sam-xl / abb_robot_driver_state_machine

This package provides a state machine for use with the abb_robot_driver package in combination with the EGM option.

ABB Robot Driver State Machine

⚠️ Please first verify if your setup is working with the examples provided by the abb_robot_driver package before using this package, specifically: ex2_rws_and_egm_6axis_robot.

Overview

This package provides a state machine for use with the abb_robot_driver package in combination with the EGM option. The main goal of this state machine is to simplify the process of getting an ABB robot with EGM "to move" using the abb_robot_driver. This is achieved by a state machine implementation that manages and monitors the state of the controller, allowing developers to request a certain (motion) state instead of calling commands like "Set Motors On" and "Start RAPID" and monitoring their results.

Authors: D. Kroezen (SAM|XL, TU Delft), A. Vatsyayan (SAM|XL, TU Delft)

Affiliation: SAM|XL, TU Delft

This package hase been developed and tested under ROS Noetic and Ubuntu 20.04.

State Transitions

An overview of the states and state transitions can be found below.

💡 The state machine currenctly automatically transitions to the EGMActiveState when started. External state transition triggers have not yet been implemented.

The state machine will exit if it detect the motors turning off (e.g. due to a emergency stop) or if the RAPID program execution is stopped. The default behaviour resets the program pointer, stops RAPID execution and turns the motors off when exiting.

States

• Initialize State
  Connects to the RWS and EGM services, automatically starts the transition to the MotorsOn state by requesting the motors to turn on. The state machine will exit if it is unable to connect to the required services or is unable to turn on the motors.

• MotorsOn State
  The motors are on. This states automatically starts the transition to Idle state by starting the main RAPID program. The state machine wil exit if it is unable to start the RAPID program.

• Idle State
  The state machine and robot controller are ready to transition to either an EGM session or by executing a RAPID routine.

  💡 Currently the Idle state automatically transitions to the EGMSessionActive state by starting an EGM session and loading the joint_position_trajectory_controller.

• EGMSessionActive State
  The EGM session is active. This state monitors the EGM session and will transition back to the Idle state if the EGM session stops (e.g. due to a time-out).

• RapidRoutineActive State

  ⚠️ Not yet implemented

  A RAPID routine is being executed. This state monitors the RAPID routine execution and will transition back to the Idle state if the routine finishes.

Montitor States

The monitor states ensure the robot controller state is in sync with the state machine, these states are executed in parallel to other states.

• MonitorMotorsOn State
  The motor status is constantly monitored to ensure the contoller is in the correct state. This state will trigger an exit of the state machine if the motors turn off unexpectedly, e.g. due to an emergency stop.

• MonitorRapidTaskRunning State
  The RAPID program is constantly monitored to ensure the controller is in the correct state. This state will trigger an exit of the state machin if the RAPID program is stopped unexpectedly, e.g. due to the stop button being pressed on the teach pendant.

Installation

Building

To build from source, clone the lastest version from this repository into your catkin workspace:

cd catkin_ws/src
git clone https://github.com/sam-xl/abb_robot_driver_state_machine

Use vcstool to clone other project packages and complete the project workspace:

vcs import src < ./src/abb_robot_driver_state_machine/dependencies.repos  

Install the dependencies of the cloned packages using rosdep:

rosdep install --from-paths src --ignore-src -y

Finally, build all packages in the workspace:

catkin build

Usage

After starting the abb_robot_driver, the state machine can be launched by using the provided launch file:

roslaunch abb_robot_driver_state_machine state_machine_bringup.launch

It is also possible to provide an EGM settings file:

roslaunch abb_robot_driver_state_machine state_machine_bringup.launch egm_settings:="/path/to/egm_settings.yaml"

Config files

The user can specify the requested EGM settings by providing a config file with the settings to either the node or the launch file.

• ./config/20220812_egm_settings_dump_abb_irb1200.yaml
  A dump of the EGM settings of an ABB IRB1200. This dump can be used as a reference to see which settings there are and what can be configured. It can also be used as a first input for your settings. Increase max_speed_deviation if you require faster joint velocities (the value is in deg/s).

• ./config/increased_speed_egm_settings.yaml
  An EGM settings file to set the max_speed_deviation from the default value (configured on the IRC5 controller) to 100.0.

If no config file is proved the default EGM settings are used as specified on the IRC5 controller. The settings in the config files are only applied for the next session and are not persistent.

Launch files

• state_machine_bringup.launch: Launches the abb_robot_driver_state_machine node.
  Arguments (for a description of the arguments, see the node description):
  • egm_settings (string, optional)
  • taskname (string, default: T_ROB1)
  • rws_namespace (string, default: /rws)
  • egm_namespace (string, default: /egm)

Nodes

This package contains a single node containing the state machine: abb_robot_driver_state_machine

state_machine_node

Starts a state machine which will automatically transition to the Idle state.

Parameters

• rws_namespace (string, default: /rws)
  Namespace of the rws services and topics to be used by the state machine

• egm_namspace (string, default: /egm)
  Namespace of the egm services and topics to be used by the state machine

• taskname (string, default: T_ROB1)
  The name of the RAPID task which is running the "StateMachine Add-In"

• egm_settings (string, optional)
  The filename (including path) of the file containing the EGM settings to apply for each EGM session.

Bugs & Feature Requests

Please report bugs and request features using the Issue Tracker.

abb_robot_driver_state_machine's Issues

Don't make rosdep "continue on errors"

The current setup instructions invoke rosdep with the -r option:

abb_robot_driver_state_machine/README.md

Lines 69 to 71 in 5dcd5f5

	Install the dependencies of the cloned packages using `rosdep`:
	rosdep install --from-paths src --ignore-src -r -y

This option makes rosdep

Continue installing despite errors.

as rosdep is responsible for installing required dependencies, there doesn't appear to be any point in asking it to continue if it couldn't do that for whatever reason. Failing early while setting up the development environment would be much better.

Suggestion: remove -r from the rosdep invocation.

Should readme clarify dependencies in dependencies.repos are not strictly needed?

Technically, the repositories/packages listed in dependencies.repos are not needed by abb_robot_driver_state_machine. The only dependencies really needed are the various messages and services it uses to communicate with the abb_robot_driver node(s).

The latter are already declared as dependencies in the manifest:

abb_robot_driver_state_machine/package.xml

Lines 11 to 13 in 5dcd5f5

	<exec_depend>abb_egm_msgs</exec_depend>
	<exec_depend>abb_rapid_sm_addin_msgs</exec_depend>
	<exec_depend>abb_robot_msgs</exec_depend>

The packages in dependencies.repos would be needed if a user is setting up abb_robot_driver itself, but then (s)he would be instructed to download those as part of the setup instructions of that package. An unsuspecting user trying to setup abb_robot_driver_state_machine would run into vcs errors due to it trying to clone repositories which are already present in the workspace.