urx is a python library to control the robots from Universal Robots. It is published under the LGPL license and comes with absolutely no guarantee.

It is meant as an easy to use module for pick and place operations, although it has been used for welding and other sensor based applications that do not require high control frequency.

Both the 'secondary port' interface and the real-time/matlab interface of the UR controller are used. urx can optionally use the python-math3d(GPL) library to receive and send transformation matrices to the robot urx is known to work with all release robots from Universal Robot.

urx was primarily developed by Olivier Roulet-Dubonnet for Sintef Raufoss Manufacturing.

Install

The easiest is probably to use pip:

pip install urx

Example use:

importurxrob=urx.Robot("192.168.0.100")
rob.set_tcp((0, 0, 0.1, 0, 0, 0))
rob.set_payload(2, (0, 0, 0.1))
sleep(0.2) #leave some time to robot to process the setup commandsrob.movej((1, 2, 3, 4, 5, 6), a, v)
rob.movel((x, y, z, rx, ry, rz), a, v)
print"Current tool pose is: ", rob.getl()
rob.movel((0.1, 0, 0, 0, 0, 0), a, v, relative=true) # move relative to current poserob.translate((0.1, 0, 0), a, v) #move tool and keep orientationrob.stopj(a)
robot.movel(x, y, z, rx, ry, rz), wait=False)
whileTrue :
sleep(0.1) #sleep first since the robot may not have processed the command yetifrobot.is_program_running():
breakrobot.movel(x, y, z, rx, ry, rz), wait=False)
while.robot.getForce() <50:
sleep(0.01)
ifnotrobot.is_program_running():
breakrobot.stopl()
try:
robot.movel((0,0,0.1,0,0,0), relative=True)
exceptRobotError, ex:
print("Robot could not execute move (emergency stop for example), do something", ex)

Development using Transform objects from math3d library:

fromurximportRobotimportmath3dasm3drobot=Robot("192.168.1.1")
mytcp=m3d.Transform() # create a matrix for our tool tcpmytcp.pos.z=0.18mytcp.orient.rotate_zb(pi/3)
robot.set_tcp(mytcp)
time.sleep(0.2)
# get current pose, transform it and move robot to new posetrans=robot.get_pose() # get current transformation matrix (tool to base)trans.pos.z+=0.3trans.orient.rotate_yb(pi/2)
robot.set_pose(trans, acc=0.5, vel=0.2) # apply the new pose#or only work with orientation parto=robot.get_orientation()
o.rotate_yb(pi)
robot.set_orientation(o)

Other interactive methods/properties

fromurximportRobotrob=Robot("192.168.1.1")
rob.x# returns current xrob.rx# returns 0 (could return x component of axis vector, but it is not very usefullrob.rx-=0.1# rotate tool around X axisrob.z_t+=0.01# move robot in tool z axis for +1cmcsys=rob.new_csys_from_xpy() # generate a new csys from 3 points: X, origin, Yrob.set_csys(csys)

Supported Grippers

Robotiq Gripper

urx can also control a Robotiq gripper attached to the UR robot. The robotiq class was primarily developed by Mark Silliman.

Example use:

importsysimporturxfromurx.gripperimportRobotiq_Two_Finger_Gripperif__name__=='__main__':
rob=urx.Robot("192.168.0.100")
robotiqgrip=Robotiq_Two_Finger_Gripper()
iflen(sys.argv) !=2:
print"false"sys.exit()
ifsys.argv[1] =="close":
robotiqgrip.close_gripper()
ifsys.argv[1] =="open":
robotiqgrip.open_gripper()
rob.send_program(robotiqgrip.ret_program_to_run())
rob.close()
print"true"sys.exit()

OnRobot RG2 Gripper

urx can control an RG2 gripper as well. The class was primarily developed by Moritz Fey.

Example use:

importsysimporturxfromurx.gripperimportOnRobotGripperRG2if__name__=='__main__':
rob=urx.Robot("192.168.0.100")
gripper=OnRobotGripperRG2(rob)
iflen(sys.argv) !=2:
print"false"sys.exit()
ifsys.argv[1] =="close":
gripper.close_gripper()
ifsys.argv[1] =="open":
gripper.open_gripper()
rob.close()
print"true"sys.exit()

Various parameters can be controlled in the open and close functions. The parameters that can be set are:

gripper.open_gripper(
target_width=110, # Width in mm, 110 is fully opentarget_force=40, # Maximum force applied in N, 40 is maximumpayload=0.5, # Payload in kgset_payload=False, # If any payload is attacheddepth_compensation=False, # Whether to compensate for finger depthslave=False, # Is this gripper the master or slave gripper?wait=2# Wait up to 2s for movement
)

The parameters are the same for opening and closing the gripper.