What does "??" mean! - (GLOSSARY) - RC Groups
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May 15, 2015, 08:54 AM
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What does "??" mean! - (GLOSSARY)


**This post is constantly updated**

I still consider myself a complete noob when it comes to multirotors and their parts, even though I have flown quite a few smaller quads, and am now moving onto a larger quad (Q500 4K if ever released).

I am very interested in building my own quads, but there is one thing that constantly messes me up when I am reading build logs or suggestions about parts and what they do, and that is all the abbreviations. When experienced guys talk about their builds and such, they have been doing it for so long that they often forget that us noobs have no clue what they are talking about, especially when they start with the jargon and abbreviations.

I think having a list of abbreviations would help a lot and make things easier for people to follow along and understand what is going on.

#
1.2/2.4/5.8Ghz - Frequency for wireless communication,(Radio Control & Video Transmission).
433/915mHz - Frequency for wireless interlink,
(Telemetry)
72/433/915Mhz - 72/433/915mHz:Frequency for wireless communication, (Radio Control)
2s/3s/4s/6s - No. Of cells in the battery that are connected in series, The total voltage is 3.7 times the number of cells.
Note:The Above Frequencies are commonly used for Radio Control,Long Range Systems, Fpv Video Transmission and Telemetry.
Some frequencies are ILLEGAL in some areas.
808 Camera - A common name for a range of tiny “spy” cameras often sold as “Keychain” cameras. There are very light in weight and used by many hobbyists for taking video from multirotor aircraft.

A
Accelerometer - An electronic component which measures acceleration on a given axis (direction) of flight.
Acro/Agility Mode - Mode where the aircraft makes sharp movements (increased angle of attack), Helps for fast forward flight (FFF).
Altitude Hold - Holds the distance from the ground without user input.
AP - Aerial Photography – a field which is growing fast due to smaller cameras and better aerial platforums
Arduino - An open source (free software) project centered around a low cost circuit board which allows for control of objects. It is easily programmable allowing for experimentation. Many quadcopter control boards (FC, Flight Controllers) are built using this board and software.
ARTF / ARF- Almost ready to fly- usually add a receiver (RX) to the model (or other minor equipment) then fly
Autonomous - not subject to control from outside, often used to describe a drone which follows a preset path using GPS or other means, as opposed to being actively steered by radio control.
AUW- All Up Weight
AWG - American Wire Gauge, the lesser the number the lower the resistivity, Usually in values of 12-14-16.
Axis - Used to describe one plane (one line) of potential flight. Most quads have at least 3-axis control and correction built in.

B
Balanced Battery Charger - A charger or internal system for Lipo batteries (or other chemistries) which uses smart technology to properly charge multiple cells within the battery and “balance” them.
Barometric Pressure Sensor - A device which uses barometer readings to determine altitude. In combination with other sensors, these can help drones determine their height above ground.
BEC- Battery elimination Circuit (in electronics it's technically called a BUCK converter cause it bucks down the input voltage to a lower level but in the RC field it's called BEC, there are several types including UBEC [switching] and linear BEC's )
BF - BaseFlight Firmware, is a Port from MultiWii 8-bit firmware for the STM32.
BLDC- Brushless DC motor
BlueScreen - When your fpv receiver has a weak signal, your monitor or tv reverts back to a blue or black screen,Whereas a Non-BlueScreen display will show flakes on top of the video.
BNF- Bind and fly, take model out of box, insert battery and bind to your existing transmitter (TX)
Bobbins - Anti Vibration Balls, Helps Reduce Jello.
Brushless Motor - Lightweight brushless motors are one of the defining features of the recent growth in popularity of electric aircraft. Brushless motors are categorically far more efficient, and far more durable than brushed motors. With small props, they can also be operated without the gearbox often required of lower RPM brushed motors, saving weight and wear on several fragile mechanical linkages. (dronepedia attribution)
Buzzer - Can be set as a beacon to find quads if lost.

