Glossary of Terms, Acronyms and Phrases found in RC

February 2013

FC or Flight Controller

A.K.A. MC or Main Controller Flight Controller or "FC" refers to a programmable logic controller responsible for some or all of an aircrafts flight control. These can be simple small circuit boards with 2 or 3 inputs and outputs relying on a gyro to a fully packaged set of real time sensors governed by a cpu and user programmable parameters. Some are full open source systems which can be modified in any way and others are closed and hardcoded with only a few flight parameters available for change.

Failsafe

Failsafe refers to a designed condition or function which is automatically enabled in the presence of a system or component failure.

Examples

1. If a wire to a safety switch is cut, or the switch itself has a mechanical failure, the circuit is left in a "Safe" condition. The JR series of Powersafe receivers have a switch circuit which if broken, cut or disconected while in the "On" condition, the receiver circuit remains "On".

2. If the control radio signal is lost, the onboard flight controller will automatically enable an autonomous, programmed action of landing, returning to home or loitering (position hold). There are many flight controllers with this feature and some which do not allow an immediate return to normal flight without a programmend functional input. In all cases it should be understood that any function designed as a "Failsafe" feature is not, by design, a controlled flight mode and should never be tested by turning off a flight control transmitter to test.

3. Switch activated failsafe - On some flight controllers this is a real and sometimes encouraged function and on most of todays radios can easily be programmed. This can present many problems including fly-aways, crashes, lost aircraft etc. so the use of this should be avoided. While having a switch activate this mode is safer than turning off a control transmitter, very often a fully autonomous flight control is acivated and ther is no gaurantee de-activation is possible until the flight has ended. (See also IOC)

FPV or First Person View

FPV refers to a type of flying where the pilot is virtually sitting in the plane via Virtual Goggles or a video display. It is an exciting way to pilot these aircraft and with goggles, incredibly immersive!

IOC or Intelligent Orientation Control

IOC is a term found in DJI flight control products and refers to two pre-programmed flight modes on multicopters. It is available on products with an active GPS. It is not an autonomous function as throttle and yaw are still fully active and no special function is needed to disable the mode.

1. HL or Home Lock - When active, this control mode allows two directional paths for the Multicopter. If the pitch control is pushed (down) the copter will move in a straight line directly away from the pre-assigned home point. If the pitch control is pulled (up), the aircraft will move in a straight line directly towards the pre-assigned home point.

2. CL or Course Lock - When active and a directional course is established the pitch control moves the copter for and aft on this established course.

It should be noted that Home Lock (HL) is a preferred method of returning to home if orientation is lost or unknown.

RHCP or Right Hand Circular Polarized

Comming soon...

RTH or Return to Home

A.K.A. RTL or Return to Land Generally RTH refers to an autonomous flight mode which brings an aircraft back to a pre-programmed starting point or Way-Point. The functional aspects of RTH can be many from a straightline flight path to a multi point flightpath. RTH often is considered a Failsafe funtion which means the return may be fully automatic. (See also - Failsafe)

OSD or On Screen Display

OSD refers to the listing of set-up or conditional data overlayed on a monitor or Video Goggle display.

• Set-Up OSD - Generally this is found in FPV camera equipment and is a means to view set-up parameters for the camera itself. Adjustments for brightness, white-balance, color depth, etc are ty[pically found here.
• Conditional Data OSD - This is where a builder has put together a means to collect and display telemetry information such as battery condition, flight heading, altitude, distance from home, etc. There are many products which are stand alone as well as integrated to choose from for this functionality. (See also - Telemetry)

I will keep adding to this and don't hesitate to correct me if I have something wrong.