RadioLink Crossflight User Manual

Radiolink Electronic Ltd
www.radiolink.com
48
the HeliRSC servo output based on the collective (throttle stick) on the RC transmitter. This mode can be
used for open loop control of the heli motor, providing no constant head speed control, but is usually used
to setup the feed-forward throttle curve baseline for the Governor mode below. Having a RSC governor is
highly desirable in order to maintain a steady tune point for the stabilization parameters.
(4) AutoThrottle - AutoThrottle requires a rotor speed sensor, and incorporates an advanced autothrottle
governor. This mode will be used if no external RSC governor is present. Primarily for ICE and Turbine
engines. The H_RSC_GOV_x. The parameters needed to set the Throttle Curve mode above, also
should be set correctly for this mode since it uses them as a basis for feed-forward control in the
Governor.
Waringing ; Setting the RSC mode to RC Passthrough requires configuring the RC receiver to hold last value
for the Motor Interlock channel (default is channel 8). If the receiver loses connection to the transmitter and
receiver is not configured correctly, the motor will shutdown and the helicopter will crash! It also means that
the pilot has to be in control of throttle during any altitude holding or autonomous modes. This can be very
difficult, can lead to a crash, and is strongly discouraged. This mode is provided only for some very
specialized, advanced users.
2. Rotor Speed Ramp and Idle Settings
The rotor speed control features an idle setting and start up and shut down logic for throttle control. The
throttle output at H_RSC_IDLE parameter determines the output to heliRSC servo output after the aircraft is
armed, but before the motor interlock is enabled.
When the motor interlock is enabled the rotor speed control will ramp the throttle from the idle setting
(H_RSC_IDLE) to flight setting (this depends on the H_RSC_MODE chosen) based on
the H_RSC_RAMP_TIME parameter . The RSC will prevent take off in non-manual throttle modes and auto
mode until the timer has reached H_RSC_RUNUP_TIME. It is very important to set H_RSC_RUNUP_TIME to
the amount of time it takes for the rotor to spin up to the flight rotor speed. This parameter has to be equal to
or greater than the Throttle Ramp Time parameter (H_RSC_RAMP_TIME).
When the motor interlock is disabled with the rotor at flight rotor speed, the rotor speed control will count down
the same amount of time as specified by the H_RSC_RUNUP_TIME. The RSC will declare rotor speed below
critical based on the Critical Rotor Speed parameter (H_RSC_CRITICAL) and will reset the runup complete
flag. It is best to set the Critical Rotor Speed parameter (H_RSC_CRITICAL) for a percentage of the runup
timer that equates to about three seconds. For example if you had a 10 second runup timer, setting the
Critical Rotor Speed parameter (H_RSC_CRITICAL) to 70% will cause the RSC to declare rotor speed below
critical three seconds from when Motor interlock is disabled. For versions 4.0 and earlier, the autopilot is able
to disarm the aicraft during auto landings after the RSC declares the rotor speed below critical. For versions
4.1 and later, the autopilot waits the length of time of the H_RSC_RUNUP_TIME to disarm the aircraft during
auto landings.
5.5.5 Internal RSC Governor
ArduPilot provides an internal RSC governor (H_RSC_MODE =4) for those applications which do not have
one externally to assure constant rotor head speed. This mode requires the setup of
the H_RSC_THRCRV_x and H_RSC_GOV_x parameters and the use of an RPM sensor for the rotor head
speed. The governor maintains desired rotor speed through a proportional controller adjusted through the
droop compensator and a feedforward controller that uses the throttle curve to help respond to sudden
loading and unloading of the rotor system. The governor is designed to handle changes in environmental
conditions and even changes in the desired RPM from the nominal settings for which the throttle curve was
originally tuned. This is accomplished through the torque compensator which adjusts the reference from the
throttle curve to maintain the desired rotor speed. The governor is designed to maintain the desired RPM

RadioLink Crossflight Specifications

General

Brand	RadioLink
Model	Crossflight
Category	Controller
Language	English