sas_robot_driver

Tip

Repository for this module: https://github.com/SmartArmStack/sas_robot_driver.
More information: https://smartarmstack.github.io/.

Quick check

docker run --rm murilomarinho/sas:jazzy /bin/bash -c "ros2 launch sas_robot_driver composer_example_launch.py"

Contents

• include/ — public C++ headers.
• src/ — library and node implementations.
• scripts/ — Python example scripts.
• launch/ — example launch files.
• config/ — example parameter configuration file.

Client–Server pair

The package implements a RobotDriverServer / RobotDriverClient pair. Both classes take a shared rclcpp::Node and a topic_prefix string that forms the namespace for all topics. When topic_prefix is "GET_FROM_NODE" (the default) the node name is used automatically.

Header files

Class	Header
sas::RobotDriverServer	sas_robot_driver/sas_robot_driver_server.hpp
sas::RobotDriverClient	sas_robot_driver/sas_robot_driver_client.hpp

Importing in Python

from sas_robot_driver import (
    RobotDriverServer,
    RobotDriverClient,
    Functionality
)

ROS 2 Nodes & Parameters

Each node loads its parameters from a YAML configuration file. The default is config/config.yaml in this package; pass a different file with the config_file:= launch argument of the corresponding launch file.

Node: sas_robot_driver_ros_composer_node

Property	Value
Executable	sas_robot_driver_ros_composer_node
ROS node name	robot_composed (set by the name launch argument of composer_launch.py)
Description	Composes multiple RobotDriver clients serially into a single robot driver, exposing one RobotDriverROS control loop for all of them.

Parameters

Parameter	Type	Mandatory / Optional	Default	Purpose
robot_driver_client_names	array of strings	Mandatory	none — must be provided	Topic prefixes of the robot-driver clients to compose
override_joint_limits_with_robot_parameter_file	bool	Mandatory	none — must be provided	Whether to take the joint limits from a robot parameter file instead of concatenating the clients' limits
robot_parameter_file_path	string	Mandatory if override_joint_limits_with_robot_parameter_file is true	none — must be provided	Path of the robot parameter file with the joint limits
thread_sampling_time_sec	double	Mandatory	none — must be provided	Sampling period of the robot control-loop thread

Node: sas_robot_watchdog_commander_node

Property	Value
Executable	sas_robot_watchdog_commander_node
ROS node name	sas_robot_watchdog_commander_node
Description	Sends periodic watchdog triggers to a robot-driver client (joint control is blacklisted).

Parameters

Parameter	Type	Mandatory / Optional	Default	Purpose
thread_sampling_time_sec	double	Mandatory	none — must be provided	Sampling period of the watchdog loop
watchdog_period	double	Mandatory	none — must be provided	Watchdog trigger period
watchdog_maximum_acceptable_delay	double	Mandatory	none — must be provided	Maximum acceptable delay before the watchdog is triggered
robot_name	string	Mandatory	none — must be provided	Topic prefix of the robot-driver client

Node: sas_robot_driver_ros_example

Property	Value
Executable	sas_robot_driver_ros_example
ROS node name	sas_robot_driver_ros_example (the launch example runs two instances named robot_1 and robot_2)
Description	Minimal example robot driver node.

Parameters

Parameter	Type	Mandatory / Optional	Default	Purpose
robot_name	string	Mandatory	none — must be provided	Name of the robot
initial_joint_positions	array of doubles (radians)	Mandatory	none — must be provided	Initial joint positions
joint_limits_min	array of doubles (radians)	Mandatory	none — must be provided	Minimum joint limits
joint_limits_max	array of doubles (radians)	Mandatory	none — must be provided	Maximum joint limits
thread_sampling_time_sec	double	Mandatory	none — must be provided	Sampling period of the robot control-loop thread

How mandatory/optional is determined in code:

• Mandatory params are read with sas::get_ros_parameter(...) — if missing, the node throws and fails to start.
• Optional params are read with sas::get_ros_optional_parameter(..., <default>) — they carry in-code defaults.

Sample launches

# Compose two example robots plus a composer node
ros2 launch sas_robot_driver composer_example_launch.py
# Single composer node
ros2 launch sas_robot_driver composer_launch.py
# Watchdog commander
ros2 launch sas_robot_driver watchdog_launch.py

Script

Demonstrates RobotDriverServer and RobotDriverClient in Python.

ros2 run sas_robot_driver sas_robot_driver_interface_example.py

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