Rearrange operations and edit paths to avoid multi-robot collisions
This article covers several ways of adjusting operations to avoid collisions in work cells with multiple robots.
As an example, a dome-shaped part requires edge following operations on five contours.
These operations will be distributed between two separate robots and processed simultaneously.
In some cases, the default robot trajectories may result in collisions between the robots.
There are many ways to solve collisions between robots. Let’s take a look at a few possible solutions.
Rearrange operations for a robot
One way of solving collisions is to change the sequence in which operations are performed for a given robot.
In this example, Robot_1 is processing operations 1 and 2, and Robot_2 is processing operations 3, 4, and 5:
There is a collision between the joints of the different robots when operations 1 and 3 are processed.
This is due to the proximity and timing of the two paths.
The sequence of Robot_2 could be changed so that operation 4 is processed first. This would leave more space between Robot_1 and Robot_2 as the operations are executed, lessening the chance of a collision.
Use the control handle to drag the operation to a different place in the sequence.
Select Calculate to see if the collision is cleared.
Rearranging the sequence of operations will also affect robot motion, including moves to and from home position and moves between operations. Pay attention to these changes and resolve any kinematic issues if they arise.
Reassign operations to different robots
If multiple robots use the same application (for example, if they are both equipped with interchangeable deburring tools), reassigning operations to different robots can solve collisions.
Use the control handle to drag the operation to a different robot.
Adjust the sequence of operations for that robot, if needed.
Select Calculate to see if the collision is cleared.
Move start point
In some cases, moving the entry/exit point on one of the paths may solve a collision. This can affect timing so that robots do not collide.
On the Device tab, in the Operations pane, right-click an operation and select Edit in task.
Select the path, then click the red ball at the entry/exit point.
Click a point along the path to move the entry/exit to a different location.
On the Task tab, select Apply and then OK to keep your changes.
On the Device tab, select Calculate.
Check to see if the collision still occurs.
Change path direction
For applications where it is possible to change the direction of a path, you can try reversing path direction to solve collisions.
On the Device tab, in the Operations pane, right-click an operation and select Edit in task.
Right-click the path (be sure to right-click one of the vectors on the path), then select Path > Invert direction.
Confirm that the path direction is reversed.
On the Task tab, select Apply and then OK to keep your changes.
On the Device tab, select Calculate.
Do not use this method for applications where path direction should not reversed, such as with plasma cutting.