andino_base

andino_base

Description

The hardware-software-ros interaction in the andino project is developed using ROS 2 Control.

This package:

• Implements andino's hardware interface.
• Provides a communication with microcontroller:
  • andino_base::MotorDriver class is in charge of the Serial communication for commanding the motors.
    • An application is provided for evaluating the communication: Check applications/motor_driver_demo.cpp. To use this application simply execute motor_driver_demo --help to see the options.
  • This communication module is used by the hardware interface implementation.

Hardware Interface

In ros2_control hardware system components are libraries, dynamically loaded by the controller manager using the pluginlib interface.

For extra information about the hardware components see Hardware Components.

The hardware interface accepts some parameters that are passed via the urdf description within the ros2_control tag (Check andino_description)

Params	Description
left_wheel_name	Name of the left wheel joint.
right_wheel_name	Name of the right wheel joint.
serial_device	Path to the serial device.
baud_rate	Baud rate of the serial communication.
timeout	Timeout for the communication.
enc_ticks_per_rev	Encoder ticks per revolution of the wheel.

State interfaces

This hardware interface implements the following state interfaces per joint (for left and right joint):

• Position: The position is obtained via encoder information from the microcontroller.
• Velocity: Velocity is calculated via encoder information from the microcontroller.

Command interfaces

This hardware interface uses the following command interfaces per joint (for left and right joint):

• Velocity: The velocity received (rad/s) is traduced to microcontroller's velocity nomenclature for the motors.

Motor Driver Application

An application for testing the connection with the microcontroller is provided. After installing this package the application called motor_driver_demo can be used.

motor_driver_demo --help

This application allows verifying the communication with the microcontroller for controlling the motors. Commands for reading the encoders or individually setting a velocity for the motors is some of the possibilities.

Extra Notes

• Serial communication: In case the serial port is denied to be open, probably the user should be added to the plugdev and dialout groups:

  sudo usermod -a -G dialout $USER
  sudo usermod -a -G plugdev $USER