When
the settings have been made and downloaded into the main unit, they can
be tested using the main telemetry display.
The
display on the right shows that the system is in control mode 2, and it
is configured for Z-lock (normal heading-hold) operation, the governor is
ON and the demanded RPM for the governor is 1,650.
It
can also be seen that the pitch/roll controls are currently in 'manual'
mode. If the auto on/off switch on the Tx is turned ON, then the 'Auto'
captions will turn green.
This
status display is very important in verifying that the system is configured
as desired. It indicates exactly what the system is doing and gives closed-loop
confidence that it will behave as expected.
The
CARVEC system has the concept of different 'control modes'. These are usually
configured on the transmitter to correspond to normal flight modes. So, for
example, when the Tx is in 'Normal', CARVEC is in control mode 1. When idle-up
1 is selected, CARVEC switches into control mode 2 and so on.
The
control-mode is determined by the control-channel from the receiver. This
channel also carries information for the two switches used by the system.
One of these is dedicated to switching the auto-pitch/roll control on or off.
The settings for each control mode must be preconfigured using the PC application
and downloaded into the CARVEC system. The advantage of this method is that
only one receiver channel is needed to control all CARVEC selections.
The
control channel is designed so that it is possible to set up most modern transmitters
to work correctly.
There
are 4 possible CARVEC control modes. Each mode is configured independently
for:
1) Tail-rotor control (either direct control with normal gyro damping, or
heading-hold mode)
2)
RPM governor switching and demanded RPM.
The
selections are made using the PC application, then downloaded into the main
unit.
It
can be seen in the example on the right that when control-mode 2 is selected
using the Tx, the system will enter heading-hold mode with a governed rotor
RPM of 1,650. A different RPM can be set by simply clicking on the value and
typing in a new one.
It
is usual to have at least one non-HH and non-governed mode. This is used when
starting the heli and spooling the rotors up to speed.
