MoveIt Action Servers

Contributors

Christos Gkournelos

Konstantinos Lotsaris

Panagiotis Angelakis

Spyros Koukas

Overview

This package holds the below custom action servers to interface with MoveIt

• Move to Joints Action server
  • Receives goal targets in Joint Space
• Move to Pose Action Server
  • Receives goal targets in Cartesian Space relative to a TF frame

Advantages

• They are easily modifiable to change the functionality
• Custom feedback
• Configuration files to launch multiple instances with different planning groups and action server topics
• Can be used as part of higher level behavior packages e.g
  • custom multi-client node / behavior node
  • FlexBe
  • Behavior trees

Demo Gifs

Joint space goal / arm home position

Joint space goal / gripper close

Cartesian Space goal / relative to end effector

Cartesian Space goal / relative to end effector

with keeping current end effector orientation during the motion

Prerequisities

A manipulator which is integrated with MoveIt e.g you can send random valid goals from the RViz plugin

# install depedencies
rosdep install --from-paths src --ignore-src -r

Configuration

On the config folder you can find the yaml parameter files used for the configuration of the action servers

Move to Joint Space - Arm

move_group: arm 
action_server_name: move_tojoints_action_server/arm/action

Move to Joint Space - Gripper

move_group: gripper
action_server_name: move_tojoints_action_server/gripper/action

Move to Cartesian Space - Arm

move_group: arm
action_server_name: move_topose_action_server/arm/action
base_link_name: arm_footprint 
ee_link_name: ee_base

launch action servers

# To start all 3 action servers

roslaunch moveit_action_handlers main_moveit_handlers.launch

# To Start 1 action server : (on the launch/include folder)

## Joint space arm 
roslaunch moveit_action_handlers move_joints_arm_action_server.launch

## Joint space gripper 
roslaunch moveit_action_handlers move_joints_gripper_action_server.launch

## Cartesian space arm 
roslaunch moveit_action_handlers move_topose_arm_action_server.launch

action definitions

move to Joint space

##Description: Moves robot arm to a specified joint space.

#goal definition
moveit_action_handlers/PropertyValuePair[] joint_pairs # list of joint_pairs (joint name + value)
float32 endEffectorVelocity
float32 endEffectorAcceleration
float32 timeoutSeconds #if this action cannot be completed within this time period it should be considered failed.
---
#result definition
bool success
uint64 millis_passed
string status  #Use the constants of ActionResultStatusConstants in the status field
---
#feedback
bool success
uint64 millis_passed
string status  #Use the constants of ActionFeedbackStatusConstants in the status field

joint pair value + name

##Usage: In MoveToJointsMoveIt.action

##Definition: A property name - Value definition.
string name
float64 value

move to Cartesian space

##Description: Moves robot arm to a specified pose relative to the frame in header.frame_id of target_pose
#goal definition

#Used to indicate which hardcoded motion constraint to use 
#e.g 0 no constraint, 1 keep the same end effector orientation
int32 constraint_mode
#similar to geometry_msgs/PoseStamped but using euler instead of quaternion
#at target_pose->header.frame_id define the tf frame 
# which the pose will be calculated relative from
moveit_action_handlers/PoseStamped target_pose

float32 endEffectorVelocity
float32 endEffectorAcceleration
float32 timeoutSeconds #if this action cannot be completed within this time period it should be considered failed.
---
#result definition
bool success
uint64 millis_passed
string status  #Use the constants of ActionResultStatusConstants in the status field
---
#feedback
bool success
uint64 millis_passed
string status  #Use the constants of ActionFeedbackStatusConstants in the status field

Feedback Constants

string PLANNING=Planning
string EXECUTING=Executing
string EMERGENCY_STOP=EmergencyStop
string OPERATIONAL_EXCEPTION=OperationalException
string CANCELLING=Cancelling

Result Constants

string SUCCESS=Success
string PLANNING_FAILED=PlanningFailed
string CONTROL_FAILED=ControlFailed
string EMERGENCY_STOP=EmergencyStop
string OPERATIONAL_EXCEPTION=OperationalException
string CANCELLED=Cancelled

How to define and send goals to the Action Servers

Demo client nodes

Demo client nodes that define action goals and send them to the servers have been developed both in python and c++

• python test clients
  • move_joints_arm_test_client.py
  • move_joints_gripper_test_client.py
  • move_topose_arm_test_client.py
• cpp test clients
  • move_joints_arm_test_client.cpp
  • move_joints_gripper_test_client.cpp
  • move_topose_arm_test_client.cpp

#e.g python (give permission with chmod +x if necessary)

# joints arm python client
rosrun moveit_action_handlers move_joints_arm_test_client.py
# joints gripper python client
rosrun moveit_action_handlers move_joints_gripper_test_client.py
# cartesian arm python client
rosrun moveit_action_handlers move_topose_arm_test_client.py

#e.g cpp

# joints arm cpp client
rosrun moveit_action_handlers move_joints_arm_test_client
# joints gripper cpp client
rosrun moveit_action_handlers move_joints_gripper_test_client
# cartesian arm cpp client
rosrun moveit_action_handlers move_topose_arm_test_client

With actionlib's axclient gui

to easily send goals to action servers you can use the actionlib's GUI action client

# to start it
rosrun actionlib axclient.py /name of action server
#e.g
# joints arm
rosrun actionlib axclient.py /move_tojoints_action_server/arm/action
# joints gripper
rosrun actionlib axclient.py /move_tojoints_action_server/gripper/action
# cartesian arm
rosrun actionlib axclient.py /move_topose_action_server/arm/action

a window will appear like this for each action server

you can fill the goal area like so

Move Joint Arm Goal

joint_pairs: [
    {name: shoulder_pan_joint, value: 0.0},
    {name: shoulder_lift_joint, value: 0.0},
    {name: elbow_joint, value: 1.5707},
    {name: wrist_1_joint, value: 0.0},
    {name: wrist_2_joint, value: 0.0},
    {name: wrist_3_joint, value: 0.0}
]
endEffectorVelocity: 0.1
endEffectorAcceleration: 0.1
timeoutSeconds: 10.0

Move Joint Gripper Goal

joint_pairs: [
    {name: finger1_joint, value: 0.02},
    {name: finger2_joint, value: 0.02}
]
endEffectorVelocity: 0.1
endEffectorAcceleration: 0.1
timeoutSeconds: 10.0

Move Cartesian Arm Goal

constraint_mode: 0
target_pose: {
    header: {
        frame_id: ee_base
    }, 
    pose: {
        position: {
            x: 0.03, 
            y: 0.0, 
            z: 0.03}, 
        orientation: {
            roll: 0.0, 
            pitch: 0.0, 
            yaw: 0.0}
        }    
}
endEffectorVelocity: 0.1
endEffectorAcceleration: 0.1
timeoutSeconds: 10.0

Contact me

panagiotis.angelakis.robot@gmail.com

Enjoy!