C
CA - Cyanoacrylate adhesive – also called superglue. This, along with Gorilla Glue and Liquid Tape, are often used in the building and repair of aerial vehicles.
Callibration - IMPORTANT Proceedure before takeoff that helps to ensure all systems are running, reduces chances of flyaways.
CCD - Charge Coupled Devices. Type of sensor of the camera used for first person view (FPV).
CF - Carbon Fibre, Most Preferred(expensive) material for multirotors, Does affect radio signals however.
CF - CleanFlight firmware, is a Fork form the BF firmware that has many more people involved with the code development.
CG / CoG- Center of gravity
Clean/Dirty Section - Sections that are isolated from each other by bobbins, helps reduce vibration to flight controller (FC) and video gear, CLEAN Section has the flight controller (FC) and Camera, DIRTY has the motors and esc.
CL - Course Lock - DJI specific term
CMOS - Complementary Metal Oxide Semi-Conductor. Type of sensor of the camera used for first person view (FPV).
CP - Circular Polarised Antenna.

D
DC- Direct Current
Diversity - Dual Receiver with Auto switching to best signal available.
DOF - degrees of freedom. Most boards are 6DOF or 10DOF. 6 DOF : gyro and accelerometer (3 gyro axes, 3 accelerometer axes) You can do autolevel with a 6DOF board but no altitude hold, heading hold, and you can't add a GPS. 10 DOF : Gyro, accelerometer, magnetometer, barometer (3 gyro axes, 3 accel axes, 3 mag axes, 1 baro axis). You can do autolevel, altitude hold, heading hold, and add a GPS. (these features are advanced and should not be messed with until you can fly and tune very well)
Drone - A newer, perhaps slang, definition is for any unmanned powered aerial vehicle, although the dictionary has not yet caught up! In terms of the news and current events, it is often used to describe aerial vehicles which can be guided from afar and contain surveillance gear, etc.
Officially, “drone” defines a humming sound or a male bee which mates with the queen.
DVR - Records Video stream to memory card;Flight Recorder that helps to locate last location incase of crash or signal loss.

E
ESC- Electronic Speed controller (this is the 3-phase converter to run brushless DC motor (BLDC) motors)
ESC timing desync" https://www.rcgroups.com/forums/show....php?t=2702444

F
FailSafe - Similar to return to home (RTH), if the signal is lost, the aircraft can be programmed to shut down motors instantly or continue to run motors.
Ferrite-Rings - Used to wrap wires around them to reduce radio frequency (RF) Noise.
FC- Flight Controller
FF- Forward flight
FFF- Fast Forward Flight
FG - Fiberglass , Material used in multirotors.
FHSS - Frequency Hopping Spread Spectrum
Flash - (verb) – To reset and/or add computer code to a chip or controller…. i.e. “I flashed the ESC”.
FlyAway - Moment when your quad has flown off to its grave, not responding to transmitter (TX) inputs and user has no control.
FOV - Field Of View, Specifies the view angle of the camera, Higher the field of view (FOV), the greater the "FishEye" Effect.
FPV- First person view
FPV Filter - Used to remove RF noise and provide "clean" DC current usually to FPV equipment. Ferrite Rings are one method of filtering.

G
GCS - Ground Control Station, Usually an app connected to your device to control your aircraft.
Gimbal - Servo/Motor controlled, Stabilisation device used to remove sudden movements from the footage. Usually 2/3 Axis movement.
GoPro - A line of small lightweight sport cameras which are often flown on multirotors to capture video.
GPS - Global Positioning System, Used in multirotors to obtain position hold and return to home (RTH) facilities.
GS - Ground Station, consists of your video receiver and video display device.
Gyro - Gyroscope - A device that measures angular velocity and helps maintain orientation

H
HeadLess Mode - The aircraft moves in preferred direction no matter the side it faces. Yaw movement does not affect direction.
Helical - Antenna for FPV devices.
Hexacopter - A multirotor aerial vehicle with 6 rotors.
HL - Home lock - DJI specific term
Hobby Grade - One step up from toy grade – these quads or parts are typically designed for better reliability and operation. Examples include quads such as the new RC Logger Extreme Eye One (brushless motors, etc.), the DJI Phantom, AR Drone and Blade 350X QX.

