No version for distro humble. Known supported distros are highlighted in the buttons above.
No version for distro iron. Known supported distros are highlighted in the buttons above.
No version for distro rolling. Known supported distros are highlighted in the buttons above.

Package Summary

Tags No category tags.
Version 1.0.0
License Apache License, Version 2.0
Build type CATKIN
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/nasa/astrobee.git
VCS Type git
VCS Version master
Last Updated 2024-03-02
Dev Status UNMAINTAINED
CI status No Continuous Integration
Released UNRELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

Package for ff nodelet stuff

Additional Links

No additional links.

Maintainers

  • Astrobee Flight Software

Authors

  • Astrobee Flight Software

\page ff_util Utility code

This package contains modular code blocks that are used throughout the flight software.

Configuration client (config_client) and server (config_server)

These two classes are essentially C++ interfaces to dynamic_reconfigure. As its name suggests, dynamic_reconfigure allows one to update parameters on a node at runtime. One great feature of this package is that it provides a Qt-based GUI for interacting with your node, which is assembled at runtime from your configuration specification.

The config server takes its parameters, metadata and default values from a LUA block. It then broadcasts the parameters and current values using dynamic_reconfigure messages. Any node in the system can use a ConfigClient to get or set parameters on a given node that supports this behavior. The parameter values will be preserved until overwritten or the system restarts.

The parameter values are cashed to rosparam values on roscore, which means that if a node dies and respawns the configuration state is not lots.

Finite state machine (ff_fsm)

This class provides skeleton code for implementing a finite state machine, which is a frequently-used paradigm for asynchronous state-based code. The class allows you to declare lambda functions (arbitrary blocks of code that are executed in the node's context) representing event-triggered state transitions. Once the finite state machine is initialized with a starting state, then the calling code simply pushes a sequence of events to the machine, and it takes care of maintaining the overall system state.

The class also provides a callback when the internal state changes. This can be used to trigger the production of action client feedback, or print the state transitions as debug output.

Name database (ff_names)

The name database ensures that we are naming our subsystems, topics, services, actions, nodes and frames consistently across all of the flight software code.

Nodelet (ff_nodelet)

ROS nodelets provide a way of reducing the transport overhead between nodes running on the same processing core. For large messages like images or point clouds, the memory copying, serialization and deserialization overhead is substantial. To circumvent this, the nodelet package provides a means of launching nodes in the same process, allowing them to exchange pointers to internal message structures rather than serializing the message across a loopback interface.

The FreeFlyerNodelet class augments the Nodelet class with the following Astrobee-specific functionality:

  1. It adds a heartbeat to every node in the system. Thus, if a node seizes or crashes then this event will be detected by the system monitor, and will possibly result in third-party intervention by the executive node.
  2. It provides a convenient mechanism to assert faults. By virtue of the fact that it inherits functionality from this class, every flight software node can call AssertFault(...) at any point to signal that it has encountered a problem. The fault is encoded in the heartbeat and collected centrally.
  3. It provides convenient function calls to get the name of the node and the robot on which it is running. This allows one to select configuration blocks based on node name, which turns out to be very useful when using a common driver for two different sensors.
  4. It provides an optional mechanism for sending diagnostics.

Serialization (ff_serialization)

This class provides a mechanism for serializing and deserializing ROS messages to binary files. This is essence provides similar functionality to rosbag but for use within code. An example use-case might be saving and loading calibrates parameters for a specific node.

Actions (ff_action)

Although it is tempting to use the request-response communication model provided by ROS services, there are many reasons why one should not. Firstly, it is a blocking mechanism, which means that all other callbacks in the same node (or nodelet) will be deferred until the response completes. Secondly, services do not handle multiple requests gracefully, nor do they allow for intermediary feedback to be sent to the user.

ROS actions provide a superior request-response communication model, at the expense of greater complexity.They are asynchronous and state-based, which means that -- as a client -- you can send a goal as a background task, and receive a callback when feedback or a result arrives. It also means that the server can accept multiple goals and offer preemption if required.

There are three main messages used in a ROS action:

  • Goal - A message sent from the client to the server containing instructions.
  • Feedback - Information sent periodically from the server to client containing progress data.
  • Result - The final result of the action, as well as any final data.

