CA Group (TF5410 TwinCAT 3 Collision Avoidance)

The CA group links axes to add Collision Avoidance to the PTP functionalities.

Dynamic values

Velocity Vel: velocity,
Acceleration Acc: positive acceleration,
Deceleration Dec: braking acceleration, negative acceleration,
Jerk: jerk.

Setpoints
and
limits

An axis traverses set dynamic values. During this motion, the maximum dynamic values set the limits for the dynamic profile.

CA Group

A CA group provides parameters to set default values for dynamic values. These default values are used for Standby Gap Control. They are not used as default parameters for Motion commands if no parameter has been specified.

Axis

The maximum values for the dynamic limits can be set in the axis parameters.
These maximum values can be determined by the physical properties (inertia, mass, maximum current, motor size, ..) of the axis or a workpiece, for example.

Gap

Neighborhood

A Gap requires two or more adjacent axes (movers).
A Gap is always located between two directly adjacent movers.

Counting direction

The Gap is defined in positive counting direction from the current mover to the mover directly ahead.
This positive counting direction corresponds to the counting direction of the setpoint generation.

Successor;
predecessor

Current mover: directly following mover, successor.
Mover directly ahead: predecessor.

Size

Size of a respective Gaps = (set position predecessor) - (set position successor).

Lower
limit

The Gap size is set to a lower limit that must not be undershot.
The parameter "Default Gap" sets a value for this lower limit for the entire CA group as long as no other gap size is set for a current mover.
An individual value for this lower limit of the Gap size can be applied as an input value to each of the motion function blocks: "MC_MoveAbsoluteCA", "MC_MoveRelativeCA", "MC_HaltCA" or "MC_GearInPosCA".

Gap Control
Mode

"Gap Control Mode" mcGapCtrlModeFast generally controls closer to this lower Gap size limit than "Gap Control Mode" mcGapCtrlModeStandard.

Gap Control
Direction

"Gap Control Direction" mcGapCtrlDirectionPositive:: The successor is the only mover that controls the size of the Gaps enclosed by the predecessor and successor.
"Gap Control Direction" mcGapCtrlDirectionBoth: Both adjacent movers control the size of the Gaps they enclose.

Opening the dialog “Parameter (Init)”

CA Group (TF5410 TwinCAT 3 Collision Avoidance) 1:

Root node of a CA group.

CA Group (TF5410 TwinCAT 3 Collision Avoidance) 2:

Parameters for a CA group.
The table column "Value" shows the preset parameter value. The table column "Comment" contains brief parameter descriptions.

Parameter	Description
Geometry
Rail Length	Length of the rail on which the axes (movers) are mounted.
Rail Is Ring	Indicates whether the rails form a closed circle. In this case (TRUE), Collision Avoidance is enabled between the first mover in the row and the last mover.
Gap Control
Default Gap Control Mode	Different modes are available for gap control (see "MC_DEFAULT_GAP_CONTROL_MODE").
Gap Control Direction	Various settings are available for the control direction of the Gaps (see section "MC_GAP_CONTROL_DIRECTION“).
Active Gap Establishing	From version 3.3, 'Collision Avoidance' does not trigger any active movement and only intervenes in the motion profile with a delay. The behavior of version 3.2, in which the 'Collision Avoidance' triggered an active movement to establish the parameterized gap, can be restored by setting the 'Active Gap Establishing' parameter in the CA group to 'True'. From version 3.3, this is set to 'False' by default.
Standby Gap Control	If TRUE, Collision Avoidance is always active, even if no motion command was issued to the axis. Notice The axes move directly after MC_GroupEnable when Standby Gap Control is TRUE. If the gap between two axes (mover) is smaller than the Default Gap (see next parameter), the axes will move to reach the demanded gap. This motion is independent of any motion command. This behavior also applies if the axes are too close to each other after a group reset.
Default Gap	This gap is used for the Standby Gap Control and if no gap was specified at any CA motion command.
Default Velocity	This velocity is used for Standby Gap Control, i.e. when no motion command is active (e.g. directly after MC_GroupEnable). It is not used as a default velocity for any motion command if no velocity was specified.
Default Acceleration	This acceleration is used for Standby Gap Control, i.e. when no motion command is active (e.g. directly after MC_GroupEnable). It is not used as a default acceleration for any motion command if no acceleration was specified.
Default Deceleration	This deceleration is used for Standby Gap Control, i.e. when no motion command is active (e.g. directly after MC_GroupEnable). It is not used as a default deceleration for any motion command if no deceleration was specified.
Default Jerk	This jerk is used for Standby Gap Control, i.e. when no motion command is active (e.g. directly after MC_GroupEnable). It is not used as a default jerk for any motion command if no jerk was specified.
GearInPosDefaultDynamicsAfterSync (hidden!)	Specifies the default dynamics used in MC_GearInPosCA AfterSyncDynamics. In the default state, the value "JobDynamics" is set. The parameter is not available for older projects (created with versions < 3.1.10), but is set internally to 'MaximumSlaveDynamics'.

	After reloading the TMC file, "JobDynamics" is set as the default value (see MC_GearInPosDefaultDynamicsAfterSync).

If an NC configuration has already been added, the MOTION subtree contains an SAF task subtree.

The SAF task subtree contains the "Objects" subtree.

The "Objects" subtree can contain a CA group.

1. Double-click the root node of the CA group whose parameters you want to view or set.

2. Select the "Parameter (Init)" tab.

The dialog “Parameter (Init)” is opened.

It contains a table with parameters for the selected CA group.

These parameters are divided into the groups "Geometry", "Gap Control" and "Misc.", if applicable.