7-PythonAPI.md

Python API

Move robot with python

Python API functions and usage

• bot = InterbotixManipulatorXS("wx250", "arm", "gripper") → create instance of InterbotixManipulatorXS (class defined here)
• bot.arm.go_to_home_pose() & bot.arm.go_to_sleep_pose()

---

• bot.arm.set_ee_pose_components(x=0.2, y=0.1, z=0.2, roll=0, pitch=0, yaw=0) → move end-effector in position x, y, z and orientation roll, pitch, jaw
• bot.arm.set_ee_cartesian_trajectory(x=0.1, z=-0.16) → add/substract to current position adn reach that end-effector
  • bot.arm.set_ee_cartesian_trajectory(pitch=1.5) → rotate in pitch but end-effector still
• bot.arm.set_joint_positions(joint_positions) → reach with the 6 joints, the 6 angles in joint_positions array
• bot.dxl.robot_write_trajectory("group", "arm", "position", trajectory) → reach a series of angles with the joint, in time
  • trajectory = [ {0.0: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0]}, {2.0: [0.0, 0.0, 0.0, 0.0, 0.5, 0.0]}, {4.0: [0.5, 0.0, 0.0, 0.0, 0.5, 0.0]}, {6.0: [-0.5, 0.0, 0.0, 0.0, 0.5, 0.0]} ]
• bot.arm.set_ee_pose_matrix(T_sd) → move end-effector in position x, y, z and orientation roll, pitch, jaw using Rotation&Traslation Matrices
  • T_sd = np.identity(4) T_sd[0,3] = 0.3 T_sd[1,3] = 0.1 T_sd[2,3] = 0.2

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• bot.arm.set_single_joint_position("waist", np.pi/2.0) → set angle in anly one joint
• bot.gripper.open() (bot.gripper.open(0.2)) (bot.gripper.close()) (bot.gripper.set_pressure(0.3))

Examples

Go to cd interbotix_ws/src/interbotix_ros_manipulators/interbotix_ros_xsarms/examples/python_demos/ to find the Python demos.

Note: u can have script where ever u want.. noo need to be in that directory

As we saw in General.md, run roslaunch interbotix_xsarm_control xsarm_control.launch robot_model:=wx250s to connect with real robot or roslaunch interbotix_xsarm_control xsarm_control.launch robot_model:=wx250s use_sim:=true to simulate it.

bartender.py

Code

from interbotix_xs_modules.arm import InterbotixManipulatorXS
import numpy as np
import sys

# This script makes the end-effector perform pick, pour, and place tasks
# Note that this script may not work for every arm as it was designed for the wx250
# Make sure to adjust commanded joint positions and poses as necessary
#
# To get started, open a terminal and type 'roslaunch interbotix_xsarm_control xsarm_control.launch robot_model:=wx250'
# Then change to this directory and type 'python bartender.py  # python3 bartender.py if using ROS Noetic'

def main():
    bot = InterbotixManipulatorXS("wx250", "arm", "gripper")

    if (bot.arm.group_info.num_joints < 5):
        print('This demo requires the robot to have at least 5 joints!')
        sys.exit()

    bot.arm.set_ee_pose_components(x=0.3, z=0.2)
    bot.arm.set_single_joint_position("waist", np.pi/2.0)
    bot.gripper.open()
    bot.arm.set_ee_cartesian_trajectory(x=0.1, z=-0.16)
    bot.gripper.close()
    bot.arm.set_ee_cartesian_trajectory(x=-0.1, z=0.16)
    bot.arm.set_single_joint_position("waist", -np.pi/2.0)
    bot.arm.set_ee_cartesian_trajectory(pitch=1.5)
    bot.arm.set_ee_cartesian_trajectory(pitch=-1.5)
    bot.arm.set_single_joint_position("waist", np.pi/2.0)
    bot.arm.set_ee_cartesian_trajectory(x=0.1, z=-0.16)
    bot.gripper.open()
    bot.arm.set_ee_cartesian_trajectory(x=-0.1, z=0.16)
    bot.arm.go_to_home_pose()
    bot.arm.go_to_sleep_pose()

if __name__=='__main__':
    main()

Explanation of code

1. improt instance of InterbotixManipulatorXS
2. in main create instance of InterbotixManipulatorXS (class defined here)
   1. bot = InterbotixManipulatorXS("wx250**s**", "arm", "gripper")
3. set bot to go to 0.3 in x direction and 0.2 in z direction
   1. bot.arm.set_ee_pose_components(x=0.3, z=0.2)
   2. (x=0.3, z=0.2) is absolute position relative base link frame. ee_link frame with respect to base frame.
4. rotate weist of 90 deg
   1. bot.arm.set_single_joint_position("waist", np.pi/2.0)
5. move end-effector forward of 0.1 meters relative to his current pos and lower it self of 0.16.
   1. bot.arm.set_ee_cartesian_trajectory(x=-0.1, z=0.16)
6. rotate end-effector
   1. bot.arm.set_ee_cartesian_trajectory(pitch=1.5)

Run code

1. cd interbotix_ws/src/interbotix_ros_manipulators/interbotics_ros_xsarms/exaples/python_demos

2. change model of robot is needed from wx250 to wx250s

   nano bartender.py

3. python bartender.py (or python3 bartender.py)

For the other demos it is the same... check them out

Resources

• Offical video tutorial