TE5920 | TwinCAT 3 Cogging Compensation for linear motors

In applications with the linear motors from the AL8000 series, the TE5920 software is used to reduce cogging. Cogging or cogging forces are created by the magnetic attraction between the iron core in the primary section and the permanent magnets in the secondary section. This physical effect leads to an unwanted and uneven “locking-in” of the motor, so that applications with extremely high demands on accuracy and synchronism, such as high-precision milling machines or digital printers, can only be implemented to a limited extent. TE5920 compensates for the cogging forces whereby, in addition to the magnetic attraction, cogging forces of the mechanical construction or energy chains can also be taken into account. This extends the range of applications of AL8000 iron-core linear motors and provides an alternative to ironless linear motors.

The TE5920 cogging compensation is based on the fully automated application of machine learning. The data required for cogging compensation are recorded by the software autonomously. For this purpose, a reference run is carried out in the individual customer application over the entire length of the magnetic track. With the help of these data, the software trains a neural network, which is finally integrated into the control system for current pre-control. Current pre-control adapted in this way can reduce tracking error by up to a factor of 7 and increase the synchronization of the machine by up to a factor of 5 – without any hardware changes to the AL8000.