Characteristics of workspace/protection area control

Workspace/protection areas

A workspace is defined as a zone that the TCP (Tool Centre Point) is not permitted to exit.

On the other hand, a protection area must never be touched by the TCP.

Workspace and protection areas can be nested to any extent required. When areas are nested, protection space control overrides workspace control. The number of workspace and protection areas is limited to 20.

Control areas as 3D objects

A workspace/protection area is defined by an object in space. Basically 2 different geometries are available. Circles or polygons can be defined by a third constant dimension.

Cylinders are defined by a full circle in the basic plane.

Polygons can be of any complexity in the basic plane. Only the convex form (self-contained chain without overlaps) is mandatory. The number of permitted motion blocks to define a polygonal shape is limited to 20 blocks.

The X/Y/Z coordinates of the control areas are referred directly to the three main axes of the channel configuration.

Example of X/Y basic plane (G17):

X → 1st main axis

Y → 2nd main axis

Z → 3rd main axis (constant due to minimum/maximum values)

Notice

Control areas are always defined as viewed by the 3 main axes of the channel configuration (Cartesian). An active Cartesian transformation #(A)CS is not considered when control areas are defined. They are always defined in the MCS coordinate system, taking into consideration any active Cartesian offsets (e.g. G54, G92, etc.).

Schematic of 2 machining units with workspace areas that are limited by 2 cylindrical workspaces (green).

Path check

In workspace/protection area control, the path between the starting and end points is checked for any violations.

With standard linear and circular motion blocks, equations search for intersections with the defined control areas.

When polynomial contouring is activated or with helical motions, the path is first segmented and the individual points are then checked. This results in the requirement for considerably more computation resources.

Control area overlaps

When there are several workspace and protection areas, they may overlap. In the figure below, a small workspace connects two other workspaces.

This permits a movement from workspace 1 to workspace 2.