The Description Of E-Cam Function - Delta ASD-A2 Series User Manual

Chapter 7 Motion Control

7.11 The Description of E-Cam Function

E-Cam is a virtual cam which is implemented by software. It includes Master axis and Slave axis.
The illustration is as the following:
In PT mode, the position command (slave) is issued by the external pulse input (master). The two
is merely the linear scaling relation (its scaling equals to e-gear ratio). However, instead of linear
scaling, E-Cam is defined by cyclic curve profile, just like the cam shape. In physical machine cam,
slave axis can operate as variable speed motion, alternating motion, intermittent motion, etc by
master axis with the constant speed motion. It is very extensive in application. Using E-Cam could
have similar effect. The following table describes the differences between E-Cam and Machine
Cam.
Structure
Smooth It is determined by the fineness of
Performance
Position
Accuracy
The longer the slave axis is, the
Long Distance
bigger the cam will be. It is not
Motion
The Necessity
of Master Axis
It is inconvenient to change and
Flexibility
modify and it is expensive as well.
Maintenance
The master axis needs space and
Others
Revision February, 2017
Machine Cam
Return to the original position
after rotating a cycle.
the real process.
Very precise (when it has no
vibration)
easy to make.
The master axis is necessary.
Machine will wear and the
maintenance is necessary.
it consumes energy as well.
E-Cam
It might not return to the original position
after rotating a cycle. The structure could
be in spiral shape like mosquito coil
incense.
It is interpolated by cubic curve via
software
The command is very precise, but the
actual position might have deviation due
to the servo delay.
Change the value of the table will do. It is
easy to realize.
The master axis is unnecessary when it is
applied to constant speed motion. It will
do by using the internal signal of the
servo drive.
It will do by re-setting the parameter.
No need to maintain.
Save the space and energy which
protects the environment.
ASDA-A2
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