Introduction

This package encapsulates a SoT graph to control a robot in the ros-control framework. The intent is to make it generic and adapted to any robot through rosparam. As the Stack-Of-Taks is a whole-body controller it tries to connect to all the available resources of the robot.

rosparam

Namespace

All the parameters regarding the SoT inside ros-control are in the namespace

/sot_controller

Setting the SoT dynamic library which contains the robot device.

Let us assume that you want to control a TALOS robot. You should then write a YAML file than can be named:

sot_talos_param.yaml

Its SoT device entity is located inside the following dynamic library:

/opt/openrobots/lib/libsot-pyrene-controller.so

Then inside the file sot_talos_param.yaml

  libname: libsot-pyrene-controller.so

Specifying the actuated state vector

To map the joints from the URDF model to the SoT actuated state vector, it is simply done by giving the ordered list of the joints name in the URDF model. For instance:

     joint_names: [ leg_left_1_joint, leg_left_2_joint, leg_left_3_joint, leg_left_4_joint, leg_left_5_joint, leg_left_6_joint,
    leg_right_1_joint, leg_right_2_joint, leg_right_3_joint, leg_right_4_joint, leg_right_5_joint, leg_right_6_joint,
    torso_1_joint,torso_2_joint,head_1_joint, head_2_joint,
    arm_left_1_joint, arm_left_2_joint, arm_left_3_joint, arm_left_4_joint, arm_left_5_joint, arm_left_6_joint, arm_left_7_joint, gripper_left_joint,
    arm_right_1_joint, arm_right_2_joint, arm_right_3_joint, arm_right_4_joint, arm_right_5_joint, arm_right_6_joint, arm_right_7_joint, gripper_right_joint
  ]

Specifying the map between the ros control data and the sot device entity.

This ros-control plugin connect to the robot (or simulated robot) by requesting the available ressources such as:

motor-angles: Reading of the motor position
joint-angles: Reading of the joint position
velocities: Reading/estimation of the joint velocities
torques: Reading/estimation of the joint torques
cmd-position: Command for the joint positions
cmd-effort: Command for the joint torques

For instance the map for a robot which maps cmd-position to joints and cmd-effort to effort in its device will have have the following lines in its param file:

map_rc_to_sot_device: { motor-angles: motor-angles ,
  joint-angles: joint-angles, velocities: velocities,
  torques: torques, cmd-joints: joints, cmd-effort: effort }

Specifying the control mode

Robots with ros-control can be controlled either in position (POSITION) or in torque (EFFORT) using the control_mode variable:

     control_mode: EFFORT

Logging

Logs of the last 5 minutes are written in /tmp/sot.log-* in binary format. Use command roscontrol-sot-parse-log /tmp/sot.log-duration.. > txtformat to get the clear text version.

stack-of-tasks / roscontrol_sot