducted from a privately owned airfield, military installation, or off airport location. • Visual line of sight operations conducted no further than 1 nautical mile latterly from the UIS pilots and at an altitude of no more than 400 feet AGL at all times • operations shall be conducted during daylight hours only • operations shall be conducted no closer than 5 NM from any airport or heliport • Alternate compliance method: in lieu of a pilot certificate, the PIC must have successfully completed, at minimum, FAA Private pilot ground instruction, and have passed the written exam. • Note: the FAA may require an instrument rating and a specific aircraft category in manned aircraft depending on the UIS seeking approval any characteristics of its flight control interface
o Fresnel Zone
o Various paths contribute to the power transmitted. Higher freqs.= smaller diameters • 2.4 GHz is 8m radius • refer to picture in lesson #4
o Patch Antenna:
o has to be pointed toward aircraft
Ground Control Station (GCS)
• C2 - Command and Control for AV - Tx and Rx and Antenna o RC transmitter - manual control o Laptop computer - autopilot control • Camera controller o A second manual controller just for camera • Video monitor - Rx(s), Diversity o Use multiple antennas depending on distant • Data monitor o Compares to instrument panel in general aviation • Navigation Monitor showing Google Maps (autopilot control) o May have multiple screens for various information • GCS power supply, charger • Battery Charger for AV battery • Power supply for AV battery charger • Antenna tracker, battery, charger o Tracks the antenna in the moving aircraft • Goggles, battery, charger • Battery tester
Barometric Pressure Sensor
• Calibrate before each flight • Block hole from relative wind o Do no block sensor hole (just like static port on r44)
Hyper and multi spectral imaging
• Combines EO and IR set of images for later dissemination • Uses false color
RC vs. UAV (FAA AC 91-57)
• Dated June 9, 1981 • Allows RC aircraft to fly in NAS • Does not allow RC aircraft to be used for commercial purposes • Stay away from populated area • Must be airworthy to fly near spectators • Always give way to full scale aircraft - land • Do not fly over 400 AGL • Within 3nm of airport must contact ATC
Accelerometer
• Determines acceleration relative to gravity • Compares G-forces to gravity • Like smartphone
Airworthiness Certificate
• FAA website- Order#:8130.34B o Display the certificate o Aircraft registration o Inspections o Certification procedures o Flight permits o Flight test areas o Operating limitations o Safety o Modifications o Lost link o Command and Control (C2) o Ground Support Equipment and Procedures
Airspace Operations
• Follow all airspace regulations just like manned flight • Class A o Observers are not required in class A o IFR flight plan • Class B o Currently UAS are not authorized. • Class C o Requests will be handled on a case-by-case basis o Transponder require o Comply to all Charlie regulation • Class D o Requests will be handled on a case-by-case basis o Must comply to all Delta regulations • Class E o If there is a tower, must comply to Delta rules Otherwise comply to Echo rules • Class G o Comply to Golf regulations o Most operations will occur in Golf
Lipo Battery series/parallel
• High cell count (voltages) are obtained through putting packs in series • Series o 1 -cell (3.7V) o 2 (7.4V) o 3 (11.1V) o 4 (14.8V) o 5 (18.5V) o 6 (22.2V) • Parallel o Capacities 100-600 mah 1P (6000mah - 6ah) 2P (12ah) 3P (18ah) 4P(24ah) o Large multi-copter Uses 4 6ah 6S batteries 1S4P configuration 22.2V, 24ah
Battery Sizing
• LiPoly Battery (Lithium Polymer) • Consists of cells • Put them Parallel increases capacity • Put them in Series increase voltage • Normally 3.7V/cell • 4.2V/cell max. o Must be exactly this number, any more is disasterous • 4S3P (4 in Series, 3 in Parallel) o 12 cells o 14.8 o Amps are tripled
LIDAR
• Light detection and ranging • Speed guns use LIDAR • Can be used in agriculture to determine productivity
Linear vs. switching regulators
• Linear regs. Burn off excess voltage by making heat. o Have heat sinks to dissipate heat • Switching regs switch the power on and off very quickly to pass the proper amount of voltage and thus won't heat up o More efficient o Use switching regulators
Lipo battery cycling
• Lipo batteries increase in capacity in the first 2-4 uses • After a few uses, cycle the battery using 3.0v as the end voltage per cell which is 100% discharged • Cycling batteries is bad for them o They do not like to be under 80% discharge o Cycle only when necessary • Write down the date and the capacity on the battery and in a record book • Check the capacity once a year or if questionable • Batteries can last for 5 years or 5 minutes
Advantages of Internal Combustion Engines
• Loner range and endurance • More power. o Electric is limited to 2 HP. o IC is unlimited • Can operate a generator to provide unlimited electrical power • Can be easier to add gas than change batteries and use a charger • Much less expensive in larger sizes. o Batteries very expensive Electric technology is limited to smaller sizes
LWIR
• Long-wave Infra-red • A.K.A Thermal Imaging • Does not require any light to function o NIR requires some light to function • Can be used for border control • Good for fire detection
Emergency Procedures
• Manned aircraft o 85% of accidents are primarily pilot error o 15% of accidents are primarily mechanical failure • Unmanned Aircraft o 10+ times the incident rate of manned aircraft o >50% of accidents are primarily mechanical failure Often fly in more dangerous situations than manned flight • Emergency Response o Aviate Fly first o Navigate Position aircraft properly o Communicate Observer and/or payload operator • As time allows ATC People nearby
