RL Locomotion State

RL locomotion State allows the robot to move with lower body while switch between arm swing and joint control in upper body. The lower body will execute a reinforcement learning based controller which allows velocity control in three directions.

On the other side, upper body is managed by a state manager task, which allows the user to switch between different upper body controllers. Avaliable controllers are:

• Default: no controller, mapped at upper body state 0.
• UpperBodyActTask: arm swing task, mapped at upper body state 1.
• UpperBodyTeleTask: joint control task, mapped at upper body state 2.

State specification

State name	Task name	Joystick mapping	DDS mapping	Frequency
RL Locomotion	LowerBodyCpgTask / UpperBodyStateManagerTask	RB+A	3	50Hz / 500Hz

Avaliable for hanging	Avaliable for standing	Auto Protection Switch
No	Yes	No

Joystick Control

Enter RL Locomotion State

After initailize AuroraCore, press bumper RB and button A at the same time to enter RL locomotion state.

Velocity Control

Use the left and right rocker to apply velocity control on the robot.

• left rocker vertical axis: move forward and backward
• left rocker horizontal axis: move left and right
• right rocker horizontal axis: turn left and right

Arm Swing Switch

The upper body state manager provides a shortcut key to turn on arm swing task. Click button B to turn on arm swing, and then click X to turn off arm swing.

Client Control

Velocity control	Stand pose control	Joint control	Joint parameter control
Yes	No	Upper Body	No

Enter RL Locomotion State

After initailize AuroraCore, use aurora client's set_fsm_state function to enter RL locomotion state.

client = AuroraClient.get_instance(domain_id=123, robot_name="fouriern1")   # initialize aurora client
time.sleep(1)

client.set_fsm_state(3)     # change to RL locomotion state

Velocity Control

Before applying velocity control through client, it is necessary to first switch velocity source in Aurora. Velocity source makes sure only one source can send velocity command at a time, ensure safety. Velocity source can be set with set_velocity_source function, where 0 refers to joystick control, and 2 refers to client control.

Once the velocity source is set to 2, velocity control is avaliable via set_velocity function.

Velocity Range: vx: [-0.5, 0.5], vyL [-0.5, 0.5], vyaw: [-1.0, 1.0]

client.set_velocity_source(2)   # set velocity source to client control
time.sleep(0.5)

client.set_velocity(0.3, 0.0, 0.0, 5.0)  # make robot move forward at 0.5 m/s for 5 seconds
time.sleep(5.0)

client.set_velocity(0.0, 0.3, 0.0, 5.0)  # make robot move left at 0.3 m/s for 5 seconds
time.sleep(5.0)

client.set_velocity(0.0, 0.0, 0.5, 5.0)  # make robot turn left at 1.0 rad/s for 5 seconds
time.sleep(5.0)

client.set_velocity(0.0, 0.0, 0.0, 1.0)  # make robot stop 

Arm Swing

To turn on arm swing task, change upper body state to 1.

client.set_upper_fsm_state(1)   # turn on arm swing

Joint Control

To apply joint control in RL locomotion state, it is necessaey to change upper body state to 2.

Once upper state is changed to 2, joint control is avaliable via set_group_cmd function. Since the position command take effects immediately, it is suggested to use interpolation in upper body joint command to avoid sharp command change.

Avaliable Control Groups: waist, left_manipulator, right_manipulator

client.set_upper_fsm_state(2)   # turn on joint control

left_manipulator_init_pose = client.get_group_state("left_manipulator", key="position")
left_manipulator_target_pose = [-1.2, 0, 0, 1.2, 0]
total_steps = 200

for i in range(total_steps):
    # interpolate from init to target pose
    left_manipulator_pose = [s + (e - s) * i / total_steps for s, e in zip(left_manipulator_init_pose, left_manipulator_target_pose)]
    client.set_group_cmd({"left_manipulator": left_manipulator_pose})
    time.sleep(0.01)

For joint specifications, please refer to robot_specs