SAMPLING METHOD AND SAMPLING APPARATUS FOR ANTI-COUNTERFEITING INFORMATION ABOUT CASH NOTE

Abstract

Disclosed are a sampling method for anti-counterfeiting information about a cash note, and a sampling apparatus for anti-counterfeiting information about a cash note, which executes the method. The sampling method for anti-counterfeiting information about a cash note comprises: through differences collected between sensors, utilizing a law of the differences to restore spatially coupled power-frequency of low-frequency electromagnetic interference signals acquired by an effective signal sensor (21); and then performing common-mode signal elimination on voltage waveform data corresponding to the anti-counterfeiting information, thereby thoroughly elimination the spatially coupled power-frequency or low-frequency electromagnetic interferences that magnetic signal sensors suffer from during the collection of magnetic anti-counterfeiting signals.

Claims

1. A sampling method for anti-counterfeiting information of a cash note, comprising: step 1 of collecting voltage waveform data V.sub.interference outputted by a sensor for obtaining interference signal and voltage waveform data V.sub.effective outputted by a sensor for obtaining effective signals, during a sampling interval of obtaining anti-counterfeiting information of cash notes by the sensor for obtaining effective signals; step 2 of calculating a response ratio coefficient K of the sensor for obtaining interference signals and the sensor for obtaining effective signals with respect to electromagnetic interference signals according to the formula: K=V.sub.effective/V.sub.interference; step 3 of sampling, by the sensor for obtaining effective signals, anti-counterfeiting information of a cash note, and outputting voltage waveform data V′.sub.effective corresponding to the anti-counterfeiting information; step 4 of collecting voltage waveform data V′.sub.interference outputted by the sensor for obtaining interference signals during a time period of the cash note passing through the sensor for obtaining effective signals; step 5 of restoring voltage waveform data V.sub.superposition superposed with an electromagnetic interference signal and outputted from the sensor for obtaining effective signals according to the formula V.sub.superposition=K*V′.sub.interference; and step 6 of performing common-mode signal elimination on the voltage waveform data corresponding to the anti-counterfeiting information according to the formula V.sub.anti-counterfeiting=V′.sub.effective−V.sub.superposition, to obtain voltage waveform data V corresponding to V.sub.anti-counterfeiting the anti-counterfeiting information after performing the common-mode signal elimination.

2. The sampling method for anti-counterfeiting information of a cash note according to claim 1, wherein the sampling method returns to step 1 after step 6 is finished and steps 1 to 6 are looped, so as to complete the sampling of anti-counterfeiting information of all cash notes.

3. The sampling method for anti-counterfeiting information of a cash note according to claim 2, wherein step 1 and step 2 are finished within the sampling interval of cash notes and the sampling interval of cash notes refers to a period from the termination of sampling a cash note to the beginning of sampling a next cash note.

4. A sampling apparatus for anti-counterfeiting information of a cash note, configured to execute the sampling method for anti-counterfeiting information of a cash note according to claim 1, wherein the sampling apparatus comprises a sensor for obtaining effective signals and a sensor for obtaining interference signals, the sensor for obtaining effective signals is located above a passage for cash notes and the sensor for obtaining interference signals is arranged near the sensor for obtaining effective signals.

5. The sampling apparatus for anti-counterfeiting information of a cash note according to claim 4, comprising a plurality of sensors for obtaining effective signals, wherein the plurality of sensors for obtaining effective signals form an array, and each of the plurality of sensors for obtaining effective signals is arranged vertically facing the passage for cash notes.

6. A sampling apparatus for anti-counterfeiting information of a cash note, configured to execute the sampling method for anti-counterfeiting information of a cash note according to claim 2, wherein the sampling apparatus comprises a sensor for obtaining effective signals and a sensor for obtaining interference signals, the sensor for obtaining effective signals is located above a passage for cash notes and the sensor for obtaining interference signals is arranged near the sensor for obtaining effective signals.

7. The sampling apparatus for anti-counterfeiting information of a cash note according to claim 6, comprising a plurality of sensors for obtaining effective signals, wherein the plurality of sensors for obtaining effective signals form an array, and each of the plurality of sensors for obtaining effective signals is arranged vertically facing the passage for cash notes.

8. A sampling apparatus for anti-counterfeiting information of a cash note, configured to execute the sampling method for anti-counterfeiting information of a cash note according to claim 3, wherein the sampling apparatus comprises a sensor for obtaining effective signals and a sensor for obtaining interference signals, the sensor for obtaining effective signals is located above a passage for cash notes and the sensor for obtaining interference signals is arranged near the sensor for obtaining effective signals.

