urx is a python library to control the robots from 'Universal robot'. 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.

#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)

#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.robotiq_two_finger_gripperimportRobotiq_Two_Finger_Gripperif__name__=='__main__':
rob=urx.Robot("192.168.0.100")
robotiqgrip=Robotiq_Two_Finger_Gripper()
if(len(sys.argv) !=2):
print"false"sys.exit()
if(sys.argv[1] =="close") :
robotiqgrip.close_gripper()
if(sys.argv[1] =="open") :
robotiqgrip.open_gripper()
rob.send_program(robotiqgrip.ret_program_to_run())
rob.close()
print"true"sys.exit()

#RG2 Gripper

urx can also control an RG2 gripper attached to the UR robot. This class was primarily developed by David Hinwood

-Gripper will contiously try to close(stopped at the set force value in newtons) if set to a width smaller than the current width while grasping an object. This is part of the design and not an error. The same functionality is embedded in the default program

-You require an ethernet connection to the robot

##Example use:

importsysimporturximporttime#import filefromurximportRG2GripperasGripClassrob=urx.Robot("10.0.0.157")
#instantiate objectgripperInstance=GripClass.RG2(rob)
#basic delay for script(to complete action, RG2 approximatly takes 1.3 seconds to close from completely open)time.sleep(2)
#set distance between pincers apart, in this case closinggripperInstance.setWidth(0)
time.sleep(2)
#open the gripper completlygripperInstance.setWidth(110)
time.sleep(2)
#returns the current width of the robotgripperInstance.getWidth()