Mimax's profile - activity

Hi there,

i'm currently developing a driver for a gripper. Or let's say.. I'm starting to develop... ;)

Anyway i was looking for a existing driver and found the WubbleGripper and PR2_gripper_action. I'll have a look at them, but i'm wondering why there isn't anything in the driver section mentioned about grippers. In my opinion grippers are probably quite essential in robotics and would be good to have some existing messages/services/actions i could build my stuff on.

Are grippers just too different to have a common base? or what's the reason why there isn't anything?

cheers Mimax

Hi,

I’ve multiple devices communicating via TCP/IP Socket. My intention is to integrate them into my ROS. Now I’m wondering whether it makes sense to have basis TCP/IP Socket Server node in ros, instead of integrating a TCP/IP Socket Connection in every ROS Node for my devices.

This service node should have services like sendByte sendASCII, etc. and publish topic for received data. I know that this is probably not fulfilling the High Level Conept of ROS but I thought it might make sense for my device nodes, since I wouldn’t have to integrate the tcp/socket every time.

Any Ideas on that?

Hi there,

i've already looked into the roswiki and answers. Unfortunately answer.ros search gave me quite a lot of finding for Error and Service... :)

my question is related to failed service calls. Usually a service call returne true. But what if a service call fails. For instance the parameters sent where not valid or some function within the service throws an error.

In this case i would just return a boolean false within the service call and if i call this service by "rosservice call /service param1 param2" in the shell i get and error message:

ERROR: service [/service] responded with an error:

However I haven't seen any way to add an message to failed service call? Is there any way to do this?

cheers Mimax

Hi there,

i've just a litte question regarding calibration of a camera and ROI. If i have calibration values for a camera and change the roi? Does this affect the calibration values in anyway and do i have to do the calibration again?

I thought that i don't have to recalibrate the camera if i just change the ROI since it can be calculated based on the calibration values of the full resolution image.

The reason why i'm asking is the camera_info_manager. I've implemented it and it works quite good.

However if change the ROI it does not affect the camera_info message in terms of ROI. I can either add the ROI to my camera_name and force the user to recalibrate the camera every time a different ROI is set or i modify my camera_info message from manager regarding ROI values.

what's the best solution?

cheers Mimax

Hi,

i haven't been using ros for a while. Today i tried to compile some ros nodes i create last month.

However i was getting an error message... I figured out that it has to do something with my geometry_msgs package.

As i tried to look at the dependencies with

rospack depends geometry_msgs

i got the same error message i got for the make command:

[rospack] woah! expanding the dependency tree made it blow up.
There must be a circular dependency somewhere.
[rospack] circular dependency

i'm using diamondback-desktop-full. I update/reinstalled it. However this didn't make anything better.

Any ideas what i'm messing up?

cheers mimax

Recently I had a discussion with a co-worker about the definition of ROS and what it actually is.

I’m not sure and that’s why I’m posting this question. I’ve seen different definitions. Middleware, Framework, Operating System. But what is the best fitting definition? If there is any!

In my opinion, I see ROS as a mixture:

The high level and service oriented communication concept could be defined as a middleware, whereas the core libraries rather do have framework functionality. And about the term OS - as it does not match the classical definition of a operating system, I’d prepend “Meta” and regard it as a “Meta-Operating System”.

Any thoughts on this?