Automatic identification method and system for train information

• US 8,509,969 B2
• Filed: 12/26/2008
• Issued: 08/13/2013
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.), Tsinghua University
• Original Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.), Tsinghua University
• Inventors: Chen, Zhiqiang, Sun, Shangmin, Xu, Xining, Lin, Weizhi, Xu, Yanwei, Guo, Zhenbin, Hu, Bin, Yang, Guang
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): ALHARBI, ADAM MOHAMED
• Application Number:
  US12/810,704
• Publication Number:
  US 20110022253A1
• Time in Patent Office: 1,691 Days
• Field of Search: None
• US Class Current: 701/19
• CPC Class Codes: B61L 1/14 Devices for indicating the passing of the end of the vehicle or train
• CPC Class Codes: B61L 1/161 characterised by the counting methods
• CPC Class Codes: B61L 1/165 Electrical
• CPC Class Codes: B61L 25/028 Determination of vehicle position and orientation within a train consist, e.g. serialisation
• CPC Class Codes: B61L 25/041 using reflecting tags
• CPC Class Codes: B61L 25/045 using reradiating tags

Abstract

The present invention relates to a method and system for automatically identifying various information of a train. The method comprises using sensors to collect wheelbase information, processing the information by signal data processing devices, thereby providing information of a train, namely: arranging a plurality of sensors along the rail in the incoming direction of the train, dividing the sensors into at least three groups, each group comprising at least two sensors; analyzing and processing the signal data stream obtained from the sensors and collected when a train vehicle passes by, thereby acquiring the speed and wheelbase of the train, and further acquiring the train segmentation information; determining the vehicle type; acquiring hook locating information; determining the train arrival; determining the train departure; acquiring vehicle number. The present invention further comprises a system for carrying out the information method for automatically identifying information of a train. The present invention can provide a plurality of types of train information with high accuracy, and is easy to be carried out.

Claims

1. A method for providing identification information of a train, comprising:

arranging an array of sensors along one rail, the array comprising a first, a second and a third up sensor groups (S1, S2, S3) arranged in an order and a first, a second and a third down sensor groups (X1, X2, X3) arranged in an opposite order, wherein each of said groups comprise at least two sensors;

calculating the speed and wheelbases of the train by using signal from the first up/down sensor group (S1/X1), and segmenting the calculated wheelbases by using known segmenting flow in a system database;

the method provides one of a first, a second and a third information, wherein determining the types of the respective carriages corresponding to the segmented wheelbases by using known carriage type distinguishing flow in the system database, and if a locomotive is distinguished and the number of wheelbases read continuously exceeds the maximum number of wheelbases of an known locomotive, it is determined that a train arrives, thereby providing the first information on the arrival of a train;

monitoring the time intervals between the signal pulses of wheels provided by respective sensor groups, if the finish time of the signal pulses of any one sensor group has exceeded the extreme time interval (Tm) determined by the maximum carriage wheelbase (hm) and a defined minimum train speed (Vm), it is determined that the signal of said sensor group has stopped, and if the signals of all sensor groups stop, it is determined that the train has departed and the second information on the train'"'"'s departure will be provided; and

determining the types of the carriages corresponding to the segmented wheelbase data by using known carriage type distinguishing flow in the system database and thereby providing the third information of the types of carriages.

2. The method according to claim 1, wherein the minimum values of the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are determined by the maximum train speed as well as the time for beam flux stabilizing required before the X-ray source (O) of a train inspection system, which is arranged on one side of the rail, starts to scan.

3. The method according to claim 2, wherein the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are in the range of 3,000-700,000 mm.

4. The method according to claim 1, wherein the value of the spacing (d4) between the photograph system (P) and X-ray source (O) is determined by the actual spacing (d1) between the first up sensor group (S1) and X-ray source (O) as well as the actual spacing (d7) between the first down sensor group (X1) and X-ray source (O), wherein P can be arranged in any place between S1 and X1.

