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Instantaneous Motion Generation for Robots and Machines.
Port of ruckig to Structured Text, TwinCAT 3.

Build/Test Documentation Issues Releases GPLv3

This repository ports pantor/ruckig to Structured Text to bring open-source powered Online-Trajectory-Generation to TwinCAT 3. Only the Community Version of Ruckig is ported and pro features are not available. Struckig itself is dual licenced, you can use the source code provided here accordingly to GPLv3. If you want to use this commercially and not disclose your own source code, Struckig is also available with a custom licence. In the latter case, contact me.

Porting progress

The original project, ruckig is a submodule of this repository. The commit-hash reflects the commits that are ported already - I try to keep up with changes that are done in ruckig.

Continuous integration & Documentation

This project is using zkbuild for continuous integration and zkdoc for generating the documentation. To run the tests manually, get a copy of TcUnit and activate the testing solution test\Struckig\Struckig_unittest.sln

Example: Create time-based profile for 1 axis

This examples shows how to create a single-axis trajectory from point A=0mm to point B=100mm. The initial state assumes that the trajectory is in stillstand and target velocity and acceleration is set to 0. The MinDuration parameter is set to 10s. Please not that MaxVelocity, MaxAcceleration and MaxJerk would allow for a shorter travel time, but if MinDuration together with Synchronization = SynchronizationType.TimeSync is set, the MinDuration parameter is considered instead.

  otg : Struckig.Otg(cycletime:=0.001, dofs:=1) := (
    EnableAutoPropagate := TRUE, //< Automatically copies the new trajectory state to the current trajectory state with every otg() call
    Synchronization :=     SynchronizationType.TimeSync, //< Set to TimeSync, otherwise MinDuration is ignored
    MinDuration :=         10.0, //< if MinDuration > 0 and Synchronization is set to TimeSync this sets the duration of the trajectory (if the other limitations would yields a shorter duration)
    MaxVelocity :=         [ 2000.0 ],
    MaxAcceleration :=     [ 20000.0 ],
    MaxJerk :=             [ 800000.0 ],
    CurrentPosition :=     [ 0.0 ],
    CurrentVelocity :=     [ 0.0 ],
    CurrentAcceleration := [ 0.0 ],
    TargetPosition :=      [ 100.0 ],
    TargetVelocity :=      [ 0.0 ],
    TargetAcceleration :=  [ 0.0 ]

// =====================================================================================================================

// axis.SetTargetPosition(otg.NewPosition[0]); send the new position to your axis, which should be in a cyclic position mode
// axis.SetVelocityOffset(otg.NewVelocity[0]); send the new velocity to your axis, e.g. with a velocity feedforward
// axis.SetTorqueOffset( accelerationTorqueFactor * otg.NewAcceleration[0]) send the new acceleration to your acces, e.g. with a current feedforward


Note: Struckig supports motions with multiple degree of freedoms with the Otg function block. If you need to use only 1 degree of freedom you can also utilize the specialized function block Otg1. The latter function block uses single variables instead of arrays, which simplifies the usage a bit.


Full port of pantor ruckig library (Community version) to IEC 61131-3 Structured Text. Online Trajectory Generation. Real-time. Time-optimal. Jerk-constrained.







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