Safety function blocks for workspace monitoring

As the synergy between humans and robots continues to expand, ensuring a safe working environment is of paramount importance. Two new function blocks are offered in the LASAL SAFETY Designer software from SIGMATEK. In combination with MDD 2000 servo drives, the Safety CPU SCP 211 and the safety functions SLS (Safely Limited Speed) and SP (Safe Position), this creates a customized workplace monitoring for all serial kinematics: "Denavit-Hartenberg (DH) Transformation" and "Collision Detection". The user only needs to set the appropriate parameters to use these functions in his project.

DH Transformation

The DH Transformation block converts a spatial coordinate system at the input into a spatial coordinate system at the output. A multi-axis robotic arm can be realized by using this module multiple times. The location coordinate system at the output of this chain represents the TCP (Tool Center Point) of the robot.

Collision Detection

The Collision Detection function block is designed to detect a collision between the Tool Center Point (TCP) of a robot and other objects. The workspace is defined by the minimum and maximum XYZ coordinates. These two points span a cube parallel to the coordinate system. This workspace is the area in which the TCP is allowed to move. In addition, an enveloping sphere is placed over the current position of the robot.

Collision Detection permanently monitors the valid area and detects collisions by comparing the enveloping sphere with the defined workspace limits. If the robot moves outside this defined range, the user can program what happens in this case, such as whether an emergency stop is triggered or some other error response.

By linking individual workspaces together, it is also possible to create complex workspaces.