Chapter 10
Electronic Gearing and Camming
10-10
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Figure 10-7.
Welding Application
In this application, the master device is the position encoder attached to the
conveyor belt, and the slave axis is the actuator that moves the welding
point. The slave axis repeatedly performs a two-segment movement:
1.
First, it follows the material with the same speed as the conveyor belt.
2.
Next, it returns to the initial position as the next material approaches.
Each segment of the move is represented with a gear ratio that dictates how
fast and which direction the welding point is moving in relative to the
conveyor belt.
This application requires the slave axis to switch from one ratio to the other
at the correct master position, otherwise the welding process is not
repeatable. If this application used gearing instead of camming, the latency,
or delay, of loading a new gear ratio might cause an accumulation of
position errors.
1
Conveyor belt
2
Movement of the welder as it follows the object, and then returns to the initial
position
3
Welding point
3
2
1
