Imaging system for processing a media

Patent metadata

Field	Value
Publication number	US-9928453-B2
Application number	US-201615229482-A
Country	US
Kind code	B2
Filing date	Aug 5, 2016
Priority date	Aug 6, 2015
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

An imaging system includes an imaging station, an actuator for driving a medium roller for controllably displacing the medium along a media transport path, and a controller assembly. The controller assembly includes a sensor device for generating a position signal and a processor for processing the position signal. The actuator is actuated in response to an actuation command from the controller assembly, which actuation command is derivable from a feedback component and a feedforward component. The feedback component is based on a position error. The processor is further arranged for determining a time dependent status parameter, which status parameter represents a status of the medium on the medium roller. The processor is further arranged for deriving an actuation command estimate based on the status parameter, and wherein the feedforward component includes the actuation command estimate.

First claim

What is claimed is:

1. An imaging system for processing a medium supplied from a medium roller, comprising:
a media transport path;
an imaging station arranged along said media transport path;
an actuator configured to drive the medium roller for controllably displacing the medium in steps along the media transport path relative to said imaging station; and
a controller assembly,
wherein the controller assembly comprises:
a sensor device configured to generate a position signal representing a position of the medium along the transport path; and
a processor configured to process the position signal,

wherein in operation, the actuator is actuated in response to an actuation command generated by the controller assembly, the actuation command being derivable from a feedback component for correcting incidental deviations in a behavior of the medium roller and a feedforward component,
wherein the feedback component is based on a position error being the difference between a position setpoint and the position signal,
wherein the feedforward component comprises an actuation command estimate derived by the processor from a time dependent status parameter, the time dependent status parameter representing an inertia of the medium on the medium roller and being derived by the processor from the position signal and the actuation command, and
wherein during operation the processor is configured to continually fit the time dependent status parameter to the amount of medium on the medium roller.

2. The imaging system according to claim 1 , wherein, when in use, the processor is configured to recursively determine the status parameter based on a previously determined value of the status parameter and a correction factor based on a difference between the sensed position of the medium and the desired position of the medium.

3. The imaging system according to claim 1 , wherein the processor is further arranged for deriving the actuation command estimate from the status parameter and the position setpoint.

4. The imaging system according to claim 1 , wherein the processor is further configured to determine the status parameter based on the position signal and a command error signal, the command error signal being the difference between the actuation command and the actuation command estimate.

5. The imaging system according to claim 1 , wherein the controller assembly further comprises a memory arranged for storing a status parameter, and wherein the processor is configured to determine a subsequent status parameter from the status parameter stored on the memory.

6. The imaging system according to claim 1 , wherein the processor configured to derive the actuation command estimate from a time derivative of the position setpoint.

7. The imaging system according to claim 6 , wherein the processor configured to determine a setpoint velocity, a setpoint acceleration, and a setpoint jerk from the position setpoint, and to determine a velocity status parameter, an acceleration status parameter, and a jerk status parameter.

8. The imaging system according to claim 1 , wherein the controller assembly and the actuator are arranged for stepwise driving the medium roller, and wherein the processor is configured to determine a displacement of the medium per step based on the position signal.

9. The imaging system according to claim 1 , wherein the controller assembly further comprises a repetitive controller configured to model the eccentricity of the medium roller based on the position signal and to adjust the actuation command in correspondence to the eccentricity of the medium roller.

10. The imaging system according to claim 1 , wherein the sensor device further comprises an observer configured to sense the angular position of the medium roll.

11. The imaging system according to claim 1 , further comprising transport pinch rollers positioned upstream of the medium roller, and a passive buffer device positioned along the transport path between the medium roller and the transport pinch rollers for engaging the medium.

12. The imaging system according to claim 11 , wherein the sensor device comprises a tension sensor configured to sense the position of the passive buffer.

13. The imaging system according to claim 1 , wherein the processor is further configured to derive an actuation command estimate by means of an inverted model system of the imaging system, the inverted model system comprising the status parameter.

14. A method for actuating a medium roller in an imaging system, the imaging system comprising a media transport path and an imaging station arranged along said media transport path, the method comprising the steps of:
inputting a position setpoint for positioning the medium roller at a predefined angular position;
generating a first actuation command for actuating the medium roller based on the position setpoint;
sensing an angular position of the medium roller;
determining a feedback component based on a position error signal based on the difference between the position setpoint and the position signal for correcting incidental deviations in a behavior of the medium roller;
deriving a feedforward component from the position setpoint;
generating a second actuation command from the feedback component and the feedforward component;
deriving a time dependent status parameter, the time dependent status parameter representing an inertia of the medium on the medium roller and being derived from the position signal and the first actuation command; and
continually fitting the time dependent status parameter to the amount of medium on the medium roller during operation,
wherein the step of determining the feedforward component further comprises the step of deriving an actuation command estimate from the time dependent status parameter and the position setpoint.

15. The method according to claim 14 , further comprising the step of:
deriving the feedforward component from the position signal sensed after actuating the medium roller by means of the first actuation command; and
determining the actuation command estimate from said position signal by means of an adaptive feedforward algorithm, the adaptive feedforward algorithm comprising an inverted model system of the imaging system.

Assignees

• Oce Tech Bv
• Oce Tech Bv

Inventors

• Winteraeken Stefan A C J
• Boonen Rik W J

Classifications

• B65H2557/262

  with key characteristics based on feed forward control · CPC title

• H04N1/00734

  Optical detectors · CPC title

• G05B13/04

  involving the use of models or simulators · CPC title

• H04N1/00732

  Mechanical detectors · CPC title

• H04N1/00779

  Adjusting settings, e.g. mode, feeding rate or type of paper · CPC title