5. The method according to claim 1, wherein the minimum values of the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are determined by the distance from the second axle of a goods carriage to its closest hook center.

6. The method according to claim 5 wherein the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are in the range of 3,000-4,500 mm.

7. The method according to claim 1, wherein when providing one of the first and second information the segmenting flow in the system database comprises:

a) extracting a sequence of the calculated wheelbase data of a train;

b) sequentially reading from said sequence a group of wheelbases to be segmented that correspond to the minimum number in the range of axle number of a single segment of train known in the system database, to form a first group of wheelbases;

c) checking if said first group of wheelbases meet the known train segmenting law in the system database;

d) dividing a segment of train according to said group of wheelbases if said law is met;

e) otherwise, sequentially reading a group of wheelbases to be segmented that correspond to an incremental second number, to form a second group of wheelbases, and repeating the checking operation of the above step c);

f) repeating the above steps until the group of wheelbases that corresponds to the maximum number is used to carry out the checking operation, and pausing as long as one checking operation therein meets the law, then segmenting one segment of train according to the group of wheelbases used in said checking operation.

8. The method according to claim 1, wherein the extreme time interval Tm is 14.4 seconds.

9. The method according to claim 1, wherein when providing the third information the segmenting flow in the system database comprises:

a) extracting a sequence of the calculated wheelbases of a train;

b) sequentially reading from said sequence a group of wheelbases to be segmented that correspond to the minimum number in the range of axle number of a single segment of train known in the system database, to form a first group of wheelbases;

c) checking if said first group of wheelbases meet the known train segmenting law in the system database;

d) dividing a segment of train according to said group of wheelbases if said law is met;

e) otherwise, sequentially reading a group of wheelbases to be segmented that correspond to an incremental second number, to form a second group of wheelbases, and repeating the checking operation of the above step c);

f) repeating the above steps until the group of wheelbases that correspond to the maximum number is used to carry out the checking operation, and pausing as long as one checking operation therein meets the law, then segmenting one segment of train according to the group of wheelbases used in said checking operation;

g) returning to the starting point of step b), continuing reading new wheelbase data to be segmented from said sequence, repeating steps b)-f) to segment a second carriage, and repeating these steps until all wheelbase data in the sequence have been read, thereby completing the segmenting of all carriages of the entire train.

10. The method according to claim 9, wherein if there is such situation as unsuccessful segmentation after using the maximum number of wheelbases in a certain round in said step f) due to occasional loss, then the step b) in the segmenting flow is altered to:

discarding the first wheelbase in the first group of wheelbases with the minimum number in said round, and supplementing a new wheelbase to be segmented, thereby forming the first group of wheelbases of a new round to repeat step b);

executing steps c)-f);

if the segmentation is still unsuccessful when the step f) has executed in this round, the first wheelbase in the new first group of wheelbases is discarded, and a next new wheelbase to be segmented is supplemented, thereby forming a newer round of first group of wheelbases to re-execute the steps b)-f);

repeating the above steps until one segment of train is successfully segmented, then returning to segment all discarded wheelbases as one segment of train.

11. The method according to claim 1, wherein the known train type distinguishing flow comprises:

i) forming a group of wheelbases from the segmented wheelbases that appear first, and when said group of wheelbases are equal to the wheelbases of a special carriage in the database, it is determined that said group of wheelbases corresponds to a special carriage type;

ii) if the first wheelbase of the said group <

1,500 mm, a goods carriage is determined;

iii) if in said group of wheelbases, the first wheelbase <

2,000 mm, and the third wheelbase <

2,000 mm, a goods carriage is determined, otherwise a locomotive is determined;

iv) when the first acquired wheelbase <

2,000 mm and the third wheelbase ≧

2,000 mm, a locomotive is determined;

v) when the first acquired wheelbase ≧

2,000 mm and the second wheelbase <

8,000 mm, a locomotive is determined;

vi) when the first acquired wheelbase ≧

2,000 mm and the second wheelbase ≧

8,000 mm, a passenger carriage is determined;

vii) when two successive carriages following one locomotive are both goods carriages, the whole train is determined to be a goods train; and

if one of the two carriages is a passenger carriage, the whole train is determined to be a passenger train.

