layered_hardware_dynamixel

A ros_control layer implementation for ROBOTIS Dynamixel actuators. See layered_hardware to understand the layered scheme.

Plugins: layered_hardware_dynamixel_plugins

layered_hardware_dynamixel/DynamixelActuatorLayer

• implements state & command interfaces for ROBOTIS Dynamixel actuators

Layer parameters (should be defined under ~<layer_name>)

serial_interface (string, default: '/dev/ttyUSB0')

• path to Usb2Dynamixel device

baudrate (int, default: 115200)

• baudrate for Usb2Dynamixel device

actuators (struct, required)

• actuator parameters (see below)

Actuator parameters (should be defined under ~<layer_name>/actuators/<actuator_name>)

id (int, required)

• id of the dynamixel actuator

torque_constant (double, required)

• torque constant for conversion between current and torque in N*m/A
• ex. if the actuator's stall torque & current are 10.6 N*m & 4.4 A at the operating voltage, it would be 2.41 (= 10.6 / 4.4)

operating_mode_map (map<string, string>, required)

• map from ROS's controller names or controller group names to Dynamixel's operating mode names
• possible operating mode names are 'clear_multi_turn', 'current_based_position', 'current', 'extended_position', 'reboot', 'torque_disable', & 'velocity'

item_map/<operating_mode_name> (map<string, int>, optional)

• pairs of Dynamixel's control table key & value
• the plugin will write values to the actuator just after changing operating modes
• ex. custom PID gains for the 'extended_position' mode

item_map:
  extended_position:
    Position_P_Gain: 800
    Position_I_Gain: 400
    Position_D_Gain: 0

Example

see launch/single_dynamixel_example.launch

Tips

• if you feel slow communication speed with actuators, try adjusting the latency timer for your usb-serial device according to this comment