I
IMU - Inertial measurement unit – a combination controller containing both accelerometer(s) and gyro(s) which together can help in orientation, navigation and stabilization, etc.
Inrunner- the stator is surrounding the magnets on this type, housing is stationary and the shaft comes from the inside, usually inrunner motors are larger
Intervalometer - A feature, based in either software or hardware, which allows a camera to take still pictures every “X” seconds. This is often used with AP (Aerial Photography) – also called interval shooting.
IOC - Intelligent Orientation Control - DJI specific term

J
Jello - Jelly Like Effect in Video created when there is alot of vibration passed on to the camera.
JST - A type of battery connector (plug) used on many quads. The other popular style is called the Walkera Connector. You can buy adapters which convert one to the other.

K
KK - The name of a multirotor flight control ( FC ) circuit board, developed initially by Rolf Bakke. The newest models are dubbed KK2. These flight controllers are quite reasonably priced – usually under $35 US each.

L
LDO -Low Drop Out voltage regulator (what a simple linear battery elimination circuit (BEC) is actually)
LHS - Local Hobby Shop – some are lucky enough to have one nearby with resident experts on R/C quads!
Lipo - Also called Lipo or li po, etc.
These are the type of battery (internal chemistry) that most electric drones currently use.
Log - Logarithm, Records Crucial Flight Data that can be viewed later on and troubleshoot problems, Also referred to as BlackBox.
Loiter - Position Hold without user controlling aircraft.
LOS - Line of sight – meaning you should see it (your drone) with your naked eye while flying!
LRS - Long Range System
LVC - Low Voltage Cutoff, Integrated in some receivers to stops use of batteries to prevent damage to them.

M
mAH - milliampere Hour, Used to specify how much charge a battery can hold.
Mobius Camera - A popular lightweight camera built especially for R/C use – it has the capability to take HD video as well as still pictures with a built in shot-to-shot timer (intervalometer).
MOD - modification – quad and drone flyers love to modify their machines in various ways!
MR - Multirotor - Aircraft that is propelled and controlled using multiple propellers(fans).
Multiwii - General purpose software initially developed to support Nintendo Wii console gyroscopes and accelerometers. Now it is used to control multirotor aircraft. The software is now installed on many Arduino circuit boards, including custom models specifically for quadcopters.
MWC - MultiWii Controller which is based on an Arduino 8-bit Atmel processors with Gyro, accelerometer and possibly Baro and Magnetometer chips added. Runs the Open source MultiWii firmware which is edited and build using the Arduino IDE and programming tools.
http://www.multiwii.com/
https://www.arduino.cc/


N
NAZA - An electronic flight controller used on mid-level and above multirotors – produced by a company called DJI, The NAZA contains the main controlled chip along with a gyro, accelerometer, and a barometric altimeter. Optional GPS & Compass modules are available.
Naze32 - an FC based on the STM32 processor and can run the Open source BaseFlight ot CleanFlight Firmware. (Not to be confused with a Naza FC).


O
Octocopter - An aerial vehicle with 8 rotors.
OPTO - Electronic speed control (ESC) that does not have a built in battery elimination circuit (BEC), Generally used when power is drawn from battery directly.
OSD- On Screen Display – a device which provides an overlay on the ground monitor screen..usually showing telemetry data such as battery life, altitude, headings, etc.
Outrunner - the outer housing of the brushless DC motor (BLDC) motor that holds the magnets is the part that's connected to the shaft and spins around the stator (the windings)

P
Payload - The amount of weight your aerial vehicle may be able to lift in addition to itself and it’s batteries.
PDB- Power distribution board
PID - Proportional, Integral, and Derivative - Gain settings in a closed loop control system.
Pitch - used to describe the angle of flight along one axis – in the case of quadcopters, usually from level.
PPM - Pulse Position Modulation, An easier way of connecting your receiver to your flight controller, By using only one cable it allows for a neater build.

Q
Quadcopter - An aerial vehicle using 4 rotors, commonly using only the varying speed of the motors to achieve both stability and direction of flight.

