Does enybody use a 4 quadrant DC motor controller with mode at a plane?
I suggest that its possible to particular recharge a battery at glading mode.
And as a result to fly more time.
What teoretical and practical benefit could be possible from this idea?
Replies
Similarly: can the hollow bodies of the plane be filled with a lifting gas to reduce weight? Will the additional lift justify the weight of making the plane air tight?
Kinetic energy depends on its velocity and mass, which can be considered constant, making velocity the only factor. The equation is E = 0.5 * mass * speed^2. A 10kg plane going 20 m/s (72 km/h) has 2 kJ of energy to draw from. That's about 180 mAh at 11.1 V. Poor.
Potential energy depends on the plane's weight and altitude. Weight is (reasonably) constant, the only variable is altitude then. The equation is E = weight * altitude, or E = mass * gravity * altitude. Again, a 10kg plane flying at 122 m (400ish ft) AGL has a little under 12 kJ of potential energy to draw from. That's about 1000 mAh at 3s voltages. Better.
Note that this assumes 100% efficiency across the board, real numbers will be very small fractions of these.
Also, conservation of energy applies - all the energy that you can possibly extract from these two pools was put there by the plane's engines while climbing/accelerating. Unless you're using thermals very efficiently, this technology will work against you, not for you.
Rec master, All the above said suggestions apply,
If you are comparing or coming from the hybrid motor concept from land automobiles with possibility of using the same in flying objects, then here are some conficting terms IMHO.
1, Primary goal when power regenration/rather power recycleing in automobiles is when you want to stop/braking which happens quite often on the road. Where and when it is not required to brake , there is no regeneration at all.
2. You have lot of mass behind the kinetic energy to use.
3. You brake quite often on the road in traffic.
4. Efficiency of IC engines are not that high and what ever you could recover goes towards the tax saveing loop holes.
5. Worst thing that could happen when regenration is applied in a automobile is either it stops dead in middle of the road or it does not stop at all( and then real braking starts). Primary power is supplied by gas IC engines or other external source. What ever is recovered is used to boost the propultion only , not replace the primary power source.
In flying objects/vehicles ,
1 your primary goal is to stay aloft or keep flying and definitly not stop in mid air. You wouldn't want to brake too often in the air anyway since there is not much of traffic or crossings any way.
2. You stop or brake almost only once in single flight and that is during end of your flight or completion of your mission.
3. To be effective in regeneration , the process should be repeated enough of times to produce enough power to ofset the complicity & cost involved in such process. Thats why solar is best option in air and wind power is best on the land.
4. Worst case scenario , when your brake jams , you crash , best case , you don't brake /regenerate at all. So there is not much to gain for amount of increased point of failures in this case.
5. If your wing is efficient enough then you could thermal which is regeneration indirectly ( ultimatly used to gain altitude or fly longer)). So focusing on thermaling or solar power would be better area to focus IMHO.
6. Focusing on more efficient motors and energy delivey via conversion may lead to near Ideal engine in next couple of decades.
Good luck.
What about regenerative braking on quadrotors? They should have fine control of rotor speed for precise maneuvering - both accelerating the rotor and decelerating it. Couldn't regen braking provide better decel control and allow longer flight times?
Are there any r/c aircraft ESC that have this feature - commercial or open source?
- Roy
There is nothing measurable to be recovered without variable pitch props, lots of research, ultra thermals.
It is better to use slope soaring or solar power, if you are obsessed with this.
You are wasting so much more using inefficient prop+motor (have you tried 50 combinations lately?).
With thermaling, one could probably stay aloft all day. The challenge is staying aloft for a night.
Quinieq (sp?) has done it. They use solar, but Thermaling is also solar.
One difficulty is to find thermals consistently. Another is the altitude required is not recommended for RC flight.
Peter