This section contains information about various tools for runing the control system of Velma.

Running the simulated system

Command

roslaunch velma_common velma_system.launch

Description

The launch file runs the whole system with robot and environment simulated in Gazebo.

Important notice: Before every start-up of the simulated system, shared memory channels must be reset using command described below. Omission of such cleanup can occasionally cause a deadlock between pair of subsystems.

Cleanup of shared memory communication channels

Command

rosrun velma_common reset_shm_comm.py

Description

This script removes all shared memory files, in /dev/shm/ directory, related to control system of Velma. This cleanup is needed when the communication channels are blocked. This problem may sometimes occur.

Running initialization and homing procedure

Command

rosrun velma_task_cs_ros_interface initialize_robot.py

Description

After every startup, the robot have to be initialized with initialize_robot.py script. The script changes state of hardware controllers of motors to enabled. Also, all motors that require homing are homed.

Geometric planner for Velma

Command

roslaunch velma_ros_plugin velma_planner.launch

Description

This launch file runs ROS node with geometric planner for Velma. The planner can be accessed using ROS services. There is a convenient Python interface for those services in rcprg_planner package.

Please refer to the test scripts and to Python API page for examples of use.

Test scripts

Command

rosrun velma_task_cs_ros_interface <script_name>

Description

The scripts test some basic performance of the whole system:

• test_head.py - movement of head only,
• test_head_complex.py - movement of head combined with movement of arms and torso; tests of behavior of head controller in situations of fault and behavior switch,
• test_relax.py - tests for behavior for self collision avoidance,
• test_jimp.py - simple movement of arms and torso,
• test_grippers.py - simple movement of gripper fingers,
• test_jimp_planning.py - movement of arms and torso using trajectory generated by planner,
• test_jimp_planning_attached.py - planning movement of arms and torso with virtual object attached to gripper,
• test_cimp_pose.py - simple movements of end effectors using control in 6-DOF task space,
• test_cimp_tool.py - changing the tool frame of end effectors,
• test_cimp_imp.py - changing the impedance of end effectors,
• test_all.py - runs all tests in sequence.

Please refer to the sources of the scripts as examples of high level control of Velma robot.

Some scripts require the planner node.

Creating a snapshot of simulation state

Example command

rosrun rcprg_gazebo_utils create_state_snapshot.py

Description

This script creates snapshot of the current state of all joints in simulation and saves it to file state_snapshot.txt in the current working directory. The snapshot can be restored, together with saved world using argument state_snapshot in launch file velma_system.launch in package velma_common or in launch file velma_gazebo_re.launch in package velma_sim_gazebo.

Below, there is an example usage of state snapshot saving and loading. We assume, that the system is running, and the world state is stable (e.g. no fast moving objects, no robot motion), and current working directory is /home/user/.

Saving the current state

First, we create a snapshot:

rosrun rcprg_gazebo_utils create_state_snapshot.py

The above command creates a file state_snapshot.txt in the current working directory. Then, in Gazebo Client, save the world using File -> Save world as.

Restoring the saved state

To run the simulation starting from the saved state, execute command:

roslaunch velma_common velma_system.launch world_name:=/home/user/saved.world state_snapshot:=/home/user/state_snapshot.txt spawn_velma:=false

Please note that full paths are required. In the above example, we assume, that world was saved in file /home/user/saved.world. The third argument spawn_velma:=false tells the launch file that model of Velma robot is already in the saved world file, and it should not be spawned from urdf file.