kartikmadhira1's profile - activity

I am currently running a master node on my Jetson TK1(IP - 10.42.0.15) and a remote PC running ubuntu(IP - 10.42.0.1). I have gone through all the setup shown in the setup and multiple machines. Also, I am able to ping into both of them and netcat results are perfect too. I have also gone through ROS answers on setting up the /etc/hosts file. But, when I try to do the rostopic list after a roscore on tegra ,I just dont see anything.

my setup on tegra is:

export ROS_IP=10.42.0.15
export ROS_HOSTNAME=10.42.0.15
export ROS_MASTER_URI=http://10.42.0.15:11311/

Variables setup on PC are:

export ROS_IP=10.42.0.1
export ROS_HOSTNAME=10.42.0.1
export ROS_MASTER_URI=http://10.42.0.15:11311/

I am currently going through the tf tutorials and have a doubt in particular in the tf listener. In the code

while(n.ok())
  {
    tf::StampedTransform tf;
    try{
      listen.lookupTransform("/turtle2","/turtle1",ros::Time(0),tf);
        }

What does turtle1 to turtle2 frame transformation mean? The turtle1 frame is already transformed to the world frame in the tf broadcaster?

I have been able to successfully make fully autonomous AMCL based Robot and now want to explore in details the working of these nodes. My questions are:

1. Are there any advanced tutorials available to understand in detail the underlying algorithms of these nodes and how the codes work, in line with the navigation tutorials we have?
2. It seems most of the nodes are based on the Probabilistic Robotics book. Any suggestions on reading the book.
3. Are there any developer options to contribute and learn the codebase for these navigation algorithms?

The answer is in respect to the flow process to be followed, not any specific node. I had used the mentioned node.

Well, I have used minimal distances in OpenCV in my people counter problem. I don't know exactly on the PCL library is that you could create a tuple and append all the euclidean distances between 2D objects. Get the least one to track and use the COM of objects for calculating the euclidean distance

Can't comment on the 3D Map, but for a 2D Map you could use the pointcloud_to_laserscan to generate 2D scan and then use the normal Map creation with the following tutorial

Try setting the map_update_angle_thresh, laser_min_dist, laser_max_dist params in the hector_slam launch file. Again this is just a logical guess.

I am currently running a differential drive setup robot configured to run on amcl, custom made odometry publisher and navigation stack(move_base, costmap_2d). I get the following continuous warnings on terminal running rviz:

Invalid argument passed to canTransform argument source_frame in tf2 frame_ids cannot be empty

Any possible solution to the warning? The robot just goes straight when setting a goal with a turn and absolutely straight goal it easily follows. Also, I have a odometry publisher I wrote using the navigation odom setup tutorials from here

Here's the tf tree:

I am currently running a differential drive setup robot configured to run on GMapping, custom made odometry publisher and navigation stack(move_base, costmap_2d). I have the following errors and warnings with the param settings given below:

1. I get the following error when giving a goal on the map (map and current position are perfect ).( I created a map from recording /scan topic on a bag file)

   [ WARN] [1487352631.099260113]: MessageFilter [target=map ]: Discarding message from [/move_base] due to empty frame_id. This message will only print once.

   [ WARN] [1487352631.099750851]: Invalid argument passed to canTransform argument source_frame in tf2 frame_ids cannot be empty

2. move_base linear and angular velocities aren't getting tracked. The robot just weirdly rotates at full speed and performs in place rotation, and goes away from the goal given. BUT , using keyboard to publish cmd_vel works and the robot moves around perfectly. Which suggests the move_base isn't configured properly.

3. Sometimes, the above two problems don't come up but the robot veers away just as it reaches the goal at a high speed(away from the goal).

The robot has a square base with motors kept at either centres of sides of square with a castor wheel at center.

My setup files are:

  TrajectoryPlannerROS:
      acc_lim_x: 0.09
      acc_lim_y: 0.0
      acc_lim_theta: .05
      max_vel_x: 0.6
      min_vel_x: 0.3
      max_vel_theta: 0.2
      min_vel_theta: 0.1
      min_in_place_vel_theta: 0.2
      holonomic_robot: false
      yaw_goal_tolerance: .2
      xy_goal_tolerance: .2
      sim_time: 1.0
      vx_samples: 12
      meter_scoring: true
      pdist_scale: 15
      heading_lookahead: 0.325
      heading_scoring: true
      dwa: true
      global_frame_id: map



     global_costmap:
          global_frame: /map
          robot_base_frame: /base_link
          update_frequency: 1.0 #before: 5.0
          publish_frequency: 0.5 #before 0.5
          static_map: true
          transform_tolerance: 0.5

    local_costmap:
      global_frame: /map
      robot_base_frame: /base_link
      update_frequency: 1.0 #before 5.0
      publish_frequency: 2.0 #before 2.0
      static_map: false
      rolling_window: true
      width: 5
      height: 5
      resolution: 0.025 #before 0.05
      transform_tolerance: 0.5

common_costmap:
    obstacle_range: 2.5
    raytrace_range: 3.0
    footprint: [[0.15, 0.15], [-0.15, 0.15], [-0.15, -0.15], [0.15, -0.15]]
    inflation_radius: 0.15
    transform_tolerance: 0.13
    meter_scoring: true
    observation_sources: scan
    scan:
      data_type: LaserScan
      topic: scan
      marking: true
      clearing: true
    map_type: costmap

move_base_params
    shutdown_costmaps: false
    controller_frequency: 5.0 #before 5.0
    controller_patience: 15
    planner_frequency: 5.0
    planner_patience: 5.0
    oscillation_timeout: 10.0
    oscillation_distance: 0.2
    conservative_reset_dist: 0.10 #distance from an obstacle at which it will unstuck itself
    recovery_behavior_enabled: false
    clearing_rotation_allowed: false

Finally figured it, firewall was at place in the master so did sudo ufw disable to allow port connections and it worked.

@epsilonjon rplidar on the master and rostopic list on PC.

@gvdhoorn tried with only ROS_IP, but without any help. messages aren't coming.