Despite their numerous advantages, there are several drawbacks with ROS actions. Firstly, there is no timeout management for connecting to a service, sending goals, receiving feedback or a result. Secondly, their constructor assumes the existence of an active ROS handle, so they cannot be use as member variables on a nodelet without a segmentation fault occurring. Fixing these deficiencies on a per-use basis requires substantial boilerplate code.

The FreeFlyerActionClient and FreeFlyerActionServer classes are essentially wrapper aroud ROS simple action client and servers respectively, providing fixes to the problems above in a reusable way.

Services (ff_services)

Similar to FreeFlyerAction, the FreeFlyerServiceClient augments ROS services with various timeouts, preventing unnecessary boilerplate code.

Performance timer (perf_timer)

This class provides a simple mechanism for timing segments of code using a pattern similar to tic() and toc() in matlab. Under the hood it uses std::chrono to query the current time according to the high-resolution clock. It maintains a running average, variance and standard deviation of the duration between the tic() and toc() calls, which can then be printed out as debug or sent as a ROS message for introspection elsewhere.

CHANGELOG
No CHANGELOG found.

Wiki Tutorials

See ROS Wiki Tutorials for more details.

Source Tutorials

Not currently indexed.

Dependant Packages

Name Repo Deps
arm github-nasa-astrobee
dock github-nasa-astrobee
light_flow github-nasa-astrobee
perch github-nasa-astrobee
states github-nasa-astrobee
comms_bridge github-nasa-astrobee
dds_ros_bridge github-nasa-astrobee
ground_dds_ros_bridge github-nasa-astrobee
ctl github-nasa-astrobee
fam github-nasa-astrobee
eps_driver github-nasa-astrobee
epson_imu github-nasa-astrobee
flashlight github-nasa-astrobee
is_camera github-nasa-astrobee
laser github-nasa-astrobee
perching_arm github-nasa-astrobee
pico_driver github-nasa-astrobee
pmc_actuator github-nasa-astrobee
signal_lights github-nasa-astrobee
smart_dock github-nasa-astrobee
speed_cam github-nasa-astrobee
temp_monitor github-nasa-astrobee
vive github-nasa-astrobee
depth_odometry github-nasa-astrobee
graph_localizer github-nasa-astrobee
ground_truth_localizer github-nasa-astrobee
handrail_detect github-nasa-astrobee
imu_augmentor github-nasa-astrobee
lk_optical_flow github-nasa-astrobee
localization_manager github-nasa-astrobee
localization_node github-nasa-astrobee
marker_tracking github-nasa-astrobee
point_cloud_common github-nasa-astrobee
vive_localization github-nasa-astrobee
access_control github-nasa-astrobee
cpu_mem_monitor github-nasa-astrobee
data_bagger github-nasa-astrobee
disk_monitor github-nasa-astrobee
executive github-nasa-astrobee
image_sampler github-nasa-astrobee
sys_monitor github-nasa-astrobee
choreographer github-nasa-astrobee
framestore github-nasa-astrobee
mapper github-nasa-astrobee
mobility github-nasa-astrobee
planner_qp github-nasa-astrobee
planner_trapezoidal github-nasa-astrobee
astrobee_gazebo github-nasa-astrobee
imu_bias_tester github-nasa-astrobee
interactive_marker_teleop github-nasa-astrobee
localization_analysis github-nasa-astrobee
localization_rviz_plugins github-nasa-astrobee
performance_tester github-nasa-astrobee

Launch files

  • launch/ff_nodelet.launch
    • Copyright (c) 2017, United States Government, as represented by the
      • class
      • name
      • default [default: true]
      • spurn [default: ]
      • nodes [default: ]
      • extra [default: ]
      • debug [default: ]
      • manager [default: ]
      • arguments [default: ]
      • output [default: screen]
      • terminal [default: ]

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged ff_util at Robotics Stack Exchange

No version for distro ardent. Known supported distros are highlighted in the buttons above.
No version for distro bouncy. Known supported distros are highlighted in the buttons above.
No version for distro crystal. Known supported distros are highlighted in the buttons above.
No version for distro eloquent. Known supported distros are highlighted in the buttons above.
No version for distro dashing. Known supported distros are highlighted in the buttons above.
No version for distro galactic. Known supported distros are highlighted in the buttons above.
No version for distro foxy. Known supported distros are highlighted in the buttons above.
No version for distro lunar. Known supported distros are highlighted in the buttons above.
No version for distro jade. Known supported distros are highlighted in the buttons above.
No version for distro indigo. Known supported distros are highlighted in the buttons above.
No version for distro hydro. Known supported distros are highlighted in the buttons above.
No version for distro kinetic. Known supported distros are highlighted in the buttons above.