R
RAW - format used in some cameras for digital still pictures – RAW files contain all of the information the camera sees and are not compressed and processed like jpg files.
RC - Radio Controlled - Any vehicle that is controlled remotely by a transmitter.
RC rate (rates, control rate) - How much the input from the receiver is interpreted. A higher RC rate means the quad will respond more to inputs from the controller (A given stick movement will cause the quad to bank more).
Receiver Pack - Seperate Battery used to power reciever without having to use the pack powering motors.
Retracts - Remote Controlled Landing Gears that can be used to remove the legs of the quad from the vision of the camera.
RF - Radio Frequency
RF Noise - Any unwanted signal that occurs at radio frequencies. Can be generated by any device; common sources include switches, brushed motors and any non-linear device.
RSSI- Received Signal Strength Indicator
RTF- Ready to fly, take model and transmitter (TX) out of box, plug in battery, take off and fly
RTH - Return to Home, Allows for the quad to return to its position of take off if something goes wrong like signal loss.
RX - Receiver -

S
Satellite Lock - For global positioning system (GPS) enabled quads, No. Of Satellites connected to, Enables user to check if there are enough satellites locked on before takeoff.
Servo - short for servomotor or servomechanism. On quadcopters and other aerial drones, these are used for various tasks (pan cameras, adjust wing flaps) and controlled by the radio from the ground.

T
Telemetry: - Signal sent back to transmitter ,usually with data on voltage and received signal strength indicator (RSSI.)
Throttle - Control used to increase or decrease the RPM (speed) of the electric motors
Toy Grade - Describes many of the common quadcopters which cost less that $100 – these use very inexpensive components and are somewhat disposable. Reliability can be spotty, however they provide a lot of functions for the price.
TPU (Thermoplastic Polyurethane) - TPU is a rubberized plastic that can protect parts in crashes and reduce vibrations by absorption, this can help prevent jello in video recordings. E.g. Camera mounts, motor mounts.
TVL - Specifies the number of lines (Horizontol/Vertical) the camera has, the more the greater the quality.
TX - Transmitter - Used to control the multirotor, and make it move and various other functions to control functions of the quad.

U
UAV - Unmanned Aerial Vehicle (drone, etc.) or unmanned autonomous vehicle
UHF - Ultra High Frequency, Used for Long Range Systems.
Ultrasonic Sensor - A sensor which uses sound waves – in the case of quadcopters and multirotors they are usually used to determine the distance from the ground by bouncing sound waves off of it. In typical use, they work only for a few meters above the ground or other surface.

V
Vtx- video transmitter (the part that goes on the quad to send the video back)
Vrx- the part that receives the video for the display / screen / goggles

W
Watts - Wattage, Total Battery Voltage multiplied by Amperes(mAH/1000), Used to find out the total watts required from a charger.
Waypoint - A location defined by a set of coordinates that identify a point in physical space. Waypoints are used for mapping out autonomous missions for quadcopters.
WOT - Wide Open Throttle – throttle stick on maximum!

X
X8 - Configuration of a quad where dual motors are placed back to back on the same axis of the quad.

Y
Yaw - used to describe the rotation of a quadcopter on a level plane around it’s center axis

Z


I'm sure there are others I'm forgetting now, and as this list grows, I'll format it better so people can find what they are looking for.

If you are going to make a suggestion for this list, please list the abbreviation, what it means, and possibly a quick definition of what it does.

Thank you to Droneflyers for the use of definitions listed on their site.
Last edited by Vimlossus; Jun 02, 2017 at 08:33 AM.
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May 15, 2015, 10:45 AM
I void warranties
OSD- On screen display
Vtx- video transmitter (the part that goes on the quad to send the video back)
Vrx- the part that receives the video for the display / screen / goggles
FPV- First person view
FF- Forward flight
FFF- Fast Forward Flight
FC- Flight Controller
RTF- Ready to fly, take model and tx out of box, plug in battery, take off and fly
BNF- Bind and fly, take model out of box, insert battery and bind to your existing tx
ARTF / ARF- Almost ready to fly- usually add a Rx to the model (or other minor equipment) then fly
ESC- Electronic Speed controller (this is the 3-phase converter to run BLDC motors)
BLDC- Brushless DC motor
Outrunner - the outer housing of the BLDC motor that holds the magnets is the part that's connected to the shaft and spins around the stator (the windings)
Inrunner- the stator is surrounding the magnets on this type, housing is stationary and the shaft comes from the inside, usually inrunner motors are larger
DC- Direct Current
BEC- Battery elimination Circuit (in electronics it's technically called a BUCK converter cause it bucks down the input voltage to a lower level but in the RC field it's called BEC, there are several types including UBEC [switching] and linear BEC's )
LDO -Low Drop Out voltage regulator (what a simple linear BEC is actually)
PDB- Power distribution board
AUW- All Up Weight
CG / CoG- Center of gravity
RSSI- Received Signal Strength Indicator

