Are there other types of drones other than traditional quadcopters, for example variable-pitch quadcopters [1], that can get more airspeed and thus cover more distance in 15 min?
What about using airplane-style drones (like traditional RC planes) + a parachute to land the package? And this way you could use nitro gas fuel to get better energy density (since you can use one big gas engine instead of having to use four tiny motors)
I have quite strong opinions about this. The only way to ensure efficient, high-load drone flight is to develop a hybrid design which uses wings to generate lift during cruise. The efficiency lost to the rotors is massive.
So I think eventually we will see tilt-rotor designs, where wings take over once the drone is airborne but the rotor disk is pitched horizontal for takeoff and landing. This massively increases energy efficiency, and makes it possible to go a lot faster.
The reason this hasn't been done with larger airplanes (the only prominent example, V-22 Osprey, demonstrates the difficulty), is that combustion engines makes the design prohibitively complex. But with electric motors, it should be very doable.
Wow, that's with a greater degree of mechanical simplicity than I thought possible. But this is exactly what I was talking about. Now if you can somehow reduce propeller drag at high horizontal speeds and also accomodate a payload and/or a larger battery and also handle adverse wind conditions, you'd have something really nice.
Sure, there are potentially other designs that will get somewhat higher speed, though at some point that will require enough extra power that it won't be worth it.
Airplane style drones can fly further, but navigation is more difficult, and parachutes will pose a lot more logistical problems than landing quadcopters (or, more accurately, multicopters; they used octocopters in the demo). One of the nice things about multicopters is how easy control and navigation systems are compared to something like an airplane or traditional helicopter.
The biggest improvement would be from better battery technology. Battery technology is improving, but very slowly compared to, say, transistor density.
Comments
Are there other types of drones other than traditional quadcopters, for example variable-pitch quadcopters [1], that can get more airspeed and thus cover more distance in 15 min?
What about using airplane-style drones (like traditional RC planes) + a parachute to land the package? And this way you could use nitro gas fuel to get better energy density (since you can use one big gas engine instead of having to use four tiny motors)
[1] http://www.youtube.com/watch?v=Vy5Ky50eGJs
I have quite strong opinions about this. The only way to ensure efficient, high-load drone flight is to develop a hybrid design which uses wings to generate lift during cruise. The efficiency lost to the rotors is massive.
So I think eventually we will see tilt-rotor designs, where wings take over once the drone is airborne but the rotor disk is pitched horizontal for takeoff and landing. This massively increases energy efficiency, and makes it possible to go a lot faster.
The reason this hasn't been done with larger airplanes (the only prominent example, V-22 Osprey, demonstrates the difficulty), is that combustion engines makes the design prohibitively complex. But with electric motors, it should be very doable.
There is an RC model called the Quad Shot that sounds similar to what you're describing. http://www.youtube.com/watch?v=IK_-yTrwNtU
Wow, that's with a greater degree of mechanical simplicity than I thought possible. But this is exactly what I was talking about. Now if you can somehow reduce propeller drag at high horizontal speeds and also accomodate a payload and/or a larger battery and also handle adverse wind conditions, you'd have something really nice.
Sure, there are potentially other designs that will get somewhat higher speed, though at some point that will require enough extra power that it won't be worth it.
Airplane style drones can fly further, but navigation is more difficult, and parachutes will pose a lot more logistical problems than landing quadcopters (or, more accurately, multicopters; they used octocopters in the demo). One of the nice things about multicopters is how easy control and navigation systems are compared to something like an airplane or traditional helicopter.
The biggest improvement would be from better battery technology. Battery technology is improving, but very slowly compared to, say, transistor density.