Package Summary

Tags No category tags.
Version 1.0.0
License Apache License, Version 2.0
Build type CATKIN
Use RECOMMENDED

Repository Summary

Checkout URI https://github.com/nasa/astrobee.git
VCS Type git
VCS Version master
Last Updated 2024-03-02
Dev Status UNMAINTAINED
CI status No Continuous Integration
Released UNRELEASED
Tags No category tags.
Contributing Help Wanted (0)
Good First Issues (0)
Pull Requests to Review (0)

Package Description

Package for ff nodelet stuff

Additional Links

No additional links.

Maintainers

  • Astrobee Flight Software

Authors

  • Astrobee Flight Software

\page ff_util Utility code

This package contains modular code blocks that are used throughout the flight software.

Configuration client (config_client) and server (config_server)

These two classes are essentially C++ interfaces to dynamic_reconfigure. As its name suggests, dynamic_reconfigure allows one to update parameters on a node at runtime. One great feature of this package is that it provides a Qt-based GUI for interacting with your node, which is assembled at runtime from your configuration specification.

The config server takes its parameters, metadata and default values from a LUA block. It then broadcasts the parameters and current values using dynamic_reconfigure messages. Any node in the system can use a ConfigClient to get or set parameters on a given node that supports this behavior. The parameter values will be preserved until overwritten or the system restarts.

The parameter values are cashed to rosparam values on roscore, which means that if a node dies and respawns the configuration state is not lots.

Finite state machine (ff_fsm)

This class provides skeleton code for implementing a finite state machine, which is a frequently-used paradigm for asynchronous state-based code. The class allows you to declare lambda functions (arbitrary blocks of code that are executed in the node's context) representing event-triggered state transitions. Once the finite state machine is initialized with a starting state, then the calling code simply pushes a sequence of events to the machine, and it takes care of maintaining the overall system state.

The class also provides a callback when the internal state changes. This can be used to trigger the production of action client feedback, or print the state transitions as debug output.

Name database (ff_names)

The name database ensures that we are naming our subsystems, topics, services, actions, nodes and frames consistently across all of the flight software code.

Nodelet (ff_nodelet)

ROS nodelets provide a way of reducing the transport overhead between nodes running on the same processing core. For large messages like images or point clouds, the memory copying, serialization and deserialization overhead is substantial. To circumvent this, the nodelet package provides a means of launching nodes in the same process, allowing them to exchange pointers to internal message structures rather than serializing the message across a loopback interface.

The FreeFlyerNodelet class augments the Nodelet class with the following Astrobee-specific functionality:

  1. It adds a heartbeat to every node in the system. Thus, if a node seizes or crashes then this event will be detected by the system monitor, and will possibly result in third-party intervention by the executive node.
  2. It provides a convenient mechanism to assert faults. By virtue of the fact that it inherits functionality from this class, every flight software node can call AssertFault(...) at any point to signal that it has encountered a problem. The fault is encoded in the heartbeat and collected centrally.
  3. It provides convenient function calls to get the name of the node and the robot on which it is running. This allows one to select configuration blocks based on node name, which turns out to be very useful when using a common driver for two different sensors.
  4. It provides an optional mechanism for sending diagnostics.

Serialization (ff_serialization)

This class provides a mechanism for serializing and deserializing ROS messages to binary files. This is essence provides similar functionality to rosbag but for use within code. An example use-case might be saving and loading calibrates parameters for a specific node.

Actions (ff_action)

Although it is tempting to use the request-response communication model provided by ROS services, there are many reasons why one should not. Firstly, it is a blocking mechanism, which means that all other callbacks in the same node (or nodelet) will be deferred until the response completes. Secondly, services do not handle multiple requests gracefully, nor do they allow for intermediary feedback to be sent to the user.

ROS actions provide a superior request-response communication model, at the expense of greater complexity.They are asynchronous and state-based, which means that -- as a client -- you can send a goal as a background task, and receive a callback when feedback or a result arrives. It also means that the server can accept multiple goals and offer preemption if required.

