sweetie_bot_joint_trajectory_editor

Trajectory Editor

TrajectoryPinkitor will make you live fun! Because it is fun to teach SweetieBot new movements. This package provide GUI for creating movement trajectories by specifying a set of way points. This package is the part of Sweetie Bot project. Full documentation is available in Russian here.

General concept

• To specify trajectory you should select active joints, set joint tolerances and specify a set of waypoints. Only selected joints' states are stored and published.

• Trajectories are stored on Parameter Server in serialized in binary form control_msgs::FollowJointTrajectoryGoal messages. Parameter ~trajectory_storage specifies namespace for serialized messages. Use store script from sweetie_bot_deploy to save and load them from .json files. TrajectoryPinkiptor doe not save trajectories to files, it only modifies parameteres value on Parameter Server.

• If you are working with real robot Set troque on/off buttons can be used to switch servos on or off. Trajectory editor set_torque_off service (std_srvs::SetBool) to control servo state. (See MainTorqueSwitch controller from sweetie_bot_controllers_joint_space package).

• New way point can be added in two ways. You can duplicate existing point or you can add current robot pose from joint_states (sensor_msgs::JointState) topic. To place robot in desired pose you can utilize joint_state_publiser GUI or MoviIt! rviz plugin. If you are working with real robot it can be placed in desired pose manually if the servos are turned off.

• When you press Set robot pose current way point is published on topic joint_states_set (sensor_msgs::JointState). If there is controller which monitors this topic it can place robot in specific pose (e.g. FollowJointState controller from sweetie_bot_controllers_joint_space package).

• When you select way point it is published on topic joints_marker_set (sensor_msgs::JointState).

• When your press Execute trajectory button FollowJointTrajectoryGoal messages is formed from current way point list and editor requests FollowJointTrajectory action server with name joint_trajectory to execute trajectory. (See ExecuteJointTrajectory controller from sweetie_bot_controllers_joint_space package)

• FollowJointTrajectoryGoal do not store information about contacts. As walkaround special joints support/<kinematic_chain_name> was introduced. Sweetie Bot action server assumes that corresponding kinemtic chain is in contact but oes not test movement consistently. Those joints are supported in TrajectoryPinkiptor interface and displayed as checkboxes. If contact is set it is active is period from the current to the next waypoint,

ROS interface

Publish topics

• joints_marker_set (JointState) --- pose clicked by user in waypoints' list.
• joint_states_set (JointState) --- publish pose if Set robot pose button is clicked.

Subscribe topics

• joint_states (JointState) --- current robot pose.

Services

• Requires: set_torque_off (std_srvs::SetBool) --- turn robot servos off.

Actionlib

• Client: joint_trajectory (FollowJointTrajectory) --- execute trajectory if Execute trajectory button is pressed.

Parameters

• ~trajectory_storage (string, default joint_trajectory) --- trajectory storage namespace.

Usage

Run SweetieBot simulation ans start trajectory editor.

roslaunch sweetie_bot_deploy joint_space_control.launch
roslaunch sweetie_bot_deploy joint_trajectory_editor.launch