Difference between revisions of "FPV"
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To build a reliable platform I want to begin with the fundamental basics and then extrapolate more specific products. | To build a reliable platform I want to begin with the fundamental basics and then extrapolate more specific products. | ||
==== Electronics ==== | |||
# Lower frequency will allow greater range, longer wavelength requires larger antenna | # Lower frequency will allow greater range, longer wavelength requires larger antenna | ||
#* Higher frequencies, 2.4GHz or 5.8GHz, will quickly get attenuated by the atmosphere | #* Higher frequencies, 2.4GHz or 5.8GHz, will quickly get attenuated by the atmosphere | ||
| Line 25: | Line 26: | ||
#* Prevent loss of control on servo failure, must be mounted close together to drive force-drive the dead servo, might drop this | #* Prevent loss of control on servo failure, must be mounted close together to drive force-drive the dead servo, might drop this | ||
# Proper cooling of video-transmitter using an appropriate heat-sink and thermal-adhesive | # Proper cooling of video-transmitter using an appropriate heat-sink and thermal-adhesive | ||
==== Plane ==== | |||
# A wing for speed and stability | |||
#* Makes it possible to fly in windy condition and greater distances | |||
# Batteries in front and electronics next to the batteries, suitable motor to create enough lift | |||
#* Front heavy for stable dives when motor is inactive | |||
# Motor mount on or close to the center of gravity | |||
#* Easier to handle at during acceleration and less wobbly | |||
# Antenna for VTx mounted at the end and center of the left-wing, while the two RC-receiver antennas on the other right-wing, shifted 90 degree | |||
#* Minimize interference between the two radio systems, 90 degree angled to allow cross-polarization, both vertical and horizontal for better signal quality at different plane orientations | |||
== Gear == | == Gear == | ||
Revision as of 14:22, 16 January 2011
Flying electronic RC planes from the ground is fun. Piloting a FPV plane from First Person View is really cool. With the arrival of light and powerful video stream transmitters and long range remote RC transmitter modules , the range of flight has increased from line-of-sight to an order-of-magnitude wider.
Research
To build a reliable platform I want to begin with the fundamental basics and then extrapolate more specific products.
Electronics
- Lower frequency will allow greater range, longer wavelength requires larger antenna
- Higher frequencies, 2.4GHz or 5.8GHz, will quickly get attenuated by the atmosphere
- One energy-source, single set of batteries for motor, camera, OSD, VTx, Rx, servos
- Minimized weight, as batteries contribute as the heaviest component
- Receiver antenna diversity for maximum flexibility of the airplane, each antenna 90 degrees perpendicular
- Omni-directional antennas will have a radiation pattern much like a form of a doughnut, with dead-spots center, above and below
- Same radiation polarization on ground station and airplane where possible, alternatively circular polarized ground antenna
- Signal quality of same polarized electric fields can be many tens of dB different [1]
- Parallel 3S 11.1V Lithium-ion Polymer batteries, both on plane and ground station
- Prevents voltage drop if one cell is bad
- Power- and signal-wiring separated as much as possible
- Noise from motor can degrade digital signals if coupled with signal-wires
- Shielded components and twisted wires to eliminate noise and oscillation, PCB ground plate facing interference source
- Minimize both ambient noise and interference from nearby components, think of a long wire as an antenna that picks up anything
- Video-transmitter on a higher frequency band than RC-transmitter, 1.3GHz VTx and 433MHz RCTx
- Having the same frequency/band on VTx and RCRx will cause signal degradation
- Video-transmitter, as well as RC-receiver, powered by 5V voltage from main Lipo-batteries
- When the main engine batteries are drained, for 3S the low voltage limit is 9.6V, the rest of the system can still function
- Clone aileron servo signal to use two servos per wing
- Prevent loss of control on servo failure, must be mounted close together to drive force-drive the dead servo, might drop this
- Proper cooling of video-transmitter using an appropriate heat-sink and thermal-adhesive
Plane
- A wing for speed and stability
- Makes it possible to fly in windy condition and greater distances
- Batteries in front and electronics next to the batteries, suitable motor to create enough lift
- Front heavy for stable dives when motor is inactive
- Motor mount on or close to the center of gravity
- Easier to handle at during acceleration and less wobbly
- Antenna for VTx mounted at the end and center of the left-wing, while the two RC-receiver antennas on the other right-wing, shifted 90 degree
- Minimize interference between the two radio systems, 90 degree angled to allow cross-polarization, both vertical and horizontal for better signal quality at different plane orientations
Gear
Video system
Cameras
- Sony SN555/VSN700 camera - 768x494 resolution, 12V
- Sony SN777 - 752x582 resolution, 12V, can be noisy [2]
Transmitters
- Lawmate - Range of different models
- Airwave
Receivers
- EagleEyes FPV Station - Receiver with antenna diversity, antenna tracking
- Immersion RC Duo 2400 diversity receiver
On-Screen Display
- ImmersionRC EzOSD - Uncluttered display, GPS on-board, signal strength indicator via I2C, current/voltage sensor with Deans
- Eagle Tree OSD Pro
- DOSD
Goggles
- Fat Shark RCV230T/922T Teleporter - All-in-one, limited 320x240 resolution and range [3]
- Fat Shard RCV922 Aviator - Video input, 640x480 resolution, Vin 6-12V [4]
Control system
Radios
The 35MHz radio will not be used, the PPM signal is feed to the long range transmitters.
Transmitters
- ImmersionRC EzUHF transmitter - Connects to any PPM radio via trainer-port, 433 MHz frequency, 200mW or 600mW power-mode, 9-12V prototype model
- Dragon Link transmitter - Transmits at 433MHz, 500mW [7]
- Thomas Scherrer OZ2CPU UHF system - Many hardware revisions, hard to keep track
Receivers
- ImmersionRC EzUHF receiver - 8-channel receivers, diversity signal/dual antenna
- Dragon Link receiver - 500mW
Other
- ImmersionRC EzAntennaTracker - Uses GPS-coordinates from EzOSD inserted in the right audio channel
Planes
- Ritewing Zephyr - Foam wing base [8] [9]
- Multiplex Easystar - Simple glider-plane [10]
- ParkZone Radian PNP - Glider, prop in front, huge easy to spot [11]
- EasyStar - Cross between glider and sport plane, 3-channel, easy to modify [12]
Other
Motor
- Hacker A30-L [13]
Propeller
- Turnigy 10x6 folding blades
Servos
Batteries
- Turnigy S3 2200 mAh
- Zippy S3 2200 mAH - Cheap Hobbyking packs
Charger
- Bantam BC-6 - Korean, high quality
Shops
- readymaderc.com - Offer a range of products from the main manufacturers
