Description

Task

When collision monitoring is used, the position command values of an axis pair generated in the CNC are monitored.

If the distance between two positions undershoots the minimum permitted value with regard to the deceleration distance required for stopping,

• the axes stop immediately depending on the specified dynamic data and
• the CNC outputs the message ID 70092.

After CNC RESET, the two axes must be positioned apart from each other.

Two axes for which the distance is monitored are referred to as a collision pair.

Several collision pairs may be formed.

Collision monitoring can be created and activated for each individual axis either

• statically, by configuration in the axis lists, or
• dynamically, by NC programming.

Error response on collision

If the collision axes are in different CNC channels, the parameter P-AXIS-00044 (coll_decelerate_chan) can force a stop in the two channels if a collision axis reports a drive error.

Axis deceleration for collision monitoring

By default the value of P-AXIS-00008 (a_max) is used for collision monitoring to calculate deceleration distances and stop the axes if a collision is detected.

The parameter P-AXIS-00267 (coll_use_a_emergency) can be used to change this deceleration to the value defined in P-AXIS-00003 (a_emergency).

Deceleration distance monitoring

The current velocity of an axis results from:

v_t = (setp_tn - setp_tn-1) / T_A

The minimum deceleration distance results from the deceleration set for collision monitoring by:

• P-AXIS-00008 (a_max),
• P-AXIS-00267 (coll_use_a_emergency),
• P-AXIS-00003 (a_emergency)

and the current velocity at:

s_brems = ½ (v_t²/a_coll)