There are three main messages used in a ROS action:

  • Goal - A message sent from the client to the server containing instructions.
  • Feedback - Information sent periodically from the server to client containing progress data.
  • Result - The final result of the action, as well as any final data.

Despite their numerous advantages, there are several drawbacks with ROS actions. Firstly, there is no timeout management for connecting to a service, sending goals, receiving feedback or a result. Secondly, their constructor assumes the existence of an active ROS handle, so they cannot be use as member variables on a nodelet without a segmentation fault occurring. Fixing these deficiencies on a per-use basis requires substantial boilerplate code.

The FreeFlyerActionClient and FreeFlyerActionServer classes are essentially wrapper aroud ROS simple action client and servers respectively, providing fixes to the problems above in a reusable way.

Services (ff_services)

Similar to FreeFlyerAction, the FreeFlyerServiceClient augments ROS services with various timeouts, preventing unnecessary boilerplate code.

Performance timer (perf_timer)

This class provides a simple mechanism for timing segments of code using a pattern similar to tic() and toc() in matlab. Under the hood it uses std::chrono to query the current time according to the high-resolution clock. It maintains a running average, variance and standard deviation of the duration between the tic() and toc() calls, which can then be printed out as debug or sent as a ROS message for introspection elsewhere.

CHANGELOG
No CHANGELOG found.

Wiki Tutorials

See ROS Wiki Tutorials for more details.

Source Tutorials

Not currently indexed.

Dependant Packages

Name Repo Deps
arm github-nasa-astrobee
dock github-nasa-astrobee
light_flow github-nasa-astrobee
perch github-nasa-astrobee
states github-nasa-astrobee
comms_bridge github-nasa-astrobee
dds_ros_bridge github-nasa-astrobee
ground_dds_ros_bridge github-nasa-astrobee
ctl github-nasa-astrobee
fam github-nasa-astrobee
eps_driver github-nasa-astrobee
epson_imu github-nasa-astrobee
flashlight github-nasa-astrobee
is_camera github-nasa-astrobee
laser github-nasa-astrobee
perching_arm github-nasa-astrobee
pico_driver github-nasa-astrobee
pmc_actuator github-nasa-astrobee
signal_lights github-nasa-astrobee
smart_dock github-nasa-astrobee
speed_cam github-nasa-astrobee
temp_monitor github-nasa-astrobee
vive github-nasa-astrobee
depth_odometry github-nasa-astrobee
graph_localizer github-nasa-astrobee
ground_truth_localizer github-nasa-astrobee
handrail_detect github-nasa-astrobee
imu_augmentor github-nasa-astrobee
lk_optical_flow github-nasa-astrobee
localization_manager github-nasa-astrobee
localization_node github-nasa-astrobee
marker_tracking github-nasa-astrobee
point_cloud_common github-nasa-astrobee
vive_localization github-nasa-astrobee
access_control github-nasa-astrobee
cpu_mem_monitor github-nasa-astrobee
data_bagger github-nasa-astrobee
disk_monitor github-nasa-astrobee
executive github-nasa-astrobee
image_sampler github-nasa-astrobee
sys_monitor github-nasa-astrobee
choreographer github-nasa-astrobee
framestore github-nasa-astrobee
mapper github-nasa-astrobee
mobility github-nasa-astrobee
planner_qp github-nasa-astrobee
planner_trapezoidal github-nasa-astrobee
astrobee_gazebo github-nasa-astrobee
imu_bias_tester github-nasa-astrobee
interactive_marker_teleop github-nasa-astrobee
localization_analysis github-nasa-astrobee
localization_rviz_plugins github-nasa-astrobee
performance_tester github-nasa-astrobee

Launch files

  • launch/ff_nodelet.launch
    • Copyright (c) 2017, United States Government, as represented by the
      • class
      • name
      • default [default: true]
      • spurn [default: ]
      • nodes [default: ]
      • extra [default: ]
      • debug [default: ]
      • manager [default: ]
      • arguments [default: ]
      • output [default: screen]
      • terminal [default: ]

Messages

No message files found.

Services

No service files found

Plugins

No plugins found.

Recent questions tagged ff_util at Robotics Stack Exchange