raahlb's profile - activity

I'm using gscam to stream the view from a USB camera. However, when viewing it in an rviz camera display only a cropped view is shown. It seems like the view is displaced by half the view size to the right and down, so only a quarter of the view is shown. When using image_view everything looks fine. Does anyone know what is causing this problem?

According to mplayer the camera image's resolution is 640x480.

I'm using the default camera_parameters.txt:

# Camera intrinsics

[image]

width
640

height
480

[default]

camera matrix
1.00000 0.00000 1.00000 
0.00000 1.00000 1.00000
0.00000 0.00000 1.00000 

distortion
0.00000 0.00000 0.00000 0.00000 0.00000 


rectification
1.00000 0.00000 0.00000 
0.00000 1.00000 0.00000 
0.00000 0.00000 1.00000 

projection
1.00000 0.00000 1.00000 0.00000 
0.00000 1.00000 1.00000 0.00000 
0.00000 0.00000 1.00000 0.00000 

and this is my GSCAM_CONFIG:

v4l2src device=/dev/video0 ! video/x-raw-rgb, width=640, height=480, framerate=30/1 ! ffmpegcolorspace ! identity name=ros ! fakesink"

Hi, Using a GPL licensed package in a commercial product should not be a problem, right? It ought not force us to release all our own software in the product under the GPL? As long as we're not linking directly towards the package, but rather just send or receive messages from it, that is.

If I understand it correctly, if we use a secret message format that we don't explain to anyone we could get into trouble. But now it's just a Scan message. It should be fine, shouldn't it?

We will still have to distribute the source code of the GPL'ed package of course, if requested too.

Regards, Rasmus Ahlberg

Hi,

I'm using laser_scan_matcher to provide a /odom frame. I understand there are some situations where it will perform very badly, for example in a corridor, as it can be hard for it to detect the forward motion. But, I also have problems with it not being able to detect the forward motion when in a dead-end corridor.

To me, it seems like a dead-end corridor would be a perfect situation: the side walls will be used for detecting rotations, the end wall will be used to detected forward/backward motion. However, it only detects about a tenth of the forward motion, if even that. The robot is only moving forwards and backwards, not turning.

Is there some parameter that could help? Currently I'm more or less randomly changing them, trying to find something that will help. I was thinking that possibly 'outliers_maxPerc' was the culprit, as the corridor is not very wide, so there are few data points from the end wall, but setting it to 0.99 didn't help. I've also tried enabling the alpha-beta filter.

Regards, Rasmus Ahlberg

Hi,

Is there some way to directly link object files (.o) from another package, or is the only possible way to do it to change the build configuration of the second package so it creates a library file?

I have an IMU sensor mounted on my robot, but without properly aligned axes. To more get more easily processed data, I want to transform its output so the axes align. This is quite easily done with some calibration and usage of the dot product. However, there seem to be no math operations defined for Vector3 in geometry_msgs.

Is the proper way to do this to create a new vector of Eigen's format, do the calculations and then convert it back to Vector3? As I've understood there's no way to just cast between the types.