Quadrotor Helicopters - Quantifying Their Flight Behavior - Discussions

Hi Everyone,

I'm in the process of making an autonomous quadrotor helicopter UAV.

A concept that I have not been able to solidify or find anywhere is what exactly quantifies the manuevering and behavior of a quadrotor helicopter?

For example, if I want the copter to move forward or strafe, I understand that I would need to change the propeller speed of a motor or multiple motors. But the question is by how much? If it's relative, then how much relatively?

I suppose what I really have not been able to find is correlating the adjustment in propeller speed to physical movements. Which motor or motors contribute to increasing the x direction, y direction, z direction, yaw, pitch, and roll? And how do you control the magnitude of these changes, ranging from slight increase to sharp increase?

I believe this is my last grey area in the concept of this project and I really appreciate any help!

Quad's move forward and strafe by first changing their attitude, or their pitch and roll angles, in order to tilt into the direction of their movement.

How much change the rotor speeds need to be and for how long is determined by how your craft is physically set up, in particular the craft's moment of inertia and the length of the rotor arms.

The magnitude of these changes are determined by your compensator, the PID types are perhaps the most popular although there are a few Fuzzy Logic ones around here.

Basically what you would do is change the desired angle that's fed into the compensator, and then let it do the rest. You'll have to setup an overseer program to adjust the desired angle as needed in order to get your desired X, Y, and Z position.

I can tell you right now that your not going to get exact movements just by calculations alone. Your going to need a battery of sensors to determine the craft's attitude and heading as well as some sort of reference system for the bot to determine where it is at, referencing to the starting position will not cut it.

Replies

Allen Babb August 15, 2011 at 4:58pm

Quad's move forward and strafe by first changing their attitude, or their pitch and roll angles, in order to tilt into the direction of their movement.

How much change the rotor speeds need to be and for how long is determined by how your craft is physically set up, in particular the craft's moment of inertia and the length of the rotor arms.

The magnitude of these changes are determined by your compensator, the PID types are perhaps the most popular although there are a few Fuzzy Logic ones around here.

Basically what you would do is change the desired angle that's fed into the compensator, and then let it do the rest. You'll have to setup an overseer program to adjust the desired angle as needed in order to get your desired X, Y, and Z position.

I can tell you right now that your not going to get exact movements just by calculations alone. Your going to need a battery of sensors to determine the craft's attitude and heading as well as some sort of reference system for the bot to determine where it is at, referencing to the starting position will not cut it.

This reply was deleted.