Method for operating a long stator linear motor
In order to improve the adaptation of a long stator linear motor to requirements or conditions of individual transport units or of the transport track it is foreseen, that a movement profile is preset for the transport unit (Tx), which is followed by the transport unit (Tx), in doing so at least one system parameter of a model of the control system ( 21 ) is determined by means of a parameter estimation method, and the value of the system parameter over time is collected and from the variation over time a wear condition of the transport unit (Tx) and/or of the transport track is deduced.
1. A method for operating a long stator linear motor by moving at least one transport unit along at least one transport track having plural successively arranged driving coils arranged along the at least one transport track, the method comprising:
predetermining a movement profile for the at least one transport unit;
controlling the plural successively arranged driving coils with a driving coil controller so that the at least one transport unit moves on a basis of the predetermined movement profile;
utilizing a model of a control system with system parameters controlled by the driving coil controller for moving the at least one transport unit;
determining, while the at least one transport unit is moved according to the predetermined movement profile, a value of at least one system parameter of the model of the control system and using parameter estimation;
repeating the determining to obtain the value of the at least one system parameter over time; and
determining, from a variation of the value of the at least one system parameter over time, a wear condition of at least one of:
the at least one transport unit; or
the at least one transport track.
2. The method of claim 1 , further comprising:
determining a set stator current (i A ) for at least one driving coil of the plural successively arranged driving coils;
using the model of the control system when calculating a stator current for the at least one driving coil; and
minimizing an error between the determined set stator current (i A ) and the calculated stator current by varying the at least one system parameter of the model of the control system.
3. The method of claim 1 , further comprising:
implementing a pilot control that acts on an input of the driving coil controller.
4. The method of claim 1 , wherein the driving coil controller comprises:
a speed controller with a speed input; and
a pilot control that calculates a speed pilot control (v vs ),
wherein the speed pilot control (v vs ) acts on the speed input.
5. The method of claim 1 , wherein the driving coil controller comprises:
a conversion block with a force input; and
a pilot control that calculates a force pilot control (F vs ),
wherein the force pilot control (F vs ) acts on the force input.