Using interference checking to prevent collisions – Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set User Manual
Page 783
Chapter 30
Using a 9/Series Dual--processing System
30-15
Using Interference Checking to Prevent Collisions
When two protected areas are about to collide, the control suspends
motion, stopping one or both of the processes and preventing a collision.
In Example 30.6, process 1 collides with process 2. Since process 2 is
stationary, the control puts process 1 in cycle suspend to prevent a
collision. Once the control detects the collision, it suspends the action.
Interference checking operates in real time. It is not checked in block
lookahead. The control detects a collision immediately before the
boundaries overlap and suspends one or both of the processes, halting the
axes with an abrupt, un-decelerated stop. In Example 30.6, even though
the endpoint of the tool for process 1 is not within the interference
boundary for process 2, the block is halted since the boundaries intersect in
route.
Example 30.6
Collision Programmed with Interference Checking On
Process 1
Process 2
N1 G90 G20;
N1 G90 G20;
N2 G00 W0 U0;
N2 G00 Z7 X9.5;
N3 G00 W12 U-10;
N3 M30;
N4 M30;
Figure 30.3
Results of Example 30.6
Z
6
8
4
6
Y
8
10
10
Process 2
Process 1
2
Collision avoided
immediately before
boundaries overlap
4
2
12
Programmed
endpoint of
process 1