User Manual

Note: The camera calibration component’s available parameters and status values are for internal use only and
may change in the future without further notice. Calibration should only be performed through the Web GUI
as described above.
6.6.4 Services
Note: The camera calibration component’s available service calls are for internal use only and may change
in the future without further notice. Calibration should only be performed through the Web GUI as described
above.
6.7 Hand-eye calibration
For applications, in which the rc_visard is integrated into one or more robot systems, it needs to be calibrated
w.r.t. some robot reference frames. For this purpose, the rc_visard is shipped with an on-board calibration routine
called the hand-eye calibration component.
Note: The implemented calibration routine is completely agnostic about the user-defined robot frame to which
the rc_visard is calibrated. It might be a robot’s end-effector (e.g., flange or tool center point) or any point on
the robot structure. The method’s only requirement is that the pose (i.e., translation and rotation) of this robot
frame w.r.t. a user-defined external reference frame (e.g., world or robot mounting point) is exactly observable
by the robot controller and can be reported to the calibration component.
The Calibration routine (Section 6.7.3) itself is an easy-to-use three-step procedure using a calibration grid.
Calibration grids for the rc_visard can be obtained from Roboception.
6.7.1 Calibration interfaces
The following two interfaces are offered to conduct hand-eye calibration:
1. All services and parameters of this component required to conduct the hand-eye calibration program-
matically are exposed by the rc_visard’s REST-API interface (Section 8.2). The respective node name
of this component is rc
_
hand
_
eye
_
calibration and the respective service calls are documented Ser-
vices (Section 6.7.5).
Note: The described approach requires a network connection between the rc_visard and the robot con-
troller to pass robot poses from the controller to the sensor’s calibration component.
2. For use cases where robot poses cannot be passed programmatically to the rc_visard’s hand-eye calibration
component, the Web GUI’s Hand-Eye Calibration tab (Section 4.5) offers a guided process to conduct the
calibration routine manually.
Note: During the process, the described approach requires the user to manually enter into the Web GUI
robot poses, which need to be accessed from the respective robot-teaching device or handheld.
6.7.2 Sensor mounting
As illustrated in Fig. 6.7.1 and Fig. 6.7.2, two different use cases w.r.t. to the mounting of the rc_visard generally
have to be considered:
a. The rc_visard is mounted on the robot, i.e., it is mechanically connected at its mounting points (Section
3.6) to a robot link (e.g., at its flange or a flange-mounted tool), and hence moves with the robot.
6.7. Hand-eye calibration 54