Delta RMC151 - Manual (Page 131)

3 Controller Features
Point B. The ratio can be calculated as follows. See the Gear Absolute (25) command for
more details.
Gear Ratio = (Slave Point B - Slave Point A) / (Master Point B - Master Point A)
Clutching
Clutching is used for relative gearing commands. Clutching is the transition of the
motion of the slave axis at the time the gearing command is issued to the final specified
ratio. Most often, this cannot be done instantaneously.
Example 1
Consider a basic gearing application where Axis 1 (the slave axis) is to gear to Axis 0
(the gear master) with a 1:1 ratio. Before gearing, Axis 0 is moving at 10 in/sec and
Axis 1 is stopped. If the gearing were to start instantaneously, then Axis 1 must go from
0 in/sec to 10 in/sec instantaneously, which is impossible.
The RMC supports several methods of clutching, making it very flexible for use in many
gearing applications.
Clutching Methods
• By Rate
Clutching by rate specifies the rate at which the slave axis' velocity changes in order
to reach the requested gear ratio. The rate is specified with an Acceleration and a
Jerk parameter. In Example 1 above, if the clutching Acceleration is 20 and the Jerk
is 1000, then Axis 1 will change from 0 in/sec to 10 in/sec at that rate. Once it
reaches 10 in/sec, it will lock in at the 1:1 ratio.
For more details, see the Gear Pos (Clutch by Rate) (39) command, which starts
gearing with clutching by rate.
• By Time
Clutching by time specifies the amount of time it should take to reach the requested
gear ratio. In Example 1 above, if the clutching time is 0.5 seconds, then Axis 1 will
go from 0 in/sec to 10 in/sec in 0.5 seconds. It will then be geared at 1:1.
For more details, see the Gear Pos (Clutch by Time) (30) command, which starts
gearing with clutching by time.
• By Distance
Clutching by distance specifies the distance in which the requested gear ratio should
be reached. This allows the user to specify the exact positions at which the axes
should be locked in at the specified gear ratio. This is especially useful for flying-
cutoff type applications.
Consider a gearing application where Axis 1 (the slave axis) is to gear to Axis 0 (the
gear master) with a 1:1 ratio. Before gearing, Axis 0 is moving at 10 in/sec and
Axis 1 is stopped. With clutching by distance, the user can specify that the axes
should start clutching when the master reaches 5 in. and reach the final gear ratio
when the master reaches 10 inches. The user also wants the slave to be at 2 inches
at this point.
Therefore, when the master reaches 5 inches, the slave will start moving when the
master reaches 5 inches. When the master reaches 10 inches, the slave will be at 2
inches, and will be geared 1:1 with the master.
For more details, see the Gear Pos (Clutch by Distance) (32) command, which
starts gearing with clutching by distance. This command is used in flying-cutoff type
applications.
Transitions
Transitions are used for absolute gearing commands. When an absolute gearing
command is issued to an axis, the axis must already be on the gearing relationship, or a
deltamotion.com 111