Thread Tools
This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Mar 04, 2013, 04:27 AM
Registered User
Jack Crossfire's Avatar
Thread OP
Discussion

Optical flow tests begin


Profiling the optical flow, there are enough unused clockcycles to theoretically process 400fps with the current algorithm. The highest the current camera can do is 320x240 at 100fps, because that's the highest clockspeed PWM can generate. 640x480 maxes out at 68fps, because the GPIO's can't handle data any faster. It's pretty noisy at 100fps.

A lot of contemplation revealed a test harness for optical flow. There are a lot of variables for desired altitude, focal length, gyro calibration, frame rate, image size. Gyro calibration removes some but not all of the angular motion. It requires a lot of movement to detect anything. If the resolution is too high, the amount of movement can exceed the motion vector range. If the resolution is too low, it can miss a lot of movement.

There are enough clockcycles to scan a much bigger frame. At least it's not catching up to the PX4Flow anymore.

AR Drone test 2 (3 min 42 sec)


The AR Drone's downward camera is 320x240, 18x the area currently scanned by Marcy 2 but probably doable at 30fps. The AR Drone scans the entire field of view at 60fps. In manual horizontal mode, it completely disables the autopilot, giving complete cyclic control until the button is released.
Last edited by Jack Crossfire; Mar 04, 2013 at 09:19 PM.
Sign up now
to remove ads between posts


Quick Reply
Message:
Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Cool Optical Flow Stabilization + GPS stabilization = stay put quadcopter, Arducopter daign Multirotor Drone Talk 5 Jan 26, 2012 12:53 PM
Discussion 3D Optical Flow Motion Tracking of Aerial Video Photoship One Aerial Photography 3 Dec 26, 2009 10:50 AM
DIY Optic Flow Sensor for autolanding (using a cheap Optical Mouse) Bg~ DIY Electronics 3 Oct 01, 2005 06:27 PM