Curious about autorotate

[fijidreamer]

I have no interest in checking it out myself! I was just curious if Typhoon H, or even drones in general, auto rotate upon freefall. If so would there be any benefit other than a minimal amount of stabilization provided by the rotations? Thanks all, I am learning a lot.

 

[jda]

I have no interest in checking it out myself! I was just curious if Typhoon H, or even drones in general, auto rotate upon freefall. If so would there be any benefit other than a minimal amount of stabilization provided by the rotations? Thanks all, I am learning a lot.

From the videos I've seen on youtube they fall like a rock!

 

[robport]

It completely depends on the failure mode. If it loses power, if falls like a rock. It loses one motor and the Yuneec Hex seems not to care. A quad will do weird things, like flipping over or a combination of flipping and spinning and it may drive itself into the ground. It all depends on what type of failure, how high it is, how fast the other motors are turning, it's center of gravity related to the failure and what the flight controller is sensing. It's not an easy physics question to answer unless it loses power.

 

[Steve Carr]

The simple answer is no.......it will not auto rotate like a full size heli.

 

[DoomMeister]

Auto rotate does not look like this:

Unexpected crash without reason

This is what loss of power to the motors looks like in FPV.

 

[Rimulator]

Does not have any inertia in those light blades. The stored energy in three large blades is traded for a flare at landing. The linkage to the blades is mechanical. Their pitch, angle of attack and thereby drag can be managed by a careful pilot. Molded, fixed pitch propellers won't flare, so, no controlled autorotation. A sycamore seed will perform an uncontrolled auto rotation. It's flying surface is blended by a counterweight, and the wing will find a pitch that maximizes efficiency. As a result, lots of spinning, fall is slowed, but it is a system that converts the energy from a fall into rapid rotation.

A quad/hex could autorotate. It would require reserve power to index the props, then it would spin like a top coming down. Using reserve power, it could automatically react to ground proximity by spinning the props, countering the rotation and reducing the landing speed. Possible, and for higher end craft, reasonable.

 

[AV9335]

I have no interest in checking it out myself! I was just curious if Typhoon H, or even drones in general, auto rotate upon freefall. If so would there be any benefit other than a minimal amount of stabilization provided by the rotations? Thanks all, I am learning a lot.

Auto rotation uses stored energy in a rotor system to provide lift in the last descent of a helicopter to the ground. A pilot will control the pitch of the main rotor blades to maintain the RPM of the main rotor to within the limitations of the design parameters (the gravity of the earth provides the energy to keep the main rotor turning) and at the last descent will use the stored energy in the rotor system to provide lift by increasing collective making a controlled one time only landing. You will either sacrifice altitude or airspeed(distance over the ground) to a safe landing spot. Because drones cannot control the pitch of their blades or drag of the blade once it stops providing thrust or lift, a drone cannot auto rotate. It just becomes uncontrollable unless it can fly one motor out. Good question though.

 

[Rimulator]

We are missing a point. Autorotation becomes valuable when there is a possibility that the power system might fail separate from the flight surfaces. In the case of our drones, power systems don't fail. In fact, they are more likely to suffer a collision or destabilizing event.

Instead of autorotation, auto deployment of soft landing technology (balloons, parachute, tethers, etc) or some way to stabilize a damaged craft would be valuable.