Gender
Male
About
Location
Halifax, Nova Scotia
Please tell us a bit about your UAV interest
Educational Fun
Hometown:
Halifax
Activity Feed
"Ha - This is so old! I started with a Turnigy 9X Tx / Rx set. "
"I agree. I have it check it once a second and it's usually fine, when not it's close enough that the normalize approximation I posted above works fine and it never does the square root. Is you're 1/sqrt() faster than taking path 2 in the FastNorm…"
"Yeah I didn't seen an obvious advantage either, but also didn't even attempt to simplify his matrix rotation - but I thought it was interesting, mostly because I couldn't find any other references to it.
You don't find you need to re-normalize…"
You don't find you need to re-normalize…"
"Seen this? Ternions.
https://www.ma.utexas.edu/mp_arc/c/05/05-53.pdf"
https://www.ma.utexas.edu/mp_arc/c/05/05-53.pdf"
"This mockup is missing acceleration control, but it does limit incremental target advancement to a specified rate and NLerps towards to final target along the shortest 'achievable' path. True acceleration limiting -> trapezoidal velocity control…"
"I find Python really useful for quickly mocking something up. Adding the visualization took about 5 minutes.
Here's a video for those how don't want to install all the python packages. "
Here's a video for those how don't want to install all the python packages. "
"I'm not sure if you dabble in python much or not, but I kept going with that port to experiment with a quaternion based position controller... then borrowed some pygame/pyopengl example code to visualize it.
The controller I put together will let…"
The controller I put together will let…"
"Had some thoughts:
What if you instead of rotating the acc into the earth frame, you instead rotated VERTICAL into the body_frame? This lets you compensate for yaw drift when titled:
if abs(gravity_b_v.x) < cos(radians(15)): gyro_drift_b_v.x =…"
What if you instead of rotating the acc into the earth frame, you instead rotated VERTICAL into the body_frame? This lets you compensate for yaw drift when titled:
if abs(gravity_b_v.x) < cos(radians(15)): gyro_drift_b_v.x =…"
"I think we're doing roughly the same thing.. I don't see where I'm accumulating in the world frame. I just wanted to keep the GyroDrift variable noise free, so it builds with it's own time constant towards correction_Body. "
"And one more tweak...
Add a GyroDrift variable to zero out the Gyro over time:
GyroDrift = Vector(0.0, 0.0, 0.0)
...
GyroVec = Sum(GyroDrift, Vector(MPU.gX, MPU.gY, MPU.gZ))
...
GyroVec = Sum(GyroVec, correction_Body) GyroDrift =…"
Add a GyroDrift variable to zero out the Gyro over time:
GyroDrift = Vector(0.0, 0.0, 0.0)
...
GyroVec = Sum(GyroDrift, Vector(MPU.gX, MPU.gY, MPU.gZ))
...
GyroVec = Sum(GyroVec, correction_Body) GyroDrift =…"
"Ah yes - I think it was my rpy conversion (axis ordering).
Here's a test running with all axes drifiting and the resulting Roll/Pitch is stable.
test2.py"
Here's a test running with all axes drifiting and the resulting Roll/Pitch is stable.
test2.py"
"Hey Phillip, I've been toying with your code for a ACC+GYRO IMU and I'm getting weird results if I inject drift onto the yaw axis...
I'm just playing in simulation, so what I've done is made a static MPU:
(I'm working in python)
class mpu: def…"
I'm just playing in simulation, so what I've done is made a static MPU:
(I'm working in python)
class mpu: def…"
"More to the point: IF the accelerometer is far enough away from the COG that it does show accelerations on rotation above the noise, then you might want to compensate for that. "
"Rotation yes - but you'll get accelerations you wouldn't normally see on a COG placed board. Maybe you'd want some code that anticipates these with all the fancy inertial nav stuff going on in there?
... and then an autotune that starts doing full…"
... and then an autotune that starts doing full…"
"Looks like I'm waking up a pretty old thread - just wondering where this got to since I just started playing with wii-esc for fun. (C based ESC firmware: https://code.google.com/p/wii-esc/)
I'm thinking of putting an RPM controller in the code that…"
I'm thinking of putting an RPM controller in the code that…"
"So I just tried the HQProp 8" reversible props. It hovered at about 60% throttle but drew 60 amps to do it! No vertical acceleration left to speak of. Dual 9's hover somewhere between 40 and 50% and draw about 30-40 amps. All-up weight is 1275g - I…"
