moto

A Python library for controlling Yaskawa MOTOMAN robots with the MotoROS option.

Installation

pip3 install git+https://github.com/tingelst/moto.git --upgrade

On the robot side, the moto library employs the ROS-Industrial robot driver found here: https://github.com/ros-industrial/motoman. Follow the official tutorial for installing the necessary files on the robot controller.

Example

The highest level API is defined in the Moto class.

from moto import Moto

Connect to the robot controller with the defined ip address <robot_ip> and define the R1 control group with six degrees of freedom.

m = Moto(
    "<robot_ip>",
    [
        ControlGroupDefinition(
            groupid="R1",
            groupno=0,
            num_joints=6,
            joint_names=[
                "joint_1_s",
                "joint_2_l",
                "joint_3_u",
                "joint_4_r",
                "joint_5_b",
                "joint_6_t",
            ],
        ),
    ],
)

If your robot system has multiple control groups, e.g. a positioner with two degrees of freedom, these can be defined as follows:

m = Moto(
    "<robot_ip>",
    [
        ControlGroupDefinition(
            groupid="R1",
            groupno=0,
            num_joints=6,
            joint_names=[
                "joint_1_s",
                "joint_2_l",
                "joint_3_u",
                "joint_4_r",
                "joint_5_b",
                "joint_6_t",
            ],
        ),
        ControlGroupDefinition(
            groupid="S1",
            groupno=1,
            num_joints=2,
            joint_names=[
                "joint_1",
                "joint_2",
            ],
        ),
    ],
)

The system supports up to 4 control groups.

Each control group can be accessed and introspected by name:

r1 = m.control_groups["R1"]
print(r1.position)

Motion

To be able to send trajectores, you must first start the trajectory mode:

m.motion.start_trajectory_mode()

The API for sending trajectories is still under development. For now, to move joint 1 you can e.g. do:

robot_joint_feedback = m.state.joint_feedback_ex()

p0 = JointTrajPtFullEx(
    number_of_valid_groups=2,
    sequence=0,
    joint_traj_pt_data=[
        JointTrajPtExData(
            groupno=0,
            valid_fields=ValidFields.TIME | ValidFields.POSITION | ValidFields.VELOCITY,
            time=0.0,
            pos=robot_joint_feedback.joint_feedback_data[0].pos,
            vel=[0.0] * 10,
            acc=[0.0] * 10,
        ),
        JointTrajPtExData(
            groupno=1,
            valid_fields=ValidFields.TIME | ValidFields.POSITION | ValidFields.VELOCITY,
            time=0.0,
            pos=robot_joint_feedback.joint_feedback_data[1].pos,
            vel=[0.0] * 10,
            acc=[0.0] * 10,
        ),
    ],
)

p1 = JointTrajPtFullEx(
    number_of_valid_groups=2,
    sequence=1,
    joint_traj_pt_data=[
        JointTrajPtExData(
            groupno=0,
            valid_fields=ValidFields.TIME | ValidFields.POSITION | ValidFields.VELOCITY,
            time=5.0,
            pos=np.deg2rad([10.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]),
            vel=[0.0] * 10,
            acc=[0.0] * 10,
        ),
        JointTrajPtExData(
            groupno=1,
            valid_fields=ValidFields.TIME | ValidFields.POSITION | ValidFields.VELOCITY,
            time=5.0,
            pos=np.deg2rad([10.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]),
            vel=[0.0] * 10,
            acc=[0.0] * 10,
        ),
    ],
)

m.motion.send_trajectory_point(p0) # Current position at time t=0.0
m.motion.send_trajectory_point(p1) # Desired position at time t=5.0

IO

You can read and write bits:

m.io.read_bit(27010)
m.io.write_bit(27010, 0)

as well as bytes:

m.io.read_group(1001)
m.io.write_group(1001, 42)

As per the documentation, only the following addresses can be written to:

• 27010 and up : Network Inputs (25010 and up on DX100 and FS100)
• 10010 and up : Universal/General Outputs

ROS2 and Real-time control

An extension of the current robot side driver with support for real-time control, and an accompanying ROS2 Control hardware interface is under development here and here, respectively.

Acknowledgements

This work is supported by the Norwegian Research Council infrastructure project MANULAB: Norwegian Manufacturing Research Laboratory under grant 269898.