Here is a video and a 3-views drawing explaining the mechanism of a new tilted coaxial system.
The machine has a frame, and a motor comprising a lower output shaft and an upper output shaft. A lower assembly of blades is fixed to the lower output shaft, and an upper assembly of blades is fixed to the upper output shaft. An orientation module is mounted on the frame, and the motor is fixed on the module. The module includes an orientation unit to pivot the motor around a pitch axis and a rolling axis. The orientation unit comprises a plate mounted on the frame via a pivot link around the pitch axis.
Components embedded in the drone:
- Camera Fatshark Pilot HD
- 200mw 5.8Ghz Tx with Spironet antenna
- 2 JR DS385 sub-micro digital servos
- 1 contrarotating bruhsless motor Maxxprod CR 2805
- 2 ESC brushless 10A
- 1 Lipo Battery 3S 2200 mah
- 1 flight controller uPilot32 (VGR-Systems)
- 1 Graupner Rx for command input
Weight: about 500g
Flight time: 10-11 minutes
The main advantage of the system is the size: features of a big quadcopter but ccarried in a bag pocket.
Comments
Cool design! I think the compactness relative to quadcopters and the mechanical durability relative to traditional co-axial helicopters are great selling points. Keep up the good work!
What about fast forward flight? Does it suffer from pendulum effect?
It could be argued that patents actually drive innovation. If someone has already found a way to solve a problem, and patents it, you'll need to find a different solution to solve the problem.
In my opinion all patent institutions should be eliminated from modern world as it stops innovations and overall growth in technology.
Why not share ideas and solutions with everyone for free? It's a bit shameful to patent solution hundereds if not thousands of people were working on for few decades.
Good work on design though :) I hope many will copy it and design something better for greater good for everyone.
That thing looks cool! It looks pretty stable as well, but accurate balancing will likely be needed for good control.
Is it true you only have one motor or do with CR-Motor do you mean a counter rotating motor? Is that different from two separate motors and can you still use torque differential for yaw control?
Hans,
The coaxial birotor has been invented and patented for years you're right !!! (ex Kamov52)
Your exemple is a simple coax birotor and this technology is used by tons of toys all around the world but it is not the same system as presented here (rigid props, tilted plates, 1 motor, etc.)
Nice to see it fly, even if for a brief period. Your efforts at miniaturizing the coax control system looks simple. I suspect the accelerometers are the feedback for the positional variations of the coax assembly. Small encoders might be tough to use in the vibration prone environment.
This airframe type might be a tool for law enforcement or other tactical uses if the propeller noise can be reduced.
-=Doug
Really cool design. I'm going to build one too :)
http://www.robotshop.com/blog/en/skybotix-coax-autonomous-micro-hel...
Ourobos, you're right, yaw control is applied on motors.
Still need some work on the pid to test it but you can tilt the entire frame even with the battery below, particularly if your integral term is based on error(stick command - real angle). Then, you keep the power of motors aligned with the frame and the yaw applied in a good way. in this way, you can have a very agressive pitch (and roll) flight.
The other solution i tried is to keep the center of gravity very low. In this way, you keep the camera always leveled and you don't need any gimbal to stabilize during translation. in the pid loop, the integral term is based on error(real angle) to stay leveled. Nevertheless, the drone is slower during translation than the first solution.