RV Manipulation Driver (RMD)

NOTE: This package defines a generic interface for using a manipulator; it is NOT intended to be run directly. To use the driver with your manipulator, you must use a package that implements the driver for your arm (e.g. "rv_panda_driver")

Overview

The RV Manipulation Driver (RMD) provides a simple unified mechanism for building high-level interface configurations for seamlessly controlling a broad range of manipulators under different actuation modes.

More concretly, RMD provides a mechanism for advertising high-level topics, services and action_servers for controlling a manipulator, which when called, not only actuate the manipulator based on the provided command, but also hot-swaps in the relevant low-level controllers for that actuation mode.

Additionally, RMD also provides a convenient mapping to the MoveIt planning framework, and provides controller switching when it receives MoveGoal requests from MoveIt.

An example configuration of RMD can be seen below:

system specification

Setup

RMD configurations are specified using the YAML file format and should be loaded via rosparam into the local namespace of RMD. This configuration defines: 1) a move_group name to be used when generating goals with the MoveIt planner, and 2) a list of controllers representing of one or more controller descriptions. This format can be seen below. 

move_group: move_group_name
controllers:
  - Controller Description 1
  - Controller Description 1

Controller Description

Each controller description is composed of the following fields:

Field Name Description Example
topic_name Specifies the topic name to which RMD will subscribe. "cartesian/velocity"
topic_type The topic type of the subscriber. "geometry_msgs/Twist"
maps (optional) The topic name that RMD will republish on to communicate with the activated low-level controller. If left unspecified, RMD will switch controllers but not republish the received message. "/cartesian_velocity_node_controller/cartesian_velocity"
controller The low-level controller required to achieve the actuation mode described by topic_name "cartesian_velocity_node_controller"
type Specifies whether to advertise a subscriber, service or action_server "subscriber"

Example Configuration

An example configuration for the Franka-Emika Panda can be seen below:

move_group: panda_arm_hand
controllers:
  - name: "cartesian/velocity"
    topic_type: "geometry_msgs/Twist"
    type: "publisher"
    controller: "cartesian_velocity_node_controller"
    maps: "/cartesian_velocity_node_controller/cartesian_velocity"
  - name: "/move_group/goal"
    topic_type: "moveit_msgs/MoveGroupActionGoal"
    type: "publisher"
    controller: "position_joint_trajectory_controller"

Extending RMD

RMD provides basic functionality, but it is often the case that you will need to extend on these capabilities to meet the requirements of a specific manipulator.

For this purpose, RMD provides access to two core interfaces, manipulation_driver and mantipulation_moveit_commander.

For an example of how these modules might be extended, see the rv_panda_driver package. The extension provided in this package provides additional functionality, such as clearing errors on the e-stop being released.

Subscribed Topics

Published Topics

Services

Action API