MWIR
• Mid-wave Infra-red • Used for air to air missiles o Can see the heat signatures • Not use commercially
Advantages of 4- cycle
• More fuel-efficient • much quieter • exhaust is not critical to performance • muffler can be smaller and more restrictive • more horsepower/torque at lower rpm o both to cycle and 4 cycle usually use gas/oil mixture o 4 cycle uses larger propellers
System Sizing - Speed Controllers
• Most speed controllers are decent quality • Do not use the least expensive ESC • Cheap speed controllers have fewer functions • Larger speed controllers don't add much weight or cost • Speed controllers must be slightly higher in amperage rating than motors o 30 amp motors us 30-40 amp ESC • Built in BEC (Battery Eliminator Circuit) are common and reliable
Propellers
• Must be perfectly sized to avoid motor overspeed o If system pulls too many amps (A), the props are to big. • Carbon Fiber (CF), Wood, or Glass reinforced nylon (GRN) • Folding • 10x6 (Diameter x Pitch) o must be sized perfectly Multi-copter = low pitch • 3-4 inch pitch Gas fixed-wind = high pitch • 12-18 inch pitch • RH or LH (right hand or left hand pitch)
NIR/SWIR
• Near Infra-red • Short wave Infra-red o Requires reflected light • Can see through smoke, fog, haze
Operations: Observers
• See and avoid o Targeting camera o See and avoid camera • Sense and avoid o Many companies working on this now • Radar • Observer qualification o Can be airborne (cannot be the manned pilot) o No further than 1 mile laterally o No further than 3000 ft. vertically o Unaided LOS • Binoculars, etc. can be used momentarily/secondarily only o Poor FOV o Distortion • Know how to read sectional maps • Know how to talk to ATC • Be familiar with NAS • Understand of FAA regulations • Considered crewmember • Cannot be pilot and observer at same time • Have 2nd class medical • Training : must have completed sufficient training to communicate to the pilot any instructions to remain clear of traffic o 14 CFR 91.111, 91.113, 91.155 Operating near other aircraft Right-of-way rules Basic VFR weather minimums ATC phraseology Knowledge of AIM
Radar
• Sends a pulse and reflects back to interpret information
SAR
• Synthetic aperture radar • Used in military to identify multiple targets • Too heavy to be considered for commercial use • Not a camera, it is a combination of antenna
CIR
• Take NIR imagery and use an algorithm to add false color o Generally used in agriculture • Ex. Tetracam
Flight Controller
• The onboard computer which takes information from all onboard sensors (above) and ground control station. Processes the date, sends out the signals to control surfaces and sensors required
System Sizing - Batteries
• Use quality batteries from Thunderpower, and others • Cheap batteries are cheap no matter what the C-rating is • Higher C-rating do not add more weight • Batteries can be the heaviest part of the AV • Use the largest battery the AV can take in terms of size and weight • Batteries are a large cost of the AV o Have multiple so there is no down time during charging • Higher C-ratings cost more
System Sizing - Motors
• Use quality motor • Cheap motors usually have cheap bearings which overheat and blow apart • Oversize the motor by about 2-6 times • Larger motors don't add significant weight. o Better motors can be sized closer to the actual current draw • Electric fixed wing which cruises 5 amps should have a 30 amp motor • Electric multi-copter which hovers at 10ams/motor should have 30 amp motor
Compass
• Used for True heading (TH) • Used when there is no speed since GPS cannot determine orientation with no speed • Does not drift long term • Can be imprecise short term
IR Sensors/Thermopile Sensors
• Used for small electric fixed wing UAVs • 4 sensors • Confused by clouds, haze and mountains
Gyros
• Uses spin to measure direction using stability o Piezo Electric Gyro Vibrates as opposed to spins
Disadvantages of Internal Combustion Engines
• Very high maintenance o 25 hrs ,which may be 1-2 days • Many parts prone to failure • Difficult to troubleshoot • High vibration • Noisy • Requires mufflers • Hot smelly • Messy • Requires starting • May require starting equipment • Require tuning • Altitude Issues • Requires electrical power for ignition • Must mix oil with gas • Must idle when on standby • Needs cool airflow over entire engine • Loses performance as temp increases • All components on the AV require thread locker • Spits fuel out of carb • Requires air filter in dusty environments • Propeller is very strong and very dangerous
• Watts =
• Watts = Volts x Amps
WAAS
• Wide area airborne surveillance • Identifies multi targets simultaneously • Not camera, use antenna
WAMI
• Wide area motion imagery • Not camera, use antenna
Wires and Connectors
• Wire is a resistor o The larger the lawyer the less the resistance. o The longer the wire more the resistance. o Use the shortest way possible. Neater. Lighter. More power. o 28gauge wire is common for under .5 amps o 22gauge wire is common for one - 3 amps o 10 - 12gauge wire for batteries and motors o silicone jacking is preferred o multi-strand wire - 60 strand is required fewer strands will break • Plugs are resistors too o Plugs cause large bolt/amp drops o uses few plugs is possible o soldered directly as much as possible o T - connectors are rated as 60 amps o radio connectors are rated at 3 amps o at 6v/1 amp, each radio plug will drop the voltage about 0.4v
