doc: Document robot configuration options

Add a page to the documentation which lists all the options of the robot
configuration files.

This is currently mostly copied from the doxygen of the Config class.

doc/configuration.rst

@@ -0,0 +1,184 @@
+*******************
+Robot Configuration
+*******************
+
+Configuration File
+==================
+
+The robot drivers based on :cpp:class:`~robot_fingers::NJointBlmcRobotDriver` are
+configured via YAML files, which has to be passed to the function that creates the
+backend (for example, see demo_single_finger_position_control_).
+
+Default configurations for the different (Tri-)Finger robots can be found in the
+``config/`` folder of the robot_fingers package.
+
+
+Options
+=======
+
+.. note::
+
+   Some of the options below expect a list with one value for each joint.  They are
+   annotated with the type ``list[N_joints]``.  The actual length of the list depends on
+   the number of joints of the robot.  The order of the joints is implicitly defined by
+   :confval:`can_ports`.
+
+
+.. confval:: can_ports: list
+
+   List of the CAN interface names to which the robot is connected.  Example:
+   ``["can0", "can1", "can2"]``.
+
+   The joints will be ordered accordingly (e.g. in actions and observations), i.e. for
+   the above example, the joint order will be
+   ``[can0-motorA, can0-motorB, can1-motorA, ...]``
+
+
+.. confval:: max_current_A: float = 0.0
+
+   Maximum current [in Ampere] that can be sent to the motor.  Commands that result in
+   higher torques will be clipped to the maximum.
+
+.. confval:: has_endstop: bool = false
+
+   Specify whether the joints have physical end stops or not.
+
+   This is, for example, relevant for homing, where the end stop can be used to
+   determine the absolute joint positions.  See also :confval:`homing_method`.
+
+   Note that not having end stops does not mean that the joint can rotate freely in
+   general.
+
+
+.. confval:: homing_method: str = "NONE"
+
+   Which method to use for homing.  See :doc:`homing` for possible values.
+
+
+.. confval:: calibration
+
+   Map with parameters related to homing and initialisation.
+
+   .. confval:: calibration.endstop_search_torques_Nm: list[N_Joints] = [0, ...]
+
+      Torque that is used to find the end stop.
+
+   .. confval:: move_steps: int = 0
+
+      Number of time steps for reaching the initial position (see
+      :confval:`initial_position_rad`) after homing.
+
+
+.. confval:: move_to_position_tolerance_rad: float = 0.0
+
+   Tolerance [in radian] for reaching the target with
+   :cpp:func:`robot_fingers::NJointBlmcRobotDriver::move_to_position` (used during
+   initialization and shutdown).
+
+
+.. confval:: safety_kd: list[N_Joints] = [0.1, ...]
+
+   D-gain to dampen velocity.
+   The default value is rather high to be on the safe side.  Depending in the
+   application you may want to reduce it, to allow faster motions.
+
+   Set to zero to completely disable damping.
+
+
+.. confval:: position_control_gains
+
+   Map with default control gains for the position PD controller.
+
+   .. confval:: kp: list[N_joints] = [0, ...]
+
+      Default P-gain for the position controller.
+
+   .. confval:: kd: list[N_joints] = [0, ...]
+
+      Default D-gain for the position controller.
+
+.. confval:: hard_position_limits_lower: list[N_joints] = [0, ...]
+
+   Hard lower limits for joint position.  Exceeding the limit with any joint results in
+   an error and robot shutdown.
+
+.. confval:: hard_position_limits_upper: list[N_joints] = [0, ...]
+
+   Hard upper limits for joint position.  Exceeding the limit with any joint results in
+   an error and robot shutdown.
+
+
+.. confval:: soft_position_limits_lower: list[N_joints] = [-inf, ...]
+
+   Soft lower limits for joint position.
+
+   Exceeding this limit with some joints results in the action for that joint being
+   adjusted to move the joint back inside the limits.
+
+.. confval:: soft_position_limits_upper: list[N_joints] = [inf, ...]
+
+   Soft upper limits for joint position.  See :confval:`soft_position_limits_lower`.
+
+
+.. confval:: home_offset_rad: list[N_joints] = [0, ...]
+
+   Offset between home position and zero.  See :doc:`homing`.
+
+
+.. confval:: initial_position_rad: list[N_joints] = [0, ...]
+
+   Initial position to which the robot moves during initialization.
+
+.. confval:: shutdown_trajectory
+
+   **Optional**
+
+   Trajectory which is executed in the shutdown method.  Use this to move the robot to a
+   "rest position" during shutdown of the robot driver.  It can consist of arbitrarily
+   many steps.  Leave it empty to not move during shutdown.
+
+   The trajectory is specified as a list of steps, each step consisting of the following
+   values:
+
+   .. confval:: shutdown_trajectory.target_position_rad: list[N_joints]
+
+      Target positions for the joints in radian.
+
+   .. confval:: shutdown_trajectory.move_steps: int
+
+      Number of time steps for reaching the target position.
+
+   Example:
+
+   .. code-block:: yaml
+
+      # first move slowly back to initial position
+      - target_position_rad: [0, 0.9, -1.7, 0, 0.9, -1.7, 0, 0.9, -1.7]
+        move_steps: 3000
+      # then move faster to the actual rest position.
+      - target_position_rad: [1.57, 1.8, -2.5, 1.57, 1.8, -2.5, 1.57, 1.8, -2.5]
+        move_steps: 1000
+
+
+.. confval:: run_duration_logfiles: list
+
+   **Optional**
+
+   List of file to which run duration logs are written.
+
+   You can specify multiple files here if you want to log the runtime of different
+   independent components separately.  For example on a robot with multiple
+   manipulators, you can have a separate log for each manipulator, so if one of them is
+   replaced, only the log file of this manipulator needs to be changed.
+
+
+
+Example
+=======
+
+As a complete example, this is the configuration file used for the TriFingerPro robots:
+
+.. literalinclude:: /PKG/config/trifingerpro.yml
+
+
+.. _demo_single_finger_position_control: https://github.com/open-dynamic-robot-initiative/robot_fingers/blob/master/demos/demo_single_finger_position_control.py

doc_mainpage.rst

@@ -18,6 +18,7 @@ software, see also our paper_ on the open-source version of the TriFinger robot.
    doc/installation.rst
    doc/getting_started.rst
    doc/singularity.rst
+   doc/configuration.rst
    doc/homing.rst
    doc/simulation_backend.rst
    doc/hardware_testing.rst