Overview

Since the zero point of some motors will change after power off, rm_calibration_controllers will move after it is started until motors reach the position we wanted,and motors position will be reset to zero,which can come true by two ways.One is that mechanical_calibration_controller stops moving after it reaches the mechanical limit.Another one is that gpio_calibration_controller moves at a fast speed until gpio changes to be different from initial gpio.Then it will retreat at a small angle and restore initial gpio.Finally it moves at a slow speed until the state of gpio changes to be different from initial gpio again.

Keywords: calibration, ROS, position.

License

The source code is released under a BSD 3-Clause license.

Author: DynamicX
Affiliation: DynamicX
Maintainer: DynamicX

The package has been tested under ROS Indigo, Melodic and Noetic on respectively Ubuntu 18.04 and 20.04. This is research code, expect that it changes often and any fitness for a particular purpose is disclaimed.

Hardware interface type

EffortJointInterface Used to send effort command to target joint to make it reach the calibration speed.
ActuatorExtraInterface Used to obtain the information of the target actuators offset, current position, the state of the whether it is stopped and the state of whether it is calibrated.
GpioStateInterface Used to obtain the state of gpio.

Installation

Installation from Packages

To install all packages from the this repository as Debian packages use

sudo apt-get install ros-noetic-calibration-controllers

Or better, use rosdep:

sudo rosdep install --from-paths src

Dependencies

roscpp
rm_common
effort_controllers
controller_interface

ROS API

Service

is_calibrated (control_msgs/QueryCalibrationState)

When requesting to this server, it will return response about whether target joint has been calibrated.

Parameters

calibration_base

search_velocity (double)

The joint velocity of calibrating.

mechanical_calibration_controller

velocity_threshold_ (double)

This is velocity threshold. When the real time velocity of target joint lower than threshold, and last for a while, it can switch CALIBRATED from MOVING.

gpio_calibration_controller

backward_angle (double)

The angle of retreat when gpio changes to be different form initial gpio for the first time.
slow_forward_velocity (double)

The velocity of second forward movement for reaching a more accurate calibration-position.
pos_threshold (double)

The threshold for the difference between the command position and the current position.

Complete description

mechanical_calibration_controller

trigger_calibration_controller:
  type: rm_calibration_controllers/MechanicalCalibrationController
  actuator: [ trigger_joint_motor ]
  velocity:
    search_velocity: 4.0
    vel_threshold: 0.001
    joint: trigger_joint
    pid: { p: 0.8, i: 0, d: 0.0, i_clamp_max: 0.0, i_clamp_min: 0.0, antiwindup: true }

gpio_calibration_controller

yaw_calibration_controller:
  type: rm_calibration_controllers/GpioCalibrationController
  actuator: [ yaw_joint_motor ]
  gpio: "yaw"
  initial_gpio_state: false
  velocity:
    search_velocity: -4.0
    slow_forward_velocity: -2.0
    joint: yaw_joint
    pid: { p: 0.19, i: 0, d: 0.0, i_clamp_max: 0.0, i_clamp_min: 0.0, antiwindup: true }
  position:
    pos_threshold: 0.01
    backward_angle: -0.15
    joint: yaw_joint
    pid: { p: 7.0, i: 0, d: 0.0, i_clamp_max: 0.0, i_clamp_min: 0.0, antiwindup: true }

Bugs & Feature Requests

Please report bugs and request features using the Issue Tracker.