robotnik_base_hw_sim

This package is intended to simulate the Robotnik base hw common in most of the platforms

1. robotnik_base_hw_sim_node

1.1 Bringup

Run the following launch inside the desired namespace.

Arguments

• robot_id: robot namespace. By default robot
• prefix: prefix for the default joints (for multirobots envs). By default it takes the robot_id + '_'
• config_yaml: default config yaml. Every robot should have one.
• publish_battery_estimation: enables the publication of the battery estimation based on internal estimation. By default true.

For Summit XL:

roslaunch robotnik_base_hw_sim robotnik_base_hw_sim.launch robot_id:=robot config_yaml:=summit_xl

For RB-THERON

roslaunch robotnik_base_hw_sim robotnik_base_hw_sim.launch robot_id:=robot config_yaml:=rb_theron

2. robotnik_elevator_controller plugin

Plugin to simulate the Elevator interface available in some robots.

It requires a transmission of hardware_interface/EffortJointInterface.

Example of control configuration:

  robotnik_elevator_controller:
    type        : "robotnik_elevator_controller/RobotnikElevatorController"
    joint:    
      elevator_joint:
        name: rb2_a_elevator_platform_joint
    elevator_position_up: 0.05
    elevator_position_down: 0.0
    # delay time to perform the elevation
    elevation_action_time: 1.0
    # params for the pickup avoiding Gazebo physics (see elevator_fake_pickup_gazebo)
    gazebo:
      # if true, the carts will be raised avoiding contact
      disable_gazebo_physics_for_pickup: true
      pickup_service: "/elevator_fake_pickup_gazebo/simple_pick"
      place_service: "/elevator_fake_pickup_gazebo/simple_place"
      # model id used in Gazebo
      robot_model: "rb2_a"
      # distance in z to move the picked cart
      elevation_offset_z: 0.07  

3. elevator_fake_pickup_gazebo node

ROS node to perform pick and place of object avoiding the physics. It uses the available gazebo ROS topics and services. It is intended to pick & place carts/trolleys with a mobile base.

The way it works:

1. Pick: removes gravity of the object to pick
2. Sets the position of the object in the same one than the robot. This is done continuosly.
3. Place: sets the gravity of the picked object and stops setting the position of the robot

3.1 bringup

roslaunch robotnik_base_hw_sim elevator_fake_pickup_gazebo.launch

Arguments:

• config_yaml: path to the yaml containing the configuration

3.2 params

YAML Example:

objects:
-
model: rb2cart
default_link: link_0
-
model: rb2cart_0
default_link: link_0

robots:
-
model: rb2_a
default_link: rb2_a_base_footprint
-
model: rb2_b
default_link: rb2_b_base_footprint

config:
# min distance for the simple pick
min_picking_distance: 0.1

3.3 topics

3.3.1 publishers

• gazebo_picking_links [gazebo_msgs/LinkStates]
  • gazebo links of the available objects to pick, based on configuration
• gazebo_picking_models [gazebo_msgs/ModelStates]
  • gazebo models of the available objects to pick, based on configuration
• gazebo_robot_links [gazebo_msgs/LinkStates]
  • gazebo links of the available robots/links able to pick, based on configuration
• gazebo_robot_models [gazebo_msgs/ModelStates]
  • gazebo models of the available robots able to pick, based on configuration
• pick_states [robotnik_base_hw_sim/PickStates]
  • List of the current elements that are attached
• state [robotnik_msgs/State]
  • Component state machine

3.3.2 subscribers

• /gazebo/link_states [gazebo_msgs/LinkStates]
  • state of all the links of Gazebo
• /gazebo/model_states [gazebo_msgs/ModelStates]
  • state of all the models of Gazebo

3.4 services

3.4.1 clients

• /gazebo/get_link_properties [gazebo_msgs/GetLinkProperties]
• /gazebo/set_link_properties [gazebo_msgs/SetLinkProperties]
• /gazebo/set_link_state [gazebo_msgs/SetLinkState]

3.4.2 servers

• pick [robotnik_base_hw_sim/Pick]
  • Pick an object and link it to a robot
  • Example:

rosservice call /elevator_fake_pickup_gazebo/pick "object_model: 'rb2cart'
object_link: 'link_0'
robot_model: 'rb2_a'
robot_link: 'rb2_a_base_footprint'
pose:
  position: {x: 0.0, y: 0.0, z: 0.2}
  orientation: {x: 0.0, y: 0.0, z: 0.0, w: 1.0}"
success: True
msg: "OK"

• place [robotnik_base_hw_sim/Place]
  • Place a picked object
  • Example:

rosservice call /elevator_fake_pickup_gazebo/place "object_model: 'rb2cart'
robot_model: 'rb2_a'"

• simple_pick [robotnik_base_hw_sim/SimplePick]
  • Pick the closest object to a robot (within a min distance)
  • Example:

rosservice call /elevator_fake_pickup_gazebo/simple_pick "robot_model: 'rb2_a'                     
pose:
  position:
    x: 0.0
    y: 0.0
    z: 0.1
  orientation:
    x: 0.0
    y: 0.0
    z: 0.0
    w: 0.0"
success: True
msg: "OK"

• simple_place[robotnik_base_hw_sim/SimplePlace]
  • Places the object(s) the robot has picked
  • Example:

rosservice call /elevator_fake_pickup_gazebo/simple_place "robot_model: 'rb2_a'"
success: True
msg: "OK"