9. The sampling apparatus for anti-counterfeiting information of a cash note according to claim 8, comprising a plurality of sensors for obtaining effective signals, wherein the plurality of sensors for obtaining effective signals form an array, and each of the plurality of sensors for obtaining effective signals is arranged vertically facing the passage for cash notes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a schematic diagram showing the difference between interference signals of two sensors located in different positions in a device;

[0015] FIG. 2 is a diagram showing main structures of a sampling apparatus for anti-counterfeiting information of a cash note; and

[0016] FIG. 3 is a schematic diagram of the proportion of a newly added data sampling time period in a sampling interval.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Modes and methods of implementation of the present disclosure are illustrated hereinafter with reference to the drawings. According to the application of a sampling method for anti-counterfeiting information of a cash note of the present disclosure in an automatic teller machine for cash notes, a sampling apparatus for anti-counterfeiting information of a cash note according to an embodiment is shown in FIG. 2. The sampling apparatus for anti-counterfeiting information of a cash note includes: sensors 21 for obtaining effective signals, existing sensors 32 for obtaining interference signals and newly added sensors 33 for obtaining interference signals, and a cash note 11 to be identified and a moving direction A of the cash note are also indicated in FIG. 2.

[0018] Generally, the sensor 21 for obtaining effective magnetic anti-counterfeiting information of a cash note is installed in a passage of a cash note identification module. There may be one or multiple sensors 21 for obtaining effective signals. In a case that there are multiple sensors 21 for obtaining effective signals, the multiple sensors 21 are arranged in a direction perpendicular to the moving direction A of the cash note. In this embodiment, there are five sensors 21, and the arrangement of the sensors 21 may be, but not limited to, similar to that shown in FIG. 2.

[0019] The newly added sensors 33 for obtaining interference signals are installed beside or near the existing sensors 32 for obtaining interference signals, as shown in FIG. 2. In this embodiment, there are five newly added sensors 33 for obtaining interference signals arranged in parallel behind the array of the sensors 21 for obtaining effective signals, and the direction of the newly added sensors 33 for obtaining interference signals is perpendicular to that of the sensors 21 for obtaining effective signals. The existing sensors 32 for obtaining interference signals are distributed on two ends of the array of the sensors 21 for obtaining effective signals and are outside the boundary of the cash note. Practically, the arrangement of the newly added sensors 33 for obtaining interference signals is not limited to the arrangement shown in FIG. 2. In practical applications, it is required to adjust the installation direction or location of the newly added sensors 33 for obtaining interference signals or to adopt other measures including shelter, to ensure the sensors 32, 33 for obtaining interference signals can not obtain effective information for anti-counterfeiting identification of a cash note when collecting voltage waveform data of anti-counterfeiting signals from the cash note.

[0020] The principles and methods of the sampling method for anti-counterfeiting information of a cash note according to the embodiment are described hereinafter. In view of the fact that the spatially coupled power-frequency or low-frequency electromagnetic interference signals have low frequency, according to the theory of electromagnetic wave, the wavelength of interference signals of 50 hertz in spatial propagation is about 6000 kilometers. By comparison, the difference in installation positions of different magnetic sensors inside the automatic teller machine for cash notes and the cash note counting and sorting machine is very tiny, therefore the difference in phase between interference signals obtained by the sensor 32 for obtaining interference signals and those obtained by the sensors 21 for obtaining effective signals is nearly zero. The voltage waveform signals outputted by the sensor 32 for obtaining interference signals and the sensor 21 for obtaining effective signals are described in the following two formulas respectively:

V.sub.interference=K.sub.1 Sin(ω.sub.1t+φ.sub.1);

V.sub.effective=K.sub.2 Sin(ω.sub.2t+φ.sub.2);

[0021] where ω represents the angular velocity corresponding to the frequency of an interference source, φ represents the phase information of corresponding signals, K.sub.1 and K.sub.2 are actually detected signal amplitudes; since ω is for the same interference source and the same sensors, it is considered that ω.sub.1=ω.sub.2, and it is known that φ.sub.1=φ.sub.2 according to the above descriptions.

[0022] In view of the above, by just collecting waveform data signals in more than a half cycle, finding the maximum value among amplitudes of the collected waveform data signals by comparison, determining an amplitude of a voltage waveform signal outputted by the sensor 32 for obtaining interference signals as a reference value, and dividing an amplitude of a voltage waveform signal outputted by the sensor 21 for obtaining effective signals by the reference value, a ratio coefficient of amplitude can be figured out, i.e.: K=V.sub.effective/V.sub.interference=K.sub.2/K.sub.1. Here K represents a ratio coefficient of amplitude responses of the two above sensors to spatially coupled power-frequency or low-frequency electromagnetic interference signals. By use of K, mutual transformation between the voltage waveforms of spatially coupled power-frequency or low-frequency electromagnetic interference signals obtained by the sensor 32 for obtaining interference signals and those obtained by the sensor 21 for obtaining effective signals can be achieved.

