Apparatus, control system, and method for controlling the light transmission of containers

An apparatus comprising a heating device for preforms a blow molding machine for producing containers from preheated preforms, a first measuring device for determining an actual temperature of the preheated preforms, and a second measuring device for determining an actual light transmission of the containers, wherein the apparatus comprises a control circuit configured for controlling light transmission of the containers, the control circuit comprising:

• a first-level control circuit, comprising:
• a first comparator configured to determine a first control difference from a target light transmission and the actual light transmission;
• a first controller configured to output a first adaptation of a process parameter of a station of the blow molding machine as a first output variable, based on the first control difference as a first input variable for a system, and further configured to control the process parameter of the station of the blow molding machine in accordance with the first adaptation, wherein the first controller is further configured to output a target temperature of the heated preform as a second output variable based on the first control difference as an input variable;
• a subordinate control circuit, comprising:
• a second comparator configured to determine a second control difference from the target temperature of the heated preforms and the actual temperature of the heated preforms;
• and
• a second controller configured to output a second adaptation of a heating behavior of the heating device as a third output variable, based on the second control difference as a second input variable for the system, and further configured to control the heating behavior of a furnace in accordance with the second adaptation.

A method for controlling a light transmission of containers, wherein the method comprises:

• determining an actual temperature of a heated preform by a first measuring device;
• determining an actual light transmission of a container produced from the heated preform, by a second measuring device;
• determining a first control difference from a target light transmission and the actual light transmission, by a first comparator;
• outputting a first adaptation of a process parameter of a station of a blow molding machine as a first output variable, by a first controller, based on the first control difference as a first input variable for a system, and controlling the process parameter of the station of the blow molding machine according to the first adaptation and outputting a target temperature of the heated preform as a second output variable, based on the first control difference as an input variable;
• determining a second control difference from the target temperature of the heated preform and the actual temperature of the heated preform by a second comparator;
• and
• outputting a second adaptation of a heating behavior of a heating device as a third output variable, by the second controller, based on the second control difference as a second input variable for a system, and controlling the heating behavior of a furnace according to the second adaptation.