harderthan's profile - activity

Hello.

I have read Unit Test wiki provided ROS wiki. And I found a wrong link which have a 404 error.

How to edit this page? It seem that it need some permission to edit the page.

Could you tell me a solution about this issue?

@gvdhoom Thanks.

There are two unknowns, but you know width of costmap already. x = i % width y = (i - x) / width

There are two unknowns, but you know width of costmap already. x = i % width y = (i - x) / width

There are two unknowns, but you know width of costmap already. x = i % width y = (i - x) / width

Are there any references of Nav2 considering large scale projects or products considering mass production? Hello. I am c

Discussion on this topic is also ongoing on Slack(https://navigation2.slack.com/archives/C012ELU8V2A/p1643352005684229)

Are there any references of Nav2 considering large scale projects or products considering mass production? Hello. I am c

Are there any references of Nav2 considering large scale projects or products considering mass production? Hello. I am c

Are there any references of Nav2 considering large scale projects or products considering mass production Hello. I am co

Hello, guys. I am trying to study rivz using this tutorials.

I saw a message, "frame_locked", parameter of the Marker header. I found the description for understanding on this link. But I can not understand what does it mean.

frame_locked [1.1+]
Tells rviz to retransform the marker into the current location of the specified frame every update cycle.

What exactly does "frame_locked" mean? When can I use it? How it work on?

Hello, experts. My environment is Ubuntu 18, ROS2 Crystal.

I installed the rqt-graph plugin to debugging. But, I can't find out the plugin on rqt-gui. In normal case, It should to be on "Plugins->introspection->Node Graph".

After $ rqt ---force-discover, it is working now. Further, other plugins come out on "Plugins" tap.

What is the "rqt --force-discover" option meaning?

The description, written on the rqt usage guide, said below.

"--force-discover force a rediscover of plugins"

Do you explain "rediscover" progress meaning?

Hello, I'm following the guide from costmap_2d for studying.

On section 5 (TF), there is the sentences.

"In order to insert data from sensor sources into the costmap, the costmap_2d::Costmap2DROS object makes extensive use of tf. Specifically, it assumes that all transforms between the coordinate frames specified by the global_frame parameter, the robot_base_frame parameter, and sensor sources are connected and up-to-date. The transform_tolerance parameter sets the maximum amount of latency allowed between these transforms. If the tf tree is not updated at this expected rate, the navigation stack stops the robot."

and, on section 8.1.4 (Parameters).

"~<name>/transform_tolerance (double, default: 0.2)"
"Specifies the delay in transform (tf) data that is tolerable in seconds. This parameter serves as a safeguard to losing a link in the tf tree while still allowing an amount of latency the user is comfortable with to exist in the system. For example, a transform being 0.2 seconds out-of-date may be tolerable, but a transform being 8 seconds out of date is not. If the tf transform between the coordinate frames specified by the global_frame and robot_base_frame parameters is transform_tolerance seconds older than ros::Time::now(), then the navigation stack will stop the robot."

After reading, I didn't understand what that mean.

TFs are just values for transformation information. And, those are from each topics which have a their coordinate. So, their frequency are different with each other by their's sensors timing. On this, why we need a tolerable value? When we need the tolerable param for navigation stack?

Is there any good information to help understanding for newbie?

Hello, experts. What the magic number 3.6 on astar_avoid.cpp mean?

avoid_start_velocity_ / 3.6

the avoid_velocity value is a flag to switch the planning logic like this.

bool avoid_velocity = (current_velocity_.twist.linear.x < avoid_start_velocity_ / 3.6);  
....
else if (state_ == AstarAvoid::STATE::STOPPING)
{
  bool replan = ((ros::WallTime::now() - start_plan_time).toSec() > replan_interval_);

  if (!found_obstacle)
  {
    ROS_INFO("STOPPING -> RELAYING, Obstacle disappers");
    state_ = AstarAvoid::STATE::RELAYING;
  }
  else if (replan && avoid_velocity)
  {
    ROS_INFO("STOPPING -> PLANNING, Start A* planning");
    state_ = AstarAvoid::STATE::PLANNING;
  }
}

I couldn't understand why it have to be 3.6. Does it have a reason mathmatically?

How to calculate the actuator position on the controller interface of the simulation package Hello. I'm trying to study

How to calculate the actuator position on the controller interface of the simulation package Hello. I'm trying to study

Hello. I'm trying to run some tutorial which have a ROS Navigation Stack sample. On doing, I couldn't understand the concept of ORIGIN field from yaml which the map_server create after mapping.

Here is a description by ROS wiki.

origin : The 2-D pose of the lower-left pixel in the map, as (x, y, yaw), with yaw as counterclockwise rotation (yaw=0 means no rotation). Many parts of the system currently ignore yaw.

What this, "the lower-left pixel in the map", mean??

Hello, guys.

I'm trying to study rviz with tutorials provided by ros wiki. I built a sample of document using catkin_make, saw the result.

On the line of this sample codes,

...
visualization_msgs::Marker points, line_strip, line_list;
...
for(ellipsis) {
    ...
    geometry_msgs::Point p;
    p.x = (int32_t)i - 50;
    p.y = y;
    p.z = z;

    points.points.push_back(p);
    ...
}
...

How can the variable of geometry_msgs::Point type use push_back()?

I saw it's msg header on the link
It is just msg consist of 3 variables of float64 type. The function, push_back(), It appears to be used like push_back of stl.

Could you tell me how this works?

[Autoware] What the magic number 3.6 mean? Hello, experts. What the magic number 3.6 on astar_avoid.cpp mean? avoid_s

[Autoware] why do nothing when the state is on STATE::STOPPING Hello, experts. I'm trying to test aster_avoid node with

[Autoware] why do nothing when the state is on STATE::STOPPING Hello, experts. I'm trying to test aster_avoid node with

Cool. Thanks