12. A method of providing identification information of a train, comprising:

arranging an array of sensors along one rail, the array comprising a first, a second and a third up sensor groups (S1, S2, S3) arranged in an order and a first, a second and a third down sensor groups (X1, X2, X3) arranged in an opposite order, wherein each of said groups comprise at least two sensors;

using a signal from the second up/third down sensor group (S2/X3) to calculate the speed and wheelbases of a train, and using known segmenting flow in a system database to segment the calculated wheelbases;

the method provides one of a first, a second and a third information, wherein

in the case of a goods train, reading the time (T1) at which the second wheel of the second carriage of two successive carriages that have been segmented arrives at the position of the second up/third down sensor group (S2/X3), thereby providing the first information that is hook locating information comprising a given amount of delay (T) for use by an X-ray system;

in the case of a passenger/goods train, reading the time (T1′

) at which the second wheel of the second carriage of two successive carriages that have been segmented arrives at the position of the third up/second down sensor group (S3/X2), thereby providing the second information that is hook locating information comprising a given amount of delay (T′

) for use by a photograph system; and

reading the carriage numbers from the electronic tags on the segmented carriages successively by the up/down carriage number reading device, determining that the electronic tag being read the maximum times belongs to the carriage being run over the carriage number reading device, thereby providing the third information that is the numbering information of the train.

13. The method according to claim 12, wherein the minimum values of the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are determined by the maximum train speed as well as the time for beam flux stabilizing required before the X-ray source (O) of a train inspection system, which is arranged on one side of the rail, starts to scan.

14. The method according to claim 13, wherein the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are in the range of 3,000-700,000 mm.

15. The method according to claim 12, wherein the value of the spacing (d4) between the photograph system (P) and X-ray source (O) is determined by the actual spacing (d1) between the first up sensor group (S1) and X-ray source (O) as well as the actual spacing (d7) of the first down sensor group (X1) and X-ray source (O), wherein P can be arranged in any place between S1 and X1.

16. The method according to claim 12, wherein the minimum values of the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are determined by the distance from the second axle of a goods carriage to its closest hook center.

17. The method according to claim 16, wherein the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are in the range of 3,000 -4,500 mm.

18. The method according to claim 12, wherein the segmenting flow in the system database comprises:

a) extracting a sequence of the calculated wheelbases of a train;

b) sequentially reading from said sequence a group of wheelbases to be segmented that correspond to the minimum number in the range of axle number of a single segment of train known in the system database, to form a first group of wheelbases;

c) checking if said first group of wheelbases meet the known train segmenting law in the system database;

d) dividing a segment of train according to said group of wheelbases if said law is met;

e) otherwise, sequentially reading a group of wheelbases to be segmented that correspond to an incremental second number, to form a second group of wheelbases, and repeating the checking operation of the above step c);

f) repeating the above steps until the group of wheelbases that correspond to the maximum number is used to carry out the checking operation, and pausing as long as one checking operation therein meets the law, then segmenting one segment of train according to the group of wheelbases used in said checking operation;

g) returning to the starting point of step b), continuing reading new wheelbases to be segmented from said sequence, repeating steps b)-f) to segment a second carriage, and repeating these steps until all wheelbases in the sequence have been read, thereby completing the segmenting of all carriages of the entire train.

19. The method according to claim 12, wherein the given amount of time delay (T) is calculated in accordance with the following formula:

20. The method according to claim 12, wherein the given amount of time delay (T′

) is calculated in accordance with the following formula;

21. The method according to claim 12, wherein the up/down carriage number reading devices are symmetrically mounted on the up/down sides of the X-ray source (O) respectively, the minimum values of the spacings (dS/d9) there between are determined in such way that interference can be decreased and reading probability can be increased.