That's all I got off the top of my head...
May 15, 2015, 11:06 AM
Registered User
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Thanks Cereal_Killer, those are really helpful!
May 15, 2015, 12:37 PM
I have a degree in crashing!
NoLimitRC's Avatar
Telemetry: Signal sent back to transmitter ,usually with data on voltage and RSSI.
GS: Ground Station, consists of your video receiver and video display device.
BlueScreen: When your fpv receiver has a weak signal, your monitor or tv reverts back to a blue or black screen,Whereas a Non-BlueScreen display will show flakes on top of the video.
AWG: American Wire Gauge, the lesser the number the lower the resistivity, Usually in values of 12-14-16.
Gimbal: Servo/Motor controlled, Stabilisation device used to remove sudden movements from the footage. Usually 2/3 Axis movement.
CCD:Type of sensor of the camera used for FPV, Charge Coupled Devices.
CMOS:Type of sensor of the camera used for FPV, Complementary Metal Oxide Semi-Conductor.
LRS: Long Range System.
UHF: Ultra High Frequency, Used for Long Range Systems.
1.2/2.4/5.8Ghz: Frequency used to transmit signal for FPV or Radio Systems.
72/433/915Mhz: Frequency used to transmit signal for FPV or Radio Systems.
CP: Circular Polarised Antenna.
Helical: Antenna for FPV devices.
Diversity: Dual Receiver with Auto switching to best signal available.
X8: Configuration of a quad where dual motors are placed back to back on the same axis of the quad.
2s/3s/4s/6s: No. Of cells in the battery that are connected in series, The total voltage is 3.7 times the number of cells.
GCS: Ground Control Station, Usually an app connected to your device to control your aircraft.
PPM: Pulse Position Modulation, An easier way of connecting your receiver to your flight controller, By using only one cable it allows for a neater build.
OPTO: ESC that does not have a built in BEC, Generally used when power is drawn from battery directly.
CF: Carbon Fibre, Most Preferred(expensive) material for multirotors, Does affect radio signals however.
FG: Fiberglass , Material used in multirotors.
GPS: Global Positioning System, Used in multirotors to obtain position hold and RTH facilities.
RTH: Return to Home, Allows for the quad to return to its position of take off if something goes wrong like signal loss.
Loiter: Position Hold without user controlling aircraft.
HeadLess Mode: The aircraft moves in preferred direction no matter the side it faces. Yaw movement does not affect direction.
Yaw: Rotation on a fixed axis.
FailSafe: Similar to RTH, if the signal is lost, the aircraft can be programmed to shut down motors instantly or continue to run motors.
Satellite Lock: For GPS enabled quads, No. Of Satellites connected to, Enables user to check if there are enough satellites locked on before takeoff.
Buzzer: Can be set as a beacon to find quads if lost.
Ferrite-Rings: Used to wrap wires around them to reduce RF Noise.
RF Noise: Insert Suitable Description :P
FlyAway: Moment when your quad has flown off to its grave.
Altitude Hold: Holds the distance from the ground without user input.
FOV: Field Of View, Specifies the view angle of the camera, Higher the FOV, the greater the "FishEye" Effect.
Will add more later. Also some might not be for multirotors and more towards fpv.






