Course 3 about ros-ethz HOT 4 CLOSED

Hi Javad,
Glad to know my code is useful to you and thanks for the comments.

1. It's a good idea to use a P-controller for x-vel. I will add the component a bit later.
2. Actually we need pillar_pos to be used to update the marker position in vizPillar() at every step, because initPillarMarker() is only called during initialization. Please note pillar_pos is the relative position to the robot and is updated in the laser callback function.
3. I guess it wouldn't matter. Why would you suggest so?

Thanks,
hnqiu

from ros-ethz.

Hi Hnqiu,
Thanks for the reply.
2. I agree with you, but I mean the first two line in vizPillar is repeated in the initPillarMarker. Isn't initPillarMarker called in every function loop?
3. because the msgwill be send before seting the forward velocity. Thus, the current command for forward speed will be used in the next time step. Although cause the time increments is very low, it is not sensible, and the program works.

Kind regards,
Javad

from ros-ethz.

Thanks Javad.

• No initPillarMarker() is only called once at initialization.
• The msg will only be sent to the topic in DriveHusky(), which is called in the laser callback function, which is AFTER initialization. Note callback functions execute when we call spinOnce().

Cheers,
hnqiu

from ros-ethz.

Hi Javad, I've updated the x-vel control in course 3 using a P controller. Thanks for opening the issue.

Cheers,
hnqiu

from ros-ethz.