22. The method according to claim 21, wherein the spacing (d8/d9) between the up/down carriage number reading device and X-ray source (O) is in the range of 100-5,500 mm.

23. A method of providing identification information of a train, comprising:

i) arranging an array of sensors along one rail, the array comprising a first, a second and a third up sensor groups (S1, S2, S3) arranged in an order and a first, a second and a third down sensor groups (X1, X2, X3) arranged in an opposite order, wherein each of said groups comprise at least two sensors;

ii) in the signal from the first up/down sensor group (S1/X1), if the signal from former appears first, then it can be determined that there is a up train, otherwise there is a down train, and the signal from the first up/down sensor group (S1/X1) is used to calculate the speed and wheelbases of the train, and a known segmenting flow in a system database is used to segment the wheelbases;

iii) using known type distinguishing flow in the database to determine the type of carriages corresponding to the segmented wheelbases, and if one carriage is determined to be locomotive and the number of wheelbases that are read successively exceeds the maximum number of wheelbases of a known locomotive, it is determined that an up/down-running train arrives, thereby providing first information on the arrival of an up/down-running train;

iv) successively determining the types of the two carriages behind said locomotive, and if at least one of them is a passenger carriage, it is determined that the train is a passenger train, otherwise a goods train, thereby providing second information on the arrived train being a passenger/goods train;

v) for a goods train, reading the time point (T1) at which the second wheel of the second one of two successive carriages arrives at the position of the second up/third down sensor groups (S2/X3), thereby providing third information on the train hook locating information that comprises a given amount of time delay (T) and is for use by a X-ray source;

vi) reading the carriage numbers from the electronic tags on the segmented carriages successively by the up/down carriage number reading device, and determining that the electronic tag being read the maximum times belongs to the carriage being running over the carriage number reading device, thereby providing fourth information on the number of each carriage;

vii) for a passenger/goods train, reading the time point (T1′

) at which the second wheel of the second one of two segmented carriages arrives at the position of the second up/third down sensor groups (S3/X2), thereby providing fifth information on vehicle hook locating that comprises a given amount of time delay (T′

) and is for use by a photograph system;

viii) monitoring the time intervals between the pulses of respective wheels from respective sensor groups, and if the finish time of the signal pulse from any one sensor group has exceeded the extreme time interval (Tm) determined by the maximum wheelbase (hm) of a carriage and a defined minimum speed of the train (Vm), it is determined that the signal from said sensor group has stopped, and if signals from all sensor groups stop, a sixth information on the train'"'"'s departure will be provided.

24. The method according to claim 23, wherein:

the minimum values of the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are determined by the maximum train speed as well as the time for beam flux stabilizing required before the X-ray source (O) of a train inspection system, which is arranged on one side of the rail, starts to scan.

25. The method according to claim 24, wherein the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are in the range of 3,000-700,000 mm.

26. The method according to claim 23, wherein the value of the spacing (d4) between the photograph system (P) and X-ray source (O) is determined by the actual spacing (d1) between the first up sensor group (S1) and X-ray source (O) as well as the actual spacing (d7) between the first down sensor group (X1) and X-ray source (O), wherein P can be arranged in any place between S1 and X1.

27. The method according to claim 23, wherein the minimum values of the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are determined by the distance from the second axle of a goods carriage to its closest hook center.

28. The method according to claim 27, wherein the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are in the range of 3,000-4,500 mm.

29. The method according to claim 23, wherein the up/down carriage number reading devices are symmetrically mounted on the up/down sides of the X-ray source (O) respectively, the minimum values of the spacings (d8/d9) therebetween are determined in such way that interference can be decreased and reading probability can be increased.

30. The method according to claim 29, wherein the spacing between the up/down carriage number reading device and X-ray source (O) is in the range of 100-5,500 mm.

