Method and apparatus for automatic sorting of unmarked power cells

1. A method for automatic sorting of cylindrical batteries, the method comprising:

generating a fan-shaped X-ray beam;

scanning the cylindrical batteries with the fan-shaped X-Ray beam;

for each cylindrical battery, capturing X-rays of the fan-shaped X-Ray beam that pass though the battery with a dual-energy X-ray detector and converting the X-rays into first and second digital images, wherein the first digital image represents X-rays at a first energy, and the second digital image represents X-rays at a second energy;

automatically analyzing the first and second digital images to determine a type of the cylindrical battery by identifying characteristic internal features of each battery type, including anode current collectors, based on a gray spectrum of at least 8 bit resolution that is looked up in a model database; and

sorting the cylindrical batteries by type.

2. The method of claim 1 , wherein the type is determined based on the gray spectrum using size indices and gray indices of the characteristic internal features in the cylindrical batteries.

3. The method of claim 1 , wherein the characteristic internal features also include gray contrasts that indicate a porous separator and a plastic cover, which are unique for each individual battery type, and further comprising indexing the characteristic internal features for the model database.

4. The method of claim 1 , wherein the gray spectrum includes 65,535 shades of gray.

5. The method of claim 1 , wherein the model database includes a branch index used for finding a branch that corresponds to the battery type.

6. The method of claim 5 , wherein each branch in the model database has its own index.

7. The method of claim 6 , wherein comparisons between the gray spectra for the sample are made within the model database branch having a corresponding index only.

8. An apparatus for automatic sorting of cylindrical batteries, the apparatus comprising:

a slanted conveyor with a guiding plank for placing batteries;

an X-Ray source generating a fan-shaped X-ray beam;

a dual-energy detector for detecting the X-ray beam at two different energies from the X-ray source;

a processing computer;

a positioning system responsive to the processing computer; and

a discharge system with discharging funnels for sorting the cylindrical batteries,

wherein the dual-energy detector detects the X-ray beam after it passes through the batteries;

for each battery, the processing computer converts X-rays of the fan-shaped X-Ray beam into first and second digital images, wherein the first digital image represents the X-rays at a first energy, and the second digital image represents the X-rays at a second energy; and

the processing computer analyzes the first and second digital images to determine a type of the cylindrical battery by identifying characteristic internal features of each battery type, including anode current collectors, based on a gray spectrum of at least 8 bit resolution that is looked up in a model database.

9. The apparatus of claim 8 , wherein the positioning system comprises at least one battery sensor, a conveyor position sensor, and a controller.

10. The apparatus of claim 8 , wherein the slanted conveyor runs through a scanner tunnel.

11. The apparatus of claim 8 , wherein the discharging funnels are mounted at a fixed distance from the scanner and at certain intervals, and wherein dedicated containers are placed along the conveyor.

12. The apparatus of claim 8 , further comprising protective screens that block scatter radiation.

13. The apparatus of claim 8 , wherein imaging positioning prevents battery image from being superimposed by that of the guiding plank.

14. A method for automatic sorting of batteries, the method comprising:

generating a fan-shaped X-ray beam;

scanning the batteries with the fan-shaped X-Ray beam;

for each battery, capturing X-rays that pass though the battery with an X-ray detector and converting the X-rays into first and second digital images, wherein the first digital image represents X-rays at a first energy, and the second digital image represents X-rays at a second energy;

automatically analyzing the first and second digital images to determine a type of the battery by identifying distinctive regions of each battery type based on a gray spectrum of at least 8 bit resolution that is looked up in a database,

wherein the distinctive regions include gray contrasts that indicate an anode current collector, a porous separator, and a plastic cover, which are unique for each individual battery type, and then indexing the distinctive regions; and

sorting the batteries by type.