How do commands behave in dynamic coordinate systems?ΒΆ
If the TCP should follow a moving target, this can be achieved by a dynamic coordinate transformation, leading to a PCS which is moving in relation to the MCS.
The activation of a dynamic transformation is done by activating MCA_SetDynamicFollower (ABB specific Function Block).
If there is a dynamic transformation active, the axis may follow the dynamic transformation or stay in the static ACS or MCS. The following example is showing the behavior. The example describes a robot fetching a screw from a fixed position and mounting it on a product that is moving on a belt.
| Step | Move command | Axes (group) behavior | Application example |
|---|---|---|---|
| 1 | Activating Transformation ACS to MCS | Group is staying still (not moving) | Initialization, MCS is static |
| 2 | MC_MoveAbsolute in MCS | Group moves to the commanded position in MCS and stays in static MCS (not moving) | Moving to standby position and waiting for products |
| 3 | Motion command in static MCS | Group moves to the commanded position in MCS and stays in static MCS (not moving) | Moving to a fixed box of screws |
| 4 | Motion command in static MCS | Picking command | Picking up a screw |
| 5 | Activating a dynamic PCS | PCS is active and moves synchronized with the belt | PCS is ready for use |
| 6 | Motion command in dynamic PCS | Group moves to commanded position in PCS and is moving together with the dynamic PCS | Placing the screw and following the product on the belt |
| 7 | Screwing command | Group is still following the product on the belt | Screw is being screwed into the product |
| 8 | Motion command in static MCS | Group moves to commanded position in MCS at the fixed screw box | Moving to the fixed box of screws and waiting for the next product on the belt |
| 9 | Motion command in dynamic PCS | Group moves to commanded position in PCS and is moving together with the dynamic PCS | Placing the screw to the new product and following the product on the belt |
Rule: An axis group stays in the coordinate system which is specified with the last motion command. If this is a PCS with dynamic transformation, it will follow the PCS (keeping the same position in this PCS).