31. The method according to claim 23, wherein the segmenting flow in the system database in said step iii) comprises:

a) extracting a sequence of the calculated wheelbases of a train;

b) sequentially reading from said sequence a group of wheelbases to be segmented that correspond to the minimum number in the range of axle number of a single segment of train known in the system database, to form a first group of wheelbases;

c) checking if said first group of wheelbases meet the known train segmenting law in the system database;

d) dividing a segment of train according to said group of wheelbases if said law is met;

e) otherwise, sequentially reading a group of wheelbases to be segmented that correspond to an incremental second number, to form a second group of wheelbases, and repeating the checking operation of the above step c);

f) repeating the above steps until the group of wheelbases that correspond to the maximum number is used to carry out the checking operation, and pausing as long as one checking operation therein meets the law, then segmenting one segment of train according to the group of wheelbases used in said checking operation;

g) returning to the starting point of step b), continuing reading new wheelbases to be segmented from said sequence, repeating steps b)-f) to segment a second carriage, and repeating these steps until all wheelbases in the sequence have been read, thereby completing the segmenting of all carriages of the entire train.

32. The method according to claim 31, wherein, if there is such situation as unsuccessful segmentation after using the maximum number of wheelbases in a certain round in said step f) due to occasional loss, then the step b) in the segmenting flow is altered to:

discarding the first wheelbase in the first group of wheelbases with the minimum number in said round, and supplementing a new wheelbase to be segmented, thereby forming the first group of wheelbases of a new round to repeat step b);

executing steps c)-f);

if the segmentation is still unsuccessful when the step f) has executed in this round, the first wheelbase in the new first group of wheelbases is discarded, and a next new wheelbase to be segmented is supplemented, thereby forming a newer round of first group of wheelbases to re-execute the steps b)-f);

repeating the above steps until one segment of train is successfully segmented, then returning to segment all discarded wheelbases as one segment of train.

33. The method according to claim 23, wherein, the known train type distinguishing flow in said step iii) comprises:

viii) forming a group of wheelbases from the segmented wheelbases that appear first, and when said group of wheelbases are equal to the wheelbases of a special carriage in the database, a special carriage type is determined;

ix) if the first wheelbase of said group <

1,500 mm , a goods carriage is determined;

x) if in said group of wheelbases, the first wheelbase <

2,000 mm, and the third wheelbase <

2,000 mm, a goods carriage is determined, otherwise a locomotive is determined;

xi) when the first acquired wheelbase <

2,000 mm and the third wheelbase ≧

2,000 mm, a locomotive is determined;

xii) when the first acquired wheelbase ≧

2,000 mm and the second wheelbase <

8,000 mm, a locomotive is determined;

xiii) when the first acquired wheelbase ≧

2,000 mm and the second wheelbase ≧

8,000 mm, a passenger carriage is determined;

xiv) when two successive carriages following one locomotive are both goods carriages, the whole train is determined to be a goods train; and

if one of the two carriages is a passenger carriage, the whole train is determined to be a passenger train.

34. The method according to claim 23, wherein the given amount of time delay (T) in said step v) is calculated in accordance with the following formula:

35. The method according to claim 23, wherein the given amount of time delay (T′

) in said step iiv) is calculated in accordance with the following formula;

36. The method according to claim 23, wherein the extreme time interval (Tm) in said step viii) is 14.4 seconds.

37. A system for automatically identifying information of a train, comprising:

a sensor array arranged along the rail, comprising three up sensor groups (S1, S2, S3) arranged in an order and three down sensor groups (X1, X2, X3) arranged in an opposite order, each of said groups comprise at least two sensors;

a signal conditioning circuit box connected to the sensor array, comprising mean for processing the signals from sensors into a sequence of regular pulse signal;

a data collecting card connected to the signal conditioning circuit box, comprising mean for calculating the speed and wheelbases of a train from the signals of the sensors;