UPDATe:



mAH: milliampere Hour, Used to specify how much charge a battery can hold.
Watts: Wattage, Total Battery Voltage multiplied by Amperes(mAH/1000), Used to find out the total watts required from a charger.
Retracts: Remote Controlled Landing Gears that can be used to remove the legs of the quad from the vision of the camera.
FOV: Field Of View, Specifies the view angle of the camera, Higher the FOV, the greater the "FishEye" Effect.
TVL: Specifies the number of lines (Horizontol/Vertical) the camera has, the more the greater the quality.
Jello: Jelly Like Effect in Video created when there is alot of vibration passed on to the camera.
Bobbins: Anti Vibration Balls, Helps Reduce Jello.
Clean/Dirty Section: Sections that are isolated from each other by bobbins, helps reduce vibration to FC and video gear, CLEAN Section has the FC and Camera, DIRTY has the motors and esc.
Log: Logarithm, Records Crucial Flight Data that can be viewed later on and troubleshoot problems, Also referred to as BlackBox.
Acro/Agility Mode: Mode where the aircraft makes sharp movements (increased angle of attack), Helps for FFF.
Callibration: IMPORTANT Proceedure before takeoff that helps to ensure all systems are running, reduces chances of flyaways.
LVC: Low Voltage Cutoff, Integrated in some receivers to stops use of batteries to prevent damage to them.
FPV Filter: Used to remove RF noise and provide "clean" DC current usually to FPV equipment. Ferrite Rings are one method of filtering.
Receiver Pack: Seperate Battery used to power reciever without having to use the pack powering motors.
DVR:Records Video stream to memory card;Flight Recorder that helps to locate last location incase of crash or signal loss.

If you want you can add DJI specific terms like Home Lock(HL), Course Lock (CL) and Intelligent Orientation Control(IOC),They will help the Phantom Pilots.
Last edited by NoLimitRC; May 16, 2015 at 05:38 AM.
May 15, 2015, 02:38 PM
OHR
OHR
Registered User
Excellent thread! Thank you.
May 15, 2015, 04:50 PM
FA3PR9WM79
Oldgazer's Avatar
Well Done Guys!

I've asked the mods to make this thread a stickie...
May 15, 2015, 08:09 PM
Registered User
Vimlossus's Avatar
Added NoLimitRC's items. There is some great stuff in here and I've learned a lot of things already!
Last edited by Vimlossus; May 16, 2015 at 12:09 AM.
May 17, 2015, 03:54 PM
I have a degree in crashing!
NoLimitRC's Avatar
If we can merge these words and the ones already above, this would be a priceless sticky thread for beginners
http://www.droneflyers.com/definitions/
But first we have to take permission from droneflyers admin.
May 17, 2015, 05:29 PM
Registered User
Vimlossus's Avatar
Added your updated NoLimitRC. I'll also add the DJI specific lingo as well since I think we need to cover just about everything.
May 18, 2015, 06:46 AM
Registered User
Thanks. This will be very helpful.
May 18, 2015, 08:05 AM
Registered User
Vimlossus's Avatar
I've been trying to keep up with every post in the beginners section here, and as I read them, if there are things I don't understand, I will post and ask here.

Here are two things I just saw on a post and have no clue what they mean.

PIDS - I hear about this a lot, but don't quite know what it is.

Alt hold D-value - The alt hold I understand, but what is the D-value referring to?
May 18, 2015, 08:35 AM
FA3PR9WM79
Oldgazer's Avatar
Quote:
Originally Posted by Vimlossus
I've been trying to keep up with every post in the beginners section here, and as I read them, if there are things I don't understand, I will post and ask here.

Here are two things I just saw on a post and have no clue what they mean.

PIDS - I hear about this a lot, but don't quite know what it is.

Alt hold D-value - The alt hold I understand, but what is the D-value referring to?
PID is an acronym for the gain settings in a closed loop control system. This type of controller has 3 settings, Proportional, Integral, and Derivative.

http://en.wikipedia.org/wiki/PID_controller
May 20, 2015, 02:51 AM
Registered User
The title/subject of this post should be corrected to something more suited like "Multirotor Acronyms, Abbreviations & Terms" or something like so
May 22, 2015, 03:53 AM
I have a degree in crashing!
NoLimitRC's Avatar
Stuck Finally!!
May 22, 2015, 08:04 AM
Registered User
Vimlossus's Avatar
I can tell you, just from me putting this list together, I don't feel like a complete idiot when reading posts about builds and other stuff. I can actually understand what these things mean, even if I don't understand it yet.

If anybody sees something they don't know, definitely ask here and let's get the meaning and/or definition of it