Operation of a multi-axis system
In order to provide an optimized multi-axis system having mechanically coupled axes, a feedforward control identification process is provided, during which actual identification variables occurring in each case at the motor are each provided to identification units associated with the feedforward controllers, wherein feedforward control parameters are identified using the actual identification variables, and closed-loop controllers are parameterized using the feedforward control parameters.
1 . A method for operating a multi-axis system having a plurality of basic axes and at least one drive axis which is mechanically coupled to the basic axes at coupling points, the positions of the coupling points on the basic axes being changeable by an associated motor in order to move the drive axis in relation to the basic axes, a closed-loop controller associated with the motors, and a feedforward controller associated with each of the motors, the method comprising:
determining, via the closed-loop controller, control input variables from specified setpoint variables and from associated corresponding actual variables occurring at the motor;
providing said control input variables to the motors in order to control the corresponding actual variables in accordance with the specified setpoint variables;
determining, via the feedforward controller, a feedforward control value based on the associated specified setpoint variable; and
superimposing said feedforward control value on the associated control input variable,
wherein a feedforward control identification process is provided, during which actual identification variables occurring on each motor are each provided to identification units associated with the feedforward controllers, feedforward control parameters being identified using the actual identification variables, and
wherein the feedforward controllers are parameterized using the feedforward control parameters.
2 . The method according to claim 1 , wherein, during the feedforward control identification process, mutually synchronized setpoint variables are provided to the identification units and are used by the identification units to identify the feedforward control parameters.
3 . The method according to claim 2 , wherein, during the feedforward control identification process, profiles of mutually synchronized setpoint variables are provided to the identification units and are used by the identification units to identify the feedforward control parameters.
4 . The method according to claim 1 , wherein further feedforward control parameters are interpolated from the determined feedforward control parameters.
5 . The method according to claim 1 , wherein, during the feedforward control identification process, profiles of the actual identification variables are provided to the identification units and are used by the identification units to identify the feedforward control parameters).
6 . The method according to claim 1 , wherein an actual current or an actual torque is in each case used as the actual identification variable for the feedforward control identification process.
7 . The method according to claim 1 , wherein the position is in each case used as the actual identification variable for the feedforward control identification process.
8 . The method according to claim 1 , wherein the feedforward control identification process takes place before normal operation of the multi-axis system.
9 . The method according to claim 1 , wherein the feedforward control identification process takes place during normal operation of the multi-axis system.
10 . The method according to claim 1 , wherein the basic axes are arranged in parallel with one another.
11 . The method according to claim 1 , wherein at least some of the motors are rotary motors.
12 . The method according to claim 11 , wherein each of the motors is a rotary motor.
13 . The method according to claim 1 , wherein at least some of the motors are linear motors.
14 . The method according to claim 13 , wherein each of the motors is a linear motor.
15 . The method according to claim 1 , wherein, during the feedforward control identification process, acceleration-proportional and/or speed-proportional and/or direction-dependent and/or constant components of the feedforward control parameters are determined.
16 . The method according to claim 1 , wherein the specified setpoint variables are setpoint positions and the associated corresponding actual variables are positions occurring at the motor.
17 . A multi-axis system comprising:
a plurality of basic axes;
a drive axis, the drive axis being mechanically coupled to the basic axes at coupling points, wherein each position of the coupling points on the basic axes are changeable by an associated motor in order to move the drive axis in relation to the basic axes;
closed-loop controllers which are each associated with the motors that are designed to determine control input variables from specified setpoint variables and from associated corresponding actual variables occurring at the motor and to provide said control input variables to the motors in order to control these corresponding actual variables in accordance with the setpoint variables;
feedforward controllers which are each associated with the basic axes that are designed to determine feedforward control values from the setpoint variables and to superimpose said values on the control input variables,
wherein identification units are provided which are each associated with the basic axes and are each designed to identify feedforward control parameters using actual identification variables occurring at the motor and to parameterize the feedforward controllers using the feedforward control parameters.
18 . The multi-axis system according to claim 17 , wherein the identification units are each designed to determine the feedforward control parameters using profiles of the actual identification variables.
19 . The multi-axis system according to claim 17 , wherein the specified setpoint variables are setpoint positions and the associated corresponding actual variables are positions occurring at the motor.