a carriage number reading device, comprising up and down carriage number reading mean mounted between rails for reading information from the electronic tags on carriages of a train;

an industrial personal computer connected to the data collecting card and carriage number reading device, comprising means for executing steps of;

i) in the signal from a first up/down sensor group (S1/X1), if the signal from former appears first, then it can be determined that there is a up train, otherwise there is a down train, and the signal from the first up/down sensor group (S1/X1) is used to calculate the speed and wheelbases of the train, and a known segmenting flow in a system database is used to segment the wheelbases;

i) using known type distinguishing flow in the database to determine the type of carriages corresponding to the segmented wheelbases, and if one carriage is determined to be locomotive and the number of wheelbases that are read successively exceeds the maximum number of wheelbases of a known locomotive, it is determined that an up/down-running train arrives, thereby providing first information on the arrival of an up/down-running train;

ii) successively determining the types of the two carriages behind said locomotive, and if at least one of them is a passenger carriage, it is determined that the train is a passenger train, otherwise a goods train, thereby providing second information on the arrived train being a passenger/goods train;

iv) for a goods train, reading the time point (T1) at which the second wheel of the second one of two successive carriages arrives at the position of the second up/third down sensor groups (S2/X3), thereby providing third information on the train hook locating information that comprises a given amount of time delay (T) and is for use by a X-ray source;

v) reading the carriage numbers from the electronic tags on the segmented carriages successively by the up/down carriage number reading device, and determining that the electronic tag being read the maximum times belongs to the carriage being running over the carriage number reading device, thereby providing fourth information on the number of each carriage;

vi) for a passenger/goods train, reading the time point (T1′

) at which the second wheel of the second one of two segmented carriages arrives at the position of the second up/third down sensor groups (S3/X2), thereby providing fifth information on vehicle hook locating that comprises a given amount of time delay (T′

) and is for use by a photograph system

as to process the speed, wheelbases and information from the electronic tags, thereby obtaining train information including an up/down-running train arrival, whether a passenger train or a goods train arrives, locomotive hook locating, carriage number and train departure.

38. The method according to claim 37, wherein the minimum values of the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are determined by the maximum speed of a train as well as the time for beam flux stabilizing required before the X-ray source (O) of a train inspection system, which is arranged on one side of the rail, starts to scan.

39. The method according to claim 38, wherein the spacing (d1) between the first up sensor group (S1) and X-ray source (O) and the spacing (d7) between the first down sensor group (X1) and X-ray source (O) are in the range of 3,000-700,000 mm.

40. The method according to claim 37, wherein the value of the spacing (d4) between the photograph system (P) and X-ray source (O) is determined by the actual spacing (d1) between the first up sensor group (S1) and X-ray source (O) as well as the actual spacing (d7) between the first down sensor group (X1) and X-ray source (O), wherein P can be arranged in any place between Si and X1.

41. The method according to claim 37, wherein the minimum values of the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are determined by the distance from the second axle of a goods carriage to its closest hook center.

42. The method according to claim 41, wherein the spacing (d2/d5) between the second/third up sensor group (S2/S3) and X-ray source (O)/photograph system (P), as well as the spacing (d3/d6) between the third/second down sensor group (X3/X2) and X-ray source (O)/photograph system (P) are in the range of 3,000-4,500 mm.

43. The method according to claim 37, wherein the up/down carriage number reading devices are symmetrically mounted on the up/down sides of the X-ray source (O) respectively, the minimum values of the spacings (d8/d9) therebetween are determined in such way that interference can be decreased and reading probability can be increased.

44. The method according to claim 43, wherein the spacings (d8/d9) between the up/down carriage number reading device and X-ray source (O) are in the range of 100-5,500 mm.

45. The method according to claim 37, wherein means for processing the signals from sensors in said signal conditioning circuit box comprises a shaping diode circuit, a voltage comparator and an optical coupler.