Actin  Version 5.5.5
Software for Robotics Simulation and Control
Collision Maps

The Collision Exclusion Plugin can be used to view or configure which manipulators in the scene can collide with each other. If a collision between two links is enabled, movement will stop when the bounding volumes of each link collide. If a collision is excluded, then the links will pass through each other. There are multiple collision exclusion maps used in the simulation.

  1. Static Collision Map: This a global map used for collision detection that is only edited by this plugin.
  2. Dynamic Collision Map: Collision exclusion map that is editable during the execution of motion scripts.
  3. Collision Avoidance Map: Map used by the Actin control system to determine which links are included in collision avoidance calculations (dodging) if enabled.
  4. Self Collision Map: Map to edit which links on a manipulator can collide with other links on the same manipulator. This is being edited when editing the Static Collision Map.
The "Static Collision Map" is stored in the EcManipulatorSystem, and doesnt change at runtime
The "Dynamic Collision Map" and the "Collision Avoidance Map" are stored in the EcManipulatorSystemConfiguration, and can change at runtime.
Each EcIndividualManipulator stores their "Self Collision Map", it is not stored in the EcManipulatorSystemConfiguration. It cannot change at runtime.

The collision exclusion dialog can be shown using Edit -> Collision Exclusion Map menu


Collision exclusion UI displays all the available links and manipulators as shown below.

Collision exclusion UI

Reading Collision Exclusion Map

At any time, it displays a collision mapping of currently selected link that is highlighted in red in the left tree widget (Current link/ Manipulator(s)). All the collision candidates for the particular links are highlighted in green in the right tree widget. It is possible to select or de-select by clicking on the item.

In the figure below, the red highlighted manipulator "Schunk P50-1" will NOT trigger a collision with green highlighted links "SDA5D Right Wrist Pitch", or "SDA5D Right Tool Roll" if their bounding volumes contact.

Exclude collision between Schunk P50-1 and SDA5D Right Wrist Pitch, or SDA5D Right Tool Roll

If you select the "SDA5D Right Wrist Pitch" link, you will see that the "SDA5D Right Wrist Pitch" link is now red (selected) and the "Schunk P50-1" manipulator and 3 other links are green (excluded).

Exclude collision between SDA5D Right Wrist Pitch -Link and multiple links and the gripper manipulator

Configuring Collision Exclusion

To define a collision exclusion mapping select which Collision Map Type from the drop down list near the top of the dialog. the different types of maps are explained above. Certain map types limit what can be selected. for example, if the static, dynamic, or collision avoidance map is selected, the dialog will only let you exclude links on other manipulators. The self collision map is the opposite, it only allows configuring links on the same manipulator.

Next we need to select a link or manipulator from the left widget. After selecting the desired link or manipulator the link or manipulator will be rendered with a red highlight. To select which link or manipulator to exclude collision with select one or more links or manipulators from the right widget. The selected links or manipulators will be highlighted green.

For example, to exclude collision between the "SDA5D Left Wrist Pitch" and a few "adjacent" links ("SDA5D Left Elbow Pitch", "SDA5D Left Wrist Roll", "SDA5D Left Tool Roll"), first select the link from the left tree widget.

Select Link

Next select the adjacent links from the right tree widget. (SDA5D Left Elbow Pitch", "SDA5D Left Wrist Roll", "SDA5D Left Tool Roll) "

Select Adjacent Links

Apply, Save, and Load

To apply the map press the apply button. To apply the map to all the othe map types, check the "All" check box.

Clear All: Clears the selections for all the map types.

Clear: Clears the currently selected map type.

Save: Allows saving of the collision exclusion map (of the selected type).

Load: allows loading of the collision exclusion map (of the selected type).