Cavity preservation

Cavity preservation operation

Programming a toolpath for cavity preservation basically generates a point based cycle, i.e. an operation, that consists of three sections:

approach (off-process)

preservation position (in-process)

retraction (off-process)

The preservation cycle is calculated and controlled by the programming attributes and events.

Programming attributes

The display of the programming attributes in the Programming defaults and Active program dashboards is defined in a Settings.xml file. With a standard installation, a default file is located at the path <install>\E2Plugin\Technologies\CavityConservationTechnology\Standard\ControllerSettings.

The following generic attributes have been defined.

Tech tab	Container	Attribute	Description
Program base
Tool data

Manufacturing geometry
Toolpath calculation
Technology base
Cavity preservation


Toolpath quality


	The program reference information.
Base frame	The reference frame of the program.


	Tool information.
Tool resource	The name of the tool.
Technology	The applied technology.
Automatic tool change
Tool frame	The tool frame that runs the toolpath.


	The mapping of the tool frame axes with the corresponding vectors on the process geometry.
Normal direction	The alignment of the tool frame Z axis with the normal direction of the process geometry.
Tangent direction	The alignment of the tool frame X axis with the tangent direction of the process geometry.


	The global transformation of the manufacturing geometry.
Translation in X,Y,Z	The global translation in X,Y or Z direction.


Rotation around X,Y,Z	The global rotation around the X,Y or Z axis.


	The offset of the toolpath element from its original location on the manufacturing geometry.
Tangential translation	The offset of a toolpath element in its tangent direction.
Bitangential translation	The offset of a toolpath element in its bi-tangent direction.
Normal translation	The offset of a toolpath element in its normal direction.

Tangent rotation	The rotation of the toolpath element round its tangent vector
Bitangent rotation	The rotation of the toolpath element round its bi-tangent vector.
Normal rotation	The rotation of the toolpath element round its normal vector.


	Additional (optimization) conditions to calculate the toolpath.
Ext. axis backprog.	The axis values of an external resource, like a positioner, as been set at the first position of the in-process path, will be propagated backwards up to the approach of that in-process path.


	The motion definition.
Motion to process point	The motion type for the tool to reach the process point.


	To define an approach motion towards the in-process toolpath.
Approach	The number of approach steps.

Motion	The motion type for the approach.
Offset reference	The reference to determine the offset directions.

Offset tangential / bitangential / normal	The local offset of the approach step from the in-process toolpath start element.


	To define a retraction motion away from the in-process toolpath.
Retract	The number of retraction steps.

Motion	The motion type for the retract.
Offset reference	The reference to determine the offset directions.

Offset tangential / bitangential / normal	To local offset of the retract step from the in-process toolpath end element.


	The toolpath quality evaluation criteria. The exact content may vary per technology.
Unreachability	Evaluates unreachable situations of the robot or machine.
Collision	Evaluates collision situations.
Singularity	Evaluates singularity situations of the robot or machine.

Process angle deviation	Evaluates the process angle deviation from its reference value.

Axis limit proximity	Evaluates the proximity to the limits of the driven axis. Separated evaluation value range for linear and circular joint axis.
Axis speed	Evaluates the axis speed of all driven axis as a (absolute) difference between the start and the end motion between positions.

Program events

The generic cavity preservation technology has the following programming events:

Motion events
Speed	Sets the velocity for the subsequent motions.
Accuracy	Sets the accuracy for the subsequent motions.
Dwell	Sets a waiting time at the path element for the tool to remain position until moving further.
Acceleration	Sets the acceleration for the subsequent motions.

IO signal events
Wait for signal	Adds a wait for an input signal event of the active controller.
Set signal	Adds a set output signal event of the active controller.
Synchronize robots	Sets an event to synchronize cooperating robots.
Set resource port	Sets a port of a resource.
Wait for resource port	Waits for a port of a resource.
Adapter actor	Sets a signal of a mechanical parent adapter to create or delete a mechanical connection during simulation.