FPV
From ivc wiki
Jump to navigationJump to search
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.
- 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
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
- ET
- 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
- Multiplex Easystar - Simple glider-plane [8]
- ParkZone Radian PNP - Glider, prop in front, huge easy to spot [9]
- EasyStar - Cross between glider and sport plane, 3-channel, easy to modify [10]
Other
Motor
- Hacker A30-L
Batteries
- Turnigy S3 2200 mAh
Charger
- Bantam BC-6 - Korean, high quality
Shops
- readymaderc.com - Offer a range of products from the main manufacturers
