pybulletX

The lightweight pybullet wrapper for robotics researchers. Build robot simulation with less code. Scale your research with less boilerplate.

Examples

Here is an example of controlling Kuka arm with PyBulletX.

import time

import numpy as np
import pybullet as p
import pybulletX as px

P_GAIN = 50
desired_joint_positions = np.array([1.218, 0.507, -0.187, 1.235, 0.999, 1.279, 0])

def main():
    px.init()

    robot = px.Robot("kuka_iiwa/model.urdf", use_fixed_base=True)
    robot.torque_control = True

    while True:
        time.sleep(0.01)

        error = desired_joint_positions - robot.get_states().joint_position
        actions = robot.action_space.new()
        actions.joint_torque = error * P_GAIN
        robot.set_actions(actions)

        p.stepSimulation()

if __name__ == "__main__":
    main()

Here is the same example but without PyBulletX.

import time

import numpy as np
import pybullet as p
import pybullet_data

P_GAIN = 50
desired_joint_positions = np.array([1.218, 0.507, -0.187, 1.235, 0.999, 1.279, 0])

def main():
    p.connect(p.GUI)

    p.setAdditionalSearchPath(pybullet_data.getDataPath())
    p.loadURDF("plane.urdf")

    robot_id = p.loadURDF("kuka_iiwa/model.urdf", useFixedBase=True)

    num_dofs = 7
    joint_indices = range(num_dofs)

    # The magic that enables torque control
    p.setJointMotorControlArray(
        bodyIndex=robot_id,
        jointIndices=joint_indices,
        controlMode=p.VELOCITY_CONTROL,
        forces=np.zeros(num_dofs),
    )

    while True:
        time.sleep(0.01)

        joint_states = p.getJointStates(robot_id, joint_indices)
        joint_positions = np.array([j[0] for j in joint_states])
        error = desired_joint_positions - joint_positions
        torque = error * P_GAIN

        p.setJointMotorControlArray(
            bodyIndex=robot_id,
            jointIndices=joint_indices,
            controlMode=p.TORQUE_CONTROL,
            forces=torque,
        )

        p.stepSimulation()

if __name__ == "__main__":
    main()

The examples above are available in examples/with_pybulletX.py and examples/without_pybulletX.py.

License

PyBulletX is licensed under MIT License.