Previously we had _smooth and non-smooth methods in the attitude
controller but as part of the move to quaternions these have been replaced
by a single call which always takes a smoothing gain
The is commit adds a new flight mode called 'Throw' to Copter that enables the copter to be thrown into the air to start motors. This mode can only be netered when the copters EKF has a valid position estimate and goes through the following states
Throw_Disarmed - The copter is disarmed and motors are off.
Throw_Detecting - The copter is armed, but motors will not spin unless THROW_MOT_START has been set to 1. The copter is waiting to detect the throw. A throw with an upwards velocity of at least 50cm/s is required to trigger the detector.
Throw_Uprighting - The throw has been detected and the copter is being uprighted with 50% throttle to maximise control authority. This state transitions when the copter is within 30 degrees of level.
Throw_HgtStabilise - The copter is kept level and height is stabilised about the target height which is 3m above the height at which the throw release was detected. This state transitions when the height is no more than 0.5m below the demanded height.
Throw_PosHold - The horizontal motion is arrested and the copter is kept at a constant position and height.
Leonard Hall
Andrew Tridgell
Randy Mackay
Paul Riseborough