[0023] A sampling method for anti-counterfeiting information of a cash note includes the following steps 1 to 6: step 1, collecting voltage waveform data V.sub.interference outputted by a sensor for obtaining interference signals and voltage waveform data V.sub.effective outputted by a sensor for obtaining effective signals during a sampling interval of collecting anti-counterfeiting information of cash notes by the sensor for obtaining effective signals; step 2, calculating a response ratio coefficient K of the sensor for obtaining interference signals and the sensor for obtaining effective signals with respect to electromagnetic interference signals according to the formula K=V.sub.effective/V.sub.interference; step 3, sampling, by the sensor for obtaining effective signals, anti-counterfeiting information of a cash note, and outputting voltage waveform data V′.sub.effective corresponding to the anti-counterfeiting information; step 4, collecting voltage waveform data V′.sub.interference outputted by the sensor for obtaining interference signals during a time period of the cash note passing through the sensor for obtaining effective signals; step 5, restoring voltage waveform data V.sub.superposition superposed with an electromagnetic interference signal and outputted from the sensor for obtaining effective signals according to the formula V.sub.superposition=K*V′.sub.interference; and step 6, performing common-mode signal elimination on the voltage waveform data corresponding to the anti-counterfeiting information according to the formula V.sub.anti-counterfeiting=V′.sub.effective−V.sub.superposition, to obtain voltage waveform data V.sub.anti-counterfeiting corresponding to the anti-counterfeiting information after performing the common-mode signal elimination. In step 1 and step 2, in the process of collecting and obtaining magnetic anti-counterfeiting information of each cash note passing through the sensor, voltage waveform signal data outputted by the sensor 32 for obtaining interference signals and the sensor 21 for obtaining effective signals is collected in sampling intervals of the cash notes, to calculate the value of K.

[0024] In steps 3 to 5, an anti-counterfeiting signal of each cash note is collected, and after finishing the collection of the anti-counterfeiting signal of each cash note, voltage waveform data V′.sub.interference outputted by the sensor 32 for obtaining acquiring interference signals within the time period of the cash note passing through the sensor 21 for obtaining effective signals is multiplied by K to obtain new voltage waveform data, the new voltage waveform data being voltage waveform data of power-frequency or low-frequency electromagnetic interference signals which is included in the voltage waveform data outputted by the sensor 21 for obtaining effective signals, i.e.: V.sub.superposition=K*V′.sub.interference.

[0025] In step 6, the voltage waveform data outputted by the sensor 21 for obtaining effective signals during the process of collecting the anti-counterfeiting signal of each cash note includes an interference signal and the anti-counterfeiting signal of the cash note, which is the superposition of the interference signal and the anti-counterfeiting signal in time domain and can be described by the formula: V′.sub.effective=V.sub.superposition+V.sub.anti-counterfeiting. By subtracting restored data V.sub.superposition from the voltage waveform data of the anti-counterfeiting signal of the cash note collected and outputted by the sensor 21 for obtaining effective signals, common-mode signal elimination is achieved, thereby eliminating electromagnetic interference signals, and obtaining accurate voltage waveform data of the anti-counterfeiting signal of the cash note, which is described by the formula: V.sub.anti-counterfeiting=V′.sub.effective−V.sub.superposition.

[0026] In specific implementations, it is preferable to add a new data sampling interval, which is half a cycle (10 milliseconds) of an interference signal with a frequency of no less than 50 hertz, before sampling the data of each cash note, as shown in FIG. 3, and the value of K is calculated during the added data sampling interval. After completing the collection of anti-counterfeiting data of a cash note, voltage waveform of the interference signal received by the sensor 21 for obtaining effective signals can be obtained by use of K, and then common-mode signal elimination is performed on the voltage waveform data corresponding to the anti-counterfeiting information, thereby thoroughly eliminating the spatially coupled power-frequency or low-frequency electromagnetic interferences that magnetic signal sensors suffer from during the collection of magnetic anti-counterfeiting signals.

[0027] In the embodiment, the added data sampling time is at least about 10 milliseconds, avoiding impacting on effective processing time at the speed of existing cash identification processing, that is, as illustrated in FIG. 3, the added data sampling time is less than the normal cash sampling interval of the existing cash identification processing device. Therefore adding the data sampling time has no impact on the effective processing time. In addition, the involved coefficient calculation and common-mode elimination processing are simple in computation, and has lower demand on system resources compared with FFT or complicated filtering algorithms, thereby having little influence on processing speed of the existing automatic teller machine for cash notes and the cash note counting and sorting machine, and having high realizability.

[0028] The foregoing description merely lists some preferred embodiments of the invention, and it should be noted that, the above preferable embodiments should not be interpreted as limiting the present disclosure. The protection scope of the present application is defined by the claims. For the person skilled in the art, many modifications and improvements may be made to the present disclosure without departing from the essence of the present disclosure, and these modifications and improvements also fall within the protection scope of the present disclosure