METHOD AND SYSTEM FOR COUNTING STACKED ITEMS

• US 20120041708A1
• Filed: 08/10/2011
• Published: 02/16/2012
• Est. Priority Date: 08/10/2010
• Status: Abandoned Application

• Current Assignee: Jacob Rutti
• Original Assignee: Jacob Rutti
• Inventors: Rutti, Jacob
• Application Number:
  US13/206,931
• Publication Number:
  US 20120041708A1
• Time in Patent Office: Days
• US Class Current: 702/128
• CPC Class Codes: G06M 2207/02 Counting of generally flat and overlapped articles, e.g. cards, newspapers
• CPC Class Codes: G06M 7/10 Counting of flat overlapped articles, e.g. of cards
• CPC Class Codes: G06M 9/00 Counting of objects in a stack thereof

Abstract

The present method proposes, according to a first aspect, a method for counting stacked items forming on one side of the stack at least one level variation lineformed by the edges of the stacked items. The method includes the telemetric measurement of a variation in level on a line of points traversing the whole side of the stack and recording a corresponding raw signal. The method subsequently includes analysing the raw signal in order to estimate one or more parameters relating to the structure of the stack, followed by processing the raw signal in one or more statistical processing operations on the basis of the estimated parameters, and analysing the processed signal in order to determine the number of stacked items.

Claims

1. A method for counting stacked items forming on one side of a stack at least one level variation line formed by the edges of the stacked items, the method comprising:

recording a raw signal corresponding to the telemetric measurement of the variation in level on a line of points traversing the side of the stack;

analysing the raw signal in order to estimate one or more parameters relating to the structure of the stack;

processing the recorded raw signal in one or more statistical processing operations on the basis of the estimated parameters; and

analysing the processed signal in order to determine the number of stacked items.

2. The counting method according to claim 1, wherein the estimated parameters include:

a mean thickness of the items in the stack, and

a dispersion factor for the thicknesses of the items in the stack.

3. The counting method according to claim 2, wherein the processing of the raw signal comprises determining an interference threshold proportional to the product of the dispersion factor and the mean thickness.

4. The counting method according to claim 2, wherein the processing of the raw signal comprises determining an interference threshold estimated on the basis of a mean thickness of the items in the stack with a thickness less than a limit thickness.

5. The counting method according to claim 2, wherein the mean thickness is determined as a function of a gross number of stacked items, estimated on the basis of the recorded raw signal.

6. The counting method according to claim 3, wherein the processing of the raw signal comprises eliminating interference peaks on the basis of the interference threshold.

7. The counting method according to claim 3, wherein the step in which the recorded raw signal is processed comprises reconstructing interruptions on the basis of the slope of the signal before and after the interruption when the interruption is longer than the interference threshold.

8. The counting method according to claim 3, wherein the step in which the recorded raw signal is processed comprises reconstructing interruptions on the basis of the value of the signal before and after the interruption when the interruption is shorter than the interference threshold.

9. The counting method according to claim 3, wherein the step in which the recorded raw signal is processed comprises filtering the signal using a moving average, the number of points of the signal on which the said moving average is calculated being determined on the basis of the interference threshold.

10. The counting method according to claim 1, wherein the step in which the processed signal is analysed comprises counting the number of changes in the sign of the derivative of the processed signal and/or counting the number of changes in direction of the processed signal point by point.

11. The counting method according to claim 1, wherein the analysing step comprises checking for the presence of stuck-together items in the stack on the basis of the recorded raw signal.

12. The counting method according to claim 1, wherein the recording step comprises recording a plurality of raw signals corresponding to measurement of the variation in the level on one or more lines of points traversing the whole side of the stack.

13. The counting method according to claim 12, wherein the recording of the plurality of raw signals is performed using a plurality of range finders, a range finder comprising a plurality of beams, and/or by scanning the side of the stack a plurality of times.

14. The counting method according to claim 12, further comprising a step in which the convergence of the results of counting the stacked items which are provided by the plurality of raw signals is checked.

15. A device for counting stacked items comprising:

a telemetric measurement system for measuring a signal corresponding to the variation in level of at least one line traversing a side of the stack formed by the stacked items;

a data storage means for recording the signal; and

a calculation means for implementing the counting method according to claim 1.