UR-Interface

Interface for communicating with the Universal Robot.
Contains a Vision module for use with a robot using openCV.

• Python 3.6.7
• OpenCV 3.4.6

Using OpenCV with Gstreamer support enabled

Robot Interface

Connect with the robot

host = "192.168.0.1"
robot = URRobot(host)

Set TCP offset

robot.set_tcp((0.05, -0.05, 0.295, 0, 0, 0))

First 3 are in metre and the last 3 values are in radians

Move robot

robot.movel((0.3, -1.0, 0.2, 0, 3.14, 0))

First 3 are in metre and the last 3 values are in radians

Get TCP position

robot.get_tcp_position()

returns 6 floats as a tuple. First 3 are the vectors in millimeter and last 3 the axis-angle in radians

Vision Module

The vision module contains the Camera class.
Camera uses 2 threads to poll and view the stream.
It uses a lock to read a single frame for procesing.

Capture stream

src = 0
camera = Camera(src)
camera.start()

src 0 will use the first available camera.
Anything else will try to find a Gstreamer sink streaming to the terminal.

View Camera stream

camera.show()

Note that the this uses the cv2.imshow() function which is not threadsafe.
Normal use is for the cv2.imshow() function to be used in the main thread.
The viewing of the camera stream must be ended if using another cv2.imshow().
If you want to show multiple frames,
stitch them together and show them via cv2.imshow() in the main thread.

Stop viewing the camera stream

camera.end()

Closes the viewing of the camera stream. The capture stream keeps polling.

Stop the capture stream

camera.stop()

Terminates the viewing of the camera stream and closes the capture stream.

Read frame

camera.read()

Returns the latest frame from the captured stream.