Elmo HARSFEN0602, HARmonica software manual 137, Example On-The-Fly Change of The Position Target

HARSFEN0602ElmoHARmonicaSoftwareManual

S t r t

S pe ed > P ? Y es

W ill s tea dy
de c eler ation at	N o
D C s to p m o tio n
be for e ta rg et?

S pe ed = S P ? Y es

A pp ly A C

PRELIMINARYDRAFT

137

A pp ly D C

A pp ly D C

M a intain S P

Figure 24 – PTP Decisions Flow Chart

All the parameters of the above flow chart, including AC,DC, SP, and the position target are updated by a BG command, or by its hardware activated equivalent.

Example – On-The-Fly Change of The Position Target

The acceleration and the final speed are AC=100000,DC=200000,SP=20000. We begin from PX=0 and set the target position by PA=100;BG.

The position reference has not yet stabilized to the position target, when the target position switched by the command

PR=-400;BG;

To the position target of (PA+PR)=-300.

The Amplifier calculates the position reference to reach the new target.

Note that in this example the position reference overshoots the original target position of 100. This is since at the time the target position was changed, the Amplifier was approaching the target using DC. When a new target is set, the Amplifier exits the state of final approach. It therefore uses the AC acceleration, which in this example is smaller, than DC. With the reduced acceleration, it cannot avoid the overshoot.